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Variation of PPARG Expression in Chemotherapy-Sensitive Patients of Hypopharyngeal Squamous Cell Carcinoma. PPAR Res 2021; 2021:5525091. [PMID: 34054937 PMCID: PMC8149230 DOI: 10.1155/2021/5525091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/30/2021] [Indexed: 11/18/2022] Open
Abstract
Our previous study showed that the upregulation of peroxisome proliferator-activated receptor gamma (PPARG) could promote chemosensitivity of hypopharyngeal squamous cell carcinoma (HSCC) in chemotherapeutic treatments. Here, we acquired two more independent expression data of PPARG to validate the expression levels of PPARG in chemotherapy-sensitive patients (CSP) and its individualized variations compared to chemotherapy-non-sensitive patients (CNSP). Our results showed that overall PPARG expression was mildly downregulated (log fold change = −0.55; p value = 0.42; overexpression in three CSPs and reduced expression in four CSPs), which was not consistent with previous results (log fold change = 0.50; p = 0.22; overexpression in nine CSPs and reduced expression in three CSPs). Both studies indicated that PPARG expression variation was significantly associated with the Tumor-Node-Metastasis (TNM) stage (p = 7.45e − 7 and 6.50e − 4, for the first and second studies, respectively), which was used as one of the predictors of chemosensitivity. The new dataset analysis revealed 51 genes with significant gene expression changes in CSPs (LFC > 1 or <-1; p value < 0.01), and two of them (TMEM45A and RBP1) demonstrated strong coexpression with PPARG (Pearson correlation coefficient > 0.6 or <-0.6). There were 21 significant genes in the data from the first study, with no significant association with PPARG and no overlap with the 51 genes revealed in this study. Our results support the connection between PPARG and chemosensitivity in HSCC tumor cells. However, significant PPARG variation exists in CSPs, which may be influenced by multiple factors, including the TNM stage.
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Tsai TL, Lai YH, HW Chen H, Su WC. Overcoming Radiation Resistance by Iron-Platinum Metal Alloy Nanoparticles in Human Copper Transport 1-Overexpressing Cancer Cells via Mitochondrial Disturbance. Int J Nanomedicine 2021; 16:2071-2085. [PMID: 33727814 PMCID: PMC7955785 DOI: 10.2147/ijn.s283147] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 02/11/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Radiation therapy remains an important treatment modality in cancer therapy, however, resistance is a major problem for treatment failure. Elevated expression of glutathione is known to associate with radiation resistance. We used glutathione overexpressing small cell lung cancer cell lines, SR3A-13 and SR3A-14, established by transfection with γ-glutamylcysteine synthetase (γ-GCS) cDNA, as a model for investigating strategies of overcoming radiation resistance. These radiation-resistant cells exhibit upregulated human copper transporter 1 (hCtr1), which also transports cisplatin. This study was initiated to investigate the effect and the underlying mechanism of iron-platinum nanoparticles (FePt NPs) on radiation sensitization in cancer cells. MATERIALS AND METHODS Uptakes of FePt NPs in these cells were studied by plasma optical emission spectrometry and transmission electron microscopy. Effects of the combination of FePt NPs and ionizing radiation were investigated by colony formation assay and animal experiment. Intracellular reactive oxygen species (ROS) were assessed by using fluorescent probes and imaged by a fluorescence-activated-cell-sorting caliber flow cytometer. Oxygen consumption rate (OCR) in mitochondria after FePt NP and IR treatment was investigated by a Seahorse XF24 cell energy metabolism analyzer. RESULTS These hCtr1-overexpressing cells exhibited elevated resistance to IR and the resistance could be overcome by FePt NPs via enhanced uptake of FePt NPs. Overexpression of hCtr1 was responsible for the increased uptake/transport of FePt NPs as demonstrated by using hCtr1-transfected parental SR3A (SR3A-hCtr1-WT) cells. Increased ROS and drastic mitochondrial damages with substantial reduction of oxygen consumption rate were observed in FePt NPs and IR-treated cells, indicating that structural and functional insults of mitochondria are the lethal mechanism of FePt NPs. Furthermore, FePt NPs also increased the efficacy of radiotherapy in mice bearing SR3A-hCtr1-WT-xenograft tumors. CONCLUSION These results suggest that FePt NPs can potentially be a novel strategy to improve radiotherapeutic efficacy in hCtr1-overexpressing cancer cells via enhanced uptake and mitochondria targeting.
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Affiliation(s)
- Tsung-Lin Tsai
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan, 701, Taiwan
- Department of Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
| | - Yu-Hsuan Lai
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
- Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
| | - Helen HW Chen
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan, 701, Taiwan
- Department of Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
- Department of Radiation Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
| | - Wu-Chou Su
- Center of Applied Nanomedicine, National Cheng Kung University, Tainan, 701, Taiwan
- Department of Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
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Liu L, Liu X. Contributions of Drug Transporters to Blood-Placental Barrier. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1141:505-548. [PMID: 31571173 DOI: 10.1007/978-981-13-7647-4_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The placenta is the only organ linking two different individuals, mother and fetus, termed as blood-placental barrier. The functions of the blood-placental barrier are to regulate material transfer between the maternal and fetal circulation. The main functional units are the chorionic villi within which fetal blood is separated by only three or four cell layers (placental membrane) from maternal blood in the surrounding intervillous space. A series of drug transporters such as P-glycoprotein (P-GP), breast cancer resistance protein (BCRP), multidrug resistance-associated proteins (MRP1, MRP2, MRP3, MRP4, and MRP5), organic anion-transporting polypeptides (OATP4A1, OATP1A2, OATP1B3, and OATP3A1), organic anion transporter 4 (OAT4), organic cation transporter 3 (OCT3), organic cation/carnitine transporters (OCTN1 and OCTN2), multidrug and toxin extrusion 1 (MATE1), and equilibrative nucleoside transporters (ENT1 and ENT2) have been demonstrated on the apical membrane of syncytiotrophoblast, some of which also expressed on the basolateral membrane of syncytiotrophoblast or fetal capillary endothelium. These transporters are involved in transport of most drugs in the placenta, in turn, affecting drug distribution in fetus. Moreover, expressions of these transporters in the placenta often vary along with the gestational ages and are also affected by pathophysiological factor. This chapter will mainly illustrate function and expression of these transporters in placentas, their contribution to drug distribution in fetus, and their clinical significance.
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Affiliation(s)
- Li Liu
- China Pharmaceutical University, Nanjing, China
| | - Xiaodong Liu
- China Pharmaceutical University, Nanjing, China.
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Ilghami R, Barzegari A, Mashayekhi MR, Letourneur D, Crepin M, Pavon-Djavid G. The conundrum of dietary antioxidants in cancer chemotherapy. Nutr Rev 2019; 78:65-76. [DOI: 10.1093/nutrit/nuz027] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Abstract
Although chemotherapy succeeds in reducing tumor burden, the efficacy is limited due to acquired drug resistance and often irreparable side effects. Studies show that antioxidants may influence the response to chemotherapy and its side effects, although their use remains controversial. The evidence shows that some chemo-drugs induce oxidative stress and lead to normal tissue apoptosis and the entry of cancer cells to a dormant G0 state. Through the suppression of oxidative stress, antioxidants could protect normal cells and bring the tumor out of dormancy so as to expose it to chemotherapies. This review is focused on the redox biology of cancer/normal cells and association of reactive oxygen species with drug resistance, cancer dormancy, and side effects. To this end, evidence from cellular, animal, and clinical studies is provided to better understand the conundrum of dietary antioxidants in cancer chemotherapy.
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Affiliation(s)
- Roghayeh Ilghami
- R. Ilghami and M. R. Mashayekhi are with the Department of Genetics, Faculty of Basic Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran. A. Barzegari is with the Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran. D. Letourneur, M. Crepin, and G. Pavon-Djavid are with the INSERM U1148, Laboratory for Vascular Translational Science, C
| | - Abolfazl Barzegari
- R. Ilghami and M. R. Mashayekhi are with the Department of Genetics, Faculty of Basic Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran. A. Barzegari is with the Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran. D. Letourneur, M. Crepin, and G. Pavon-Djavid are with the INSERM U1148, Laboratory for Vascular Translational Science, C
| | - Mohammad Reza Mashayekhi
- R. Ilghami and M. R. Mashayekhi are with the Department of Genetics, Faculty of Basic Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran. A. Barzegari is with the Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran. D. Letourneur, M. Crepin, and G. Pavon-Djavid are with the INSERM U1148, Laboratory for Vascular Translational Science, C
| | - Didier Letourneur
- R. Ilghami and M. R. Mashayekhi are with the Department of Genetics, Faculty of Basic Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran. A. Barzegari is with the Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran. D. Letourneur, M. Crepin, and G. Pavon-Djavid are with the INSERM U1148, Laboratory for Vascular Translational Science, C
| | - Michel Crepin
- R. Ilghami and M. R. Mashayekhi are with the Department of Genetics, Faculty of Basic Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran. A. Barzegari is with the Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran. D. Letourneur, M. Crepin, and G. Pavon-Djavid are with the INSERM U1148, Laboratory for Vascular Translational Science, C
| | - Graciela Pavon-Djavid
- R. Ilghami and M. R. Mashayekhi are with the Department of Genetics, Faculty of Basic Science, Tabriz Branch, Islamic Azad University, Tabriz, Iran. A. Barzegari is with the Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran. D. Letourneur, M. Crepin, and G. Pavon-Djavid are with the INSERM U1148, Laboratory for Vascular Translational Science, C
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Mistry RK, Brewer AC. Redox-Dependent Regulation of Sulfur Metabolism in Biomolecules: Implications for Cardiovascular Health. Antioxid Redox Signal 2019; 30:972-991. [PMID: 28661184 DOI: 10.1089/ars.2017.7224] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
SIGNIFICANCE Sulfur-containing amino acids are integral to the molecular mechanisms that underlie many aspects of cellular function and homeostasis, facilitated by reversible changes in the oxidation states of sulfur atoms. Sulfur-containing amino acids are metabolically linked by interacting pathways that impact the one-carbon metabolic cycle and generation of methyl groups, the folate cycle, and maintenance of the major cellular redox buffer; glutathione. Dysregulation of these pathways is associated with diverse pathologies, notably of the cardiovascular (CV) system, which are typically characterized by inappropriate plasma levels of sulfur-containing amino acids. Recent Advances: Perhaps not surprisingly, the cellular redox state has emerged as a major regulator of many enzymatic processes within these metabolic cycles. The metabolism of cysteine can also result in the production of hydrogen sulfide (H2S), a signaling molecule whose activity is potentially linked to intracellular levels of both reactive oxygen species (ROS) and molecular oxygen. CRITICAL ISSUES In most cases, the endogenous physiological sources of ROS that might mediate the interlinked metabolic pathways of sulfur-containing biomolecules remain unknown. However, the family of NADPH oxidases, and Nox4 in particular, is emerging as a likely candidate. FUTURE DIRECTIONS This review focuses on the current knowledge of key aspects of sulfur metabolism, which are regulated by redox-based chemical reactions, and the likely intracellular oxidant sources that might mediate this regulation. This knowledge will be important to guide future targeted therapeutic interventions in diverse CV disorders.
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Affiliation(s)
- Rajesh K Mistry
- Department of Cardiology, BHF Centre of Research Excellence, King's College London, London, United Kingdom
| | - Alison C Brewer
- Department of Cardiology, BHF Centre of Research Excellence, King's College London, London, United Kingdom
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Bernhard A, Rasinger JD, Betancor MB, Caballero MJ, Berntssen MHG, Lundebye AK, Ørnsrud R. Tolerance and dose-response assessment of subchronic dietary ethoxyquin exposure in Atlantic salmon (Salmo salar L.). PLoS One 2019; 14:e0211128. [PMID: 30682099 PMCID: PMC6347454 DOI: 10.1371/journal.pone.0211128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 01/08/2019] [Indexed: 12/25/2022] Open
Abstract
Ethoxyquin (EQ; 6-Ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline) has been used as an antioxidant in feed components for pets, livestock and aquaculture. However, possible risks of EQ used in aquafeed for fish health have not yet been characterized. The present study investigated the toxicity and dose-response of subchronic dietary EQ exposure at doses ranging from 41 to 9666 mg EQ/kg feed in Atlantic salmon (Salmo salar L.). Feed at concentrations higher than 1173 mg EQ/kg were rejected by the fish, resulting in reduced feed intake and growth performance. No mortality was observed in fish exposed to any of the doses. A multi-omic screening of metabolome and proteome in salmon liver indicated an effect of dietary EQ on bioenergetics pathways and hepatic redox homeostasis in fish fed concentrations above 119 mg EQ/kg feed. Increased energy expenditure associated with an upregulation of hepatic fatty acid β-oxidation and induction and carbohydrate catabolic pathways resulted in a dose-dependent depletion of intracytoplasmic lipid vacuoles in liver histological sections, decreasing whole body lipid levels and altered purine/pyrimidine metabolism. Increased GSH and TBARS in the liver indicated a state of oxidative stress, which was associated with activation of the NRF2-mediated oxidative stress response and glutathione-mediated detoxification processes. However, no oxidative DNA damage was observed. As manifestation of altered energy metabolism, the depletion of liver intracytoplasmic lipid vacuoles was considered the critical endpoint for benchmark dose assessment, and a BMDL10 of 243 mg EQ/kg feed was derived as a safe upper limit of EQ exposure in Atlantic salmon.
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Affiliation(s)
| | | | - Monica B. Betancor
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
| | - Maria José Caballero
- Department of Morphology, Veterinary School, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
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Han L, Zhou Z, Ma Y, Batistel F, Osorio J, Loor J. Phosphorylation of nuclear factor erythroid 2-like 2 (NFE2L2) in mammary tissue of Holstein cows during the periparturient period is associated with mRNA abundance of antioxidant gene networks. J Dairy Sci 2018; 101:6511-6522. [DOI: 10.3168/jds.2017-14257] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/14/2018] [Indexed: 12/13/2022]
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Brown IAM, Gulbransen BD. The antioxidant glutathione protects against enteric neuron death in situ, but its depletion is protective during colitis. Am J Physiol Gastrointest Liver Physiol 2018; 314:G39-G52. [PMID: 28882823 PMCID: PMC5866372 DOI: 10.1152/ajpgi.00165.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Enteric glia play an important neuroprotective role in the enteric nervous system (ENS) by producing neuroprotective compounds such as the antioxidant reduced glutathione (GSH). The specific cellular pathways that regulate glial production of GSH and how these pathways are altered during, or contribute to, neuroinflammation in situ and in vivo are not fully understood. We investigated this issue using immunohistochemistry to localize GSH synthesis enzymes within the myenteric plexus and tested how the inhibition of GSH synthesis with the selective inhibitor l-buthionine sulfoximine impacts neuronal survival and inflammation. Both enteric glia and neurons express the cellular machinery necessary for GSH synthesis. Furthermore, glial GSH synthesis is necessary for neuronal survival in isolated preparations of myenteric plexus. In vivo depletion of GSH does not induce colitis but alters myenteric plexus neuronal phenotype and survival. Importantly, global depletion of glutathione is protective against some macroscopic and microscopic measures of colonic inflammation. Together, our data highlight the heterogeneous roles of GSH in the myenteric plexus of the ENS and during gastrointestinal inflammation. NEW & NOTEWORTHY Our results show that both enteric glia and neurons express the cellular machinery necessary for glutathione (GSH) synthesis and that glial GSH synthesis is necessary for neuronal survival in isolated enteric nervous system (ENS) preparations. In vivo depletion of GSH with the selective inhibitor l-buthionine sulfoximine is not sufficient to induce inflammation but does alter neuronal neurochemical composition and survival. Together, our data highlight novel heterogeneous roles for GSH in the ENS and during gastrointestinal inflammation.
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Affiliation(s)
- Isola A. M. Brown
- 1Department of Physiology, Michigan State University, East Lansing, Michigan,2Pharmacology and Toxicology Program, Michigan State University, East Lansing, Michigan
| | - Brian D. Gulbransen
- 1Department of Physiology, Michigan State University, East Lansing, Michigan,3Neuroscience Program, Michigan State University, East Lansing, Michigan
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Li Y, Yu S, Gan X, Zhang Z, Wang Y, Wang Y, An R. MRP-1 and BCRP Promote the Externalization of Phosphatidylserine in Oxalate-treated Renal Epithelial Cells: Implications for Calcium Oxalate Urolithiasis. Urology 2017; 107:271.e9-271.e17. [PMID: 28577929 DOI: 10.1016/j.urology.2017.05.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/19/2017] [Accepted: 05/22/2017] [Indexed: 01/13/2023]
Abstract
OBJECTIVE To investigate the possible involvement of multidrug resistance-associated protein 1 (MRP-1) and breast cancer resistance protein (BCRP) in the oxalate-induced redistribution of phosphatidylserine (PS) in renal epithelial cell membranes. METHODS A western blot analysis was used to examine the MRP-1 and BCRP expression levels. Surface-expressed PS was detected by the annexin V-binding assay. The cell-permeable fluorogenic probe 2,7-dichlorofluorescein diacetate was used to measure the intracellular reactive oxygen species (ROS) level. A rat model of hyperoxaluria was obtained using 0.5% ethylene glycol and 1.0% ammonium chloride. In addition, certain animals received verapamil (50 mg/kg body weight), which is a common inhibitor of MRP-1 and BCRP. The degree of nephrolithiasis was assessed histomorphometrically using sections stained by Pizzolato method and by measuring the calcium oxalate crystal content in the renal tissue. RESULTS Oxalate produced a concentration-dependent increase in the synthesis of MRP-1 and BCRP. Treatment with MK571 and Ko143 (MRP-1- and BCRP-specific inhibitors, respectively) significantly attenuated the oxalate-induced PS externalization. Adding the antioxidant N-acetyl-l-cysteine significantly reduced MRP-1 and BCRP expression. In vivo, markedly decreased nephrocalcinosis was observed compared with that in the rat model of hyperoxaluria without verapamil treatment. CONCLUSION Oxalate induces the upregulation of MRP-1 and BCRP, which act as phospholipid floppases causing PS externalization in the renal epithelial cell membrane. The process is mediated by intracellular ROS production. The ROS-mediated increase in the synthesis of MRP-1 and BCRP can play an important role in hyperoxaluria-promoted calcium oxalate urolithiasis by facilitating phosphatidylserine redistribution in renal epithelial cells.
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Affiliation(s)
- YiFu Li
- Department of Urology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - ShiLiang Yu
- Department of Urology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - XiuGuo Gan
- Department of Urology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Ze Zhang
- Department of Urology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yan Wang
- Department of Urology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - YingWei Wang
- Department of Pathology, First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - RuiHua An
- Department of Urology, First Affiliated Hospital of Harbin Medical University, Harbin, China.
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Gordillo GM, Biswas A, Khanna S, Spieldenner JM, Pan X, Sen CK. Multidrug Resistance-associated Protein-1 (MRP-1)-dependent Glutathione Disulfide (GSSG) Efflux as a Critical Survival Factor for Oxidant-enriched Tumorigenic Endothelial Cells. J Biol Chem 2016; 291:10089-103. [PMID: 26961872 DOI: 10.1074/jbc.m115.688879] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 12/28/2022] Open
Abstract
Endothelial cell tumors are the most common soft tissue tumors in infants. Tumor-forming endothelial (EOMA) cells are able to escape cell death fate despite excessive nuclear oxidant burden. Our previous work recognized perinuclear Nox-4 as a key contributor to EOMA growth. The objective of this work was to characterize the mechanisms by which EOMA cells evade oxidant toxicity and thrive. In EOMA cells, compared with in the cytosol, the nuclear GSSG/GSH ratio was 5-fold higher. Compared to the ratio observed in healthy murine aortic endothelial (MAE) cells, GSSG/GSH was over twice as high in EOMA cells. Multidrug resistance-associated protein-1 (MRP-1), an active GSSG efflux mechanism, showed 2-fold increased activity in EOMA compared with MAE cells. Hyperactive YB-1 and Ape/Ref-1 were responsible for high MRP-1 expression in EOMA. Proximity ligand assay demonstrated MRP-1 and YB-1 binding. Such binding enabled the nuclear targeting of MRP-1 in EOMA in a leptomycin-B-sensitive manner. MRP-1 inhibition as well as knockdown trapped nuclear GSSG, causing cell death of EOMA. Disulfide loading of cells by inhibition of GSSG reductase (bischoloronitrosourea) or thioredoxin reductase (auranofin) was effective in causing EOMA death as well. In sum, EOMA cells survive a heavy oxidant burden by rapid efflux of GSSG, which is lethal if trapped within the cell. A hyperactive MRP-1 system for GSSG efflux acts as a critical survival factor for these cells, making it a potential target for EOMA therapeutics.
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Affiliation(s)
- Gayle M Gordillo
- From the Department of Plastic Surgery, Davis Heart and Lung Research Institute, and
| | - Ayan Biswas
- From the Department of Plastic Surgery, Davis Heart and Lung Research Institute, and
| | - Savita Khanna
- Davis Heart and Lung Research Institute, and Department of Surgery
| | | | - Xueliang Pan
- Center for Biostatistics, Ohio State University Wexner Medical Center, Columbus, Ohio 43212
| | - Chandan K Sen
- Davis Heart and Lung Research Institute, and Department of Surgery
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Effect of FosPeg® mediated photoactivation on P-gp/ABCB1 protein expression in human nasopharyngeal carcinoma cells. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 148:82-87. [PMID: 25900553 DOI: 10.1016/j.jphotobiol.2015.03.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 03/17/2015] [Accepted: 03/24/2015] [Indexed: 11/24/2022]
Abstract
Multidrug resistance (MDR) refers to the ability of cancer cells to develop cross resistance to a range of anticancer drugs which are structurally and functionally unrelated. P-glycoprotein (P-gp) is the best studied MDR phenotype in photodynamic therapy (PDT) treated cells. Our pervious study demonstrated that FosPeg® mediated PDT is effective to NPC cell line models. In this in vitro study, the expression of MDR1 gene and its product P-gp in undifferentiated, poorly differentiated and well differentiated human nasopharyngeal carcinoma (NPC) cells were investigated. The influence of P-gp efflux activities on photosensitizer FosPeg® was also examined. Regardless of the differentiation status, PDT tested NPC cell lines all expressed P-gp protein. Results indicated that FosPeg® photoactivation could heighten the expression of MDR1 gene and P-gp transporter protein in a dose dependent manner. Up to 2-fold increase of P-gp protein expression were seen in NPC cells after FosPeg® mediated PDT. Interestingly, our finding demonstrated that FosPeg® mediated PDT efficiency is independent to the MDR1 gene and P-gp protein expression in NPC cells. FosPeg® itself is not the substrate of P-gp transporter protein and no efflux of FosPeg® were observed in NPC cells. Therefore, the PDT efficiency would not be affected even though FosPeg® mediated PDT could induce MDR1 gene and P-gp protein expression in NPC cells. FosPeg® mediated PDT could be a potential therapeutic approach for MDR cancer patients.
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Niu WN, Yadav PK, Adamec J, Banerjee R. S-glutathionylation enhances human cystathionine β-synthase activity under oxidative stress conditions. Antioxid Redox Signal 2015; 22:350-61. [PMID: 24893130 PMCID: PMC4307034 DOI: 10.1089/ars.2014.5891] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
AIMS Cystathionine β-synthase (CBS) catalyzes the first and rate-limiting step in the two-step trans-sulfuration pathway that converts homocysteine to cysteine. It is also one of three major enzymes responsible for the biogenesis of H2S, a signaling molecule. We have previously demonstrated that CBS is activated in cells challenged by oxidative stress, but the underlying molecular mechanism of this regulation has remained unclear. RESULTS Here, we demonstrate that S-glutathionylation of CBS enhances its activity ∼2-fold in vitro. Loss of this post-translational modification in the presence of dithiothreitol results in reversal to basal activity. Cys346 was identified as the site for S-glutathionylation by a combination of mass spectrometric, mutagenesis, and activity analyses. To test the physiological relevance of S-glutathionylation-dependent regulation of CBS, HEK293 cells were oxidatively challenged with peroxide, which is known to enhance the trans-sulfuration flux. Under these conditions, CBS glutathionylation levels increased and were correlated with a ∼3-fold increase in CBS activity. INNOVATION Collectively, our results reveal a novel post-translational modification of CBS, that is, glutathionylation, which functions as an allosteric activator under oxidative stress conditions permitting enhanced synthesis of both cysteine and H2S. CONCLUSIONS Our study elucidates a molecular mechanism for increased cysteine and therefore glutathione, synthesis via glutathionylation of CBS. They also demonstrate the potential for increased H2S production under oxidative stress conditions, particularly in tissues where CBS is a major source of H2S.
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Affiliation(s)
- Wei-Ning Niu
- 1 The Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University , Xi'an, China
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Huang H, Lu-Bo Y, Haddad GG. A Drosophila ABC transporter regulates lifespan. PLoS Genet 2014; 10:e1004844. [PMID: 25474322 PMCID: PMC4256198 DOI: 10.1371/journal.pgen.1004844] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 10/23/2014] [Indexed: 01/08/2023] Open
Abstract
MRP4 (multidrug resistance-associated protein 4) is a member of the MRP/ABCC subfamily of ATP-binding cassette (ABC) transporters that are essential for many cellular processes requiring the transport of substrates across cell membranes. Although MRP4 has been implicated as a detoxification protein by transport of structurally diverse endogenous and xenobiotic compounds, including antivirus and anticancer drugs, that usually induce oxidative stress in cells, its in vivo biological function remains unknown. In this study, we investigate the biological functions of a Drosophila homolog of human MRP4, dMRP4. We show that dMRP4 expression is elevated in response to oxidative stress (paraquat, hydrogen peroxide and hyperoxia) in Drosophila. Flies lacking dMRP4 have a shortened lifespan under both oxidative and normal conditions. Overexpression of dMRP4, on the other hand, is sufficient to increase oxidative stress resistance and extend lifespan. By genetic manipulations, we demonstrate that dMRP4 is required for JNK (c-Jun NH2-terminal kinase) activation during paraquat challenge and for basal transcription of some JNK target genes under normal condition. We show that impaired JNK signaling is an important cause for major defects associated with dMRP4 mutations, suggesting that dMRP4 regulates lifespan by modulating the expression of a set of genes related to both oxidative resistance and aging, at least in part, through JNK signaling. The drug transporters are often known for their ability to transport different physiological-related compounds across cell membranes. Although the abnormal up-regulation of some these transporters is believed to be the common cause of the clinic problem called drug resistance, the biological functions of these transporters remain largely unknown. Here we show that a Drosophila homolog of the mammalian drug transporter plays a role in lifespan regulation. Mutations of this gene increase the sensitivity to oxidative stress and reduce lifespan, while overexpression of this gene increases resistance to oxidative stress and extends lifespan. By molecular and genetic analyses, we have linked functions of this gene to a key signaling transduction pathway that has been known to be important in lifespan regulation.
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Affiliation(s)
- He Huang
- Department of Pediatrics (Division of Respiratory Medicine), University of California San Diego, La Jolla, California, United States of America
| | - Ying Lu-Bo
- Department of Pediatrics (Division of Respiratory Medicine), University of California San Diego, La Jolla, California, United States of America
| | - Gabriel G. Haddad
- Department of Pediatrics (Division of Respiratory Medicine), University of California San Diego, La Jolla, California, United States of America
- Rady Children's Hospital San Diego, San Diego, California, United States of America
- * E-mail:
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14
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Ishikawa T. Genetic polymorphism in the NRF2 gene as a prognosis marker for cancer chemotherapy. Front Genet 2014; 5:383. [PMID: 25408701 PMCID: PMC4219421 DOI: 10.3389/fgene.2014.00383] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/17/2014] [Indexed: 12/26/2022] Open
Abstract
NF-E2-related factor 2 (NRF2) is a transcription factor that controls the expression of a variety of antioxidant and detoxification genes. Accumulating evidence strongly suggests that NRF2 mediates cancer cell proliferation and drug resistance, as well. Single nucleotide polymorphism (SNP) -617C > A in the anti-oxidant response element-like loci of the human NRF2 gene play a pivotal role in the positive feedback loop of transcriptional activation of the NRF2 gene. Since the SNP (-617A) reportedly decreases the binding affinity to the transcription factors of NRF2/small multiple alignment format (MafK), the homozygous -617A/A allele may attenuate the positive feedback loop of transcriptional activation of the NRF2 gene and reduce the NRF2 protein level. As the consequence, cancer cells are considered to become more sensitive to therapy and less aggressive than cancer cells harboring the -617C (WT) allele. Indeed, Japanese lung cancer patients carrying SNP homozygous alleles (c. -617A/A) exhibited remarkable survival over 1,700 days after surgical operation (log-rank p = 0.021). The genetic polymorphism in the human NRF2 gene is considered as one of prognosis markers for cancer therapy.
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Affiliation(s)
- Toshihisa Ishikawa
- Personalized Medicine Research Institute, NGO Personalized Medicine and Healthcare, Yokohama Japan ; RIKEN Center for Life Science Technologies, Yokohama Japan
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15
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Triggering of protection mechanism against Phoneutria nigriventer spider venom in the brain. PLoS One 2014; 9:e107292. [PMID: 25211468 PMCID: PMC4161398 DOI: 10.1371/journal.pone.0107292] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 08/11/2014] [Indexed: 01/03/2023] Open
Abstract
Severe accidents caused by the "armed" spider Phoneutria nigriventer cause neurotoxic manifestations in victims. In experiments with rats, P. nigriventer venom (PNV) temporarily disrupts the properties of the BBB by affecting both the transcellular and the paracellular route. However, it is unclear how cells and/or proteins participate in the transient opening of the BBB. The present study demonstrates that PNV is a substrate for the multidrug resistance protein-1 (MRP1) in cultured astrocyte and endothelial cells (HUVEC) and increases mrp1 and cx43 and down-regulates glut1 mRNA transcripts in cultured astrocytes. The inhibition of nNOS by 7-nitroindazole suggests that NO derived from nNOS mediates some of these effects by either accentuating or opposing the effects of PNV. In vivo, MRP1, GLUT1 and Cx43 protein expression is increased differentially in the hippocampus and cerebellum, indicating region-related modulation of effects. PNV contains a plethora of Ca(2+), K(+) and Na(+) channel-acting neurotoxins that interfere with glutamate handling. It is suggested that the findings of the present study are the result of a complex interaction of signaling pathways, one of which is the NO, which regulates BBB-associated proteins in response to PNV interference on ions physiology. The present study provides additional insight into PNV-induced BBB dysfunction and shows that a protective mechanism is activated against the venom. The data shows that PNV has qualities for potential use in drug permeability studies across the BBB.
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Nair PMG, Park SY, Chung JW, Choi J. Transcriptional regulation of glutathione biosynthesis genes, γ-glutamyl-cysteine ligase and glutathione synthetase in response to cadmium and nonylphenol in Chironomus riparius. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2013; 36:265-273. [PMID: 23686006 DOI: 10.1016/j.etap.2013.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 06/02/2023]
Abstract
We characterized Chironomus riparius glutathione (GSH) biosynthesis genes, γ-glutamyl-cysteine ligase catalytic subunit (cr-gcl) and glutathione synthetase (cr-gs) and studied their expression after cadmium (Cd) and nonylphenol (NP) exposure. The full length cDNA of the Cr-GCL catalytic subunit was 2185 base pair (bp) in length containing an open reading frame of 1905bp, a 13bp 5' and 267bp 3' untranslated regions. The theoretical molecular mass of the deduced amino acid sequence (633) was 72.65kDa with an estimated pI of 5.42. The partial cDNA of Cr-GS was 739bp in length consisting 221 amino acids. The deduced amino acid sequence of Cr-GCL and Cr-GS cDNAs showed high conservation with homologs from other species. In phylogenetic analysis Cr-GCL and Cr-GS were grouped with equivalent genes from insects belonging to the dipteran order. The expression of cr-gcl and cr-gs was measured using quantitative real-time PCR after exposure to sub lethal concentrations of Cd (2, 10 and 20mg/L) and NP (10, 50 and 100μg/L) for 12, 24, 48 and 72h using real-time PCR methods. The mRNA expression of Cr-GCL and Cr-GS was significantly modulated after exposure to different concentrations of Cd and NP for different time periods. Total GSH levels showed a non-significant decrease after exposure to Cd for 24h. However, no change in GSH levels was observed after exposure to NP for 24h. These results suggest that Cr-GS and Cr-GCL expression is modulated by Cd and NP stress and may play an important role in detoxification of xenobiotics and antioxidant defense. We conclude that Cr-GS and Cr-GCL could be used as biomarkers of Cd and NP stress in aquatic environment for the studied species.
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Affiliation(s)
- Prakash M Gopalakrishnan Nair
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea
| | - Sun Young Park
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea
| | - Ji Woong Chung
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea
| | - Jinhee Choi
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea.
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Frota MLCD, Klamt F, Dal-Pizzol F, Schiengold M, Moreira JCF. Retinol-inducedmdr1andmdr3 modulation in cultured rat Sertoli cells is attenuated by free radical scavengers. Redox Rep 2013; 9:161-5. [PMID: 15327746 DOI: 10.1179/135100004225005192] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The effects of retinol on modulation of mdr genes in Sertoli cells were investigated. The hypothesis that free radical scavengers may attenuate the effect of retinol was also tested. Sertoli cells isolated from 15-day-old Wistar rats were cultured for 48 h and then treated with retinol for 24 h with or without free radical scavengers (1 mM mannitol, 0.1 mM Trolox or superoxide dismutase [200 U/ml]). Expression of mdr1, mdr2 and mdr3 genes was monitored by RT-PCR. Mitochondrial superoxide production was used as an index of ROS production. Expression of mdr1 and mdr3 was inhibited by retinol treatment (7 microM, 24 h), while mdr2 was not detected in response to any of the treatments. We also observed that retinol supplementation (7 microM, 24 h) increased superoxide production. The observed inhibition of mdr genes was attenuated by all co-treatments, suggesting that retinol-induced ROS are required for inhibition of mdr1 and mdr3 expression. The results suggest that retinol may play an important role in the modulation of the mdr gene family in cultured rat Sertoli cells and that these effects appear to be mediated by ROS.
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18
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Andérica-Romero AC, González-Herrera IG, Santamaría A, Pedraza-Chaverri J. Cullin 3 as a novel target in diverse pathologies. Redox Biol 2013; 1:366-72. [PMID: 24024173 PMCID: PMC3757711 DOI: 10.1016/j.redox.2013.07.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 06/28/2013] [Accepted: 07/09/2013] [Indexed: 12/12/2022] Open
Abstract
Recent evidence suggests that the malfunctioning disposal system of cell protein called ubiquitin–proteasome system (UPS) plays an important role in the development of disorders, including cancer and neurodegenerative diseases. Accumulating evidence suggests that the abnormal regulation of the E3 ubiquitin ligases, essential components of the UPS, contributes to uncontrolled proliferation, genomic instability and cancer, since these ligases and their substrates are involved in the regulation of cell cycle progression, gene transcription, signal transduction, DNA replication and others. Through selective degradation of specific substrates, E3 ligases regulate different biological processes. Cullins are a family of proteins that confer substrate specificity to multimeric complex of E3 ligases acting as scaffold proteins. So far, seven members of the cullin family of proteins have been identified. Interestingly, the data generated by several groups indicate that cullin 3 (Cul3) has begun to emerge as a protein involved in the etiopathology of multiple diseases. In this paper we examine the latest advances in basic research on the biology of Cul3 and how it could help to direct drug discovery efforts on this target. The most important system for protein degradation is the ubiquitin–proteasome system. The specific substrate for ubiquitination is highly specific and this activity can be provided by the E3 ubiquitin ligases. The E3 ubiquitin ligases based on cullins are the type of ubiquitin ligases more studied. The cullin 3 complex has emerged as a target due to its interaction with a wide range of BTB-proteins. Cullin 3 could be a molecule with a high therapeutic potential.
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Affiliation(s)
- Ana Cristina Andérica-Romero
- Facultad de Química, Departamento de Biología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, 04510 México D.F., México
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19
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Fonseca LM, Alvarez AB, Rodrigues RC, Santos DHF, Lopes AG, Capella MAM. ABCC1 is related to the protection of the distal nephron against hyperosmolality and high sodium environment: possible implications for cancer chemotherapy. PLoS One 2013; 8:e68049. [PMID: 23840808 PMCID: PMC3695945 DOI: 10.1371/journal.pone.0068049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 05/23/2013] [Indexed: 01/15/2023] Open
Abstract
Aims Glutathione (GSH) plays an important role in protecting cells against oxidative damage. ABCC1 protein transports GSH. Although this protein is largely studied in cancer, due to multidrug resistance phenotype, its role in the tubular cells of the kidney is unknown. The goal of this study was to find out whether ABCC1 has a role in protecting cells from the distal nephron against the stress caused by high medullar osmolality. Main Methods MA104 cells were treated with high concentrations of sodium chloride, urea, or both to raise the osmolality of the culture medium. Cell viability was accessed by MTT and trypan blue assays. ABCC1 expression and extrusion of carboxi-fluorescein (CF), a fluorescent ABCC1 substrate, were measured by flow cytometry. Key Findings Incubation of MA104 cells in a high sodium concentration medium resulted in changes in cell granularity and altered expression and activity of ABCC1. Urea did not alter ABCC1 expression or activity, but reversed the observed NaCl effects. High sodium concentrations also had a negative effect on cell viability and urea also protected cells against this effect. Significance Our findings demonstrate that ABCC1 plays a significant role in the protection of kidney epithelial cells against the stress caused by high sodium environment present in renal medulla.
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Affiliation(s)
- Leonardo M. Fonseca
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Adriana B. Alvarez
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rachel C. Rodrigues
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Diego H. F. Santos
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Anibal G. Lopes
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcia A. M. Capella
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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20
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Ji L, Li H, Gao P, Shang G, Zhang DD, Zhang N, Jiang T. Nrf2 pathway regulates multidrug-resistance-associated protein 1 in small cell lung cancer. PLoS One 2013; 8:e63404. [PMID: 23667609 PMCID: PMC3646742 DOI: 10.1371/journal.pone.0063404] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Accepted: 04/02/2013] [Indexed: 12/02/2022] Open
Abstract
Although multidrug-resistance-associated protein-1 (MRP1) is a major contributor to multi-drug resistance (MDR), the regulatory mechanism of Mrp1 still remains unclear. Nrf2 is a transcription factor that regulates cellular defense response through antioxidant response elements (AREs) in normal tissues. Recently, Nrf2 has emerged as an important contributor to chemo-resistance in tumor tissues. In the present study, the role of Nrf2-ARE pathway on regulation of Mrp1 was investigated. Compared with H69 lung cancer cells, H69AR cells with MDR showed significantly higher Nrf2-ARE pathway activity and expression of Mrp1 as well. When Nrf2 was knocked down in H69AR cells, MRP1's expression decreased accordingly. Moreover, those H69AR cells with reduced Nrf2 level restored sensitivity to chemo-drugs. To explore how Nrf2-ARE pathway regulates Mrp1, the promoter of Mrp1 gene was searched, and two putative AREs—ARE1 and ARE2—were found. Using reporter gene and ChIP assay, both ARE1 and ARE2 showed response to and interaction with Nrf2. In 40 cases of cancer tissues, the expression of Nrf2 and MRP1 was measured by immunohistochemistry (IHC). As the quantitive data of IHC indicated, both Nrf2 and MRP1 showed significantly higher expression in tumor tissue than adjacent non-tumor tissue. And more important, the correlation analysis of the two genes proved that their expression was correlative. Taken together, theses data suggested that Nrf2-ARE pathway is required for the regulatory expression of Mrp1 and implicated Nrf2 as a new therapeutic target for MDR.
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Affiliation(s)
- Lili Ji
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Pathology, Medical School of Nantong University, Nantong, Jiangsu Province, China
| | - Hui Li
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Pan Gao
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Guoguo Shang
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Donna D. Zhang
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, Arizona, United States of America
| | - Nong Zhang
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China
- * E-mail: (NZ); (TJ)
| | - Tao Jiang
- Department of Pathology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, Arizona, United States of America
- * E-mail: (NZ); (TJ)
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21
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Lu SC. Glutathione synthesis. Biochim Biophys Acta Gen Subj 2012; 1830:3143-53. [PMID: 22995213 DOI: 10.1016/j.bbagen.2012.09.008] [Citation(s) in RCA: 1439] [Impact Index Per Article: 119.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 09/05/2012] [Accepted: 09/10/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND Glutathione (GSH) is present in all mammalian tissues as the most abundant non-protein thiol that defends against oxidative stress. GSH is also a key determinant of redox signaling, vital in detoxification of xenobiotics, and regulates cell proliferation, apoptosis, immune function, and fibrogenesis. Biosynthesis of GSH occurs in the cytosol in a tightly regulated manner. Key determinants of GSH synthesis are the availability of the sulfur amino acid precursor, cysteine, and the activity of the rate-limiting enzyme, glutamate cysteine ligase (GCL), which is composed of a catalytic (GCLC) and a modifier (GCLM) subunit. The second enzyme of GSH synthesis is GSH synthetase (GS). SCOPE OF REVIEW This review summarizes key functions of GSH and focuses on factors that regulate the biosynthesis of GSH, including pathological conditions where GSH synthesis is dysregulated. MAJOR CONCLUSIONS GCL subunits and GS are regulated at multiple levels and often in a coordinated manner. Key transcription factors that regulate the expression of these genes include NF-E2 related factor 2 (Nrf2) via the antioxidant response element (ARE), AP-1, and nuclear factor kappa B (NFκB). There is increasing evidence that dysregulation of GSH synthesis contributes to the pathogenesis of many pathological conditions. These include diabetes mellitus, pulmonary and liver fibrosis, alcoholic liver disease, cholestatic liver injury, endotoxemia and drug-resistant tumor cells. GENERAL SIGNIFICANCE GSH is a key antioxidant that also modulates diverse cellular processes. A better understanding of how its synthesis is regulated and dysregulated in disease states may lead to improvement in the treatment of these disorders. This article is part of a Special Issue entitled Cellular functions of glutathione.
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Affiliation(s)
- Shelly C Lu
- Keck School of Medicine USC, Los Angeles, CA 90033, USA.
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22
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Lo YL, Wang W, Ho CT. 7,3',4'-Trihydroxyisoflavone modulates multidrug resistance transporters and induces apoptosis via production of reactive oxygen species. Toxicology 2012; 302:221-32. [PMID: 22914566 DOI: 10.1016/j.tox.2012.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 07/31/2012] [Accepted: 08/02/2012] [Indexed: 11/16/2022]
Abstract
The development of multidrug resistance (MDR) to conventional chemoradiation therapy usually leads to failure in treating cervical cancer. This study aims to explore the effects and mechanisms of 7,3',4'-trihydroxyisoflavone (7,3',4'-THIF), one of the major metabolites of daidzein, on potentiating cytotoxicity of epirubicin (Epi), an anticancer drug in human cervical cancer HeLa cells. The cytotoxicity of Epi remarkably increased when it was combined with 7,3',4'-THIF. The cotreatment increased the reactive oxygen species (ROS) levels, including hydrogen peroxide and superoxide free radicals. 7,3',4'-THIF was shown to down-regulate the MDR1 promoter region composed of the elements of AP1, GC-box, and Y-box, as demonstrated by a luciferase assay. A negative regulation of hMDR1 gene with multiple transcription factors by this isoflavone may provide a novel molecular mechanism for MDR modulation. The mRNA expressions of MDR1, MDR-associated protein (MRP) 1, and MRP2 for the combined treatment were significantly lower than those of the Epi treatment. This result implies that MDR transporter-mediated Epi resistance is inhibited at various degrees by the addition of 7,3',4'-THIF. This isoflavone significantly enhanced intracellular Epi accumulation in HeLa cells. 7,3',4'-THIF and/or Epi triggered apoptosis through the upregulation of p53, Bax, and caspase-9. Apoptosis induction was also confirmed by the reduced mitochondrial membrane potential, increased sub-G1 and G2/M phases, nuclear DNA fragmentation, and chromatin condensation. Our findings demonstrate for the first time that 7,3',4'-THIF causes cell death in human cervical cancer cells through the ROS-dependent suppression of MDR transporters and p53-mediated activation of the intrinsic mitochondrial pathway of apoptosis. Thus, 7,3',4'-THIF has the potential to enhance the activity of a broad range of cancer chemotherapeutics in the MDR spectrum with the advantage of reducing adverse effects.
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Affiliation(s)
- Yu-Li Lo
- Department of Biological Sciences and Technology, National University of Tainan, Tainan, Taiwan.
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23
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Franchi N, Ferro D, Ballarin L, Santovito G. Transcription of genes involved in glutathione biosynthesis in the solitary tunicate Ciona intestinalis exposed to metals. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 114-115:14-22. [PMID: 22417760 DOI: 10.1016/j.aquatox.2012.02.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 01/11/2012] [Accepted: 02/12/2012] [Indexed: 05/31/2023]
Abstract
Exposure to metals is known to generate oxidative stress risk in living organisms, which are able to respond with the induction of antioxidant defenses, both enzymatic and non-enzymatic. Glutathione (GSH) is considered to be an important cellular component involved in protecting cells, both as metal chelating agent and oxygen radical scavenger. In this work we used molecular techniques to analyze the nucleotide and predicted amino acid sequences of genes involved in GSH biosynthesis, γ-glutamyl-cysteine ligase catalytic subunit (ci-gclc), γ-glutamyl-cysteine ligase modifier subunit (ci-gclm) and GSH synthase (ci-gs) in the solitary tunicate Ciona intestinalis. We also studied the transcription of the above genes after in vivo exposure to Cd, Cu and Zn by semiquantitativ RT-PCR to improve our knowledge about the relationship between metal-induced oxidative stress and GSH production and locate mRNA expression by in situ hybridization (ISH). These genes exhibit a good level of sequence conservation with metazoan homologs generally, especially for residues important for the activity of the enzymes. Phylogenetic analyses indicate that the three enzymes evolved in different ways, Ci-GCLC and Ci-GS being mostly correlated with invertebrate proteins, Ci-GCLM being as sister group of vertebrate GCLMs. Our in silico analyses of the ci-gs and ci-gclc promoter regions revealed putative consensus sequences similar to mammalian metal-responsive elements (MRE) and antioxidant response elements (ARE), indicating that the transcription of these genes may directly depend on metals and/or reactive oxygen species. Results highlight a statistically significant increase in gene transcription, demonstrating that metal treatments have inducible effects on these genes. They can modulate gene transcription not only through MREs but also through AREs, as a consequence of metal-dependent ROS formation. The ISH location of Ci-GS and Ci-GCLC mRNAs shows that the cells most involved in glutathione biosynthesis are circulating hemocytes. The data presented here emphasize the importance of complex metal regulation of ci-gclc, ci-gclm and ci-gs transcription, which can create an efficient detoxification pathway allowing C. intestinalis to survive in continued elevated presence of metals in the environment.
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Affiliation(s)
- N Franchi
- Department of Biology, University of Padova, Via U. Bassi 58/B, 35100 Padova, Italy
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24
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Pasanen AK, Kuitunen H, Haapasaari KM, Karihtala P, Kyllönen H, Soini Y, Turpeenniemi-Hujanen T, Kuittinen O. Expression and prognostic evaluation of oxidative stress markers in an immunohistochemical study of B-cell derived lymphomas. Leuk Lymphoma 2012; 53:624-31. [DOI: 10.3109/10428194.2011.624226] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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25
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Hasan NM, Lutsenko S. Regulation of copper transporters in human cells. CURRENT TOPICS IN MEMBRANES 2012; 69:137-61. [PMID: 23046650 DOI: 10.1016/b978-0-12-394390-3.00006-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Copper is essential for normal growth and development of human organisms. The role of copper as a cofactor of important metabolic enzymes, such as cytochrome c oxidase, superoxide dismutase, lysyl oxidase, dopamine-β-hydroxylase, and many others, has been well established. In recent years, new regulatory roles of copper have emerged. Accumulating evidence points to the involvement of copper in lipid metabolism, antimicrobial defense, neuronal activity, resistance of tumor cells to platinum-based chemotherapeutic drugs, kinase-mediated signal transduction, and other essential cellular processes. For many of these processes, the precise mechanism of copper action remains to be established. Nevertheless, it is increasingly clear that many regulatory and signaling events are associated with changes in the intracellular localization and abundance of copper transporters, as well as distinct compartmentalization of copper itself. In this review, we discuss current data on regulation of the localization and abundance of copper transporters in response to metabolic and signaling events in human cells. Regulation by kinase-mediated phosphorylation will be addressed along with the emerging area of the redox-driven control of copper transport. We highlight mechanistic questions that await further testing.
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Affiliation(s)
- Nesrin M Hasan
- Department of Physiology, Johns Hopkins University, Baltimore, MD, USA
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26
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Andersen FA. Annual Review of Cosmetic Ingredient Safety Assessments: 2007-2010. Int J Toxicol 2011; 30:73S-127S. [DOI: 10.1177/1091581811412618] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Quezada C, Alarcón S, Cárcamo JG, Yáñez A, Casanello P, Sobrevia L, San Martín R. Increased expression of the multidrug resistance-associated protein 1 (MRP1) in kidney glomeruli of streptozotocin-induced diabetic rats. Biol Chem 2011; 392:529-37. [DOI: 10.1515/bc.2011.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Oxidative stress has been linked to the podocytopathy, mes-angial expansion and progression of diabetic nephropathy. The major cell defence mechanism against oxidative stress is reduced glutathione (GSH). Some ABC transporters have been shown to extrude GSH, oxidised glutathione or their conjugates out of the cell, thus implying a role for these transporters in GSH homeostasis. We found a remarkable expression of mRNA for multidrug resistance-associated proteins (MRP/ABCC) 1, 3, 4 and 5 in rat glomeruli. Three weeks after induction of diabetes in glomeruli of streptozotocin-treated rats, we observed a decline in reduced GSH levels and an increase in the expression and activity of MRP1 (ABCC1). These lower GSH levels were improved by ex vivo treatment with pharmacological inhibitors of MRP1 activity (MK571). We conclude that increased activity of MRP1 in diabetic glomeruli is correlated with an inadequate adaptive response to oxidative stress.
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Role of glutathione in the regulation of Cisplatin resistance in cancer chemotherapy. Met Based Drugs 2010; 2010. [PMID: 20885916 PMCID: PMC2946579 DOI: 10.1155/2010/430939] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 08/25/2010] [Indexed: 12/18/2022] Open
Abstract
Three mechanisms have been proposed for the role of glutathione (GSH) in regulating cisplatin (CDDP) sensitivities that affects its ultimate cell-killing ability: (i) GSH may serve as a cofactor in facilitating multidrug resistance protein 2- (MRP2-) mediated CDDP efflux in mammalian cells, since MRP2-transfected cells were shown to confer CDDP resistance; (ii) GSH may serve as a redox-regulating cytoprotector based on the observations that many CDDP-resistant cells overexpress GSH and γ-glutamylcysteine synthesis (γ-GCS), the rate-limiting enzyme for GSH biosynthesis; (iii) GSH may function as a copper (Cu) chelator. Elevated GSH expression depletes the cellular bioavailable Cu pool, resulting in upregulation of the high-affinity Cu transporter (hCtr1) which is also a CDDP transporter. This has been demonstrated that overexpression of GSH by transfection with γ-GCS conferred sensitization to CDDP toxicity. This review describes how these three models were developed and critically reviews their importance to overall CDDP cytotoxicity in cancer cell treatments.
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Jose M, Thomas SV. Role of multidrug transporters in neurotherapeutics. Ann Indian Acad Neurol 2010; 12:89-98. [PMID: 20142853 PMCID: PMC2812747 DOI: 10.4103/0972-2327.53076] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2009] [Revised: 05/14/2009] [Accepted: 06/02/2009] [Indexed: 11/30/2022] Open
Abstract
Acquired resistance to antibiotics and other chemotherapeutic agents is a major problem in the practice of neurology and other branches of medicine. There are several mechanisms by which drug resistance is acquired. Multidrug transporters are important glycoproteins located in the cell membrane that actively transport small lipophilic molecules from one side of the cell membrane to the other, most often from the inside to the outside of a cell. They have important protective role yet may prove inconvenient in chemotherapy. In epilepsy and other disorders this mechanism augments the elimination of drugs from their target cells and leads to drug resistance. In this review, we have discussed the biochemical characteristics of multidrug transporters and the mechanisms by which these membrane bound proteins transport their target molecules from one side to the other side of the cell membrane. We have also briefly discussed the application of this knowledge in the understanding of drug resistance in various clinical situations with particular reference to neurological disorders. These proteins located in the placenta have important role in preventing the transplacental movement of drugs in to the fetus which may result in congenital malformations or other defects. The molecular genetic mechanisms that govern the expression of these important proteins are discussed briefly. The potential scope to develop targeted chemotherapeutic agents is also discussed.
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Affiliation(s)
- Manna Jose
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Bodiga S, Gruenloh SK, Gao Y, Manthati VL, Dubasi N, Falck JR, Medhora M, Jacobs ER. 20-HETE-induced nitric oxide production in pulmonary artery endothelial cells is mediated by NADPH oxidase, H2O2, and PI3-kinase/Akt. Am J Physiol Lung Cell Mol Physiol 2010; 298:L564-74. [PMID: 20061439 DOI: 10.1152/ajplung.00298.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have shown that 20-hydroxyeicosatetraenoic acid (20-HETE) increases both superoxide and nitric oxide (NO) production in bovine pulmonary artery endothelial cells (BPAECs). The current study was designed to determine mechanisms underlying 20-HETE-stimulated NO release, and particularly the role of NADPH oxidase, reactive oxygen species, and PI3-kinase in stimulated NO release. Intracellular hydrogen peroxide (H(2)O(2)) and NO production were detected by dichlorofluorescein or dihydrorhodamine and diaminofluorescein fluorescence, respectively. Activation of endothelial nitric oxide synthase (eNOS) (Ser1179) and Akt (Ser473) was assessed by comparing the ratio of phosphorylated to total protein expression by Western blotting. Addition of 20-HETE to BPAECs caused an increase in superoxide and hydrogen peroxide, but not peroxynitrite. 20-HETE-evoked activation of Akt and eNOS, as well as enhanced NO release, are dependent on H(2)O(2) as opposed to superoxide in that these endpoints are blocked by PEG-catalase and not PEG-superoxide dismutase. Similarly, 20-HETE-stimulated NO production in BPAECs is blocked by NADPH oxidase inhibitors apocynin or gp91 blocking peptide, and by PI3-kinase/Akt blockers wortmannin, LY-294002, or Akt inhibitor, implicating NADPH oxidase, PI3-kinase, and Akt signaling pathways, respectively, in this process. Together, these data suggest the following scheme: 20-HETE stimulates NADPH oxidase-dependent formation of superoxide. Superoxide is rapidly dismutated to hydrogen peroxide, which then mediates activation of PI3-kinase/Akt, phosphorylation of eNOS, and enhanced release of NO from eNOS in response to 20-HETE in BPAECs.
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Affiliation(s)
- Sreedhar Bodiga
- Division of Pulmonary and Critical Care Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Abstract
Hormesis defines an effect where exposure to a low dose of a toxic agent results in a beneficial response. It has been described in organisms exposed to low-dose radiation, heat stress, and chemicals. The effect is characterised by a J-shaped dose-response as opposed to a linear dose-response. Confirmation of the general phenomena of hormesis has proved difficult due to the lack of appropriate methodology and the absence of well-defined mechanisms to support the experimental observations. In the nutritional field there are few reports of its existence. The clearest illustration of the effect is seen in animals that are energy restricted when there is a clear benefit in the reduction of age-related disease, and an extension of maximum lifespan. DNA microarray experiments have shown that there is a down regulation of the stress-response genes that are up regulated through the ageing process. Electrophilic phytochemicals, that have been shown to have beneficial health effects at low doses, up regulate the antioxidant-electrophile response element. This probably occurs through an alteration in the redox state of the target cells which causes activation of protein kinases, the activation of the Nrf2 transcription factor and the up regulation of the phase II enzymes, similar to responses that occur under mild chemical stress. This situation might enable organisms to adapt to stress such that the effects of a subsequent exposure to a harmful challenge are reduced. There may be a permanent alteration in cellular homeostasis, or redox state, if the low level exposure is maintained. It remains to be proven if such a situation occurs in response to chronic low-dose exposure to dietary phytochemicals such that the target cells are better able to respond to a subsequent stress challenge.
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Affiliation(s)
- David G Lindsay
- CEBAS (CSIC), Campus de Espinardo, Apartado de Correos 4195, MURCIA, 30100, Spain.
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Silverstein PS, Audus KL, Qureshi N, Kumar A. Lipopolysaccharide increases the expression of multidrug resistance-associated protein 1 (MRP1) in RAW 264.7 macrophages. J Neuroimmune Pharmacol 2009; 5:516-20. [PMID: 19894120 DOI: 10.1007/s11481-009-9180-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 10/14/2009] [Indexed: 02/05/2023]
Abstract
Multidrug resistance-associated protein 1 (MRP-1) is a ubiquitously expressed member of the ATP-binding cassette transporter family. MRP-1 is one of the primary transporters of glutathione and glutathione conjugates. This protein also transports antiretroviral therapeutics, such as HIV-1 protease inhibitors (PI). We hypothesized that inflammatory mediators that activate macrophages would modify the expression and activity of MRP-1 in macrophages. Real-time PCR assays, western blots, and calcein efflux assays were used to show that exposure of macrophage cell line RAW 264.7 to lipopolysaccharide (LPS) increased expression of MRP-1 at the levels of mRNA, protein, and functional activity. Treatment of macrophages with LPS resulted in 2-fold increases of MRP-1 expression or functional activity. LPS-mediated increases in calcein efflux were repressed by the MRP-specific inhibitor MK-571. These results suggest that the effectiveness of HIV-1 PI therapy may be compromised by the presence of opportunistic infections.
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Affiliation(s)
- Peter S Silverstein
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
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Zhang H, Forman HJ. Redox regulation of gamma-glutamyl transpeptidase. Am J Respir Cell Mol Biol 2009; 41:509-15. [PMID: 19684307 DOI: 10.1165/rcmb.2009-0169tr] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
gamma-Glutamyl transpeptidase (GGT) catalyzes the transfer of the glutamyl moiety from glutathione, and glutathione S-conjugates to acceptors to form another amide or to water to produce free glutamate. Functionally, GGT plays important roles in glutathione homeostasis and mercapturic acid metabolism. The expression of GGT is increased as an adaptive response upon the exposure of oxidative stress. The underlying mechanism of this, however, is nebulous, as GGT gene structure is complex and its transcription is usually controlled by multiple promoters that generate several subtypes of GGT mRNAs. Studies reveal that signaling pathways such as Ras, ERK, p38MAPK, and PI3K are involved in the induction of GGT gene expression in response to oxidative stress. Thus, not surprisingly, induction of GGT mRNA subtypes and the involvement of multiple signaling pathways vary depending on cell type and stimuli.
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Affiliation(s)
- Hongqiao Zhang
- School of Natural Sciences, University of California, Merced, Merced, CA 95340, USA
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Adachi T, Nakagawa H, Hagiya Y, Yasuoka T, Ishikawa T. Transport−Metabolism Interplay: LXRα-Mediated Induction of Human ABC Transporter ABCC2 (cMOAT/MRP2) in HepG2 Cells. Mol Pharm 2009; 6:1678-88. [DOI: 10.1021/mp9001156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Tatsuhiko Adachi
- Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-60 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Hiroshi Nakagawa
- Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-60 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Yuichiro Hagiya
- Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-60 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Tatsuya Yasuoka
- Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-60 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Toshihisa Ishikawa
- Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B-60 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
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Valtaud C, Foyer CH, Fleurat-Lessard P, Bourbouloux A. Systemic effects on leaf glutathione metabolism and defence protein expression caused by esca infection in grapevines. FUNCTIONAL PLANT BIOLOGY : FPB 2009; 36:260-279. [PMID: 32688645 DOI: 10.1071/fp08293] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 01/12/2009] [Indexed: 05/26/2023]
Abstract
Esca is a devastating disease of Vitis vinifera L., caused by fungal pathogen(s) inhabiting the wood. The pathogens induce symptoms in the foliage, which are associated with structural and biochemical changes in leaves. The present study was undertaken to examine the effects of the disease on leaf glutathione metabolism in field-grown plants. The glutathione pool decreased and defence proteins such as PR-proteins and chitinases were expressed in the leaves before the appearance of visible symptoms in esca-infected canes. Glutathione depletion was increased as the disease developed in the leaves. The ratio of glutathione disulfide (GSSG) to the total glutathione pool was slightly decreased in leaves without visible symptoms, but it was significantly increased as the disease progressed. The abundance of γ-glutamylcysteine synthetase (γ-ECS) transcripts and of γ-ECS protein was greatly decreased in leaves exhibiting esca symptoms. Although glutathione reductase and glutathione peroxidase transcripts were largely unchanged by the spread of the esca disease, leaf glutathione S-transferase (GST) activities, the amounts of mRNAs encoding GSTU1 and GSTF2 and the abundance of the GSTU1 and GSTF2 proteins were highest at the early stages of infection and then decreased as visible symptoms appeared in the leaves. The GSTF2 protein, which was more abundant than GSTU1, was found in the nucleus and in the cytoplasm, whereas the GSTU1 protein was found largely in the plastids. These data demonstrate that the fungi involved in the esca disease induce pronounced systemic effects in the leaves before the appearance of visible damage. We conclude that the expression of GSTs, the extent of glutathione accumulation and the ratio of GSSG to total glutathione are early indicators of the presence of the esca disease in grapevine canes and thus these parameters can be used as stress markers in field-grown vines.
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Affiliation(s)
- Christophe Valtaud
- Université de Poitiers, Laboratoire de Physiologie et Biochimie Végétales, UMR-CNRS 6161, Bâtiment Botanique, 40 Avenue du Recteur Pineau, F-86022 Poitiers, France
| | - Christine H Foyer
- School of Agriculture, Food and Rural Development, Agriculture Building, The University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Pierrette Fleurat-Lessard
- Université de Poitiers, Laboratoire de Physiologie et Biochimie Végétales, UMR-CNRS 6161, Bâtiment Botanique, 40 Avenue du Recteur Pineau, F-86022 Poitiers, France
| | - Andrée Bourbouloux
- Université de Poitiers, Laboratoire de Physiologie et Biochimie Végétales, UMR-CNRS 6161, Bâtiment Botanique, 40 Avenue du Recteur Pineau, F-86022 Poitiers, France
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Kuo MT. Redox regulation of multidrug resistance in cancer chemotherapy: molecular mechanisms and therapeutic opportunities. Antioxid Redox Signal 2009; 11:99-133. [PMID: 18699730 PMCID: PMC2577715 DOI: 10.1089/ars.2008.2095] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The development of multidrug resistance to cancer chemotherapy is a major obstacle to the effective treatment of human malignancies. It has been established that membrane proteins, notably multidrug resistance (MDR), multidrug resistance protein (MRP), and breast cancer resistance protein (BCRP) of the ATP binding cassette (ABC) transporter family encoding efflux pumps, play important roles in the development of multidrug resistance. Overexpression of these transporters has been observed frequently in many types of human malignancies and correlated with poor responses to chemotherapeutic agents. Evidence has accumulated showing that redox signals are activated in response to drug treatments that affect the expression and activity of these transporters by multiple mechanisms, including (a) conformational changes in the transporters, (b) regulation of the biosynthesis cofactors required for the transporter's function, (c) regulation of the expression of transporters at transcriptional, posttranscriptional, and epigenetic levels, and (d) amplification of the copy number of genes encoding these transporters. This review describes various specific factors and their relevant signaling pathways that are involved in the regulation. Finally, the roles of redox signaling in the maintenance and evolution of cancer stem cells and their implications in the development of intrinsic and acquired multidrug resistance in cancer chemotherapy are discussed.
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Affiliation(s)
- Macus Tien Kuo
- Department of Molecular Pathology (Unit 951), The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
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Choi CH, Bark H, Chung JM, Park EK, Kim SH. Elevated Reactive Oxygen Species but not Glutathione Regulate Mercury Resistance to AML-2/DX100 Cells. Immunopharmacol Immunotoxicol 2008; 28:545-55. [PMID: 16997801 DOI: 10.1080/08923970600927918] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The multidrug resistance-associated protein (MRP1) mediates cellular efflux of various xenobiotics and cellular resistance to heavy metals. Previously we reported that MRP1 mediates resistance to mercury exposure and possible mechanism mediating MRP1 expression after mercury exposure. This study was designed to investigate the role of reactive oxygen species (ROS) and glutathione on the resistance of AML-2/DX100 cells to mercuric chloride. The MRP1 overexpressing cells (AML-2/DX100) cells showed less scavenging activity to ROS induced by mercury while no difference in the basal glutathione levels between AML-2/WT and AML-2/DX100 cells. Mercury induced the activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) but not c-jun-N-terminal kinase in AML-2/DX100 cells. The specific inhibitor for p38 MAPK and ERK, and antioxidant decreased the production of MRP1 and therefore resistance of AML-2/DX100 cells against mercury exposure. These results suggest that induction of ROS and downstream p38 MAPK and ERK were involved in the resistance of cells to mercury by expression MRP1 in AML-2/DX100 cells.
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Affiliation(s)
- Cheol-Hee Choi
- Department of Pharmacology, College of Medicine, Chosun University, Gwangju, Republic of Korea
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38
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Toyoda Y, Hagiya Y, Adachi T, Hoshijima K, Kuo MT, Ishikawa T. MRP class of human ATP binding cassette (ABC) transporters: historical background and new research directions. Xenobiotica 2008; 38:833-62. [DOI: 10.1080/00498250701883514] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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39
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Lu SC. Regulation of glutathione synthesis. Mol Aspects Med 2008; 30:42-59. [PMID: 18601945 DOI: 10.1016/j.mam.2008.05.005] [Citation(s) in RCA: 1338] [Impact Index Per Article: 83.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 05/23/2008] [Accepted: 05/26/2008] [Indexed: 02/07/2023]
Abstract
Glutathione (GSH) is a ubiquitous intracellular peptide with diverse functions that include detoxification, antioxidant defense, maintenance of thiol status, and modulation of cell proliferation. GSH is synthesized in the cytosol of all mammalian cells in a tightly regulated manner. The major determinants of GSH synthesis are the availability of cysteine, the sulfur amino acid precursor, and the activity of the rate-limiting enzyme, glutamate cysteine ligase (GCL). GCL is composed for a catalytic (GCLC) and modifier (GCLM) subunit and they are regulated at multiple levels and at times differentially. The second enzyme of GSH synthesis, GSH synthase (GS) is also regulated in a coordinated manner as GCL subunits and its up-regulation can further enhance the capacity of the cell to synthesize GSH. Oxidative stress is well known to induce the expression of GSH synthetic enzymes. Key transcription factors identified thus far include Nrf2/Nrf1 via the antioxidant response element (ARE), activator protein-1 (AP-1) and nuclear factor kappa B (NFkappaB). Dysregulation of GSH synthesis is increasingly being recognized as contributing to the pathogenesis of many pathological conditions. These include diabetes mellitus, pulmonary fibrosis, cholestatic liver injury, endotoxemia and drug-resistant tumor cells. Manipulation of the GSH synthetic capacity is an important target in the treatment of many of these disorders.
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Affiliation(s)
- Shelly C Lu
- Department of Medicine, Division of Gastroenterology and Liver Diseases, USC Research Center for Liver Diseases, USC-UCLA Research Center for Alcoholic Liver and Pancreatic Diseases, Keck School of Medicine USC, Los Angeles, CA 90033, USA.
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Aiba I, Hossain A, Kuo MT. Elevated GSH level increases cadmium resistance through down-regulation of Sp1-dependent expression of the cadmium transporter ZIP8. Mol Pharmacol 2008; 74:823-33. [PMID: 18556457 DOI: 10.1124/mol.108.046862] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Cadmium is a nonessential toxic metal in mammals. Its toxicity is mainly caused by interactions with cellular proteins that result in protein dysfunction and then disturb normal cellular functions. Glutathione (GSH) has been reported to play a role in cadmium resistance by serving as a cofactor for multidrug resistance protein 1/GS-X pump-mediated cadmium elimination. To further investigate the role of GSH in cadmium toxicity, we carried out a comparative study using small-cell lung cancer-derived cell lines, SR3A, and those that were stably transfected with glutamate cysteine ligase catalytic subunit (GCLC), a rate-limiting enzyme in GSH biosynthesis. These GCLC stably transfected cell lines produced higher levels of GSH and were more resistant to cadmium toxicity than the parental cell line was. The rates of cadmium uptake were reduced in these GCLC-transfected cell lines, which were associated with down-regulation of the cadmium transporter ZIP8/SLC39A8. Further analyses demonstrated that Sp1 binding site at the proximal promoter region of ZIP8 was sensitive to the GSH level and that the expression level of transcription factor Sp1 was reduced by increased GSH levels. We also demonstrated that low concentrations of cadmium exposure down-regulated ZIP8 expression with concomitant reduction of Sp1 expression. Taken together, these results demonstrate the importance of Sp1 in the regulation of ZIP8 expression. More important, our results reveal a new mechanism by which elevated GSH levels confer cadmium resistance by down-regulation of ZIP8 expression through the suppression of Sp1.
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Affiliation(s)
- Isamu Aiba
- Department of Molecular Pathology, M.D. Anderson Cancer Center, Houston, TX 77054, USA
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Chen HHW, Song IS, Hossain A, Choi MK, Yamane Y, Liang ZD, Lu J, Wu LYH, Siddik ZH, Klomp LWJ, Savaraj N, Kuo MT. Elevated glutathione levels confer cellular sensitization to cisplatin toxicity by up-regulation of copper transporter hCtr1. Mol Pharmacol 2008; 74:697-704. [PMID: 18523133 DOI: 10.1124/mol.108.047969] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Previous studies have demonstrated that treating cultured cells with cisplatin (CDDP) up-regulated the expression of glutathione (GSH) and its de novo rate-limiting enzyme glutamate-cysteine ligase (GCL), which consists of a catalytic (GCLC) and a modifier (GCLM) subunit. It has also been shown that many CDDP-resistant cell lines exhibit high levels of GCLC/GCLM and GSH. Because the GSH system is the major intracellular regulator of redox conditions that serve as an important detoxification cytoprotector, these results have been taken into consideration that elevated levels of GCL/GSH are responsible for the CDDP resistance. In contrast to this context, we demonstrated here that overexpression of GSH by transfection with an expression plasmid containing the GCLC cDNA conferred sensitization to CDDP through up-regulation of human copper transporter (hCtr) 1, which is also a transporter for CDDP. Depleting GSH levels in these transfected cells reversed CDDP sensitivity with concomitant reduction of hCtr1 expression. Although rates of copper transport were also up-regulated in the transfected cells, these cells exhibited biochemical signature of copper deficiency, suggesting that GSH functions as an intracellular copper-chelator and that overexpression of GSH can alter copper metabolism. More importantly, our results reveal a new role of GSH in the regulation of CDDP sensitivity. Overproduction of GSH depletes the bioavailable copper pool, leading to up-regulation of hCtr1 and sensitization of CDDP transport and cell killing. These findings also have important implications in that modulation of the intracellular copper pool may be a novel strategy for improving chemotherapeutic efficacy of platinum-based antitumor agents.
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Affiliation(s)
- Helen H W Chen
- Department of Molecular Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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Ronaldson PT, Bendayan R. HIV-1 viral envelope glycoprotein gp120 produces oxidative stress and regulates the functional expression of multidrug resistance protein-1 (Mrp1) in glial cells. J Neurochem 2008; 106:1298-313. [PMID: 18485102 DOI: 10.1111/j.1471-4159.2008.05479.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Brain human immunodeficiency virus type-1 (HIV-1) infection is associated with oxidative stress, which may lead to HIV-1 encephalitis, a chronic neurodegenerative condition. In vitro, oxidative stress can be induced in glial cells by exposure to HIV-1 envelope protein glycoprotein (gp120). Multidrug resistance proteins (Mrps) are known to efflux endogenous substrates (i.e. GSH and GSSG) involved in cellular defense against oxidative stress. Altered GSH/GSSG export may contribute to oxidative damage during HIV-1 encephalitis. At present, it is unknown if gp120 exposure can alter the functional expression of Mrp isoforms. Heat-shock protein 70, inducible nitric oxide synthase, intracellular GSSG, 2',7'-dichlorofluorescein fluorescence, and extracellular nitrite were increased in primary cultures of rat astrocytes triggered with gp120, suggesting an oxidative stress response. RT-PCR and immunoblot analysis demonstrated increased Mrp1 mRNA (2.3-fold) and protein (2.2-fold), respectively, in gp120 treated astrocytes while Mrp4 mRNA or protein expression was not changed. Cellular retention of 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, an established Mrp substrate, was reduced (twofold) in gp120-treated astrocytes, suggesting increased Mrp-mediated transport. In addition, GSH and GSSG export were enhanced in gp120-triggered cells. These data suggest that gp120 can up-regulate Mrp1, but not Mrp4, functional expression in cultured astrocytes. Our observation of increased GSH/GSSG efflux in response to gp120 treatment implies that Mrp isoforms may be involved in regulating the oxidative stress response in glial cells.
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Affiliation(s)
- Patrick T Ronaldson
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
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Maher JM, Dieter MZ, Aleksunes LM, Slitt AL, Guo G, Tanaka Y, Scheffer GL, Chan JY, Manautou JE, Chen Y, Dalton TP, Yamamoto M, Klaassen CD. Oxidative and electrophilic stress induces multidrug resistance-associated protein transporters via the nuclear factor-E2-related factor-2 transcriptional pathway. Hepatology 2007; 46:1597-610. [PMID: 17668877 DOI: 10.1002/hep.21831] [Citation(s) in RCA: 248] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
UNLABELLED Multidrug resistance-associated proteins (Mrps) are adenosine triphosphate-dependent transporters that efflux chemicals out of cells. In the liver, Mrp2 transports bilirubin-glucuronide, glutathione (GSH), and drug conjugates into bile, whereas Mrp3 and Mrp4 efflux these entities into blood. The purpose of this study was to determine whether oxidative conditions (that is, the disruption of hepatic GSH synthesis) or the administration of nuclear factor-E2-related factor-2 (Nrf2) activators (oltipraz and butylated hydroxyanisole) can induce hepatic Mrp transporters and whether that induction is through the Nrf2 transcriptional pathway. Livers from hepatocyte-specific glutamate-cysteine ligase catalytic subunit-null mice had increased nuclear Nrf2 levels, marked gene and protein induction of the Nrf2 target gene NAD(P)H:quinone oxidoreductase 1, as well as Mrp2, Mrp3, and Mrp4 expression. The treatment of wild-type and Nrf2-null mice with oltipraz and butylated hydroxyanisole demonstrated that the induction of Mrp2, Mrp3, and Mrp4 is Nrf2-dependent. In Hepa1c1c7 cells treated with the Nrf2 activator tert-butyl hydroquinone, chromatin immunoprecipitation with Nrf2 antibodies revealed the binding of Nrf2 to antioxidant response elements in the promoter regions of mouse Mrp2 [-185 base pairs (bp)], Mrp3 (-9919 bp), and Mrp4 (-3767 bp). CONCLUSION The activation of the Nrf2 regulatory pathway stimulates the coordinated induction of hepatic Mrps.
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Affiliation(s)
- Jonathan M Maher
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
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Do JH, Oh SH, Song EJ, Chung JS, Kang CD, Lee EY. Treatment Outcome of Multidrug Resistance Related mRNA Expression and c-Jun-N-Terminal Kinase Activity in Patients with Acute Myeloid Leukemia. Ann Lab Med 2007; 27:229-36. [DOI: 10.3343/kjlm.2007.27.4.229] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Jeong Hwa Do
- Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Seung Hwan Oh
- Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Eun Ju Song
- Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Joo Seop Chung
- Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Chi Duk Kang
- Department of Biochemistry, Pusan National University School of Medicine, Busan, Korea
| | - Eun Yup Lee
- Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea
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Karihtala P, Soini Y. Reactive oxygen species and antioxidant mechanisms in human tissues and their relation to malignancies. APMIS 2007; 115:81-103. [PMID: 17295675 DOI: 10.1111/j.1600-0463.2007.apm_514.x] [Citation(s) in RCA: 216] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Reactive oxygen species (ROS) are formed in mammalian cells as a consequence of aerobic respiration. Despite multiple conserved redox modulating systems, a given proportion of ROS continuously escape from the mitochondrial respiratory chain, being sufficiently potent to damage cells in various ways, including numerous carcinogenic DNA mutations. Oxidative stress resulting from an imbalanced ratio between ROS production and detoxification may also disturb physiological signal transduction, lead to chain reactions in lipid layers, and damage DNA repair enzymes. The significance of ROS and antioxidant systems in carcinogenesis is still complicated and in many ways contradictory. Enhanced antioxidant mechanisms in tumor cells in vivo have been implicated in chemoresistance and lead to poor prognosis, whereas most in vitro studies have reported tumor-suppressing properties of antioxidant enzymes. The present review aims to clarify the significance of oxidative stress and the role of cell redox state modulating systems in human malignancies in light of the current literature.
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Affiliation(s)
- Peeter Karihtala
- Department of Pathology, University of Oulu and Oulu University Hospital, Oulu, Finland.
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Nakata K, Tanaka Y, Nakano T, Adachi T, Tanaka H, Kaminuma T, Ishikawa T. Nuclear receptor-mediated transcriptional regulation in Phase I, II, and III xenobiotic metabolizing systems. Drug Metab Pharmacokinet 2007; 21:437-57. [PMID: 17220560 DOI: 10.2133/dmpk.21.437] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Studies of the genetic regulation involved in drug metabolizing enzymes and drug transporters are of great interest to understand the molecular mechanisms of drug response and toxic events. Recent reports have revealed that hydrophobic ligands and several nuclear receptors are involved in the induction or down-regulation of various enzymes and transporters involved in Phase I, II, and III xenobiotic metabolizing systems. Nuclear receptors (NRs) form a family of ligand-activated transcription factors (TFs). These proteins modulate the regulation of target genes by contacting their promoter or enhancer sequences at specific recognition sites. These target genes include metabolizing enzymes such as cytochrome P450s (CYPs), transporters, and NRs. Thus it was now recognized that these NRs play essential role in sensing processing xenobiotic substances including drugs, environmental chemical pollutants and nutritional ingredients. From literature, we picked up target genes of each NR in xenobiotic response systems. Possible cross-talk, by which xenobiotics may exert undesirable effects, was listed. For example, the role of NRs was comprehensively drawn up in cholesterol and bile acid homeostasis in human hepatocyte. Summarizing current states of related research, especially for in silico response element search, we tried to elucidate nuclear receptor mediated xenobiotic processing loops and direct future research.
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Krause MS, Oliveira LP, Silveira EMS, Vianna DR, Rossato JS, Almeida BS, Rodrigues MF, Fernandes AJM, Costa JAB, Curi R, de Bittencourt PIH. MRP1/GS-X pump ATPase expression: is this the explanation for the cytoprotection of the heart against oxidative stress-induced redox imbalance in comparison to skeletal muscle cells? Cell Biochem Funct 2007; 25:23-32. [PMID: 16868918 DOI: 10.1002/cbf.1343] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Striated muscle activity is always accompanied by oxidative stress (OxStress): the more intense muscle work and/or its duration, the more a redox imbalance may be attained. In spite of cardiac muscle functioning continuously, it is well known that the heart does not suffer from OxStress-induced damage over a broad physiological range. Although the expression of antioxidant enzymes may be of importance in defending heart muscle against OxStress, a series of combined antioxidant therapeutic approaches have proved to be mostly ineffective in avoiding cellular injury. Hence, additional mechanisms may be involved in heart cytoprotection other than antioxidant enzyme activities. The strong cardiotoxic effect of doxorubicin-induced cancer chemotherapy shed light on the possible role for multidrug resistance-associated proteins (MRP) in this context. Muscle activity-induced 'physiological' OxStress enhances the production of glutathione disulfide (GSSG) thus increasing the ratio of GSSG to glutathione (GSH) content inside the cells, which, in turn, leads to redox imbalance. Since MRP1 gene product (a GS-X pump ATPase) is a physiological GSSG transporter, adult Wistar rats were tested for MRP1 expression and activity in the heart and skeletal muscle (gastrocnemius), in as much as the latter is known to be extremely sensitive to muscle activity-induced OxS. MRP1 expression was completely absent in skeletal muscle. In contrast, the heart showed an exercise training-dependent induction of MRP1 protein expression which was further augmented (2.4-fold) as trained rats were challenged with a session of acute exercise. On the other hand, inducible expression of the 70-kDa heat shock protein (HSP70), a universal marker of cellular stress, was completely absent in the heart of sedentary and acutely exercised rats, whereas skeletal muscle showed a conspicuous exercise-dependent HSP70 expression, which decreased by 45% with exercise training. This effect was paralleled by a 58% decrease in GSH content in skeletal muscle which was even higher (an 80%-fall) after training thus leading to a marked redox imbalance ([GSSG]/[GSH] raised up to 38-fold). In the heart, GSH contents and [GSSG]/[GSH] ratio remained virtually unchanged even after exercise challenges, while GS-X pump activity was found to be 20% higher in the heart related to skeletal muscle. These findings suggest that an intrinsic higher capacity to express the MRP1/GS-X pump may dictate the redox status in the heart muscle thus protecting myocardium by preventing GSSG accumulation in cardiomyocytes as compared to skeletal muscle fibres.
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Affiliation(s)
- Maurício S Krause
- Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
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Roles of Multidrug Resistance Genes in Breast Cancer Chemoresistance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 608:23-30. [DOI: 10.1007/978-0-387-74039-3_2] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Bakos E, Homolya L. Portrait of multifaceted transporter, the multidrug resistance-associated protein 1 (MRP1/ABCC1). Pflugers Arch 2006; 453:621-41. [PMID: 17187268 DOI: 10.1007/s00424-006-0160-8] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2006] [Revised: 05/10/2006] [Accepted: 05/24/2006] [Indexed: 10/23/2022]
Abstract
MRP1 (ABCC1) is a peculiar member of the ABC transporter superfamily for several aspects. This protein has an unusually broad substrate specificity and is capable of transporting not only a wide variety of neutral hydrophobic compounds, like the MDR1/P-glycoprotein, but also facilitating the extrusion of numerous glutathione, glucuronate, and sulfate conjugates. The transport mechanism of MRP1 is also complex; a composite substrate-binding site permits both cooperativity and competition between various substrates. This versatility and the ubiquitous tissue distribution make this transporter suitable for contributing to various physiological functions, including defense against xenobiotics and endogenous toxic metabolites, leukotriene-mediated inflammatory responses, as well as protection from the toxic effect of oxidative stress. In this paper, we give an overview of the considerable amount of knowledge which has accumulated since the discovery of MRP1 in 1992. We place special emphasis on the structural features essential for function, our recent understanding of the transport mechanism, and the numerous assignments of this transporter.
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Affiliation(s)
- Eva Bakos
- Institute of Enzymology, Hungarian Academy of Sciences, Budapest, Hungary
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