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Hirai T, Saito S, Fujimori H, Matsushita K, Nishio T, Okayasu R, Masutani M. Radiosensitization by PARP inhibition to proton beam irradiation in cancer cells. Biochem Biophys Res Commun 2016; 478:234-240. [PMID: 27425251 DOI: 10.1016/j.bbrc.2016.07.062] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022]
Abstract
The poly(ADP-ribose) polymerase (PARP)-1 regulates DNA damage responses and promotes base excision repair. PARP inhibitors have been shown to enhance the cytotoxicity of ionizing radiation in various cancer cells and animal models. We have demonstrated that the PARP inhibitor (PARPi) AZD2281 is also an effective radiosensitizer for carbon-ion radiation; thus, we speculated that the PARPi could be applied to a wide therapeutic range of linear energy transfer (LET) radiation as a radiosensitizer. Institutes for biological experiments using proton beam are limited worldwide. This study was performed as a cooperative research at heavy ion medical accelerator in Chiba (HIMAC) in National Institute of Radiological Sciences. HIMAC can generate various ion beams; this enabled us to compare the radiosensitization effect of the PARPi on cells subjected to proton and carbon-ion beams from the same beam line. After physical optimization of proton beam irradiation, the radiosensitization effect of the PARPi was assessed in the human lung cancer cell line, A549, and the pancreatic cancer cell line, MIA PaCa-2. The effect of the PARPi, AZD2281, on radiosensitization to Bragg peak was more significant than that to entrance region. The PARPi increased the number of phosphorylated H2AX (γ-H2AX) foci and enhanced G2/M arrest after proton beam irradiation. This result supports our hypothesis that a PARPi could be applied to a wide therapeutic range of LET radiation by blocking the DNA repair response.
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Affiliation(s)
- Takahisa Hirai
- Department of Radiation Oncology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan; Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan
| | - Soichiro Saito
- Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan
| | - Hiroaki Fujimori
- Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan
| | - Keiichiro Matsushita
- Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima-shi, Hiroshima, Japan
| | - Teiji Nishio
- Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima-shi, Hiroshima, Japan
| | - Ryuichi Okayasu
- International Open Laboratory, National Institute of Radiological Science, Chiba-shi, Chiba, Japan
| | - Mitsuko Masutani
- Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo, Japan; Department of Frontier Life Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
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Yang SY, Kang JH, Seomun Y, Lee KW. Caffeic acid induces glutathione synthesis through JNK/AP-1-mediated γ-glutamylcysteine ligase catalytic subunit induction in HepG2 and primary hepatocytes. Food Sci Biotechnol 2015. [DOI: 10.1007/s10068-015-0241-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Vellinger C, Gismondi E, Felten V, Rousselle P, Mehennaoui K, Parant M, Usseglio-Polatera P. Single and combined effects of cadmium and arsenate in Gammarus pulex (Crustacea, Amphipoda): understanding the links between physiological and behavioural responses. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 140-141:106-116. [PMID: 23770824 DOI: 10.1016/j.aquatox.2013.05.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 05/06/2013] [Accepted: 05/13/2013] [Indexed: 06/02/2023]
Abstract
This study aimed at investigating the individual and interactive effects of cadmium (Cd) and arsenate (AsV) in Gammarus pulex (Crustacea, Amphipoda) through the use of several biomarkers. Individuals were exposed for 240 h to two concentrations of AsV or Cd alone, and all the possible binary mixtures of these concentrations of AsV and Cd in a complete factorial design. The pattern of the biomarkers' responses to Cd and AsV alone or in mixture was similar in Gammarus pulex, even if the response intensity varied depending on the tested conditions. G. pulex responded to contamination with increased mobilization of the detoxification systems [i.e. γ-glutamyl-cystein ligase activity (GCL), reduced glutathione content (GSH) and metallothionein concentrations (MT)]. This response seems to imply changes in energy reserve utilization (total lipids and proteins are used prior to glycogen reserves), but also a possible energy reallocation from locomotion to detoxification processes. The observed increase in lipid peroxidation could be relied to the increasing gammarid mortality, despite the higher mobilization of detoxification systems. Even if the outcome of the complex interactions between AsV and Cd remains difficult to unravel, such studies are critically important for better assessing the effects of stressors on organisms, populations and communities in a multi-contamination context of ecosystems.
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Affiliation(s)
- Céline Vellinger
- Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), CNRS UMR 7360, Université de Lorraine - Metz, France.
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Fitzpatrick AM, Jones DP, Brown LAS. Glutathione redox control of asthma: from molecular mechanisms to therapeutic opportunities. Antioxid Redox Signal 2012; 17:375-408. [PMID: 22304503 PMCID: PMC3353819 DOI: 10.1089/ars.2011.4198] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 01/22/2012] [Accepted: 01/22/2012] [Indexed: 12/11/2022]
Abstract
Asthma is a chronic inflammatory disorder of the airways associated with airway hyper-responsiveness and airflow limitation in response to specific triggers. Whereas inflammation is important for tissue regeneration and wound healing, the profound and sustained inflammatory response associated with asthma may result in airway remodeling that involves smooth muscle hypertrophy, epithelial goblet-cell hyperplasia, and permanent deposition of airway extracellular matrix proteins. Although the specific mechanisms responsible for asthma are still being unraveled, free radicals such as reactive oxygen species and reactive nitrogen species are important mediators of airway tissue damage that are increased in subjects with asthma. There is also a growing body of literature implicating disturbances in oxidation/reduction (redox) reactions and impaired antioxidant defenses as a risk factor for asthma development and asthma severity. Ultimately, these redox-related perturbations result in a vicious cycle of airway inflammation and injury that is not always amenable to current asthma therapy, particularly in cases of severe asthma. This review will discuss disruptions of redox signaling and control in asthma with a focus on the thiol, glutathione, and reduced (thiol) form (GSH). First, GSH synthesis, GSH distribution, and GSH function and homeostasis are discussed. We then review the literature related to GSH redox balance in health and asthma, with an emphasis on human studies. Finally, therapeutic opportunities to restore the GSH redox balance in subjects with asthma are discussed.
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Affiliation(s)
- Anne M Fitzpatrick
- Department of Pediatrics, Emory University, Atlanta, Georgia 30322, USA.
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Gismondi E, Rigaud T, Beisel JN, Cossu-Leguille C. Microsporidia parasites disrupt the responses to cadmium exposure in a gammarid. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2012; 160:17-23. [PMID: 22035920 DOI: 10.1016/j.envpol.2011.09.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 08/01/2011] [Accepted: 09/14/2011] [Indexed: 05/31/2023]
Abstract
Microsporidia parasites are commonly found in amphipods, where they are often asymptomatic, vertically-transmitted and have several effects on host sexuality and behaviour. As amphipods are often used as models in ecotoxicological studies, we investigated the effect of microsporidian infections on energy reserves and defence capacities of Gammarus roeseli under cadmium stress. Only females were infected by two microsporidia parasites: Dictyocoela roeselum or Dictyocoela muelleri. In physiological conditions, microsporidia had no major effect on energy reserves and defence capacities of G. roeseli, while under cadmium exposure, energy reserves and antioxidant defence were weaker in infected females. Moreover, higher malondialdehyde levels detected in infected females revealed that they suffered more cellular damages. Our results suggest that microsporidia may affect gammarid fitness in stressful conditions, when parasitic stress cannot be compensated by the host. Consequently, microsporidia parasites should be a factor necessary to take into account in ecotoxicology studies involving amphipods.
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Affiliation(s)
- Eric Gismondi
- Laboratoire des Interactions Ecotoxicologie Biodiversité Ecosystèmes (LIEBE), Université Paul Verlaine - METZ, CNRS UMR 7146, Campus Bridoux, Avenue du Général Delestraint, 57070 Metz, France.
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Backos DS, Fritz KS, Roede JR, Petersen DR, Franklin CC. Posttranslational modification and regulation of glutamate-cysteine ligase by the α,β-unsaturated aldehyde 4-hydroxy-2-nonenal. Free Radic Biol Med 2011; 50:14-26. [PMID: 20970495 PMCID: PMC3014730 DOI: 10.1016/j.freeradbiomed.2010.10.694] [Citation(s) in RCA: 233] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 09/27/2010] [Accepted: 10/11/2010] [Indexed: 11/21/2022]
Abstract
4-Hydroxy-2-nonenal (4-HNE) is a lipid peroxidation product formed during oxidative stress that can alter protein function via adduction of nucleophilic amino acid residues. 4-HNE detoxification occurs mainly via glutathione (GSH) conjugation and transporter-mediated efflux. This results in a net loss of cellular GSH, and restoration of GSH homeostasis requires de novo GSH biosynthesis. The rate-limiting step in GSH biosynthesis is catalyzed by glutamate-cysteine ligase (GCL), a heterodimeric holoenzyme composed of a catalytic (GCLC) and a modulatory (GCLM) subunit. The relative levels of the GCL subunits are a major determinant of cellular GSH biosynthetic capacity and 4-HNE induces the expression of both GCL subunits. In this study, we demonstrate that 4-HNE can alter GCL holoenzyme formation and activity via direct posttranslational modification of the GCL subunits in vitro. 4-HNE directly modified Cys553 of GCLC and Cys35 of GCLM in vitro, which significantly increased monomeric GCLC enzymatic activity, but reduced GCL holoenzyme activity and formation of the GCL holoenzyme complex. In silico molecular modeling studies also indicate these residues are likely to be functionally relevant. Within a cellular context, this novel posttranslational regulation of GCL activity could significantly affect cellular GSH homeostasis and GSH-dependent detoxification during periods of oxidative stress.
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Affiliation(s)
- Donald S. Backos
- Department of Pharmaceutical Sciences, Graduate Program in Toxicology, School of Pharmacy, University of Colorado Denver, Aurora, CO 80045
| | - Kristofer S. Fritz
- Department of Pharmaceutical Sciences, Graduate Program in Toxicology, School of Pharmacy, University of Colorado Denver, Aurora, CO 80045
| | - James R. Roede
- Department of Medicine, Pulmonary Division, Emory University School of Medicine, Atlanta, GA 30322
| | - Dennis R. Petersen
- Department of Pharmaceutical Sciences, Graduate Program in Toxicology, School of Pharmacy, University of Colorado Denver, Aurora, CO 80045
| | - Christopher C. Franklin
- Department of Pharmaceutical Sciences, Graduate Program in Toxicology, School of Pharmacy, University of Colorado Denver, Aurora, CO 80045
- University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO 80045
- to whom correspondence should be addressed: University of Colorado Denver, Department of Pharmaceutical Sciences, School of Pharmacy, C238-P15, Research-2, 12700 E. 19th Avenue, Room 3009, Aurora, CO 80045, Phone: 303-724-6124, FAX: 303-724-7266,
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Cheng YH, Ou BR, Cheng LC, Lu JH, Yeh JY. Glutathione regulation in arsenic-induced porcine aortic endothelial cells. Toxicol In Vitro 2008; 22:1832-9. [DOI: 10.1016/j.tiv.2008.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Revised: 08/11/2008] [Accepted: 08/27/2008] [Indexed: 10/21/2022]
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Lin T, Yang MS. Benzo[a]pyrene-induced elevation of GSH level protects against oxidative stress and enhances xenobiotic detoxification in human HepG2 cells. Toxicology 2007; 235:1-10. [PMID: 17416446 DOI: 10.1016/j.tox.2007.03.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 03/01/2007] [Accepted: 03/01/2007] [Indexed: 01/30/2023]
Abstract
Glutathione (GSH) is one of the most important antioxidants in mammalian cells. It also plays an important role in chemical detoxification. Some evidence showed that polycyclic aromatic hydrocarbons, such as benzo[a]pyrene (B[a]P [50-32-8]), could increase GSH content as a defense mechanism against oxidative stress as well as to promote its detoxification. However, there has been very little study on clarifying the role GSH plays in antioxidation and detoxification actions. Therefore, the present study aims to analyze intracellular glutathione metabolism in the human hepatoma cells (HepG2) upon exposure to B[a]P. Exposure of the cells to B[a]P (1-100 microM) for 24 h did not cause significant cell death in this cell line. By selecting the sublethal concentration of 10 microM, B[a]P caused a significant increase in GSH and a small (13%) but significant decrease in glutathione reductase activity. However, there was no change in the activity of glutathione peroxidase, and no detectable increase in reactive oxygen species (ROS) production. Treatment with B[a]P caused up to 1.5 folds increase in gamma-glutamylcysteine synthatase (gamma-GCS) activity over control. Buthioneine sulfoximine (BSO), an inhibitor of gamma-GCS, could suppress GSH increase in a dose-dependent manner. Assessment of the oxidative state of the cells indicated that the increase in GSH caused the cells to become more reduced. Thus, the results concluded that cells were not suffering from oxidative stress at 24 h after treatment with 10 microM B[a]P. Upon analyzing the activities of detoxification enzymes, there was an increase in the activity of CYP1A subfamily monooxygenases and glutathione S-transferase. Both changes occurred prior to the changes in gamma-GCS activity and the increase in GSH. In summary, results of the present study demonstrate that B[a]P caused an activation of detoxification enzymes. The increase in intracellular GSH level was due to activation of gamma-GCS activities. Oxidative stress may not be an important risk factor for B[a]P (at 10 microM of up to 24 h) induced injury.
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Affiliation(s)
- T Lin
- Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong, PR China
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Ochiai T, Shimeno H, Mishima KI, Iwasaki K, Fujiwara M, Tanaka H, Shoyama Y, Toda A, Eyanagi R, Soeda S. Protective effects of carotenoids from saffron on neuronal injury in vitro and in vivo. Biochim Biophys Acta Gen Subj 2007; 1770:578-84. [PMID: 17215084 DOI: 10.1016/j.bbagen.2006.11.012] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 11/24/2006] [Accepted: 11/28/2006] [Indexed: 11/25/2022]
Abstract
Crocus sativus L. (saffron) has been used as a spice for flavoring and coloring food preparations, and in Chinese traditional medicine as an anodyne or tranquilizer. Our previous study demonstrated that crocin, a carotenoid pigment of saffron, can suppress the serum deprivation-induced death of PC12 cells by increasing glutathione (GSH) synthesis and thus inhibiting neutral sphingomyelinase (nSMase) activity and ceramide formation. The carotenoid pigments of saffron consist of crocetin di-(beta-d-glucosyl)-ester [dicrocin], crocetin-(beta-d-gentiobiosyl)-(beta-d-glucosyl)-ester [tricrocin] and crocetin-di-(beta-d-gentiobiosyl)-ester [crocin]. Saffron also contains picrocrocin, the substance causing saffron's bitter taste. In this study, to confirm whether neuroprotective effects of saffron are caused solely by crocin, we examined the antioxidant and GSH-synthetic activities of these crocins in PC12 cells under serum-free and hypoxic conditions. Measurements of cell viability, peroxidized membrane lipids and caspase-3 activity showed that the rank order of the neuroprotective potency at a concentration of 10 muM was crocin>tricrocin>dicrocin and picrocrocin (the latter two crocins had a little or no potency). In addition, we show that among these saffron's constituents, crocin most effectively promotes mRNA expression of gamma-glutamylcysteinyl synthase (gamma-GCS), which contributes to GSH synthesis as the rate-limiting enzyme, and that the carotenoid can significantly reduce infarcted areas caused by occlusion of the middle cerebral artery (MCA) in mice.
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Affiliation(s)
- Takashi Ochiai
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
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Ochiai T, Soeda S, Ohno S, Tanaka H, Shoyama Y, Shimeno H. Crocin prevents the death of PC-12 cells through sphingomyelinase-ceramide signaling by increasing glutathione synthesis. Neurochem Int 2004; 44:321-30. [PMID: 14643749 DOI: 10.1016/s0197-0186(03)00174-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crocin is a pharmacologically active component of Crocus sativus L. (saffron) that has been used in traditional Chinese medicine. In a previous study, we demonstrated that crocin inhibits apoptosis in PC-12 cells by affecting the function of tumor necrosis factor-alpha. In this study, we found that depriving cultured PC-12 cells of serum/glucose causes a rapid increase in cellular ceramide levels, followed by an increase in the phosphorylation of c-jun kinase (JNK). The accumulation of ceramide was found to depend on the activation of magnesium-dependent neutral sphingomyelinase (N-SMase), but not on de novo synthesis. The serum/glucose-deprived PC-12 cells also decreased the cellular levels of glutathione (GSH), which is the potent inhibitor of N-SMase. Treating the PC-12 cells with crocin prevented N-SMase activation, ceramide production, and JNK phosphorylation. We also found that the chemical can enhance the activities of GSH reductase and gamma-glutamylcysteinyl synthase (gamma-GCS), contributing to a stable GSH supply that blocks the activation of N-SMase. Thus our data suggest that crocin combats the serum/glucose deprivation-induced ceramide formation in PC-12 cells by increasing GSH levels and prevents the activation of JNK pathway, which is reported to have a role of the signaling cascade downstream ceramide for neuronal cell death.
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Affiliation(s)
- Takashi Ochiai
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
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Nakajima A, Yamada K, Zou LB, Yan Y, Mizuno M, Nabeshima T. Interleukin-6 protects PC12 cells from 4-hydroxynonenal-induced cytotoxicity by increasing intracellular glutathione levels. Free Radic Biol Med 2002; 32:1324-32. [PMID: 12057770 DOI: 10.1016/s0891-5849(02)00845-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxidative stress plays an important role in neuronal cell death associated with many different neurodegenerative conditions, and it is reported that 4-hydroxynonenal (HNE), an aldehydic product of membrane lipid peroxidation, is a key mediator of neuronal cell death induced by oxidative stress. Previously, we have demonstrated that interleukin-6 (IL-6) protects PC12 cells from serum deprivation and 6-hydroxydopamine-induced toxicity. Therefore, in the present study, we examined the effects of interleukins on HNE toxicity in PC12 cells. Exposure of PC12 cells to HNE resulted in a decrease in levels of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction, which was due to necrotic and apoptotic cell death. Addition of IL-6 24 h before HNE treatment provided a concentration-dependent protection against HNE toxicity, whereas neither IL-1beta nor IL-2 had any effect. Addition of glutathione (GSH)-ethyl ester, but not superoxide dismutase or catalase, before HNE treatment to the culture medium protected PC12 cells from HNE toxicity. We found that IL-6 increases intracellular GSH levels and the activity of gamma-glutamylcysteine synthetase (gamma-GCS) in PC12 cells. Buthionine sulfoximine (BSO), an inhibitor of gamma-GCS, reversed the protective effect of IL-6 against HNE toxicity. These results suggest that IL-6 protects PC12 cells from HNE-induced cytotoxicity by increasing intracellular levels of GSH.
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Affiliation(s)
- Akira Nakajima
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Japan
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Ray S, Watkins DN, Misso NLA, Thompson PJ. Oxidant stress induces gamma-glutamylcysteine synthetase and glutathione synthesis in human bronchial epithelial NCI-H292 cells. Clin Exp Allergy 2002; 32:571-7. [PMID: 11972604 DOI: 10.1046/j.0954-7894.2002.01294.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The bronchial epithelium is exposed to reactive oxygen species (ROS) derived from cigarette smoke, air pollutants and activated leucocytes. Glutathione (GSH) prevents ROS-mediated loss of cell function, tissue injury and inflammation, and its synthesis is regulated by gamma-glutamylcysteine synthetase (gamma-GCS). However, the capacity of bronchial epithelial cells to adapt to oxidative stress and the mechanisms involved are not known. OBJECTIVE To investigate the effects of oxidative stress on the regulation of GSH synthesis in human bronchial epithelial (NCI-H292) cells. METHODS NCI-H292 cells were exposed to menadione and intracellular GSH concentrations were measured by spectrophotometry. gamma-GCS activity was measured by HPLC assay and changes in gamma-GCS mRNA by Northern blotting. RESULTS Exposure to menadione (MQ, 10-200 microm, 30-120 min) decreased total cellular GSH content, measured immediately after exposure to MQ. However, GSH content measured 6-12 h after withdrawal of the oxidant stress (MQ, 50 microm, 30 min), increased c. two fold over baseline levels (P < 0.001). gamma-GCS activity measured 6 h (21.7 +/- 3.4 nmol/min/mg, SD, n = 5, P < 0.01) or 12 h (23.2 +/- 4.6, P < 0.001) after MQ treatment was also significantly increased compared with untreated cells (12.8 +/- 1.0). Similarly, gamma-GCS mRNA expression increased 1.3-1.6-fold relative to GAPDH mRNA, 3-6 h after MQ treatment. The MQ-induced increase in gamma-GCS mRNA expression was completely inhibited by actinomycin D. CONCLUSIONS Bronchial epithelial (NCI-H292) cells respond rapidly and sensitively to oxidant stress, and this adaptive response is mediated by increased gamma-GCS mRNA transcription and enzyme activity.
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Affiliation(s)
- S Ray
- Asthma and Allergy Research Institute, and Department of Medicine, The University of Western Australia, Perth, Australia
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