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Sample records for glutathione systems differ

  1. Glutathione system in young spontaneously hypertensive rats.

    PubMed

    Lee, S K; Arunkumar, Sundaram; Sirajudeen, K N S; Singh, H J

    2010-12-01

    Glutathione (GSH) forms a part of the antioxidant system that plays a vital role in preventing oxidative stress, and an imbalance in the oxidant/antioxidant system has been linked to the pathogenesis of hypertension. The aim of this study was to investigate the status of the GSH system in the kidney of spontaneously hypertensive rats (SHR). Components of the GSH system, including glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), and total GSH content, were measured in the kidneys of 4, 6, 8, 12, and 16 weeks old SHR and Wistar-Kyoto (WKY) rats. Systolic blood pressure of SHR was significantly higher from the age of 6 weeks onwards compared with age-matched WKY rats. GPx activity in the SHR was significantly lower from the age of 8 weeks onwards when compared to that in age-matched WKY rats. No significant differences were evident in the GPx-1 protein abundance, and its relative mRNA levels, GR, GST activity, and total GSH content between SHR and age-matched WKY rats. The lower GPx activity suggests of an impairment of the GSH system in the SHR, which might be due to an abnormality in its protein rather than non-availability of a cofactor. Its role in the development of hypertension in SHR however remains unclear. PMID:20680541

  2. Modulation of exogenous glutathione in antioxidant defense system against Cd stress in the two barley genotypes differing in Cd tolerance.

    PubMed

    Chen, Fei; Wang, Fang; Wu, Feibo; Mao, Weihua; Zhang, Guoping; Zhou, Meixue

    2010-08-01

    Soil cadmium (Cd) contamination has posed a serious problem for safe food production and become a potential agricultural and environmental hazard worldwide. Greenhouse hydroponic experiments were conducted to investigate the modulation of exogenous GSH (reduced glutathione) in antioxidant defense system against the Cd-induced toxicity in plants exposed to 5 muM Cd using two barley genotypes differing in Cd tolerance. Addition of 20 mg L(-1) GSH in 5 muM Cd culture medium significantly alleviated Cd-induced growth inhibition, especially for the sensitive genotype Dong 17 and dramatically depressed O(2)(-), H(2)O(2) and malondialdehyde (MDA) accumulation. GSH mediated intracellular GSH content to keep the level over the control especially in the case of Cd-induced GSH reduction. External GSH counteracted Cd-induced alterations of certain antioxidant enzymes, e.g. brought root dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and glutathione peroxidase (GPX) activities of the both genotypes down towards the control level, but elevated the depressed ascorbate peroxidase (APX) and catalase (CAT) activities in Dong 17 after 10-15 d treatment. The examination of APX and superoxide dismutase (SOD) isoenzymes revealed GSH significantly increased MnSOD, sAPX and tAPX activities in the both genotypes, and strongly stimulated Cd-induced decrease in cAPX in the sensitive genotype. Furthermore, External GSH up-regulated root cAPX and leaf cAPX, CAT1, and CAT2 expression at transcript level in Dong 17 to achieve stimulation. These data, especially from the results of depressed O(2)(-), H(2)O(2) and MDA accumulation and elevated Cd-induced decrease in GSH content and APX (strongly stimulated cAPX, sAPX and tAPX) and CAT activities by GSH addition in the sensitive genotype, suggest that elevated intracellular GSH and stimulated APX (especially cAPX, sAPX and tAPX iosenzymes) and CAT activities, when concerning ROS scavenging systems, play an important role

  3. Glutathione

    PubMed Central

    Noctor, Graham; Queval, Guillaume; Mhamdi, Amna; Chaouch, Sejir; Foyer, Christine H.

    2011-01-01

    Glutathione is a simple sulfur compound composed of three amino acids and the major non-protein thiol in many organisms, including plants. The functions of glutathione are manifold but notably include redox-homeostatic buffering. Glutathione status is modulated by oxidants as well as by nutritional and other factors, and can influence protein structure and activity through changes in thiol-disulfide balance. For these reasons, glutathione is a transducer that integrates environmental information into the cellular network. While the mechanistic details of this function remain to be fully elucidated, accumulating evidence points to important roles for glutathione and glutathione-dependent proteins in phytohormone signaling and in defense against biotic stress. Work in Arabidopsis is beginning to identify the processes that govern glutathione status and that link it to signaling pathways. As well as providing an overview of the components that regulate glutathione homeostasis (synthesis, degradation, transport, and redox turnover), the present discussion considers the roles of this metabolite in physiological processes such as light signaling, cell death, and defense against microbial pathogen and herbivores. PMID:22303267

  4. [The different aspects of the biological role of glutathione].

    PubMed

    Bilska, Anna; Kryczyk, Agata; Włodek, Lidia

    2007-01-01

    Glutathione plays a key role in maintaining a physiological balance between prooxidants and antioxidants, crucial for the life and death of a cell. Glutathione occurs in the human body in several redox forms, of which reduced glutathione (GSH), oxidized glutathione (GSSG), S-nitrosoglutathione (GSNO), and mixed disulfides of glutathione with proteins are the most important. There is a clear relationship between the levels of different redox forms of glutathione and the regulation of cellular metabolism in a broad sense. Therefore, each of these forms of glutathione can be beneficial or harmful to the organism depending on the cell type and its metabolic status. In such a situation, elevation of GSH level can constitute a very important factor aiding treatment. A rise in GSH level is beneficial in all pathological states, accompanied by lowered GSH content, while a lowering of GSH level is an indication to induce short-term immunosuppression required in organ transplantation and in tumor cells to selectively increase their sensitivity to chemo- and radiotherapy. GSH itself cannot be used as a therapeutic since it is not transported through plasma membranes. Cysteine, an amino acid which limits glutathione biosynthesis, also cannot be used in therapy due to its high neurotoxicity. For this reason, there is currently an intensive search for possibilities of modulating cellular glutathione and cysteine levels, and this problem can be the subject of interdisciplinary studies combining such scientific fields as biology, pharmacology, toxicology, and clinical medicine. PMID:17679914

  5. Role of glutathione metabolism and glutathione-related antioxidant defense systems in hypertension.

    PubMed

    Robaczewska, J; Kedziora-Kornatowska, K; Kozakiewicz, M; Zary-Sikorska, E; Pawluk, H; Pawliszak, W; Kedziora, J

    2016-06-01

    The risk of developing chronic hypertension increases with age. Among others factors, increased oxidative stress is a well-recognized etiological factor for the development of hypertension. The co-occurrence of oxidative stress and hypertension may occur as a consequence of a decrease in antioxidant defense system activity or elevated reactive oxygen species generation. Glutathione is a major intracellular thiol-disulfide redox buffer that serves as a cofactor for many antioxidant enzymes. Glutathione-related parameters are altered in hypertension, suggesting that there is an association between the glutathione-related redox system and hypertension. In this review, we provide mechanistic explanations for how glutathione maintains blood pressure. More specifically, we discuss glutathione's role in combating oxidative stress and maintaining nitric oxide bioavailability via the formation of nitrosothiols and nitrosohemoglobin. Although impaired vasodilator responses are observed in S-nitrosothiol-deficient red blood cells, this potential hypertensive mechanism is currently overlooked in the literature. Here we fill in this gap by discussing the role of glutathione in nitric oxide metabolism and controlling blood pressure. We conclude that disturbances in glutathione metabolism might explain age-dependent increases in blood pressure. PMID:27511994

  6. Gender differences in glutathione metabolism in Alzheimer's disease.

    PubMed

    Liu, Honglei; Harrell, Lindy E; Shenvi, Swapna; Hagen, Tory; Liu, Rui-Ming

    2005-03-15

    The mechanism underlying Alzheimer's disease (AD), an age-related neurodegenerative disease, is still an area of significant controversy. Oxidative damage of macromolecules has been suggested to play an important role in the development of AD; however, the underlying mechanism is still unclear. In this study, we showed that the concentration of glutathione (GSH), the most abundant intracellular free thiol and an important antioxidant, was decreased in red blood cells from male AD patients compared with age- and gender-matched controls. However, there was no difference in blood GSH concentration between the female patients and female controls. The decrease in GSH content in red blood cells from male AD patients was associated with reduced activities of glutamate cysteine ligase and glutathione synthase, the two enzymes involved in de novo GSH synthesis, with no change in the amount of oxidized glutathione or the activity of glutathione reductase, suggesting that a decreased de novo GSH synthetic capacity is responsible for the decline in GSH content in AD. These results showed for the first time that GSH metabolism was regulated differently in male and female AD patients. PMID:15693022

  7. Glutathione Redox System in β-Thalassemia/Hb E Patients

    PubMed Central

    Tangjaidee, Thongchai; Hatairaktham, Suneerat; Charoensakdi, Ratiya; Panichkul, Narumol; Siritanaratkul, Noppadol; Fucharoen, Suthat

    2013-01-01

    β-thalassemia/Hb E is known to cause oxidative stress induced by iron overload. The glutathione system is the major endogenous antioxidant that protects animal cells from oxidative damage. This study aimed to determine the effect of disease state and splenectomy on redox status expressed by whole blood glutathione (GSH)/glutathione disulfide (GSSG) and also to evaluate glutathione-related responses to oxidation in β-thalassemia/Hb E patients. Twenty-seven normal subjects and 25 β-thalassemia/Hb E patients were recruited and blood was collected. The GSH/GSSG ratio, activities of glutathione-related enzymes, hematological parameters, and serum ferritin levels were determined in individuals. Patients had high iron-induced oxidative stress, shown as significantly increased serum ferritin, a decreased GSH/GSSG ratio, and increased activities of glutathione-related enzymes. Splenectomy increased serum ferritin levels and decreased GSH levels concomitant with unchanged glutathione-related enzyme activities. The redox ratio had a positive correlation with hemoglobin levels and negative correlation with levels of serum ferritin. The glutathione system may be the body's first-line defense used against oxidative stress and to maintain redox homeostasis in thalassemic patients based on the significant correlations between the GSH/GSSH ratio and degree of anemia or body iron stores. PMID:24223032

  8. Effect of fish oil on glutathione redox system in multiple sclerosis

    PubMed Central

    Sorto-Gomez, Tania E; Ortiz, Genaro G; Pacheco-Moises, Fermín P; Torres-Sanchez, Erandis D; Ramirez-Ramirez, Viridiana; Macias-Islas, Miguel A; de la Rosa, Alfredo Celis; Velázquez-Brizuela, Irma E

    2016-01-01

    Multiple sclerosis (MS) is a chronic, inflammatory and autoimmune disease of the central nervous system. Dysregulation of glutathione homeostasis and alterations in glutathione-dependent enzyme activities are implicated in the induction and progression of MS. Evidence suggests that Omega-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory, antioxidant and neuroprotective effects. The aim of the present work was to evaluate the effect of fish oil on the activity of glutathione reductase (GR), content of reduced and oxidized glutathione, and GSH/GSSG ratio in MS. 50 patients with relapsing-remitting MS were enrolled. The experimental group received orally 4 g/day of fish oil for 12 months. Fish oil supplementation resulted in a significant increase in n-3 fatty acids and a decrease n-6 fatty acids. No differences in glutathione reductase activity, content of reduced and oxidized glutathione, and GSH/GSSG ratio were found. Conclusion: Glutathione reductase activity was not significantly different between the groups; however, fish oil supplementation resulted in smaller increase in GR compared with control group, suggesting a possible effect on antioxidant defence mechanisms. PMID:27335704

  9. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Glutathione test system. 862.1365 Section 862.1365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  10. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Glutathione test system. 862.1365 Section 862.1365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  11. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Glutathione test system. 862.1365 Section 862.1365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  12. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Glutathione test system. 862.1365 Section 862.1365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  13. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Glutathione test system. 862.1365 Section 862.1365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems §...

  14. The glutathione system: a new drug target in neuroimmune disorders.

    PubMed

    Morris, Gerwyn; Anderson, George; Dean, Olivia; Berk, Michael; Galecki, Piotr; Martin-Subero, Marta; Maes, Michael

    2014-12-01

    Glutathione (GSH) has a crucial role in cellular signaling and antioxidant defenses either by reacting directly with reactive oxygen or nitrogen species or by acting as an essential cofactor for GSH S-transferases and glutathione peroxidases. GSH acting in concert with its dependent enzymes, known as the glutathione system, is responsible for the detoxification of reactive oxygen and nitrogen species (ROS/RNS) and electrophiles produced by xenobiotics. Adequate levels of GSH are essential for the optimal functioning of the immune system in general and T cell activation and differentiation in particular. GSH is a ubiquitous regulator of the cell cycle per se. GSH also has crucial functions in the brain as an antioxidant, neuromodulator, neurotransmitter, and enabler of neuron survival. Depletion of GSH leads to exacerbation of damage by oxidative and nitrosative stress; hypernitrosylation; increased levels of proinflammatory mediators and inflammatory potential; dysfunctions of intracellular signaling networks, e.g., p53, nuclear factor-κB, and Janus kinases; decreased cell proliferation and DNA synthesis; inactivation of complex I of the electron transport chain; activation of cytochrome c and the apoptotic machinery; blockade of the methionine cycle; and compromised epigenetic regulation of gene expression. As such, GSH depletion has marked consequences for the homeostatic control of the immune system, oxidative and nitrosative stress (O&NS) pathways, regulation of energy production, and mitochondrial survival as well. GSH depletion and concomitant increase in O&NS and mitochondrial dysfunctions play a role in the pathophysiology of diverse neuroimmune disorders, including depression, myalgic encephalomyelitis/chronic fatigue syndrome and Parkinson's disease, suggesting that depleted GSH is an integral part of these diseases. Therapeutical interventions that aim to increase GSH concentrations in vivo include N-acetyl cysteine; Nrf-2 activation via hyperbaric

  15. Glutathione cycle in stable chronic obstructive pulmonary disease.

    PubMed

    Biljak, Vanja Radisić; Rumora, Lada; Cepelak, Ivana; Pancirov, Dolores; Popović-Grle, Sanja; Sorić, Jasna; Grubisić, Tihana Zanić

    2010-08-01

    Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and oxidant/antioxidant imbalance. Glutathione is the most abundant cellular low-molecular weight thiol and the glutathione redox cycle is the fundamental component of the cellular antioxidant defence system. Concentration of total glutathione and catalytic activities of glutathione peroxidase and glutathione reductase were determined in peripheral blood of patients (n = 109) and healthy subjects (n = 51). Concentration of total glutathione in patients was not changed in comparison to healthy controls. However, we found statistically significant difference between patients with moderate and severe disease stages. Glutathione reductase activity was increased, while glutathione proxidase activity was decreased in the patients with COPD, when compared to healthy controls. We found no significant difference in glutathione peroxidase and glutathione reductase activities between stages. Patients who smoked had lower concentration of total glutathione compared with former smokers and never-smoking patients. Lung function parameters were inversely associated with glutathione level. Evidence is presented for differential modulation of glutathione peroxidase and glutathione reductase activities in peripheral blood of patients with stable COPD. We suppose that in addition to glutathione biosynthesis, glutathione reductase-dependent regulation of the glutathione redox state is vital for protection against oxidative stress. PMID:20648694

  16. Yeast mitochondrial glutathione is an essential antioxidant with mitochondrial thioredoxin providing a back-up system.

    PubMed

    Gostimskaya, Irina; Grant, Chris M

    2016-05-01

    Glutathione is an abundant, low-molecular-weight tripeptide whose biological importance is dependent upon its redox-active free sulphydryl moiety. Its role as the main determinant of thiol-redox control has been challenged such that it has been proposed to play a crucial role in iron-sulphur clusters maturation, and only a minor role in thiol redox regulation, predominantly as a back-up system for the cytoplasmic thioredoxin system. Here, we have tested the importance of mitochondrial glutathione in thiol-redox regulation. Glutathione reductase (Glr1) is an oxidoreductase which converts oxidized glutathione to its reduced form. Yeast Glr1 localizes to both the cytosol and mitochondria and we have used a Glr1(M1L) mutant that is constitutively localized to the cytosol to test the requirement for mitochondrial Glr1. We show that the loss of mitochondrial Glr1 specifically accounts for oxidant sensitivity of a glr1 mutant. Loss of mitochondrial Glr1 does not influence iron-sulphur cluster maturation and we have used targeted roGFP2 fluorescent probes to show that oxidant sensitivity is linked to an altered redox environment. Our data indicate mitochondrial glutathione is crucial for mitochondrial thiol-redox regulation, and the mitochondrial thioredoxin system provides a back-up system, but cannot bear the redox load of the mitochondria on its own. PMID:26898146

  17. Yeast mitochondrial glutathione is an essential antioxidant with mitochondrial thioredoxin providing a back-up system

    PubMed Central

    Gostimskaya, Irina; Grant, Chris M.

    2016-01-01

    Glutathione is an abundant, low-molecular-weight tripeptide whose biological importance is dependent upon its redox-active free sulphydryl moiety. Its role as the main determinant of thiol-redox control has been challenged such that it has been proposed to play a crucial role in iron–sulphur clusters maturation, and only a minor role in thiol redox regulation, predominantly as a back-up system for the cytoplasmic thioredoxin system. Here, we have tested the importance of mitochondrial glutathione in thiol-redox regulation. Glutathione reductase (Glr1) is an oxidoreductase which converts oxidized glutathione to its reduced form. Yeast Glr1 localizes to both the cytosol and mitochondria and we have used a Glr1M1L mutant that is constitutively localized to the cytosol to test the requirement for mitochondrial Glr1. We show that the loss of mitochondrial Glr1 specifically accounts for oxidant sensitivity of a glr1 mutant. Loss of mitochondrial Glr1 does not influence iron–sulphur cluster maturation and we have used targeted roGFP2 fluorescent probes to show that oxidant sensitivity is linked to an altered redox environment. Our data indicate mitochondrial glutathione is crucial for mitochondrial thiol-redox regulation, and the mitochondrial thioredoxin system provides a back-up system, but cannot bear the redox load of the mitochondria on its own. PMID:26898146

  18. Dual targeting of the thioredoxin and glutathione systems in cancer and HIV.

    PubMed

    Benhar, Moran; Shytaj, Iart Luca; Stamler, Jonathan S; Savarino, Andrea

    2016-05-01

    Although the use of antioxidants for the treatment of cancer and HIV/AIDS has been proposed for decades, new insights gained from redox research have suggested a very different scenario. These new data show that the major cellular antioxidant systems, the thioredoxin (Trx) and glutathione (GSH) systems, actually promote cancer growth and HIV infection, while suppressing an effective immune response. Mechanistically, these systems control both the redox- and NO-based pathways (nitroso-redox homeostasis), which subserve innate and cellular immune defenses. Dual inhibition of the Trx and GSH systems synergistically kills neoplastic cells in vitro and in mice and decreases resistance to anticancer therapy. Similarly, the population of HIV reservoir cells that constitutes the major barrier to a cure for AIDS is exquisitely redox sensitive and could be selectively targeted by Trx and GSH inhibitors. Trx and GSH inhibition may lead to a reprogramming of the immune response, tilting the balance between the immune system and cancer or HIV in favor of the former, allowing elimination of diseased cells. Thus, therapies based on silencing of the Trx and GSH pathways represent a promising approach for the cure of both cancer and AIDS and warrant further investigation. PMID:27135880

  19. Synaptic NMDA receptor activity is coupled to the transcriptional control of the glutathione system

    PubMed Central

    Baxter, Paul S.; Bell, Karen F.S.; Hasel, Philip; Kaindl, Angela M.; Fricker, Michael; Thomson, Derek; Cregan, Sean P.; Gillingwater, Thomas H.; Hardingham, Giles E.

    2015-01-01

    How the brain's antioxidant defenses adapt to changing demand is incompletely understood. Here we show that synaptic activity is coupled, via the NMDA receptor (NMDAR), to control of the glutathione antioxidant system. This tunes antioxidant capacity to reflect the elevated needs of an active neuron, guards against future increased demand and maintains redox balance in the brain. This control is mediated via a programme of gene expression changes that boosts the synthesis, recycling and utilization of glutathione, facilitating ROS detoxification and preventing Puma-dependent neuronal apoptosis. Of particular importance to the developing brain is the direct NMDAR-dependent transcriptional control of glutathione biosynthesis, disruption of which can lead to degeneration. Notably, these activity-dependent cell-autonomous mechanisms were found to cooperate with non-cell-autonomous Nrf2-driven support from astrocytes to maintain neuronal GSH levels in the face of oxidative insults. Thus, developmental NMDAR hypofunction and glutathione system deficits, separately implicated in several neurodevelopmental disorders, are mechanistically linked. PMID:25854456

  20. Variations in the distribution of selenium between erythrocyte glutathione peroxidase and hemoglobin in different human populations

    SciTech Connect

    Whanger, P.D.; Robinson, M.F.; Feldman, E.B.; Beilstein, M.A.; Butler, J.A.

    1986-03-01

    The majority of erythrocyte (RBC) selenium (Se) is associated with glutathione peroxidase (GPx) in animals, but most of it is with hemoglobin (Hb) in human RBCs. Dietary forms of Se may influence this distribution since a rat study showed that selenite promoted the deposition of Se in GPx but selenomethionine (SeMet) resulted in greater amounts with Hb. Three different populations of people were chosen to investigate some possible reasons for the Se distribution in human RBC proteins. An average of 12% of the RBC Se (0.71 ng Se/mg Hb) was associated with GPx in people living in Oregon, but nearly 30% of the Se was associated with GPx in RBC (0.26 ng Se/mg Hb) from New Zealanders. Georgia residents with low RBC Se levels (0.35 ng Se/mg Hb) had 38% of the Se associated with GPx as compared to 29% for those with higher RBC levels (0.56 ng Se/mg Hb). In a third group of people the amount of Se tended to be higher in RBC GPx from non-vegetarian OSU students than from vegetarians. The predominant form of Se in meat appears to be selenocysteine, which is metabolized similarly to selenite, and presumably contributes to this difference since many plant foods contain Se as SeMet. These are examples of many possible factors affecting the relative distribution of Se in human RBC proteins.

  1. Dynamic compartment specific changes in glutathione and ascorbate levels in Arabidopsis plants exposed to different light intensities

    PubMed Central

    2013-01-01

    Background Excess light conditions induce the generation of reactive oxygen species (ROS) directly in the chloroplasts but also cause an accumulation and production of ROS in peroxisomes, cytosol and vacuoles. Antioxidants such as ascorbate and glutathione occur in all cell compartments where they detoxify ROS. In this study compartment specific changes in antioxidant levels and related enzymes were monitored among Arabidopsis wildtype plants and ascorbate and glutathione deficient mutants (vtc2-1 and pad2-1, respectively) exposed to different light intensities (50, 150 which was considered as control condition, 300, 700 and 1,500 μmol m-2 s-1) for 4 h and 14 d. Results The results revealed that wildtype plants reacted to short term exposure to excess light conditions with the accumulation of ascorbate and glutathione in chloroplasts, peroxisomes and the cytosol and an increased activity of catalase in the leaves. Long term exposure led to an accumulation of ascorbate and glutathione mainly in chloroplasts. In wildtype plants an accumulation of ascorbate and hydrogen peroxide (H2O2) could be observed in vacuoles when exposed to high light conditions. The pad2-1 mutant reacted to long term excess light exposure with an accumulation of ascorbate in peroxisomes whereas the vtc2-1 mutant reacted with an accumulation of glutathione in the chloroplasts (relative to the wildtype) and nuclei during long term high light conditions indicating an important role of these antioxidants in these cell compartments for the protection of the mutants against high light stress. Conclusion The results obtained in this study demonstrate that the accumulation of ascorbate and glutathione in chloroplasts, peroxisomes and the cytosol is an important reaction of plants to short term high light stress. The accumulation of ascorbate and H2O2 along the tonoplast and in vacuoles during these conditions indicates an important route for H2O2 detoxification under these conditions. PMID

  2. Antioxidant action of glutathione and the ascorbic acid/glutathione pair in a model white wine.

    PubMed

    Sonni, Francesca; Clark, Andrew C; Prenzler, Paul D; Riponi, Claudio; Scollary, Geoffrey R

    2011-04-27

    Glutathione was assessed individually, and in combination with ascorbic acid, for its ability to act as an antioxidant with respect to color development in an oxidizing model white wine system. Glutathione was utilized at concentrations normally found in wine (30 mg/L), as well as at concentrations 20-fold higher (860 mg/L), the latter to afford ascorbic acid (500 mg/L) to glutathione ratios of 1:1. The model wine systems were stored at 45 °C without sulfur dioxide and at saturated oxygen levels, thereby in conditions highly conducive to oxidation. Under these conditions the results demonstrated the higher concentration of glutathione could initially provide protection against oxidative coloration, but eventually induced color formation. In the period during which glutathione offered a protective effect, the production of xanthylium cation pigment precursors and o-quinone-derived phenolic compounds was limited. When glutathione induced coloration, polymeric pigments were formed, but these were different from those found in model wine solutions without glutathione. In the presence of ascorbic acid, high concentrations of glutathione were able to delay the decay in ascorbic acid and inhibit the reaction of ascorbic acid degradation products with the wine flavanol compound (+)-catechin. However, on depletion, the glutathione again induced the production of a range of different polymeric pigments. These results highlight new mechanisms through which glutathione can offer both protection and spoilage during the oxidative coloration of a model wine. PMID:21384873

  3. Interaction between nitric oxide and subsets of human T lymphocytes with differences in glutathione metabolism

    PubMed Central

    Roozendaal, Ramon; Kauffman, Henk F; Dijkhuis, Anne-Jan; Ommen, Elisabeth T V; Postma, Dirkje S; De Monchy, Jan G R; Vellenga, Edo

    2002-01-01

    Nitric oxide (NO) modulates human T-lymphocyte responses through several mechanisms. In the current study we show that interactions between NO and glutathione (GSH) metabolism are related to the selective persistent inhibition of interferon-γ (IFN-γ) production by NO, which we previously identified. T cells were exposed to NO using the NO-donor compound Spermine-nonoate (Sper) and activated using anti-CD3 plus anti-CD28 monoclonal antibodies. Persistent inhibition of IFN-γ by Sper was prevented by addition of the GSH precursor l-cysteine, which inhibits Sper induced GSH depletion. Subsets of cells were either susceptible (GSHlow) or resistant (GSHhigh) to NO-induced GSH depletion. The GSHlow subset was characterized by enhanced numbers of CD4+ cells, reduced numbers of activated cells as characterized by CD25 and CD69, and reduced numbers of memory (CD45RO+) cells relative to the GSHhigh population. Rather than directly affecting susceptibility to NO, these surface markers reflected different expression patterns. Particularly, the GSHlow subset was further characterized by decreased activity of the GSH synthesis related enzymes multi-drug resistance related protein (MRP)-1 and γ-glutamyltranspeptidase (γ-GT). Blocking γ-GT, using acivicin was shown to exacerbate NO-induced GSH depletion and NO-induced apoptosis. Since NO induced apoptosis selectively affects IFN-γ production these findings implicate GSH metabolism in the modulation and maintenance of the T helper (Th)1/Th2 balance. PMID:12423309

  4. Modular evolution of glutathione peroxidase genes in association with different biochemical properties of their encoded proteins in invertebrate animals

    PubMed Central

    Bae, Young-An; Cai, Guo-Bin; Kim, Seon-Hee; Zo, Young-Gun; Kong, Yoon

    2009-01-01

    Background Phospholipid hydroperoxide glutathione peroxidases (PHGPx), the most abundant isoforms of GPx families, interfere directly with hydroperoxidation of lipids. Biochemical properties of these proteins vary along with their donor organisms, which has complicated the phylogenetic classification of diverse PHGPx-like proteins. Despite efforts for comprehensive analyses, the evolutionary aspects of GPx genes in invertebrates remain largely unknown. Results We isolated GPx homologs via in silico screening of genomic and/or expressed sequence tag databases of eukaryotic organisms including protostomian species. Genes showing strong similarity to the mammalian PHGPx genes were commonly found in all genomes examined. GPx3- and GPx7-like genes were additionally detected from nematodes and platyhelminths, respectively. The overall distribution of the PHGPx-like proteins with different biochemical properties was biased across taxa; selenium- and glutathione (GSH)-dependent proteins were exclusively detected in platyhelminth and deuterostomian species, whereas selenium-independent and thioredoxin (Trx)-dependent enzymes were isolated in the other taxa. In comparison of genomic organization, the GSH-dependent PHGPx genes showed a conserved architectural pattern, while their Trx-dependent counterparts displayed complex exon-intron structures. A codon for the resolving Cys engaged in reductant binding was found to be substituted in a series of genes. Selection pressure to maintain the selenocysteine codon in GSH-dependent genes also appeared to be relaxed during their evolution. With the dichotomized fashion in genomic organizations, a highly polytomic topology of their phylogenetic trees implied that the GPx genes have multiple evolutionary intermediate forms. Conclusion Comparative analysis of invertebrate GPx genes provides informative evidence to support the modular pathways of GPx evolution, which have been accompanied with sporadic expansion/deletion and exon

  5. Different roles of functional residues in the hydrophobic binding site of two sweet orange tau glutathione S-transferases.

    PubMed

    Lo Piero, Angela R; Mercurio, Valeria; Puglisi, Ivana; Petrone, Goffredo

    2010-01-01

    Glutathione S-transferases (GSTs) catalyze the conjugation of glutathione to hydrophobic compounds, contributing to the metabolism of toxic chemicals. In this study, we show that two naturally occurring tau GSTs (GSTUs) exhibit distinctive kinetic parameters towards 1-chloro-2,4-dinitrobenzene (CDNB), although they differ only in three amino acids (Arg89, Glu117 and Ile172 in GSTU1 are replaced by Pro89, Lys117 and Val172 in GSTU2). In order to understand the effects of the single mismatched residues, several mutant GSTs were generated through site-directed mutagenesis. The analysis of the kinetic parameters of the mutants led to the conclusion that Glu117 provides a critical contribution to the maintenance of a high-affinity CDNB-binding site. However, the substitution E117K gives rise to mutants showing increased k(cat) values for CDNB, suggesting that Lys117 might positively influence the formation of the transition state during catalysis. No changes in the K(m) values towards glutathione were found between the naturally occurring GSTs and mutants, except for the mutant caused by the substitution R89P in GSTU1, which showed a sharp increase in K(m). Moreover, the analysis of enzyme reactivation after denaturation showed that this R89P substitution leads to a two-fold enhancement of the refolded enzyme yield, suggesting that the insertion of proline might induce critical structural modifications. In contrast, the substitution P89R in GSTU2 does not modify the reactivation yield and does not impair the affinity of the mutant for glutathione, suggesting that all three residues investigated in this work are fundamental in the creation of enzymes characterized by unique biochemical properties. PMID:19954490

  6. CHANGES IN GLUTATHIONE SYSTEM AND LIPID PEROXIDATION IN RAT BLOOD DURING THE FIRST HOUR AFTER CHLORPYRIFOS EXPOSURE.

    PubMed

    Rosalovsky, V P; Grabovska, S V; Salyha, Yu T

    2015-01-01

    Chlorpyrifos (CPF) is a highly toxic organophosphate compound, widely used as an active substance of many insecticides. Along with the anticholinesterase action, CPF may affect other biochemical mechanisms, particularly through disrupting pro- and antioxidant balance and inducing free-radical oxidative stress. Origins and occurrence of these phenomena are still not fully understood. The aim of our work was to investigate the effects of chlorpyrifos on key parameters of glutathione system and on lipid peroxidation in rat blood in the time dynamics during one hour after exposure. We found that a single exposure to 50 mg/kg chlorpyrifos caused a linear decrease in butyryl cholinesterase activity, increased activity of glutathione peroxidase and glutathione reductase, alterations in the levels of glutathione, TBA-active products and lipid hydroperoxides during 1 hour after poisoning. The most significant changes in studied parameters were detected at the 15-30th minutes after chlorpyrifos exposure. PMID:26717603

  7. Effect of melatonin supplementation and cross-fostering on renal glutathione system and development of hypertension in spontaneously hypertensive rats.

    PubMed

    Siew-Keah, Lee; Sundaram, Arunkumar; Sirajudeen, K N S; Zakaria, Rahimah; Singh, H J

    2014-03-01

    Antenatal and postnatal environments are hypothesised to influence the development of hypertension. This study investigates the synergistic effect of cross-fostering and melatonin supplementation on the development of hypertension and renal glutathione system in spontaneously hypertensive rats (SHR). In one experiment, 1-day-old male SHR pups were fostered to either SHR (shr-SHR) or Wistar-Kyoto rats, (shr-WKY). In a concurrent experiment, SHR dams were given melatonin in drinking water (10 mg/kg body weight) from day 1 of pregnancy. Immediately following delivery, 1-day-old male pups were fostered either to SHR (Mel-shr-SHR) or WKY (Mel-shr-WKY) dams receiving melatonin supplementation until weaning on day 21. Upon weaning, melatonin supplementation was continued to these pups until the age of 16 weeks. Systolic blood pressures (SBP) were recorded at the age of 4, 6, 8, 12 and 16 weeks. Renal antioxidant activities were measured. Mean SBP of shr-WKY, Mel-shr-SHR and Mel-shr-WKY was significantly lower than that in shr-SHR until the age of 8 weeks. At 12 and 16 weeks of age, mean SBP of Mel-shr-WKY was lower than those in non-treated shr-SHR and shr-WKY pups but was not significantly different from that in Mel-shr-SHR. Renal glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities were significantly higher in Mel-shr-SHR and Mel-shr-WKY at 16 weeks of age. It appears that combination of cross-fostering and melatonin supplementation exerts no synergistic effect on delaying the rise in blood pressure in SHR. The elevated GPx and GST activities are likely to be due to the effect of melatonin supplementation. PMID:23975651

  8. The role of the glutathione system in seizures induced by diphenyl diselenide in rat pups.

    PubMed

    Prigol, Marina; Brüning, César Augusto; Nogueira, Cristina W; Zeni, Gilson

    2011-08-15

    The present study investigated the role of the glutathione system in seizures induced by diphenyl diselenide (PhSe)(2) (50 mg/kg) in rat pups (post natal day, 12-14). Reduced glutathione (GSH) (300 nmol/site; i.c.v.), administered 20 min before (PhSe)(2), abolished the appearance of seizures, protected against the inhibition of catalase and δ-aminolevulinic dehydratase (δ-ALA-D) activities and increased glutathione peroxidase (GPx) activity induced by (PhSe)(2). Administration of l-buthionine sulfoximine (BSO, a GSH-depleting compound) (3.2 μmol/site; i.c.v.) 24h before (PhSe)(2) increased the percentage (42-100%) of rat pups which had seizure episodes, reduced the onset for the first convulsive episode. In addition, BSO increased thiobarbituric acid reactive species (TBARS) levels and decreased GSH content, catalase, δ-ALA-D and Na(+), K(+)-ATPase activities. Treatment with sub effective doses of GSH (10 nmol/site) and d-2-amino-7-phosphonoheptanoic acid (AP-7, an antagonist of the glutamate site at the NMDA receptor; 5mg/kg, i.p.) abolished the appearance of seizures induced by (PhSe)(2) in rat pups. Sub effective doses of GSH and kynurenic acid (an antagonist of strychnine-insensitive glycine site at the NMDA receptor; 40 mg/kg, i.p.) were also able in abolishing the appearance of seizures induced by (PhSe)(2). In conclusion, administration of GSH protected against seizure episodes induced by (PhSe)(2) in rat pups by reducing oxidative stress and, at least in part, by acting as an antagonist of glutamate and glycine modulatory sites in the NMDA receptor. PMID:21620807

  9. Unveiling the roles of the glutathione redox system in vivo by analyzing genetically modified mice

    PubMed Central

    Fujii, Junichi; Ito, Jun-itsu; Zhang, Xuhong; Kurahashi, Toshihiro

    2011-01-01

    Redox status affects various cellular activities, such as proliferation, differentiation, and death. Recent studies suggest pivotal roles of reactive oxygen species not only in pathogenesis under oxidative insult but also in intracellular signal transduction. Glutathione is present in several millimolar concentrations in the cytoplasm and has multiple roles in the regulation of cellular homeostasis. Two enzymes, γ-glutamylcysteine synthetase and glutathione synthetase, constitute the de novo synthesis machinery, while glutathione reductase is involved in the recycling of oxidized glutathione. Multidrug resistant proteins and some other transporters are responsible for exporting oxidized glutathione, glutathione conjugates, and S-nitrosoglutathione. In addition to antioxidation, glutathione is more positively involved in cellular activity via its sulfhydryl moiety of a molecule. Animals in which genes responsible for glutathione metabolism are genetically modified can be used as beneficial and reliable models to elucidate roles of glutathione in vivo. This review article overviews recent progress in works related to genetically modified rodents and advances in the elucidation of glutathione-mediated reactions. PMID:21980221

  10. A novel persulfide detection method reveals protein persulfide- and polysulfide-reducing functions of thioredoxin and glutathione systems.

    PubMed

    Dóka, Éva; Pader, Irina; Bíró, Adrienn; Johansson, Katarina; Cheng, Qing; Ballagó, Krisztina; Prigge, Justin R; Pastor-Flores, Daniel; Dick, Tobias P; Schmidt, Edward E; Arnér, Elias S J; Nagy, Péter

    2016-01-01

    Hydrogen sulfide signaling involves persulfide formation at specific protein Cys residues. However, overcoming current methodological challenges in persulfide detection and elucidation of Cys regeneration mechanisms from persulfides are prerequisites for constructing a bona fide signaling model. We here establish a novel, highly specific protein persulfide detection protocol, ProPerDP, with which we quantify 1.52 ± 0.6 and 11.6 ± 6.9 μg/mg protein steady-state protein persulfide concentrations in human embryonic kidney 293 (HEK293) cells and mouse liver, respectively. Upon treatment with polysulfides, HEK293 and A549 cells exhibited increased protein persulfidation. Deletion of the sulfide-producing cystathionine-γ-lyase or cystathionine-β-synthase enzymes in yeast diminished protein persulfide levels, thereby corroborating their involvement in protein persulfidation processes. We here establish that thioredoxin (Trx) and glutathione (GSH) systems can independently catalyze reductions of inorganic polysulfides and protein persulfides. Increased endogenous persulfide levels and protein persulfidation following polysulfide treatment in thioredoxin reductase-1 (TrxR1) or thioredoxin-related protein of 14 kDa (TRP14) knockdown HEK293 cells indicated that these enzymes constitute a potent regeneration system of Cys residues from persulfides in a cellular context. Furthermore, TrxR1-deficient cells were less viable upon treatment with toxic amounts of polysulfides compared to control cells. Emphasizing the dominant role of cytosolic disulfide reduction systems in maintaining sulfane sulfur homeostasis in vivo, protein persulfide levels were markedly elevated in mouse livers where hepatocytes lack both TrxR1 and glutathione reductase (TR/GR-null). The different persulfide patterns observed in wild-type, GR-null, and TR/GR-null livers suggest distinct roles for the Trx and GSH systems in regulating subsets of protein persulfides and thereby fine-tuning sulfide

  11. A novel persulfide detection method reveals protein persulfide- and polysulfide-reducing functions of thioredoxin and glutathione systems

    PubMed Central

    Dóka, Éva; Pader, Irina; Bíró, Adrienn; Johansson, Katarina; Cheng, Qing; Ballagó, Krisztina; Prigge, Justin R.; Pastor-Flores, Daniel; Dick, Tobias P.; Schmidt, Edward E.; Arnér, Elias S. J.; Nagy, Péter

    2016-01-01

    Hydrogen sulfide signaling involves persulfide formation at specific protein Cys residues. However, overcoming current methodological challenges in persulfide detection and elucidation of Cys regeneration mechanisms from persulfides are prerequisites for constructing a bona fide signaling model. We here establish a novel, highly specific protein persulfide detection protocol, ProPerDP, with which we quantify 1.52 ± 0.6 and 11.6 ± 6.9 μg/mg protein steady-state protein persulfide concentrations in human embryonic kidney 293 (HEK293) cells and mouse liver, respectively. Upon treatment with polysulfides, HEK293 and A549 cells exhibited increased protein persulfidation. Deletion of the sulfide-producing cystathionine-γ-lyase or cystathionine-β-synthase enzymes in yeast diminished protein persulfide levels, thereby corroborating their involvement in protein persulfidation processes. We here establish that thioredoxin (Trx) and glutathione (GSH) systems can independently catalyze reductions of inorganic polysulfides and protein persulfides. Increased endogenous persulfide levels and protein persulfidation following polysulfide treatment in thioredoxin reductase-1 (TrxR1) or thioredoxin-related protein of 14 kDa (TRP14) knockdown HEK293 cells indicated that these enzymes constitute a potent regeneration system of Cys residues from persulfides in a cellular context. Furthermore, TrxR1-deficient cells were less viable upon treatment with toxic amounts of polysulfides compared to control cells. Emphasizing the dominant role of cytosolic disulfide reduction systems in maintaining sulfane sulfur homeostasis in vivo, protein persulfide levels were markedly elevated in mouse livers where hepatocytes lack both TrxR1 and glutathione reductase (TR/GR-null). The different persulfide patterns observed in wild-type, GR-null, and TR/GR-null livers suggest distinct roles for the Trx and GSH systems in regulating subsets of protein persulfides and thereby fine-tuning sulfide

  12. Prenatal methylmercury exposure hampers glutathione antioxidant system ontogenesis and causes long-lasting oxidative stress in the mouse brain

    SciTech Connect

    Stringari, James; Nunes, Adriana K.C.; Franco, Jeferson L.; Bohrer, Denise; Garcia, Solange C.; Dafre, Alcir L.; Milatovic, Dejan; Souza, Diogo O.; Rocha, Joao B.T.; Aschner, Michael; Farina, Marcelo

    2008-02-15

    During the perinatal period, the central nervous system (CNS) is extremely sensitive to metals, including methylmercury (MeHg). Although the mechanism(s) associated with MeHg-induced developmental neurotoxicity remains obscure, several studies point to the glutathione (GSH) antioxidant system as an important molecular target for this toxicant. To extend our recent findings of MeHg-induced GSH dyshomeostasis, the present study was designed to assess the developmental profile of the GSH antioxidant system in the mouse brain during the early postnatal period after in utero exposure to MeHg. Pregnant mice were exposed to different doses of MeHg (1, 3 and 10 mg/l, diluted in drinking water, ad libitum) during the gestational period. After delivery, pups were killed at different time points - postnatal days (PND) 1, 11 and 21 - and the whole brain was used for determining biochemical parameters related to the antioxidant GSH system, as well as mercury content and the levels of F{sub 2}-isoprostane. In control animals, cerebral GSH levels significantly increased over time during the early postnatal period; gestational exposure to MeHg caused a dose-dependent inhibition of this developmental event. Cerebral glutathione peroxidase (GPx) and glutathione reductase (GR) activities significantly increased over time during the early postnatal period in control animals; gestational MeHg exposure induced a dose-dependent inhibitory effect on both developmental phenomena. These adverse effects of prenatal MeHg exposure were corroborated by marked increases in cerebral F{sub 2}-isoprostanes levels at all time points. Significant negative correlations were found between F{sub 2}-isoprostanes and GSH, as well as between F{sub 2}-isoprostanes and GPx activity, suggesting that MeHg-induced disruption of the GSH system maturation is related to MeHg-induced increased lipid peroxidation in the pup brain. In utero MeHg exposure also caused a dose-dependent increase in the cerebral levels of

  13. Early changes in system [Formula: see text] and glutathione in the retina of diabetic rats.

    PubMed

    Carpi-Santos, Raul; Ferreira, Marcos Josf; Pereira Netto, Annibal Duarte; Giestal-de-Araujo, Elizabeth; Ventura, Ana Lucia Marques; Cossenza, Marcelo; Calaza, Karin C

    2016-05-01

    Diabetic retinopathy (DR), the main cause of blindness among diabetic patients, affects both neuronal and vascular cells of the retina. Studies show that neuronal cell death begins after 4 weeks of diabetes and could be related with an increase in oxidative stress. System [Formula: see text] is a glutamate/cystine exchanger, formed by a catalytic subunit called xCT and a regulatory subunit 4F2hc, whose activity is crucial to the synthesis of glutathione, which is a key antioxidant molecule for cells. Although some studies have shown that glutamate transport mediated by excitatory amino acid transporters (EAATs) in diabetic rats is downregulated, there are no studies investigating system [Formula: see text] in this context. To evaluate whether system [Formula: see text] is modified by early onset of diabetes, primary retinal cell culture exposed to high glucose and retinas of rats 3 weeks after streptozotocin injection were used. We observed that xCT subunit protein expression both in cultures and in vivo were diminished. Furthermore, system [Formula: see text] activity and GSH levels were also decreased whereas oxidative stress was increased in retinas of diabetic animals. Therefore, this study raises the possibility that alterations in system [Formula: see text] expression and activity could occur during early onset of diabetes. In that way, system [Formula: see text] modifications could be related to increased ROS in diabetic retinopathy. PMID:26706282

  14. Mechanism-based biomarker gene sets for glutathione depletion-related hepatotoxicity in rats

    SciTech Connect

    Gao Weihua; Mizukawa, Yumiko; Nakatsu, Noriyuki; Minowa, Yosuke; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro

    2010-09-15

    Chemical-induced glutathione depletion is thought to be caused by two types of toxicological mechanisms: PHO-type glutathione depletion [glutathione conjugated with chemicals such as phorone (PHO) or diethyl maleate (DEM)], and BSO-type glutathione depletion [i.e., glutathione synthesis inhibited by chemicals such as L-buthionine-sulfoximine (BSO)]. In order to identify mechanism-based biomarker gene sets for glutathione depletion in rat liver, male SD rats were treated with various chemicals including PHO (40, 120 and 400 mg/kg), DEM (80, 240 and 800 mg/kg), BSO (150, 450 and 1500 mg/kg), and bromobenzene (BBZ, 10, 100 and 300 mg/kg). Liver samples were taken 3, 6, 9 and 24 h after administration and examined for hepatic glutathione content, physiological and pathological changes, and gene expression changes using Affymetrix GeneChip Arrays. To identify differentially expressed probe sets in response to glutathione depletion, we focused on the following two courses of events for the two types of mechanisms of glutathione depletion: a) gene expression changes occurring simultaneously in response to glutathione depletion, and b) gene expression changes after glutathione was depleted. The gene expression profiles of the identified probe sets for the two types of glutathione depletion differed markedly at times during and after glutathione depletion, whereas Srxn1 was markedly increased for both types as glutathione was depleted, suggesting that Srxn1 is a key molecule in oxidative stress related to glutathione. The extracted probe sets were refined and verified using various compounds including 13 additional positive or negative compounds, and they established two useful marker sets. One contained three probe sets (Akr7a3, Trib3 and Gstp1) that could detect conjugation-type glutathione depletors any time within 24 h after dosing, and the other contained 14 probe sets that could detect glutathione depletors by any mechanism. These two sets, with appropriate scoring

  15. The role of glutathione reductase and related enzymes on cellular redox homoeostasis network.

    PubMed

    Couto, Narciso; Wood, Jennifer; Barber, Jill

    2016-06-01

    In this review article we examine the role of glutathione reductase in the regulation, modulation and maintenance of cellular redox homoeostasis. Glutathione reductase is responsible for maintaining the supply of reduced glutathione; one of the most abundant reducing thiols in the majority of cells. In its reduced form, glutathione plays key roles in the cellular control of reactive oxygen species. Reactive oxygen species act as intracellular and extracellular signalling molecules and complex cross talk between levels of reactive oxygen species, levels of oxidised and reduced glutathione and other thiols, and antioxidant enzymes such as glutathione reductase determine the most suitable conditions for redox control within a cell or for activation of programmed cell death. Additionally, we discuss the translation and expression of glutathione reductase in a number of organisms including yeast and humans. In yeast and human cells, a single gene expresses more than one form of glutathione reductase, destined for residence in the cytoplasm or for translocation to different organelles; in plants, however, two genes encoding this protein have been described. In general, insects and kinetoplastids (a group of protozoa, including Plasmodia and Trypanosoma) do not express glutathione reductase or glutathione biosynthetic enzymes. Instead, they express either the thioredoxin system or the trypanothione system. The thioredoxin system is also present in organisms that have the glutathione system and there may be overlapping functions with cross-talk between the two systems. Finally we evaluate therapeutic targets to overcome oxidative stress associated cellular disorders. PMID:26923386

  16. Beta-carotene reduces oxidative stress, improves glutathione metabolism and modifies antioxidant defense systems in lead-exposed workers

    SciTech Connect

    Kasperczyk, Sławomir; Dobrakowski, Michał; Kasperczyk, Janusz; Ostałowska, Alina; Zalejska-Fiolka, Jolanta; Birkner, Ewa

    2014-10-01

    The aim of this study was to determine whether beta-carotene administration reduces oxidative stress and influences antioxidant, mainly glutathione-related, defense systems in workers chronically exposed to lead. The population consisted of two randomly divided groups of healthy male volunteers exposed to lead. Workers in the first group (reference group) were not administered any antioxidants, while workers in the second group (CAR group) were treated orally with 10 mg of beta-carotene once a day for 12 weeks. Biochemical analysis included measuring markers of lead-exposure and oxidative stress in addition to the levels and activities of selected antioxidants. After treatment, levels of malondialdehyde, lipid hydroperoxides and lipofuscin significantly decreased compared with the reference group. However, the level of glutathione significantly increased compared with the baseline. Treatment with beta-carotene also resulted in significantly decreased glutathione peroxidase activity compared with the reference group, while the activities of other glutathione-related enzymes and of superoxide dismutase were not significantly changed. However, the activities of glucose-6-phosphate dehydrogenase and catalase, as well as the level of alpha-tocopherol, were significantly higher after treatment compared with the baseline. Despite controversy over the antioxidant properties of beta-carotene in vivo, our findings showed reduced oxidative stress after beta-carotene supplementation in chronic lead poisoning. - Highlights: • Beta-carotene reduces oxidative stress in lead-exposed workers. • Beta-carotene elevates glutathione level in lead-exposed workers. • Beta-carotene administration could be beneficial in lead poisoning.

  17. Glutathione-dependent induction of local and systemic defense against oxidative stress by exogenous melatonin in cucumber (Cucumis sativus L.).

    PubMed

    Li, Hao; He, Jie; Yang, Xiaozhen; Li, Xin; Luo, Dan; Wei, Chunhua; Ma, Jianxiang; Zhang, Yong; Yang, Jianqiang; Zhang, Xian

    2016-03-01

    Melatonin is involved in defending against oxidative stress caused by various environmental stresses in plants. In this study, the roles of exogenous melatonin in regulating local and systemic defense against photooxidative stress in cucumber (Cucumis sativus) and the involvement of redox signaling were examined. Foliar or rhizospheric treatment with melatonin enhanced tolerance to photooxidative stress in both melatonin-treated leaves and untreated systemic leaves. Increased melatonin levels are capable of increasing glutathione (reduced glutathione [GSH]) redox status. Application of H2 O2 and GSH also induced tolerance to photooxidative stress, while inhibition of H2 O2 accumulation and GSH synthesis compromised melatonin-induced local and systemic tolerance to photooxidative stress. H2 O2 treatment increased the GSH/oxidized glutathione (GSSG) ratio, while inhibition of H2 O2 accumulation prevented a melatonin-induced increase in the GSH/GSSG ratio. Additionally, inhibition of GSH synthesis blocked H2 O2 -induced photooxidative stress tolerance, whereas scavenging or inhibition of H2 O2 production attenuated but did not abolish GSH-induced tolerance to photooxidative stress. These results strongly suggest that exogenous melatonin is capable of inducing both local and systemic defense against photooxidative stress and melatonin-enhanced GSH/GSSG ratio in a H2 O2 -dependent manner is critical in the induction of tolerance. PMID:26681257

  18. Proteomic profiling analysis reveals that glutathione system plays important roles responding to osmotic stress in wheat (Triticum aestivum L.) roots.

    PubMed

    Ma, Jianhui; Dong, Wen; Zhang, Daijing; Gao, Xiaolong; Jiang, Lina; Shao, Yun; Tong, Doudou; Li, Chunxi

    2016-01-01

    Wheat is one of the most important crops in the world, and osmotic stress has become one of the main factors affecting wheat production. Understanding the mechanism of the response of wheat to osmotic stress would be greatly significant. In the present study, isobaric tag for relative and absolute quantification (iTRAQ) was used to analyze the changes of protein expression in the wheat roots exposed to different osmotic stresses. A total of 2,228 expressed proteins, including 81 differentially expressed proteins, between osmotic stress and control, were found. The comprehensive analysis of these differentially expressed proteins revealed that osmotic stress increased the variety of expressed proteins and suppressed the quantity of expressed proteins in wheat roots. Furthermore, the proteins for detoxifying and reactive oxygen species scavenging, especially the glutathione system, played important roles in maintaining organism balance in response to osmotic stress in wheat roots. Thus, the present study comprehensively describes the protein expression changes in wheat roots in response to osmotic stress, providing firmer foundation to further study the mechanism of osmotic resistance in wheat. PMID:27602297

  19. High-intensity physical exercise disrupts implicit memory in mice: involvement of the striatal glutathione antioxidant system and intracellular signaling.

    PubMed

    Aguiar, A S; Boemer, G; Rial, D; Cordova, F M; Mancini, G; Walz, R; de Bem, A F; Latini, A; Leal, R B; Pinho, R A; Prediger, R D S

    2010-12-29

    Physical exercise is a widely accepted behavioral strategy to enhance overall health, including mental function. However, there is controversial evidence showing brain mitochondrial dysfunction, oxidative damage and decreased neurotrophin levels after high-intensity exercise, which presumably worsens cognitive performance. Here we investigated learning and memory performance dependent on different brain regions, glutathione antioxidant system, and extracellular signal-regulated protein kinase 1/2 (ERK1/2), serine/threonine protein kinase (AKT), cAMP response element binding (CREB) and dopamine- and cyclic AMP-regulated phosphoprotein (DARPP)-32 signaling in adult Swiss mice submitted to 9 weeks of high-intensity exercise. The exercise did not alter the animals' performance in the reference and working memory versions of the water maze task. On the other hand, we observed a significant impairment in the procedural memory (an implicit memory that depends on basal ganglia) accompanied by a reduced antioxidant capacity and ERK1/2 and CREB signaling in this region. In addition, we found increased striatal DARPP-32-Thr-75 phosphorylation in trained mice. These findings indicate an increased vulnerability of the striatum to high-intensity exercise associated with the disruption of implicit memory in mice and accompanied by alteration of signaling proteins involved in the plasticity of this brain structure. PMID:20888397

  20. Proteomic profiling analysis reveals that glutathione system plays important roles responding to osmotic stress in wheat (Triticum aestivum L.) roots

    PubMed Central

    Dong, Wen; Zhang, Daijing; Gao, Xiaolong; Shao, Yun; Tong, Doudou

    2016-01-01

    Wheat is one of the most important crops in the world, and osmotic stress has become one of the main factors affecting wheat production. Understanding the mechanism of the response of wheat to osmotic stress would be greatly significant. In the present study, isobaric tag for relative and absolute quantification (iTRAQ) was used to analyze the changes of protein expression in the wheat roots exposed to different osmotic stresses. A total of 2,228 expressed proteins, including 81 differentially expressed proteins, between osmotic stress and control, were found. The comprehensive analysis of these differentially expressed proteins revealed that osmotic stress increased the variety of expressed proteins and suppressed the quantity of expressed proteins in wheat roots. Furthermore, the proteins for detoxifying and reactive oxygen species scavenging, especially the glutathione system, played important roles in maintaining organism balance in response to osmotic stress in wheat roots. Thus, the present study comprehensively describes the protein expression changes in wheat roots in response to osmotic stress, providing firmer foundation to further study the mechanism of osmotic resistance in wheat. PMID:27602297

  1. [The state of enzymatic redox system of glutathione in the blood of patients with lymphosarcoma (non-Hodgkin's lymphoma].

    PubMed

    Gavriliuk, L A; Robu, M V; Vratichian, A I; Lysyĭ, L T

    2009-06-01

    Lipid peroxidation (LPO) processes are enhanced and metabolism is disturbed in patients with lymphosarcoma (LS) (non-Hodgkin's lymphoma). The blood enzymatic redox system was analyzed in patients with LS of two types: lymphoblastic LS (LB LS) and prolymphocytic LS (PL LS). The activities of glutathione reductase (GR), glutathione peroxidase (GP), glutathione dehydroascorbate reductase (GDAR), gamma-glutamyl transpeptidase (GGT), and glucose-6-phosphate dehydrogenase (G6PDH) were spectrophotometrically (Humalyzer 2000, DE) determined in the peripheral plasma, white blood cells, lymphocytes, and red blood cells of 32 aged 42-57 years who had LS and 25 healthy individuals. Peripheral blood lymphocytes and leukocytes were obtained by the method developed by A. Böyum. A search for a correlation was made by the Spearman method. The activities of the enzymes and the data of the correlation analysis suggested antioxidant defense system imbalance and metabolic disturbances in patients with LS. Close functional correlations between GR and GP, GR and G6PDH persisted in patients with both types of the disease. Functional relationships between GR and GDAR remained only in patients with PL LS (r = 0.946; p < 0.001). That between GR and GGT was impaired in patients with LS. A correlation between the activity of antioxidant enzymes and the proliferative activity of blood cells was found in patients with LB LS, which may be used as an additional biochemical test in the differential diagnosis of LS. PMID:19642581

  2. Impaired Glutathione Redox System Paradoxically Suppresses Angiotensin II-Induced Vascular Remodeling

    PubMed Central

    Izawa, Kazuma; Okada, Motoi; Sumitomo, Kazuhiro; Nakagawa, Naoki; Aizawa, Yoshiaki; Kawabe, Junichi; Kikuchi, Kenjiro; Hasebe, Naoyuki

    2014-01-01

    Background Angiotensin II (AII) plays a central role in vascular remodeling via oxidative stress. However, the interaction between AII and reduced glutathione (GSH) redox status in cardiovascular remodeling remains unknown. Methods In vivo: The cuff-induced vascular injury model was applied to Sprague Dawley rats. Then we administered saline or a GSH inhibitor, buthionine sulfoximine (BSO, 30 mmol/L in drinking water) for a week, subsequently administered 4 more weeks by osmotic pump with saline or AII (200 ng/kg/minute) to the rats. In vitro: Incorporation of bromodeoxyuridine (BrdU) was measured to determine DNA synthesis in cultured rat vascular smooth muscle cells (VSMCs). Results BSO reduced whole blood GSH levels. Systolic blood pressure was increased up to 215±4 mmHg by AII at 4 weeks (p<0.01), which was not affected by BSO. Superoxide production in vascular wall was increased by AII and BSO alone, and was markedly enhanced by AII+BSO. The left ventricular weight to body weight ratio was significantly increased in AII and AII+BSO as compared to controls (2.52±0.08, 2.50±0.09 and 2.10±0.07 mg/g respectively, p<0.05). Surprisingly, the co-treatment of BSO totally abolished these morphological changes. Although the vascular circumferential wall stress was well compensated in AII, significantly increased in AII+BSO. The anti-single-stranded DNA staining revealed increasing apoptotic cells in the neointima of injured arteries in BSO groups. BrdU incorporation in cultured VSMCs with AII was increased dose-dependently. Furthermore it was totally abolished by BSO and was reversed by GSH monoethyl ester. Conclusions We demonstrated that a vast oxidative stress in impaired GSH redox system totally abolished AII-induced vascular, not cardiac remodeling via enhancement of apoptosis in the neointima and suppression of cell growth in the media. The drastic suppression of remodeling may result in fragile vasculature intolerable to mechanical stress by AII. PMID

  3. Glutathione-induced drought stress tolerance in mung bean: coordinated roles of the antioxidant defence and methylglyoxal detoxification systems

    PubMed Central

    Nahar, Kamrun; Hasanuzzaman, Mirza; Alam, Md. Mahabub; Fujita, Masayuki

    2015-01-01

    Drought is considered one of the most acute environmental stresses presently affecting agriculture. We studied the role of exogenous glutathione (GSH) in conferring drought stress tolerance in mung bean (Vigna radiata L. cv. Binamoog-1) seedlings by examining the antioxidant defence and methylglyoxal (MG) detoxification systems and physiological features. Six-day-old seedlings were exposed to drought stress (−0.7 MPa), induced by polyethylene glycol alone and in combination with GSH (1 mM) for 24 and 48 h. Drought stress decreased seedling dry weight and leaf area; resulted in oxidative stress as evidenced by histochemical detection of hydrogen peroxide (H2O2) and O2⋅− in the leaves; increased lipid peroxidation (malondialdehyde), reactive oxygen species like H2O2 content and O2⋅− generation rate and lipoxygenase activity; and increased the MG level. Drought decreased leaf succulence, leaf chlorophyll and relative water content (RWC); increased proline (Pro); decreased ascorbate (AsA); increased endogenous GSH and glutathione disulfide (GSSG) content; decreased the GSH/GSSG ratio; increased ascorbate peroxidase and glutathione S-transferase activities; and decreased the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and catalase. The activities of glyoxalase I (Gly I) and glyoxalase II (Gly II) increased due to drought stress. In contrast to drought stress alone, exogenous GSH enhanced most of the components of the antioxidant and glyoxalase systems in drought-affected mung bean seedlings at 24 h, but GSH did not significantly affect AsA, Pro, RWC, leaf succulence and the activities of Gly I and DHAR after 48 h of stress. Thus, exogenous GSH supplementation with drought significantly enhanced the antioxidant components and successively reduced oxidative damage, and GSH up-regulated the glyoxalase system and reduced MG toxicity, which played a significant role in improving the physiological features and drought

  4. Forming different planetary systems

    NASA Astrophysics Data System (ADS)

    Zhou, Ji-Lin; Xie, Ji-Wei; Liu, Hui-Gen; Zhang, Hui; Sun, Yi-Sui

    2012-08-01

    With the increasing number of detected exoplanet samples, the statistical properties of planetary systems have become much clearer. In this review, we summarize the major statistical results that have been revealed mainly by radial velocity and transiting observations, and try to interpret them within the scope of the classical core-accretion scenario of planet formation, especially in the formation of different orbital architectures for planetary systems around main sequence stars. Based on the different possible formation routes for different planet systems, we tentatively classify them into three major catalogs: hot Jupiter systems, standard systems and distant giant planet systems. The standard system can be further categorized into three sub-types under different circumstances: solar-like systems, hot Super-Earth systems, and subgiant planet systems. We also review the theory of planet detection and formation in binary systems as well as planets in star clusters.

  5. Differences in response of glucuronide and glutathione conjugating enzymes to aflatoxin B/sub 1/ and N-acetylaminofluorene in underfed rats

    SciTech Connect

    Rajpurohit, R.; Krishnaswamy, K.

    1988-01-01

    Changes in the hepatic drug/xenobiotic-metabolizing enzymes in underfed rats exposed to aflatoxin B/sub 1/ and N-acetylaminofluorene were investigated. Neither carcinogen, fed at the level of 10 ..mu..g and 0.667 mg per 100 g body weight, respectively, over a period of 3 wk, had any significant influence on cytochrome P-450 and aryl hydrocarbon hydroxylase in the undernourished rats. Significantly low activities of UDP-glucuronyltransferase and glutathione S-transferase were observed in food-restricted animals fed on aflatoxin B/sub 1/. N-acetylaminofluorene, on the other hand stimulated both the enzyme activities in the underfed group, to as much observed in the respective well-fed treated group. UDP-Glucuronyltransferase and glutathione S-transferase in undernutrition seem to respond differently to aflatoxin B/sub 1/ and N-acetylaminofluorene. Further studies are needed to assess the possible consequences of such alterations.

  6. Systemic and mucosal immune responses after intranasal administration of recombinant Mycobacterium bovis bacillus Calmette-Guérin expressing glutathione S-transferase from Schistosoma haematobium.

    PubMed

    Kremer, L; Dupré, L; Riveau, G; Capron, A; Locht, C

    1998-12-01

    A major goal of current vaccine development is the induction of strong immune responses against protective antigens delivered by mucosal routes. One of the most promising approaches in that respect relies on the use of live recombinant vaccine carriers. In this study, Mycobacterium bovis BCG was engineered to produce an intracellular glutathione S-transferase from Schistosoma haematobium (Sh28GST). The gene encoding Sh28GST was placed under the control of the mycobacterial hsp60 promoter on a replicative shuttle plasmid containing a mercury resistance operon as the only selectable marker. The recombinant Sh28GST produced in BCG bound glutathione and expressed enzymatic activity, indicating that its active site was properly folded. Both intraperitoneal and intranasal immunizations of BALB/c mice with the recombinant BCG resulted in strong anti-Sh28GST antibody responses, which were enhanced by a boost. Mice immunized intranasally produced a mixed response with the production of Sh28GST-specific immunoglobulin G1 (IgG1), IgG2a, IgG2b, and IgA in the serum. In addition, high levels of anti-Sh28GST IgA were also found in the bronchoalveolar lavage fluids, demonstrating that intranasal delivery of the recombinant BCG was able to induce long-lasting secretory and systemic immune responses to antigens expressed intracellularly. Surprisingly, intranasal immunization with the BCG producing the Sh28GST induced a much stronger specific humoral response than intranasal immunization with BCG producing the glutathione S-transferase from Schistosoma mansoni, although the two antigens have over 90% identity. This difference was not observed after intraperitoneal administration. PMID:9826340

  7. [Experimental Evaluation of Radioprotective Efficacy of Synthetic Genistein on Criteria of Glutathione System and Lipid Peroxidation in Erythrocytes of Peripheral Blood in Irradiated Rats].

    PubMed

    Grebenyuk, A N; Tarumov, R A; Basharin, V A; Kovtun, V U

    2015-01-01

    The study was aimed to evaluate experimentally the radioprotective effectiveness of synthetic genistein in terms of the glutathione system and lipid peroxidation in erythrocytes of irradiated rats. The animals were exposed to single acute X-ray irradiation at a dose of 6 Gy. Genistein was administered intraperitoneally at 200 mg/kg 1 hour before radiation exposure. The irradiation caused the initiation of lipid peroxidation in the background depletion of reduced glutathione. Decrease by 25% in the number of malondialdehyde in the rats treated with genistein was registered 5 min after irradiation compared with the control. It is established thatl day after irradiation the level of reduced glutathione in the rats treated with genistein was 26% higher. However, intraperitoneal administration of genistein did not cause statistically significant changes in the activity of glutathione reductase, glutathione-S-transferase, or glucose-6-phosphate dehydrogenase during the whole period of observation. The results suggest that the radioprotective effect of synthetic genistein is implemented, along with other mechanisms, by stimulating the glutathione system and reducing the severity of lipid peroxidation. PMID:26863780

  8. A glutathione conjugate of hepoxilin A3: Formation and action in the rat central nervous system

    SciTech Connect

    Pace-Asciak, C.R.; Laneuville, O.; Su, W.G.; Corey, E.J.; Gurevich, N.; Wu, P.; Carlen, P.L. )

    1990-04-01

    Incubation of (8R)- and (8S)-(1-14C)hepoxilin A3 (where hepoxilin A3 is 8-hydroxy-11,12-epoxyeicosa-(5Z,9E,14Z)-trienoic acid) and glutathione with homogenates of rat brain hippocampus resulted in a product that was identified as the (8R) and (8S) diastereomers of 11-glutathionyl hepoxilin A3 by reversed-phase high performance liquid chromatographic comparison with the authentic standard made by total synthesis. Identity was further confirmed by cleavage of the isolated product with gamma-glutamyltranspeptidase to yield the corresponding cysteinylglycinyl conjugate that was identical by reversed-phase high performance liquid chromatographic analysis with the enzymic cleavage product derived from the synthetic glutathionyl conjugate. The glutathionyl and cysteinylglycinyl conjugate are referred to as hepoxilin A3-C and hepoxilin A3-D, respectively, by analogy with the established leukotriene nomenclature. Formation of hepoxilin A3-C was greatly enhanced with a concomitant decrease in formation of the epoxide hydrolase product, trioxilin A3, when the epoxide hydrolase inhibitor trichloropropene oxide was added to the incubation mixture demonstrating the presence of a dual metabolic pathway in this tissue involving hepoxilin epoxide hydrolase and glutathione S-transferase processes. Hepoxilin A3-C was tested using intracellular electrophysiological techniques on hippocampal CA1 neurons and found to be active at concentrations as low as 16 nM in causing membrane hyperpolarization, enhanced amplitude and duration of the post-spike train afterhyperpolarization, a marked increase in the inhibitory postsynaptic potential, and a decrease in the spike threshold. These findings suggest that these products in the hepoxilin pathway of arachidonic acid metabolism formed by the rat brain may function as neuromodulators.

  9. Inhibition of Astrocytic Glutamine Synthetase by Lead is Associated with a Slowed Clearance of Hydrogen Peroxide by the Glutathione System

    PubMed Central

    Robinson, Stephen R.; Lee, Alan; Bishop, Glenda M.; Czerwinska, Hania; Dringen, Ralf

    2015-01-01

    Lead intoxication in humans is characterized by cognitive impairments, particularly in the domain of memory, where evidence indicates that glutamatergic neurotransmission may be impacted. Animal and cell culture studies have shown that lead decreases the expression and activity of glutamine synthetase (GS) in astrocytes, yet the basis of this effect is uncertain. To investigate the mechanism responsible, the present study exposed primary astrocyte cultures to a range of concentrations of lead acetate (0–330 μM) for up to 24 h. GS activity was significantly reduced in cells following 24 h incubation with 100 or 330 μM lead acetate. However, no reduction in GS activity was detected when astrocytic lysates were co-incubated with lead acetate, suggesting that the mechanism is not due to a direct interaction and involves intact cells. Since GS is highly sensitive to oxidative stress, the capacity of lead to inhibit the clearance of hydrogen peroxide (H2O2) was investigated. It was found that exposure to lead significantly diminished the capacity of astrocytes to degrade H2O2, and that this was due to a reduction in the effectiveness of the glutathione system, rather than to catalase. These results suggest that the inhibition of GS activity in lead poisoning is a consequence of slowed H2O2 clearance, and supports the glutathione pathway as a primary therapeutic target. PMID:26696846

  10. Cecropin A-induced apoptosis is regulated by ion balance and glutathione antioxidant system in Candida albicans.

    PubMed

    Yun, JiEun; Lee, Dong Gun

    2016-08-01

    Cecropin A, isolated from the giant silk moth Hyalophora cecropia, is a 37-mer peptide that exerts potent antimicrobial effects. We investigated cecropin A-induced apoptosis associated with ion balance and redox state of Candida albicans. The antifungal effect of cecropin A, associated with ion movement was verified by significant increase of cell viability following pretreatment of ion channel blockers. Cecropin A induced undesired ion movement such as calcium accumulation and potassium leakage. Furthermore, the reduction of phosphatidylserine (PS) externalization was detected following pretreatment of ion channel blockers. Based on these results, we confirmed that ion imbalance regulates the apoptotic activity of cecropin A. Moreover, cecropin A decreased NADPH and glutathione levels, which are crucial factors in the intracellular antioxidant defense system. The decreased intracellular antioxidant capacity induced oxidative stress by generating reactive oxygen species (ROS). Moreover, several apoptotic features such as mitochondrial depolarization, caspase activation, and DNA fragmentation were observed in cecropin A-treated cells. In conclusion, disrupted ion balance and intracellular glutathione redox state play a key role in cecropin A-induced apoptosis in C. albicans. © 2016 IUBMB Life, 68(8):652-662, 2016. PMID:27338801

  11. Differences in Redox Regulatory Systems in Human Lung and Liver Tumors Suggest Different Avenues for Therapy

    PubMed Central

    Tobe, Ryuta; Carlson, Bradley A.; Tsuji, Petra A.; Lee, Byeong Jae; Gladyshev, Vadim N.; Hatfield, Dolph L.

    2015-01-01

    A common characteristic of many cancer cells is that they suffer from oxidative stress. They, therefore, require effective redox regulatory systems to combat the higher levels of reactive oxygen species that accompany accelerated growth compared to the normal cells of origin. An elevated dependence on these systems in cancers suggests that targeting these systems may provide an avenue for retarding the malignancy process. Herein, we examined the redox regulatory systems in human liver and lung cancers by comparing human lung adenocarcinoma and liver carcinoma to their respective surrounding normal tissues. Significant differences were found in the two major redox systems, the thioredoxin and glutathione systems. Thioredoxin reductase 1 levels were elevated in both malignancies, but thioredoxin was highly upregulated in lung tumor and only slightly upregulated in liver tumor, while peroxiredoxin 1 was highly elevated in lung tumor, but downregulated in liver tumor. There were also major differences within the glutathione system between the malignancies and their normal tissues. The data suggest a greater dependence of liver on either the thioredoxin or glutathione system to drive the malignancy, while lung cancer appeared to depend primarily on the thioredoxin system. PMID:26569310

  12. Detection of glutathione within single mice hepatocytes using microfluidic chips coupled with a laser-induced fluorescence system.

    PubMed

    Hao, Minglu; Liu, Rutao; Zhang, Hao; Li, Yating; Jing, Mingyang

    2014-05-01

    A rapid and accurate detection of glutathione (GSH) content in single cells is important to the early diagnosis and prevention of diseases. A microfluidic system allows the manipulation of trace amounts of reagents and single cells in a simple and cheap glass chip coupled with laser induced fluorescence (LIF) detection. 2,3-Naphthalenedicarboxaldehyde (NDA) was used as the derivatization reagent to label GSH in cells. Microchannel surface derivatization and optimization of injection and separation were investigated in detail, and then the GSH in single mice hepatocyte was separated and detected under optimum conditions with a linear range of 5×10(-4) M~5×10(-3) M and a detection limit of 4.47×10(-5) M. This study provides a simple and effective method for rapid GSH detection in single cells using few reagents. PMID:24534424

  13. Detection of glutathione within single mice hepatocytes using microfluidic chips coupled with a laser-induced fluorescence system

    NASA Astrophysics Data System (ADS)

    Hao, Minglu; Liu, Rutao; Zhang, Hao; Li, Yating; Jing, Mingyang

    A rapid and accurate detection of glutathione (GSH) content in single cells is important to the early diagnosis and prevention of diseases. A microfluidic system allows the manipulation of trace amounts of reagents and single cells in a simple and cheap glass chip coupled with laser induced fluorescence (LIF) detection. 2,3-Naphthalenedicarboxaldehyde (NDA) was used as the derivatization reagent to label GSH in cells. Microchannel surface derivatization and optimization of injection and separation were investigated in detail, and then the GSH in single mice hepatocyte was separated and detected under optimum conditions with a linear range of 5 × 10-4 M ˜ 5 × 10-3 M and a detection limit of 4.47 × 10-5 M. This study provides a simple and effective method for rapid GSH detection in single cells using few reagents.

  14. Selective Targeting of the Cysteine Proteome by Thioredoxin and Glutathione Redox Systems

    PubMed Central

    Go, Young-Mi; Roede, James R.; Walker, Douglas I.; Duong, Duc M.; Seyfried, Nicholas T.; Orr, Michael; Liang, Yongliang; Pennell, Kurt D.; Jones, Dean P.

    2013-01-01

    Thioredoxin (Trx) and GSH are the major thiol antioxidants protecting cells from oxidative stress-induced cytotoxicity. Redox states of Trx and GSH have been used as indicators of oxidative stress. Accumulating studies suggest that Trx and GSH redox systems regulate cell signaling and metabolic pathways differently and independently during diverse stressful conditions. In the current study, we used a mass spectrometry-based redox proteomics approach to test responses of the cysteine (Cys) proteome to selective disruption of the Trx- and GSH-dependent systems. Auranofin (ARF) was used to inhibit Trx reductase without detectable oxidation of the GSH/GSSG couple, and buthionine sulfoximine (BSO) was used to deplete GSH without detectable oxidation of Trx1. Results for 606 Cys-containing peptides (peptidyl Cys) showed that 36% were oxidized more than 1.3-fold by ARF, whereas BSO-induced oxidation of peptidyl Cys was only 10%. Mean fold oxidation of these peptides was also higher by ARF than BSO treatment. Analysis of potential functional pathways showed that ARF oxidized peptides associated with glycolysis, cytoskeleton remodeling, translation and cell adhesion. Of 60 peptidyl Cys oxidized due to depletion of GSH, 41 were also oxidized by ARF and included proteins of translation and cell adhesion but not glycolysis or cytoskeletal remodeling. Studies to test functional correlates showed that pyruvate kinase activity and lactate levels were decreased with ARF but not BSO, confirming the effects on glycolysis-associated proteins are sensitive to oxidation by ARF. These data show that the Trx system regulates a broader range of proteins than the GSH system, support distinct function of Trx and GSH in cellular redox control, and show for the first time in mammalian cells selective targeting peptidyl Cys and biological pathways due to deficient function of the Trx system. PMID:23946468

  15. In vitro and in vivo effects of three different Mitragyna speciosa korth leaf extracts on phase II drug metabolizing enzymes--glutathione transferases (GSTs).

    PubMed

    Azizi, Juzaili; Ismail, Sabariah; Mordi, Mohd Nizam; Ramanathan, Surash; Said, Mohd Ikram Mohd; Mansor, Sharif Mahsufi

    2010-01-01

    In the present study, we investigate the effects of three different Mitragyna speciosa extracts, namely methanolic, aqueous and total alkaloid extracts, on glutathione transferase-specific activity in male Sprague Dawley rat liver cytosol in vitro and in vivo. In the in vitro study, the effect of Mitragyna speciosa extracts (0.01 to 750 microg/mL) against the specific activity of glutathione transferases was examined in rat liver cytosolic fraction from untreated rats. Our data show concentration dependent inhibition of cytosolic GSTs when Mitragyna speciosa extract was added into the reaction mixture. At the highest concentration used, the methanolic extract showed the highest GSTs specific activity inhibition (61%), followed by aqueous (50%) and total alkaloid extract (43%), respectively. In in vivo study, three different dosages; 50, 100 and 200 mg/kg for methanolic and aqueous extracts and 5, 10 and 20 mg/kg for total alkaloid extract were given orally for 14 days. An increase in GST specific activity was generally observed. However, only Mitragyna speciosa aqueous extract with a dosage of 100 mg/kg showed significant results: 129% compared to control. PMID:20110902

  16. Activity of carboxylesterase and glutathione S-transferase in different life-stages of carabid beetle (Poecilus cupreus) exposed to toxic metal concentrations.

    PubMed

    Wilczek, Grazyna; Kramarz, Paulina; Babczyńska, Agnieszka

    2003-04-01

    Among the cytoplasmatic enzymes responsible for neutralization of organic xenobiotics, carboxylesterases (CarE) and glutathione S-transferases (GST) play important roles. Our study tested to what extent dietary Zn or Cd could modify the activity of CarE and GST at different life-stages of the carabid beetle Poecilus cupreus. Treatment and stage effects generally were statistically significant. For CarE activity in the beetles exposed to cadmium, only treatment was a significant factor. In all cases, the interaction between studied factors was statistically significant, implying that the physiological condition of the animals may enhance or reduce enzyme activity. We also observed differences between animals treated with cadmium and zinc in the pattern of enzyme activity, and a difference in GST activity measured with two different substrates. Our results confirmed that in studying enzyme activity under metal stress one should consider the animal's life-stage and sex. PMID:12727300

  17. IN VITRO INHIBITION OF GLUTATHIONE REDUCTASE BY ARSENOTRI-GLUTATHIONE

    EPA Science Inventory

    Arsenotriglutathione, a product of the reduction of arsenate and the complexation of arsenite by glutathione, is a mixed type inhibitor of the reduction of glutathione disulfide by purified yeast glutathione reductase or the glutathione reductase activity in rabbit erythrocyte ly...

  18. Marked differences in drug-induced methemoglobinemia in sheep are not due to RBC glucose-6-phosphate dehydrogenase, reduced glutathione, or methemoglobin reductase activity

    SciTech Connect

    Martin, D.G.; Guertler, A.T.; Lagutchik, M.S.; Woodard, C.L.; Leonard, D.A.

    1993-05-13

    Benzocaine is a commonly used topical anesthetic that is structurally similar to current candidates for cyanide prophylaxis. Benzocaine induces profound methemoglobinemia in some sheep but not others. After topical benzocaine administration certain sheep respond to form MHb (elevated MHb 16-50% after a 56-280 mg dose, a 2-10 second spray with benzocine), while other phenotypically similar sheep fail to significantly form MHb (less than a 2% increase from baseline). Deficiencies in Glucose-6-phosphate dehydrogenase (G-6-PD), reduced glutathione (GSH), and MHb reductase increase the susceptibility to methemoglobinemia in man and animals. Sheep are used as a model for G-6-PD deficiency in man, and differences in this enzyme level could cause the variable response seen in these sheep. Similarly, differences in GSH and MHb reductase could be responsible for the observed differences in MHb formation.

  19. Responses of the hepatic glutathione antioxidant defense system and related gene expression in juvenile common carp after chronic treatment with tributyltin.

    PubMed

    Li, Zhi-Hua; Li, Ping; Shi, Ze-Chao

    2015-04-01

    Recently, residual organotin compounds have generally been recognised as relevant sources of aquatic environmental pollutants. However, the effects of these contaminants on the glutathione (GSH)-antioxidant system of fishes have not been adequately studied. In the current study, the chronic effects of tributyltin (TBT) found within antifouling paints for ships, on the GSH antioxidant system and related gene expression in the liver of juvenile common carp (Cyprinus carpio) were investigated. Fishes were exposed to sub-lethal concentrations of TBT (75 ng/L, 0.75 and 7.5 μg/L) for 15, 30 and 60 days. GSH levels and GSH-related enzymes activities, including glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), were quantified in the fish liver. The levels of malondialdehyde were also measured as a marker of oxidative damage. In addition, the expression levels of gstp1, gr and gpx1 in common carp chronically exposed to TBT were determined. The results of the current study indicate that chronic exposure of TBT results in reactive oxygen species stress in the liver of common carp, and mRNA expression levels are more sensitive than related enzyme levels. In short, the measured GSH-related indices could potentially be used as molecular indicators for monitoring organotin compounds in the aquatic environment. PMID:25582114

  20. Dual targeting of the thioredoxin and glutathione antioxidant systems in malignant B cells: a novel synergistic therapeutic approach.

    PubMed

    Kiebala, Michelle; Skalska, Jolanta; Casulo, Carla; Brookes, Paul S; Peterson, Derick R; Hilchey, Shannon P; Dai, Yun; Grant, Steven; Maggirwar, Sanjay B; Bernstein, Steven H

    2015-02-01

    B-cell malignancies are a common type of cancer. One approach to cancer therapy is to either increase oxidative stress or inhibit the stress response systems on which cancer cells rely. In this study, we combined nontoxic concentrations of Auranofin (AUR), an inhibitor of the thioredoxin system, with nontoxic concentrations of buthionine-sulfoximine (BSO), a compound that reduces intracellular glutathione levels, and investigated the effect of this drug combination on multiple pathways critical for malignant B-cell survival. Auranofin interacted synergistically with BSO at low concentrations to trigger death in multiple malignant B-cell lines and primary mantle-cell lymphoma cells. Additionally, there was less toxicity toward normal B cells. Low AUR concentrations inhibited thioredoxin reductase (TrxR) activity, an effect significantly increased by BSO cotreatment. Overexpression of TrxR partially reversed AUR+BSO toxicity. Interestingly, the combination of AUR+BSO inhibited nuclear factor κB (NF-κB) signaling. Moreover, synergistic cell death induced by this regimen was attenuated in cells overexpressing NF-κB proteins, arguing for a functional role for NF-κB inhibition in AUR+BSO-mediated cell death. Together, these findings suggest that AUR+BSO synergistically induces malignant B-cell death, a process mediated by dual inhibition of TrxR and NF-κB, and such an approach warrants further investigation in B-cell malignancies. PMID:25448488

  1. Glutathione permeability of CFTR.

    PubMed

    Linsdell, P; Hanrahan, J W

    1998-07-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) forms an ion channel that is permeable both to Cl- and to larger organic anions. Here we show, using macroscopic current recording from excised membrane patches, that the anionic antioxidant tripeptide glutathione is permeant in the CFTR channel. This permeability may account for the high concentrations of glutathione that have been measured in the surface fluid that coats airway epithelial cells. Furthermore, loss of this pathway for glutathione transport may contribute to the reduced levels of glutathione observed in airway surface fluid of cystic fibrosis patients, which has been suggested to contribute to the oxidative stress observed in the lung in cystic fibrosis. We suggest that release of glutathione into airway surface fluid may be a novel function of CFTR. PMID:9688865

  2. Glutathione in cyanobacteria

    NASA Technical Reports Server (NTRS)

    Bermudes, D.

    1985-01-01

    The effects of light and O2 on glutathione production were determined. Results of light and dark studies under normal and reduced oxygen tensions were compared to determine the effect of reduction in oxygen tension on glutathione levels. The growth rate of Anacystis nidulans and concurrent production of glutathione is presented. The generation of time of Anacystis nidulans was approximately 12 hours. Results of light and dark incubation of Aphanothece halophytica dominated planktonic microbial community from Pond 4 and Anacystis nidulans under high and low oxygen tension is also presented. It appears that light grown Anacystis nidulans cells have equal amounts of glutathione while dark grown cells produce more glutathione in the presence of increased O2.

  3. The antioxidant glutathione in the fish cell lines EPC and BCF-2: response to model pro-oxidants as measured by three different fluorescent dyes.

    PubMed

    Jos, A; Cameán, A M; Pflugmacher, S; Segner, H

    2009-04-01

    Reduced glutathione (GSH) protects cells against injury by oxidative stress and maintains a range of vital functions. In vitro cell cultures have been used as experimental models to study the role of GSH in chemical toxicity in mammals; however, this approach has been rarely used with fish cells to date. The present study aimed to evaluate sensitivity and specificity of three fluorescent dyes for measuring pro-oxidant-induced changes of GSH contents in fish cell lines: monochlorobimane (mBCl), 5-chloromethylfluorescein diacetate (CMFDA) and 7-amino-4-chloromethylcoumarin (CMAC-blue). Two cell lines were studied, the EPC line established from a skin tumour of carp Cyprinus carpio, and BF-2 cells established from fins of bluegill sunfish Lepomis macrochirus. The cells were exposed for 6 and 24 h to low cytotoxic concentrations of pro-oxidants including hydrogen peroxide, paraquat (PQ), copper and the GSH synthesis inhibitor, L-buthionine-SR-sulfoximine (BSO). The results indicate moderate differences in the GSH response between EPC and BF-2 cells, but distinct differences in the magnitude of the GSH response for the four pro-oxidants. Further, the choice of GSH dye can critically affect the results, with CMFDA appearing to be less specific for GSH than mBCl and CMAC-blue. PMID:19444932

  4. Enzyme-catalysed conjugations of glutathione with unsaturated compounds

    PubMed Central

    Boyland, E.; Chasseaud, L. F.

    1967-01-01

    1. Rat-liver supernatant catalyses the reaction of diethyl maleate with glutathione. 2. Evidence is presented that the enzyme involved is different from the known glutathione-conjugating enzymes, glutathione S-alkyltransferase, S-aryltransferase and S-epoxidetransferase. 3. Rat-liver supernatant catalyses the reaction of a number of other αβ-unsaturated compounds, including aldehydes, ketones, lactones, nitriles and nitro compounds, with glutathione: separate enzymes may be responsible for these reactions. PMID:6035529

  5. Ground difference compensating system

    DOEpatents

    Johnson, Kris W.; Akasam, Sivaprasad

    2005-10-25

    A method of ground level compensation includes measuring a voltage of at least one signal with respect to a primary ground potential and measuring, with respect to the primary ground potential, a voltage level associated with a secondary ground potential. A difference between the voltage level associated with the secondary ground potential and an expected value is calculated. The measured voltage of the at least one signal is adjusted by an amount corresponding to the calculated difference.

  6. The properties of mesoporous silica nanoparticles functionalized with different PEG-chain length via the disulfide bond linker and drug release in glutathione medium.

    PubMed

    Xie, Zhifei; Gong, Huameng; Liu, Mingxing; Zhu, Hongda; Sun, Honghao

    2016-01-01

    In this paper, a novel drug-loaded material (MSNs-SS-PEG) was obtained by grafting the thiol-linked methoxy polyethylene glycol (MeOPEG-SH) onto the thiol-functionalized mesoporous silica nanoparticles (MSNs-SH) via the disulfide bond linker. In our designed experiment, three different chain lengths of PEG (PEG(1000), PEG(5000), and PEG(1000)-PEG(5000)) were used. The silica materials were characterized by Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering, field emission scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption measurements, and X-ray diffraction. The morphology of the MSNs-SS-PEG was spherical with an average diameter of about 150 nm. Due to the covalent modification of hydrophilic MeOPEG, the MSNs-SS-PEG was coated by a thin polymer shell, showing stable and inerratic MCM-41 type mesoporous structure as well as high specific surface areas and large pore volumes. Moreover, the releases of doxorubicin hydrochloride (DOX) from these materials at 10 mM of glutathione were investigated. The PEG functionalization could effectively cap drugs in the mesoporous channels. The release of DOX from the MSNs-SS-PEG(n) revealed redox-responsive characteristic. The obtained results showed that the MSNs-SS-PEG might be promising drug delivery carrier materials, which could play an important role in the development of drug delivery. PMID:26540096

  7. Expression differences for genes involved in lignin, glutathione and sulphate metabolism in response to cadmium in Arabidopsis thaliana and the related Zn/Cd-hyperaccumulator Thlaspi caerulescens.

    PubMed

    van de Mortel, Judith E; Schat, Henk; Moerland, Perry D; Ver Loren van Themaat, Emiel; van der Ent, Sjoerd; Blankestijn, Hetty; Ghandilyan, Artak; Tsiatsiani, Styliani; Aarts, Mark G M

    2008-03-01

    Cadmium (Cd) is a widespread, naturally occurring element present in soil, rock, water, plants and animals. Cd is a non-essential element for plants and is toxic at higher concentrations. Transcript profiles of roots of Arabidopsis thaliana (Arabidopsis) and Thlaspi caerulescens plants exposed to Cd and zinc (Zn) are examined, with the main aim to determine the differences in gene expression between the Cd-tolerant Zn-hyperaccumulator T. caerulescens and the Cd-sensitive non-accumulator Arabidopsis. This comparative transcriptional analysis emphasized the role of genes involved in lignin, glutathione and sulphate metabolism. Furthermore the transcription factors MYB72 and bHLH100 were studied for their involvement in metal homeostasis, as they showed an altered expression after exposure to Cd. The Arabidopsis myb72 knockout mutant was more sensitive to excess Zn or iron (Fe) deficiency than wild type, while Arabidopsis transformants overexpressing bHLH100 showed increased tolerance to high Zn and nickel (Ni) compared to wild-type plants, confirming their role in metal homeostasis in Arabidopsis. PMID:18088336

  8. Mercury species, selenium, metallothioneins and glutathione in two dolphins from the southeastern Brazilian coast: Mercury detoxification and physiological differences in diving capacity.

    PubMed

    Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tercia G; Pinheiro, Ana Beatriz; Di Beneditto, Ana Paula M

    2016-06-01

    In the present study, the concentration of trace elements, total mercury (Hg) and selenium (Se) and mercury forms (MeHg, Hginorg and HgSe) in the vulnerable coastal dolphins Pontoporia blainvillei and Sotalia guianensis were appraised and compared, using metallothioneins (MT) and glutathione (GSH) as biomarkers for trace element exposure. The trace element concentrations varied between muscle and liver tissues, with liver of all dolphin specimens showing higher Hg and Se concentrations than those found in muscle. Hg, MeHg and Hginorg molar concentrations showed a clear increase with Se molar concentrations in the liver of both dolphins, and Se concentrations were higher than those of Hg on a molar basis. Se plays a relevant role in the detoxification of MeHg in the hepatic tissue of both dolphins, forming Hg-Se amorphous crystals in liver. In contrast, MT were involved in the detoxification process of Hginorg in liver. GSH levels in P. blainvillei and S. guianensis muscle tissue suggest that these dolphins have different diving capacities. Muscle Hg concentrations were associated to this tripeptide, which protects dolphin cells against Hg stress. PMID:27038210

  9. Comparative Hepatotoxicity of Aflatoxin B1 among Workers Exposed to Different Organic Dust with Emphasis on Polymorphism Role of Glutathione S-Transferase Gene

    PubMed Central

    Saad-Hussein, Amal; Shahy, Eman M.; Shaheen, Weam; Taha, Mona M.; Mahdy-Abdallah, Heba; Ibrahim, Khadiga S.; Hafez, Salwa F.; Fadl, Nevein N.; El-Shamy, Karima A.

    2016-01-01

    AIM: The study aimed to investigate effects of organic dust exposure from different sources on aflatoxin B1-albumin adducts (AFB1/Alb), and role of glutathione S-transferase (GST) gene polymorphism in hepatotoxicity of (AFB1) among exposed workers. MATERIAL AND METHODS: Liver enzymes, AFB1/Alb, and GST polymorphism were estimated in 132 wheat flour dust and 87 woods sawmill workers, and 156 controls. RESULTS: Results revealed that AFB1/Alb and liver enzymes were significantly elevated in exposed workers compared to controls, and were significantly higher in sawmill workers compared to flour workers. AFB1/Alb in flour and sawmill workers with GSTT1 and GSTM1&GSTT1 null genotypes were significantly higher than controls, and in sawmill workers with GSTM1&GSTT1 null than flour workers. Liver enzymes (ALT and AST) in sawmill workers were significantly higher than flour workers and controls in all GST polymorphism; except in GSTT1 polymorphism, where these enzymes were significantly higher in the two exposed groups than controls. CONCLUSIONS: In conclusion, organic dust exposure may cause elevation in AFB1/Alb and liver enzymes of exposed workers, and GST gene polymorphism plays an important role in susceptibility to hepatic parenchymal cell injury; except in workers with GSTT1&GSTM1 null genotype, gene susceptibility seemed to have little role and the main role was for environmental exposures. PMID:27335608

  10. Cyclic voltammetric study of the redox system of glutathione using the disulfide bond reductant tris(2-carboxyethyl)phosphine.

    PubMed

    Kizek, René; Vacek, Jan; Trnková, Libuse; Jelen, Frantisek

    2004-06-01

    The stabilization of the reduction state of proteins and peptides is very important for the monitoring of protein-protein, protein-DNA and protein-xenobiotic interactions. The reductive state of protein or peptide is characterized by the reactive sulfhydryl group. Glutathione in the reduced (GSH) and oxidized (GSSG) forms was studied by cyclic voltammetry. Tris(2-carboxyethyl)phosphine (TCEP) as the disulfide bond reductant and/or hydrogen peroxide as the sulfhydryl group oxidant were used. Cyclic voltammetry measurements, following the redox state of glutathione, were performed on a hanging mercury drop electrode (HMDE) in borate buffer (pH 9.2). It was shown that in aqueous solutions TCEP was able to reduce disulfide groups smoothly and quantitatively. The TCEP response at -0.25 V vs. Ag/AgCl/3 M KCl did not disturb the signals of the thiol/disulfide redox couple. The origin of cathodic and anodic signals of GSH (at -0.44 and -0.37 V) and GSSG (at -0.69 and -0.40 V) glutathione forms is discussed. It was shown that the application of TCEP to the conservation of sulfhydryl groups in peptides and proteins can be useful instrument for the study of peptides and proteins redox behavior. PMID:15110242

  11. Effect of a microemulsion system on hapten-peptide reactivity studies: examples of hydroxycitronellal and citral, fragrance skin sensitizers, with glutathione.

    PubMed

    Merckel, Fabien; Bernard, Guillaume; Mutschler, Julien; Giménez-Arnau, Elena; Gerberick, G Frank; Lepoittevin, Jean-Pierre

    2010-09-20

    In chemico methods, based on the assessment of hapten reactivity toward peptides, have been proposed as alternative methods for the assessment of the skin sensitizing potential of chemicals. However, even if these approaches seem very promising, a major drawback inherent to most in vitro methods is the poor water solubility of many organic molecules in aqueous media. Thus, semiorganic media based on buffer solutions and organic cosolvents such as ethanol or acetonitrile have been proposed, but a narrow equilibrium should be found between the peptide and chemical solubilities. Microemulsions have been shown to be very valuable when reacting a lipophilic organic compound soluble in hydrophobic media with a very hydrophilic organic substance insoluble in most organic solvents. However, the reaction rate between polar and apolar reactants can be influenced, in some cases, by the use of microemulsions. On the basis of NMR experiments, we have compared the reactivity of hydroxycitronellal 1 and citral 2, two weak fragrance sensitizers of major clinical relevance, toward glutathione used as a model nucleophile in a water/acetonitrile 2:1 mixture and in a microemulsion based on chloroform/water/tert-butanol/sodium dodecylsulphate. Hydroxycitronellal and citral were found to react with the thiol group of glutathione to form, in both media, identical adducts, but the observed reaction rates were found to be different. In the case of hydroxycitronellal, the observed reaction rate of glutathione addition on the aldehyde was found to be about three times higher in the microemulsion compared to the classical semiorganic mixture. In the case of citral, the situation was more complex as the Michael addition of glutathione on the conjugated double bond was found to be significantly faster in the classical semiorganic mixture, while the subsequent reaction of a second glutathione molecule on the aldehyde was found to be faster in the microemulsion. This chloroform

  12. Simulation of interindividual differences in inactivation of reactive para-benzoquinone imine metabolites of diclofenac by glutathione S-transferases in human liver cytosol.

    PubMed

    den Braver, Michiel W; Zhang, Yongjie; Venkataraman, Harini; Vermeulen, Nico P E; Commandeur, Jan N M

    2016-07-25

    Diclofenac is a widely prescribed NSAID that causes severe idiosyncratic drug induced liver injury (IDILI) in a small part of the patient population. Formation of protein-reactive metabolites is considered to play a role in the development of diclofenac-induced IDILI. Therefore, a high hepatic activity of enzymes involved in bioactivation of diclofenac is expected to increase the risk for liver injury. However, the extent of covalent protein binding may also be determined by activity of protective enzymes, such as glutathione S-transferases (GSTs). This is supported by an association study in which a correlation was found between NSAID-induced IDILI and the combined null genotypes of GSTM1 and GSTT1. In the present study, the activity of 10 different recombinant human GSTs in inactivation of protein-reactive quinoneimine (QI) metabolites of diclofenac was tested. Both at low and high GSH concentrations, high activities of GSTA1-1, A2-2, A3-3, M1-1, M3-3 and P1-1 in the inactivation of these QIs were found. By using the expression levels of GSTs in livers of 22 donors, a 6-fold variation in GST-dependent inactivation of reactive diclofenac metabolites was predicted. Moreover, it was shown in vitro that GSTs can strongly increase the efficiency of GSH to protect against the alkylation of the model thiol N-acetylcysteine by reactive diclofenac metabolites. The results of this study demonstrate that variability of GST expression may significantly contribute to the inter-individual differences in susceptibility to diclofenac-induced liver injury. In addition, expression levels of GSTs in in vitro models for hepatotoxicity may be important factors determining sensitivity to diclofenac cytotoxicity. PMID:27183920

  13. Selenium, glutathione peroxidase and other selenoproteins

    SciTech Connect

    Wilhelmsen, E.C.

    1983-01-01

    Selenium, as essential trace element, has long been associated with protein. The essentiality of selenium is partially understood as glutathione peroxidase contains an essential selenocysteine. Glutathione peroxidase has been purified from many tissues including rat liver. An estimated molecular weight of 105,000 was obtained for glutathione peroxidase by comparison to standards. A subunit size of 26,000 was obtained by SDS-gel electrophoresis. Glutathione peroxidase is not the only selenoprotein in the rat. In seven rat tissues examined, there were many different subunit sizes and change groups representing between 9 and 23 selenoproteins. Selenocysteine in glutathione peroxidase accounts for ca. 36% of the selenium in the rat. The mode of synthesis of glutathione peroxidase and the other selenoproteins is not understood. Glutathione peroxidase is strongly and reversibly inhibited by mercaptocarboxylic acids and other mercaptans, including some used as slow-acting drugs for the symtomatic treatment of rheumatoid arthritis. The mechanism and chemistry of this inhibition is discussed. This inhibition may provide a link between selenium and arthritis.

  14. An enzyme catalysing the conjugation of epoxides with glutathione

    PubMed Central

    Boyland, E.; Williams, K.

    1965-01-01

    1. Liver supernatant preparations from rats and ferrets catalyse the conjugation of some epoxides with glutathione. The enzyme involved might be called `glutathione S-epoxidetransferase', as it is different from glutathione S-aryltransferase, the enzyme catalysing the conjugation of 1,2-dichloro-4-nitrobenzene, 4-nitro-pyridine N-oxide and other cyclic compounds with glutathione and from the enzyme catalysing the conjugation of iodomethane and glutathione. 2. The enzyme does not catalyse the reaction with cysteine. It is not inactivated by dialysis but is unstable at pH 5·0. 3. The role of the enzyme in metabolism of foreign compounds is discussed. PMID:14342229

  15. Species differences in kidney necrosis and DNA damage, distribution and glutathione-dependent metabolism of 1,2-dibromo-3-chloropropane (DBCP).

    PubMed

    Søderlund, E J; Låg, M; Holme, J A; Brunborg, G; Omichinski, J G; Dahl, J E; Nelson, S D; Dybing, E

    1990-04-01

    Species differences and mechanisms of 1,2-dibromo-3-chloropropane (DBCP) nephrotoxicity were investigated by studying DBCP renal necrosis and DNA damage, distribution and glutathione-dependent metabolism in rats, mice, hamsters and guinea pigs. Extensive renal tubular necrosis was observed in rats 48 hr after a single intraperitoneal administration (21-170 mumol/kg) of DBCP. Significantly less necrosis was found in mice and guinea pigs, whereas no renal damage was evident (less than 680 mumol/kg) in hamsters. The activation of DBCP to DNA damaging intermediates in vivo, as measured by alkaline elution of DNA isolated from kidney nuclei 60 min. after intraperitoneal injection of DBCP, was compared in all four species. Distinct DNA damage was detected in rats, mice and hamsters as early as 10 min. after administration of DBCP and within 30 min. in guinea pigs. Rats and guinea pigs showed similar sensitivity towards DBCP-induced DNA damage (extensive DNA damage greater than 21 mumol/kg DBCP), whereas in mice and hamsters a 10-50 times higher DBCP dose was needed to cause a similar degree of DNA damage. Renal DBCP concentrations at various time-points (20 min., 1, 3 and 8 hr) after intraperitoneal administration (85 mumol/kg) revealed that the initial (20 min.) DBCP concentration was substantially higher in rats and guinea pigs compared to the other two species. Furthermore, kidney elimination of DBCP occurred at a significantly lower rate in rats than in mice, hamsters and guinea pigs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2371234

  16. Glutathione and mitochondria

    PubMed Central

    Ribas, Vicent; García-Ruiz, Carmen; Fernández-Checa, José C.

    2014-01-01

    Glutathione (GSH) is the main non-protein thiol in cells whose functions are dependent on the redox-active thiol of its cysteine moiety that serves as a cofactor for a number of antioxidant and detoxifying enzymes. While synthesized exclusively in the cytosol from its constituent amino acids, GSH is distributed in different compartments, including mitochondria where its concentration in the matrix equals that of the cytosol. This feature and its negative charge at physiological pH imply the existence of specific carriers to import GSH from the cytosol to the mitochondrial matrix, where it plays a key role in defense against respiration-induced reactive oxygen species and in the detoxification of lipid hydroperoxides and electrophiles. Moreover, as mitochondria play a central strategic role in the activation and mode of cell death, mitochondrial GSH has been shown to critically regulate the level of sensitization to secondary hits that induce mitochondrial membrane permeabilization and release of proteins confined in the intermembrane space that once in the cytosol engage the molecular machinery of cell death. In this review, we summarize recent data on the regulation of mitochondrial GSH and its role in cell death and prevalent human diseases, such as cancer, fatty liver disease, and Alzheimer’s disease. PMID:25024695

  17. Hepatobiliary transport of glutathione and glutathione conjugate in rats with hereditary hyperbilirubinemia.

    PubMed Central

    Elferink, R P; Ottenhoff, R; Liefting, W; de Haan, J; Jansen, P L

    1989-01-01

    TR- mutant rats have an autosomal recessive mutation that is expressed as a severely impaired hepatobiliary secretion of organic anions like bilirubin-(di)glucuronide and dibromosulphthalein (DBSP). In this paper, the hepatobiliary transport of glutathione and a glutathione conjugate was studied in normal Wistar rats and TR- rats. It was shown that glutathione is virtually absent from the bile of TR- rats. In the isolated, perfused liver the secretion of glutathione and the glutathione conjugate, dinitrophenyl-glutathione (GS-DNP), from hepatocyte to bile is severely impaired, whereas the sinusoidal secretion from liver to blood is not affected. The secretion of GS-DNP was also studied in isolated hepatocytes. The secretion of GS-DNP from cells isolated from TR- rat liver was significantly slower than from normal hepatocytes. Efflux of GS-DNP was a saturable process with respect to intracellular GS-DNP concentration: Vmax and Km for efflux from TR- cells was 498 nmol/min.g dry wt and 3.3 mM, respectively, as compared with 1514 nmol/min.g dry wt and 0.92 mM in normal hepatocytes. These results suggest that the canalicular transport system for glutathione and glutathione conjugates is severely impaired in TR- rats, whereas sinusoidal efflux is unaffected. Because the defect also comes to expression in isolated hepatocytes, efflux of GS-DNP from normal hepatocytes must predominantly be mediated by the canalicular transport mechanism, which is deficient in TR- rats. PMID:2760197

  18. Effects of fraxetin on glutathione redox status.

    PubMed

    Martín-Aragón, S; Benedí, J M; Villar, A M

    1997-01-01

    We have evaluated the effects of an oral treatment of mice with fraxetin (25 mg/kg for 30 days) on the glutathione system (GSH, GSSG, and GSSG/GSH ratio as stress index), glutathione reductase (GR) and glutathione peroxidase (GPx) in liver supernatants from male C57BL/6J mice (18-month old). A significant antioxidant effect in vivo was found under this treatment by a decrease in the GSSG/GSH ratio and an increased activity of GR compared with the control mice. GSSG rate and GSSG/GSH ratio were correlated with the decline of GPx++ activity. Our results of increased GR activity could be considered as a supercompensation in glutathione redox status that involves a decrease in the accumulation of GSSG, as well as, in GSSG/GSH ratio. Finally, we suggest that this possible mechanism of supercompensation could lead to an enhancement in the average life span. PMID:9162171

  19. Systemic chromosome instability in Shugoshin-1 mice resulted in compromised glutathione pathway, activation of Wnt signaling and defects in immune system in the lung

    PubMed Central

    Yamada, H Y; Kumar, G; Zhang, Y; Rubin, E; Lightfoot, S; Dai, W; Rao, C V

    2016-01-01

    Mitotic error-mediated chromosome instability (CIN) can lead to aneuploidy, chromothripsis, DNA damage and/or whole chromosome gain/loss. CIN may prompt rapid accumulation of mutations and genomic alterations. Thus, CIN can promote carcinogenesis. This CIN process results from a mutation in certain genes or environmental challenge such as smoking, and is highly prevalent in various cancers, including lung cancer. A better understanding of the effects of CIN on carcinogenesis will lead to novel methods for cancer prevention and treatment. Previously Shugoshin-1 (Sgo1−/+) mice, a transgenic mouse model of CIN, showed mild proneness to spontaneous lung and liver cancers. In this study, adoptive (T/B-cell based) immunity-deficient RAG1−/− Sgo1−/+ double mutant mice developed lung adenocarcinomas more aggressively than did Sgo1−/+ or RAG1−/− mice, suggesting immune system involvement in CIN-mediated lung carcinogenesis. To identify molecular causes of the lung adenocarcinoma, we used systems biology approach, comparative RNAseq, to RAG1−/− and RAG1−/− Sgo1−/+. The comparative RNAseq data and follow-up analyses in the lungs of naive Sgo1−/+ mice demonstrate that, (i) glutathione is depleted, making the tissue vulnerable to oxidative stress, (ii) spontaneous DNA damage is increased, (iii) oncogenic Wnt signaling is activated, (iv) both major branches of the immune system are weakened through misregulations in signal mediators such as CD80 and calreticulin and (v) the actin cytoskeleton is misregulated. Overall, the results show multi-faceted roles of CIN in lung carcinoma development in Sgo1−/+ mice. Our model presents various effects of CIN and will help to identify potential targets to prevent CIN-driven carcinogenesis in the lung. PMID:27526110

  20. Systemic chromosome instability in Shugoshin-1 mice resulted in compromised glutathione pathway, activation of Wnt signaling and defects in immune system in the lung.

    PubMed

    Yamada, H Y; Kumar, G; Zhang, Y; Rubin, E; Lightfoot, S; Dai, W; Rao, C V

    2016-01-01

    Mitotic error-mediated chromosome instability (CIN) can lead to aneuploidy, chromothripsis, DNA damage and/or whole chromosome gain/loss. CIN may prompt rapid accumulation of mutations and genomic alterations. Thus, CIN can promote carcinogenesis. This CIN process results from a mutation in certain genes or environmental challenge such as smoking, and is highly prevalent in various cancers, including lung cancer. A better understanding of the effects of CIN on carcinogenesis will lead to novel methods for cancer prevention and treatment. Previously Shugoshin-1 (Sgo1(-/+)) mice, a transgenic mouse model of CIN, showed mild proneness to spontaneous lung and liver cancers. In this study, adoptive (T/B-cell based) immunity-deficient RAG1(-/-) Sgo1(-/+) double mutant mice developed lung adenocarcinomas more aggressively than did Sgo1(-/+) or RAG1(-/-) mice, suggesting immune system involvement in CIN-mediated lung carcinogenesis. To identify molecular causes of the lung adenocarcinoma, we used systems biology approach, comparative RNAseq, to RAG1(-/-) and RAG1(-/-) Sgo1(-/+). The comparative RNAseq data and follow-up analyses in the lungs of naive Sgo1(-/+) mice demonstrate that, (i) glutathione is depleted, making the tissue vulnerable to oxidative stress, (ii) spontaneous DNA damage is increased, (iii) oncogenic Wnt signaling is activated, (iv) both major branches of the immune system are weakened through misregulations in signal mediators such as CD80 and calreticulin and (v) the actin cytoskeleton is misregulated. Overall, the results show multi-faceted roles of CIN in lung carcinoma development in Sgo1(-/+) mice. Our model presents various effects of CIN and will help to identify potential targets to prevent CIN-driven carcinogenesis in the lung. PMID:27526110

  1. Changes in biosynthesis and metabolism of glutathione upon ochratoxin A stress in Arabidopsis thaliana.

    PubMed

    Wang, Yan; Zhao, Weiwei; Hao, Junran; Xu, Wentao; Luo, Yunbo; Wu, Weihong; Yang, Zhuojun; Liang, Zhihong; Huang, Kunlun

    2014-06-01

    Ochratoxin A (OTA) is one of the most toxic mycotoxins, which is toxic to plants and simulates oxidative stress. Glutathione is an important antioxidant in plants and is closely associated with detoxification in cells. We have previously shown that OTA exposure induces obvious expression differences in genes associated with glutathione metabolism. To characterize glutathione metabolism and understand its role in OTA phytotoxicity, we observed the accumulation of GSH in the detached leaves of Arabidopsis thaliana under OTA treatment. OTA stimulated a defense response through enhancing glutathione-S-transferase, glutathione peroxidase, glutathione reductase activities, and the transcript levels of these enzymes were increased to maintain the total glutathione content. Moreover, the level of oxidized glutathione (GSSG) was increased and the ascorbate-glutathione cycle fluctuated in response to OTA. The depletion of glutathione using buthionine sulfoximine (BSO, inhibitor of glutamate-cysteine ligase) had no profound effect on OTA toxicity, as glutathione was regenerated through the ascorbate-glutathione cycle to maintain the total glutathione content. The ROS, MDA and GSH accumulation was significantly affected in the mutant gsh1, gr1 and gpx2 after treatment with OTA, which indicated that glutathione metabolism is directly involved in the oxidative stress response of Arabidopsis thaliana subjected to OTA. In conclusion, date demonstrate that glutathione-associated metabolism is closely related with OTA stress and glutathione play a role in resistance of Arabidopsis subjected to OTA. PMID:24662377

  2. Effects of concentrated drinking water injection on glutathione and glutathione-dependent enzymes in liver of Cyprinus carpio L.

    PubMed

    Elia, Antonia Concetta; Fanetti, Alessia; Dörr, Ambrosius Josef Martin; Taticchi, Maria I

    2008-06-01

    Two drinking water production plants located in North Italy, collecting water from the River Po (Plants 1 and 2) were chosen for this study. Water samples were collected before and after the disinfection process and at two points along the piping system. Water samples were concentrated by the solid-phase extraction system and injected intraperitoneally into specimens of Cyprinus carpio. The concentration of water samples was 3 l/equiv. In order to assess the effects of the water samples on carp liver, total glutathione and glutathione-dependent enzymes, such as glutathione S-transferase, glutathione peroxidase, glutathione reductase and glyoxalase I, were measured following this treatment for 6 days at two experimental times (3 and 6 days). Both water plant-treated carp showed a general increase of the enzymatic activities of glutathione S-transferase, and glutathione reductase which might be employed as potential biomarkers of oxidative stress induced by disinfected river water. Plant 1-treated carp showed higher glyoxalase I and glutathione levels and lower glutathione peroxidase activity. A depleted level of total glutathione and of glyoxalase I for specimens of water plant 2 (for both experimental times), without correlation with the distances in the pipeline, suggests that river plant water can also lead to potentially adverse effects on selected biochemical parameters in C. carpio. PMID:18457861

  3. Deficient glutathione in the pathophysiology of mycotoxin-related illness.

    PubMed

    Guilford, Frederick T; Hope, Janette

    2014-02-01

    Evidence for the role of oxidative stress in the pathophysiology of mycotoxin-related illness is increasing. The glutathione antioxidant and detoxification systems play a major role in the antioxidant function of cells. Exposure to mycotoxins in humans requires the production of glutathione on an "as needed" basis. Research suggests that mycotoxins can decrease the formation of glutathione due to decreased gene expression of the enzymes needed to form glutathione. Mycotoxin-related compromise of glutathione production can result in an excess of oxidative stress that leads to tissue damage and systemic illness. The review discusses the mechanisms by which mycotoxin-related deficiency of glutathione may lead to both acute and chronic illnesses. PMID:24517907

  4. Deficient Glutathione in the Pathophysiology of Mycotoxin-Related Illness

    PubMed Central

    Guilford, Frederick T.; Hope, Janette

    2014-01-01

    Evidence for the role of oxidative stress in the pathophysiology of mycotoxin-related illness is increasing. The glutathione antioxidant and detoxification systems play a major role in the antioxidant function of cells. Exposure to mycotoxins in humans requires the production of glutathione on an “as needed” basis. Research suggests that mycotoxins can decrease the formation of glutathione due to decreased gene expression of the enzymes needed to form glutathione. Mycotoxin-related compromise of glutathione production can result in an excess of oxidative stress that leads to tissue damage and systemic illness. The review discusses the mechanisms by which mycotoxin-related deficiency of glutathione may lead to both acute and chronic illnesses. PMID:24517907

  5. Glutathione is a Physiologic Reservoir of Neuronal Glutamate

    PubMed Central

    Koga, Minori; Serritella, Anthony V.; Messmer, Marcus M.; Hayashi-Takagi, Akiko; Hester, Lynda D.; Snyder, Solomon H.; Sawa, Akira; Sedlak, Thomas W.

    2013-01-01

    Glutamate, the principal excitatory neurotransmitter of the brain, participates in a multitude of physiologic and pathologic processes, including learning and memory. Glutathione, a tripeptide composed of the amino acids glutamate, cysteine, and glycine, serves important cofactor roles in antioxidant defense and drug detoxification, but glutathione deficits occur in multiple neuropsychiatric disorders. Glutathione synthesis and metabolism are governed by a cycle of enzymes, the γ-glutamyl cycle, which can achieve intracellular glutathione concentrations of 1-10 millimolar. Because of the considerable quantity of brain glutathione and its rapid turnover, we hypothesized that glutathione may serve as a reservoir of neural glutamate. We quantified glutamate in HT22 hippocampal neurons, PC12 cells and primary cortical neurons after treatment with molecular inhibitors targeting three different enzymes of the glutathione metabolic cycle. Inhibiting 5-oxoprolinase and γ-glutamyl transferase, enzymes that liberate glutamate from glutathione, leads to decreases in glutamate. In contrast, inhibition of γ-glutamyl cysteine ligase, which uses glutamate to synthesize glutathione, results in substantial glutamate accumulation. Increased glutamate levels following inhibition of glutathione synthesis temporally precede later effects upon oxidative stress. PMID:21539809

  6. Brain glutathione redox system significance for the control of silica-coated magnetite nanoparticles with or without mercury co-exposures mediated oxidative stress in European eel (Anguilla anguilla L.).

    PubMed

    Anjum, Naser A; Srikanth, Koigoora; Mohmood, Iram; Sayeed, Iqbal; Trindade, Tito; Duarte, Armando C; Pereira, Eduarda; Ahmad, Iqbal

    2014-06-01

    This in vitro study investigates the impact of silica-coated magnetite particles (Fe3O4@SiO2/SiDTC, hereafter called IONP; 2.5 mg L(-1)) and its interference with co-exposure to persistent contaminant (mercury, Hg; 50 μg L(-1)) during 0, 2, 4, 8, 16, 24, 48, and 72 h on European eel (Anguilla anguilla) brain and evaluates the significance of the glutathione (GSH) redox system in this context. The extent of damage (membrane lipid peroxidation, measured as thiobarbituric acid reactive substances, TBARS; protein oxidation, measured as reactive carbonyls, RCs) decreased with increasing period of exposure to IONP or IONP + Hg which was accompanied with differential responses of glutathione redox system major components (glutathione reductase, GR; glutathione peroxidase, GPX; total GSH, TGSH). The occurrence of antagonism between IONP and Hg impacts was evident at late hour (72 h), where significantly decreased TBARS and RC levels and GR and glutathione sulfo-transferase (GST) activity imply the positive effect of IONP + Hg concomitant exposure against Hg-accrued negative impacts [vs. early (2 h) hour of exposure]. A period of exposure-dependent IONP alone and IONP + Hg joint exposure-accrued impact was perceptible. Additionally, increased susceptibility of the GSH redox system to increased period of exposure to Hg was depicted, where insufficiency of elevated GR for the maintenance of TGSH required for membrane lipid and cellular protein protection was displayed. Overall, a fine-tuning among brain glutathione redox system components was revealed controlling IONP + Hg interactive impacts successfully. PMID:24627197

  7. Cell free glutathione synthesizing activity of mercury resistant bacteria

    SciTech Connect

    Gachhui, R.; Pahan, K.; Ray, S., R.; Chaudhuri, J.; Mandal, A. )

    1991-03-01

    Reduced glutathione (GSH) is present in all living cells and is known to have a generalized role in protecting the cells from heavy metal toxicity. Depletion of both GSH and glutathione reductase (GR) level upon treatment with mercuric chloride (HgCl{sub 2}) is reported in various organs of rat. However, the effect of HgCl{sub 2} on glutathione level in bacterial system is not known. In the present communication, the authors report the results of their investigation on the glutathione status in mercury resistant bacterial cells exposed to HgCl{sub 2}.

  8. Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H2O2-Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System

    PubMed Central

    Fan, Fangfang; Zhuo, Rui; Ma, Fuying; Gong, Yangmin; Wan, Xia; Jiang, Mulan

    2012-01-01

    Laccase is a copper-containing polyphenol oxidase that has great potential in industrial and biotechnological applications. Previous research has suggested that fungal laccase may be involved in the defense against oxidative stress, but there is little direct evidence supporting this hypothesis, and the mechanism by which laccase protects cells from oxidative stress also remains unclear. Here, we report that the expression of the laccase gene from white rot fungus in Pichia pastoris can significantly enhance the resistance of yeast to H2O2-mediated oxidative stress. The expression of laccase in yeast was found to confer a strong ability to scavenge intracellular H2O2 and to protect cells from lipid oxidative damage. The mechanism by which laccase gene expression increases resistance to oxidative stress was then investigated further. We found that laccase gene expression in Pichia pastoris could increase the level of glutathione-based antioxidative activity, including the intracellular glutathione levels and the enzymatic activity of glutathione peroxidase, glutathione reductase, and γ-glutamylcysteine synthetase. The transcription of the laccase gene in Pichia pastoris was found to be enhanced by the oxidative stress caused by exogenous H2O2. The stimulation of laccase gene expression in response to exogenous H2O2 stress further contributed to the transcriptional induction of the genes involved in the glutathione-dependent antioxidative system, including PpYAP1, PpGPX1, PpPMP20, PpGLR1, and PpGSH1. Taken together, these results suggest that the expression of the laccase gene in Pichia pastoris can enhance the resistance of yeast to H2O2-mediated oxidative stress by stimulating the glutathione-based antioxidative system to protect the cell from oxidative damage. PMID:22706050

  9. Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

    PubMed Central

    Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

    2015-01-01

    Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (μg/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Findings Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Conclusions Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity. PMID:26076368

  10. Expression of glutathione, glutathione peroxidase and glutathione S-transferase pi in canine mammary tumors

    PubMed Central

    2014-01-01

    Background Glutathione (GSH) is one of the most important agents of the antioxidant defense system of the cell because, in conjunction with the enzymes glutathione peroxidase (GSH-Px) and glutathione S transferase pi (GSTpi), it plays a central role in the detoxification and biotransformation of chemotherapeutic drugs. This study evaluated the expression of GSH and the GSH-Px and GSTpi enzymes by immunohistochemistry in 30 canine mammary tumors, relating the clinicopathological parameters, clinical outcome and survival of the bitches. In an in vitro study, the expression of the genes glutamate cysteine ligase (GCLC) and glutathione synthetase (GSS) that synthesize GSH and GSH-Px gene were verified by qPCR and subjected to treatment with doxorubicin, to check the resistance of cancer cells to chemotherapy. Results The immunohistochemical expression of GSH, GSH-Px and GSTpi was compared with the clinical and pathological characteristics and the clinical outcome in the bitches, including metastasis and death. The results showed that high immunoexpression of GSH was correlated to the absence of tumor ulceration and was present in dogs without metastasis (P < 0.05). There was significant correlation of survival with the increase of GSH (P < 0.05). The expression of the GSH-Px and GSTpi enzymes showed no statistically significant correlation with the analyzed variables (p > 0.05). The analysis of the relative expression of genes responsible for the synthesis of GSH (GCLC and GSS) and GSH-Px by quantitative PCR was done with cultured cells of 10 tumor fragments from dogs with mammary tumors. The culture cells showed a decrease in GCLC and GSS expression when compared with no treated cells (P < 0.05). High GSH immunoexpression was associated with better clinical outcomes. Conclusion Therefore, high expression of the GSH seems to play an important role in the clinical outcome of patients with mammary tumors and suggest its use as prognostic marker. The in

  11. Characterization of recombinant glutathione reductase from the psychrophilic Antarctic bacterium Colwellia psychrerythraea.

    PubMed

    Ji, Mikyoung; Barnwell, Callie V; Grunden, Amy M

    2015-07-01

    Glutathione reductases catalyze the reduction of oxidized glutathione (glutathione disulfide, GSSG) using NADPH as the substrate to produce reduced glutathione (GSH), which is an important antioxidant molecule that helps maintain the proper reducing environment of the cell. A recombinant form of glutathione reductase from Colwellia psychrerythraea, a marine psychrophilic bacterium, has been biochemically characterized to determine its molecular and enzymatic properties. C. psychrerythraea glutathione reductase was shown to be a homodimer with a molecular weight of 48.7 kDa using SDS-PAGE, MALDI-TOF mass spectrometry and gel filtration. The C. psychrerythraea glutathione reductase sequence shows significant homology to that of Escherichia coli glutathione reductase (66 % identity), and it possesses the FAD and NADPH binding motifs, as well as absorption spectrum features which are characteristic of flavoenzymes such as glutathione reductase. The psychrophilic C. psychrerythraea glutathione reductase exhibits higher k cat and k cat/K m at lower temperatures (4 °C) compared to mesophilic Baker's yeast glutathione reductase. However, C. psychrerythraea glutathione reductase was able to complement an E. coli glutathione reductase deletion strain in oxidative stress growth assays, demonstrating the functionality of C. psychrerythraea glutathione reductase over a broad temperature range, which suggests its potential utility as an antioxidant enzyme in heterologous systems. PMID:26101017

  12. Hepatic metallothionein and Glutathione-S-Transferase responses in two populations of rice frogs, Fejervarya limnocharis, naturally exposed to different environmental cadmium levels.

    PubMed

    Othman, Mohd Sham; Khonsue, Wichase; Kitana, Jirarach; Thirakhupt, Kumthorn; Robson, Mark; Borjan, Marija; Kitana, Noppadon

    2012-08-01

    Glutathione-S-Transferase (GST) and metallothionein are important biomarker endpoints in studying the effect of Cd exposure. The purpose of this research was to study the correlation between hepatic GST and metallothionein with hepatic Cd in wild Fejervarya limnocharis exposed to environmental Cd. Results showed that frogs from contaminated sites had significantly higher hepatic metallothionein (3.58 mg/kg wet weight) and GST activity (0.259 μmol/min/mg total protein) than those from the reference site (2.36 mg/kg wet weight and 0.157 μmol/min/mg total protein respectively). There was a significantly positive correlation between hepatic Cd and GST activity (r = 0.802, p = 0.009) but not between hepatic Cd and metallothionein (r = 0.548, p = 0.139). The results concluded that while frogs from the contaminated site had higher GST and metallothionein, only GST showed significant positive correlation with hepatic Cd levels, indicating that hepatic GST activity may be used as a biomarker endpoint. PMID:22722596

  13. Hepatic Metallothionein and Glutathione-S-Transferase Responses in Two Populations of Rice Frogs, Fejervarya limnocharis, Naturally Exposed to Different Environmental Cadmium Levels

    PubMed Central

    Othman, Mohd Sham; Khonsue, Wichase; Kitana, Jirarach; Thirakhupt, Kumthorn; Robson, Mark; Borjan, Marija

    2014-01-01

    Glutathione-S-Transferase (GST) and metallothionein are important biomarker endpoints in studying the effect of Cd exposure. The purpose of this research was to study the correlation between hepatic GST and metallothionein with hepatic Cd in wild Fejervarya limnocharis exposed to environmental Cd. Results showed that frogs from contaminated sites had significantly higher hepatic metallothionein (3.58 mg/kg wet weight) and GST activity (0.259 μmol/min/mg total protein) than those from the reference site (2.36 mg/kg wet weight and 0.157 μmol/min/mg total protein respectively). There was a significantly positive correlation between hepatic Cd and GST activity (r = 0.802, p = 0.009) but not between hepatic Cd and metallothionein (r = 0.548, p = 0.139). The results concluded that while frogs from the contaminated site had higher GST and metallothionein, only GST showed significant positive correlation with hepatic Cd levels, indicating that hepatic GST activity may be used as a biomarker endpoint. PMID:22722596

  14. Dual Targeting of the Thioredoxin and Glutathione Anti-Oxidant Systems in Malignant B-cells; A Novel Synergistic Therapeutic Approach

    PubMed Central

    Kiebala, Michelle; Skalska, Jolanta; Casulo, Carla; Brookes, Paul S.; Peterson, Derick R.; Hilchey, Shannon P.; Dai, Yun; Grant, Steven; Maggirwar, Sanjay B.; Bernstein, Steven H.

    2015-01-01

    B-cell malignancies are a common type of cancer. One approach to cancer therapy is to either increase oxidative stress or inhibit the stress response systems on which cancer cells rely. In this study, we combined non-toxic concentrations of Auranofin (AUR), an inhibitor of the thioredoxin (Trx) system, with non-toxic concentrations of buthionine-sulfoximine (BSO), a compound that reduces intracellular glutathione (GSH) levels, and investigated the effect of this drug combination on multiple pathways critical for malignant B-cell survival. AUR interacted synergistically with BSO at low concentrations to trigger death in multiple malignant B-cell lines and primary mantle cell lymphoma (MCL) cells. Additionally, there was less toxicity toward normal B-cells. Low AUR concentrations inhibited Trx reductase (TrxR) activity, an effect significantly increased by BSO co-treatment. TrxR over-expression partially reversed AUR+BSO toxicity. Interestingly, the combination of AUR+BSO inhibited NF-κB signaling. Moreover, synergistic cell death induced by this regimen was attenuated in cells over-expressing NF-κB proteins, arguing for a functional role for NF-κB inhibition in AUR+BSO-mediated cell death. Together, these findings suggest that AUR+BSO synergistically induce malignant B-cell death, a process mediated by dual inhibition of TrxR and NF-κB, and such an approach warrants further investigation in B-cell malignancies. PMID:25448488

  15. Effects of cyanobacterial lipopolysaccharides from microcystis on glutathione-based detoxification pathways in the zebrafish (Danio rerio) embryo.

    PubMed

    Jaja-Chimedza, Asha; Gantar, Miroslav; Mayer, Gregory D; Gibbs, Patrick D L; Berry, John P

    2012-06-01

    Cyanobacteria ("blue-green algae") are recognized producers of a diverse array of toxic secondary metabolites. Of these, the lipopolysaccharides (LPS), produced by all cyanobacteria, remain to be well investigated. In the current study, we specifically employed the zebrafish (Danio rerio) embryo to investigate the effects of LPS from geographically diverse strains of the widespread cyanobacterial genus, Microcystis, on several detoxifying enzymes/pathways, including glutathione-S-transferase (GST), glutathione peroxidase (GPx)/glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT), and compared observed effects to those of heterotrophic bacterial (i.e., E. coli) LPS. In agreement with previous studies, cyanobacterial LPS significantly reduced GST in embryos exposed to LPS in all treatments. In contrast, GPx moderately increased in embryos exposed to LPS, with no effect on reciprocal GR activity. Interestingly, total glutathione levels were elevated in embryos exposed to Microcystis LPS, but the relative levels of reduced and oxidized glutathione (i.e., GSH/GSSG) were, likewise, elevated suggesting that oxidative stress is not involved in the observed effects as typical of heterotrophic bacterial LPS in mammalian systems. In further support of this, no effect was observed with respect to CAT or SOD activity. These findings demonstrate that Microcystis LPS affects glutathione-based detoxification pathways in the zebrafish embryo, and more generally, that this model is well suited for investigating the apparent toxicophore of cyanobacterial LPS, including possible differences in structure-activity relationships between heterotrophic and cyanobacterial LPS, and teleost fish versus mammalian systems. PMID:22822454

  16. Survival of Escherichia coli cells on solid copper surfaces is increased by glutathione.

    PubMed

    Große, Cornelia; Schleuder, Grit; Schmole, Christin; Nies, Dietrich H

    2014-11-01

    Bacteria are rapidly killed on solid copper surfaces, so this material could be useful to limit the spread of multiple-drug-resistant bacteria in hospitals. In Escherichia coli, the DNA-protecting Dps protein and the NADH:ubiquinone oxidoreductase II Ndh were not involved in tolerance to copper ions or survival on solid copper surfaces. Decreased copper tolerance under anaerobic growth conditions in the presence of ascorbate and with melibiose as the carbon source indicated that sodium-dependent symport systems may provide an import route for Cu(I) into the cytoplasm. Glutathione-free ΔcopA ΔgshA double mutants of E. coli were more rapidly inactivated on solid copper surfaces than glutathione-containing wild-type cells. Therefore, while DNA protection by Dps was not required, glutathione was needed to protect the cytoplasm and the DNA against damage mediated by solid copper surfaces, which may explain the differences in the molecular mechanisms of killing between glutathione-containing Gram-negative and glutathione-free Gram-positive bacteria. PMID:25192999

  17. Survival of Escherichia coli Cells on Solid Copper Surfaces Is Increased by Glutathione

    PubMed Central

    Große, Cornelia; Schleuder, Grit; Schmole, Christin

    2014-01-01

    Bacteria are rapidly killed on solid copper surfaces, so this material could be useful to limit the spread of multiple-drug-resistant bacteria in hospitals. In Escherichia coli, the DNA-protecting Dps protein and the NADH:ubiquinone oxidoreductase II Ndh were not involved in tolerance to copper ions or survival on solid copper surfaces. Decreased copper tolerance under anaerobic growth conditions in the presence of ascorbate and with melibiose as the carbon source indicated that sodium-dependent symport systems may provide an import route for CuI into the cytoplasm. Glutathione-free ΔcopA ΔgshA double mutants of E. coli were more rapidly inactivated on solid copper surfaces than glutathione-containing wild-type cells. Therefore, while DNA protection by Dps was not required, glutathione was needed to protect the cytoplasm and the DNA against damage mediated by solid copper surfaces, which may explain the differences in the molecular mechanisms of killing between glutathione-containing Gram-negative and glutathione-free Gram-positive bacteria. PMID:25192999

  18. Involvement of Antibiotic Efflux Machinery in Glutathione-Mediated Decreased Ciprofloxacin Activity in Escherichia coli.

    PubMed

    Goswami, Manish; Subramanian, Mahesh; Kumar, Ranjeet; Jass, Jana; Jawali, Narendra

    2016-07-01

    We have analyzed the contribution of different efflux components to glutathione-mediated abrogation of ciprofloxacin's activity in Escherichia coli and the underlying potential mechanism(s) behind this phenomenon. The results indicated that glutathione increased the total active efflux, thereby partially contributing to glutathione-mediated neutralization of ciprofloxacin's antibacterial action in E. coli However, the role of glutathione-mediated increased efflux becomes evident in the absence of a functional TolC-AcrAB efflux pump. PMID:27139480

  19. Glutathione-related factors are not correlated with sensitivity of human tumour cells to actinomycin D.

    PubMed

    Zhang, K; Yang, E B; Zhao, Y N; Wong, K P; Mack, P

    2000-02-28

    Glutathione (GSH) contents and activities of glutathione S-transferases (GST), glutathione reductase (GSH-RD), glutathione peroxidase (GSHpx) and glutathione conjugate export pump (GS-X pump) were determined in eight human tumour cell lines with different sensitivities to melphalan, a substrate of glutathione conjugation, and actinomycin D which has not been shown to be detoxified by glutathione-related mechanisms. Chang liver cells with highest GSH content and highest activities of GST, GSH-RD, GSHpx and GS-X pump were found to be most resistant to melphalan. Statistical analysis showed significant correlations between sensitivities of the human tumour cells to melphalan and the glutathione-related factors (r = 0.72-0.79; except for GST, r = 0.65, P = 0.08), while there were no significant correlations observed between sensitivities of the human tumour cells to actinomycin D and all the glutathione-related factors tested (r = -0.25-0.14). Significant correlations of the glutathione-related factors to resistance of human tumour cells to melphalan, a substrate of glutathione conjugation, but not to resistance of the human tumour cells to actinomycin D which has not been shown to be detoxified by glutathione-related mechanisms suggested that glutathione-related mechanisms contribute to drug resistance by increased detoxification of the drugs involved. PMID:10737727

  20. The concentration of ascorbic acid and glutathione in 13 provenances of Acacia melanoxylon.

    PubMed

    Wujeska-Klause, Agnieszka; Bossinger, Gerd; Tausz, Michael

    2016-04-01

    Climate change can negatively affect sensitive tree species, affecting their acclimation and adaptation strategies. A common garden experiment provides an opportunity to test whether responses of trees from different provenances are genetically driven and if this response is related to factors at the site of origin. We hypothesized that antioxidative defence systems and leaf mass area ofAcacia melanoxylonR. Br. samples collected from different provenances will vary depending on local rainfall. Thirteen provenances ofA. melanoxylonoriginating from different rainfall habitats (500-2000 mm) were grown for 5 years in a common garden. For 2 years, phyllode samples were collected during winter and summer, for measurements of leaf mass area and concentrations of glutathione and ascorbic acid. Leaf mass area varied between seasons, years and provenances ofA. melanoxylon, and an increase was associated with decreasing rainfall at the site of origin. Ascorbic acid and glutathione concentrations varied between seasons, years (i.e., environmental factors) and among provenances ofA. melanoxylon In general, glutathione and ascorbic acid concentrations were higher in winter compared with summer. Ascorbic acid and glutathione were different among provenances, but this was not associated with rainfall at the site of origin. PMID:26960387

  1. Immunohistochemical demonstration of salmon olfactory glutathione S-transferase class pi (N24) in the olfactory system of lacustrine sockeye salmon during ontogenesis and cell proliferation.

    PubMed

    Yanagi, S; Kudo, H; Doi, Y; Yamauchi, K; Ueda, H

    2004-06-01

    In mammals, glutathione S-transferase (GST) in the olfactory epithelium is involved in assistance of the olfactory reception by the xenobiotic metabolism. We previously reported the protein and gene expressions of salmon olfactory GST class pi (soGST) in the olfactory receptor cells (ORCs) of the salmonid fish. However, the chronological appearances of soGST in ORCs during ontogeny and cell proliferation are still unknown in this species. In this study, we performed immunohistochemistry of soGST using an antibody specific to soGST in the olfactory system (olfactory placode, olfactory pit, olfactory epithelium, olfactory nerve and olfactory bulb) of lacustrine sockeye salmon ( Oncorhynchus nerka) embryos and 5-bromo-2'-deoxyuridine (BrdU) experimental fish. The projection of olfactory nerve bundles from the olfactory pit to the presumptive olfactory bulb was identified at embryonic day 28 after fertilization. The olfactory cilia were first detected on the apical surface of ORCs at day 43. soGST-immunoreactivity was first detected within the olfactory pit cells at day 55. At 58 day, the number of soGST-immunoreactive cells increased markedly in the olfactory epithelia, and soGST-immunoreactive fibers were observed in the olfactory nerves and olfactory bulbs. By in vivo uptake of BrdU in 1-year-old fish, we observed for the first time at day 7 after labeling that the olfactory epithelia showed ORCs in which both soGST-immunoreactivity and BrdU coexisted. These results indicate that soGST is synthesized in the mature ORCs of lacustrine sockeye salmon after cell formation and differentiation. PMID:15156400

  2. Effects of copper overload in P19 neurons: impairment of glutathione redox homeostasis and crosstalk between caspase and calpain protease systems in ROS-induced apoptosis.

    PubMed

    Jazvinšćak Jembrek, Maja; Vlainić, Josipa; Radovanović, Vedrana; Erhardt, Julija; Oršolić, Nada

    2014-12-01

    Copper, a transition metal with essential biological functions, exerts neurotoxic effects when present in excess. The aim of the present study was to better elucidate cellular and molecular mechanisms of CuSO4 toxicity in differentiated P19 neurons. Exposure to 0.5 mM CuSO4 for 24 h provoked moderate decrease in viability, accompanied with barely increased generation of reactive oxygen species (ROS) and caspase-3/7 activity. Glutathione (GSH) and ATP contents were depleted, lactate dehydrogenase inactivated, and glyceraldehyde-3-phosphate dehydrogenase overexpressed. In severely damaged neurons exposed to only two times higher concentration, classical caspase-dependent apoptosis was triggered as evidenced by marked caspase-3/7 activation and chromatin condensation. Multifold increase in ROS, together with very pronounced ATP and GSH loss, strongly suggests impairment of redox homeostasis. At higher copper concentration protease calpains were also activated, and neuronal injury was prevented in the presence of calpain inhibitor leupeptin through the mechanism that affects caspase activation. MK-801 and nifedipine, inhibitors of calcium entry, and H-89 and UO126, inhibitors of PKA and ERK signaling respectively, exacerbated neuronal death only in severely damaged neurons, while ROS-scavenger quercetin and calcium chelator BAPTA attenuated toxicity only at lower concentration. In a dose-dependent manner copper also provoked transcriptional changes of genes involved in intracellular signaling and induction of apoptosis (p53, c-fos, Bcl-2 and Bax). The obtained results emphasize differences in triggered neuronal-death processes in a very narrow range of concentrations and give further insight into the molecular mechanisms of copper toxicity with the potential to improve current therapeutic approaches in curing copper-related neurodegenerative diseases. PMID:25216733

  3. Saving the zone of stasis: is glutathione effective?

    PubMed

    Zor, Fatih; Ozturk, Serdar; Deveci, Mustafa; Karacalioglu, Ozgur; Sengezer, Mustafa

    2005-12-01

    One of the main subjects that burn researches are focused on is saving the zone of stasis. There are many molecules that are used for this purpose, but all have their drawbacks. Glutathione is one of the major buffer molecules of the cells and is known to increase the thermo-resistance of the cells. In this study, the effect of the systemic glutathione on the zone of stasis was evaluated. The results showed that glutathione is an effective molecule for saving the zone of stasis. It is well-known cheap, and easy to use. PMID:16278048

  4. Effect of 4-week feeding of deoxynivalenol- or T-2-toxin-contaminated diet on lipid peroxidation and glutathione redox system in the hepatopancreas of common carp (Cyprinus carpio L.).

    PubMed

    Pelyhe, Csilla; Kövesi, Benjámin; Zándoki, Erika; Kovács, Balázs; Szabó-Fodor, Judit; Mézes, Miklós; Balogh, Krisztián

    2016-05-01

    The purpose of study was to investigate the effects of T-2 toxin (4.11 mg T-2 toxin and 0.45 mg HT-2 toxin kg(-1) feed) and deoxynivalenol (5.96 and 0.33 mg 15-acetyl deoxynivalenol (DON) kg(-1) feed) in 1-year-old common carp juveniles in a 4-week feeding trial. The exposure of mycotoxins resulted in increased mortality in both groups consuming mycotoxin-contaminated diet. Parameters of lipid peroxidation were not affected during the trial, and antioxidant defence also did not show response to oxidative stress; however, glutatione peroxidase activity slightly, but significantly, decreased in the T-2 toxin group. Glutathione S-transferase activity showed moderate decrease as effect of T-2 toxin, which suggests its effect on xenobiotic transformation. Reduced glutathione concentration showed moderate changes as effect of DON exposure, but T-2 toxin has no effect. Expression of phospholipid hydroperoxide glutathione peroxidase (GPx4) genes showed different response to mycotoxin exposure. T-2 toxin caused dual response in the expression of gpx4a (early and late downregulation and mid-term upregulation), but continuous upregulation was found as effect of deoxynivalenol. Expression of the other gene, gpx4b, was upregulated by both trichothecenes during the whole period. The results suggested that trichothecenes have some effect on free radical formation and antioxidant defence, but the changes depend on the duration of exposure and the dose applied, and in case of glutathione peroxidase, there was no correlation between expression of genes and enzyme activity. PMID:26920403

  5. Effect of glutathione addition in sparkling wine.

    PubMed

    Webber, Vanessa; Dutra, Sandra Valduga; Spinelli, Fernanda Rodrigues; Marcon, Ângela Rossi; Carnieli, Gilberto João; Vanderlinde, Regina

    2014-09-15

    This study aims to evaluate the effect of the addition of glutathione (GSH) on secondary aromas and on the phenolic compounds of sparkling wine elaborated by traditional method. It was added 10 and 20 mg L(-1) of GSH to must and to base wine. The determination of aroma compounds was performed by gas chromatography. Phenolic compounds and glutathione content were analyzed by high performance liquid chromatography. Sparkling wines with addition of GSH to must showed lower levels of total phenolic compounds and hydroxycinnamic acids. Furthermore, the sparkling wine with addition of GSH to must showed higher levels of 2-phenylethanol, 3-methyl-1-butanol and diethyl succinate, and lower concentrations of ethyl decanoate, octanoic and decanoic acids. The GSH addition to the must show a greater influence on sparkling wine than to base wine, however GSH addition to base wine seems retain higher SO2 free levels. The concentration of GSH added showed no significant difference. PMID:24767072

  6. Relationship of glutathione S-transferase genotypes with side-effects of pulsed cyclophosphamide therapy in patients with systemic lupus erythematosus

    PubMed Central

    Zhong, Shilong; Huang, Min; Yang, Xiuyan; Liang, Liuqin; Wang, Yixi; Romkes, Marjorie; Duan, Wei; Chan, Eli; Zhou, Shu-Feng

    2006-01-01

    Aims Cyclophosphamide (CTX) is an established treatment of severe systemic lupus erythematosus (SLE). Cytotoxic CTX metabolites are mainly detoxified by multiple glutathione S-transferases (GSTs). However, data are lacking on the relationship between the short-term side-effects of CTX therapy and GST genotypes. In the present study, the effects of common GSTM1, GSTT1, and GSTP1 genetic mutations on the severity of myelosuppression, gastrointestinal (GI) toxicity, and infection incidences induced by pulsed CTX therapy were evaluated in patients SLE. Methods DNA was extracted from peripheral leucocytes in patients with confirmed SLE diagnosis (n = 102). GSTM1 and GSTT1 null mutations were analyzed by a polymerase chain reaction (PCR)-multiplex procedure, whereas the GSTP1 codon 105 polymorphism (Ile→Val) was analyzed by a PCR-restriction fragment length polymorphism (RFLP) assay. Results Our study demonstrated that SLE patients carrying the genotypes with GSTP1 codon 105 mutation [GSTP1*-105I/V (heterozygote) and GSTP1*-105 V/V (homozygote)] had an increased risk of myelotoxicity when treated with pulsed high-dose CTX therapy (Odds ratio (OR) 5.00, 95% confidence interval (CI) 1.96, 12.76); especially in patients younger than 30 years (OR 7.50, 95% CI 2.14, 26.24), or in patients treated with a total CTX dose greater than 1.0 g (OR 12.88, 95% CI 3.16, 52.57). Similarly, patients with these genotypes (GSTP1*I/V and GSTP1*V/V) also had an increased risk of GI toxicity when treated with an initial pulsed high-dose CTX regimen (OR 3.33, 95% CI 1.03, 10.79). However, GSTM1 and GSTT1 null mutations did not significantly alter the risks of these short-term side-effects of pulsed high-dose CTX therapy in SLE patients. Conclusions The GSTP1 codon 105 polymorphism, but not GSTM1 or GSTT1 null mutations, significantly increased the risks of short-term side-effects of pulsed high-dose CTX therapy in SLE patients. Because of the lack of selective substrates for a GST enzyme

  7. Co-expression of glutathione S-transferase with methionine aminopeptidase: a system of producing enriched N-terminal processed proteins in Escherichia coli.

    PubMed Central

    Hwang, D D; Liu, L F; Kuan, I C; Lin, L Y; Tam, T C; Tam, M F

    1999-01-01

    We describe here an Escherichia coli expression system that produces recombinant proteins enriched in the N-terminal processed form, by using glutathione S-transferase cGSTM1-1 and rGSTT1-1 as models, where c and r refer to chick and rat respectively. Approximately 90% of the cGSTM1-1 or rGSTT1-1 overexpressed in E. coli under the control of a phoA promoter retained the initiator methionine residue that was absent from the mature isoenzymes isolated from tissues. The amount of initiator methionine was decreased to 40% of the expressed cGSTM1-1 when the isoenzyme was co-expressed with an exogenous methionine aminopeptidase gene under the control of a separate phoA promoter. The recombinant proteins expressed were mainly methionine aminopeptidase. The yield of cGSTM1-1 was decreased to 10% of that expressed in the absence of the exogenous methionine aminopeptidase gene. By replacing the phoA with its natural promoter, the expression of methionine aminopeptidase decreased drastically. The yield of the co-expressed cGSTM1-1 was approx. 60% of that in the absence of the exogenous methionine aminopeptidase gene; approx. 65% of the initiator methionine residues were removed from the enzyme. Under similar conditions, N-terminal processing was observed in approx. 70% of the recombinant rGSTT1-1 expressed. By increasing the concentration of phosphate in the growth medium, the amount of initiator methionine on cGSTM1-1 was decreased to 14% of the overexpressed isoenzymes, whereas no further improvement could be observed for rGSTT1-1. The initiator methionine residue does not affect the enzymic activities of either cGSTM1-1 or rGSTT1-1. However, the epoxidase activity and the 4-nitrobenzyl chloride-conjugating activity of the purified recombinant rGSTT1-1 are markedly higher that those reported recently for the same isoenzyme isolated from rat livers. PMID:10024508

  8. Characterization of thyroidal glutathione reductase

    SciTech Connect

    Raasch, R.J.

    1989-01-01

    Glutathione levels were determined in bovine and rat thyroid tissue by enzymatic conjugation with 1-chloro-2,4-dinitrobenzene using glutathione S-transferase. Bovine thyroid tissue contained 1.31 {+-} 0.04 mM reduced glutathione (GSH) and 0.14 {+-} 0.02 mM oxidized glutathione (GSSG). In the rat, the concentration of GSH was 2.50 {+-} 0.05 mM while GSSG was 0.21 {+-} 0.03 mM. Glutathione reductase (GR) was purified from bovine thyroid to electrophoretic homogeneity by ion exchange, affinity and molecular exclusion chromatography. A molecular weight range of 102-109 kDa and subunit size of 55 kDa were determined for GR. Thyroidal GR was shown to be a favoprotein with one FAD per subunit. The Michaelis constants of bovine thyroidal GR were determined to be 21.8 {mu}M for NADPH and 58.8 {mu}M for GSSG. The effect of thyroid stimulating hormone (TSH) and thyroxine (T{sub 4}) on in vivo levels of GR and glucose 6-phosphate dehydrogenase were determined in rat thyroid homogenates. Both enzymes were stimulated by TSH treatment and markedly reduced following T{sub 4} treatment. Lysosomal hydrolysis of ({sup 125}I)-labeled and unlabeled thyroglobulin was examined using size exclusion HPLC.

  9. Delayed Cardiomyopathy in Dystrophin Deficient mdx Mice Relies on Intrinsic Glutathione Resource

    PubMed Central

    Khouzami, Lara; Bourin, Marie-Claude; Christov, Christo; Damy, Thibaud; Escoubet, Brigitte; Caramelle, Philippe; Perier, Magali; Wahbi, Karim; Meune, Christophe; Pavoine, Catherine; Pecker, Françoise

    2010-01-01

    Oxidative stress contributes to the pathogenesis of Duchenne muscular dystrophy (DMD). Although they have been a model for DMD, mdx mice exhibit slowly developing cardiomyopathy. We hypothesized that disease process was delayed owing to the development of an adaptive mechanism against oxidative stress, involving glutathione synthesis. At 15 to 20 weeks of age, mdx mice displayed a 33% increase in blood glutathione levels compared with age-matched C57BL/6 mice. In contrast, cardiac glutathione content was similar in mdx and C57BL/6 mice as a result of the balanced increased expression of glutamate cysteine ligase catalytic and regulatory subunits ensuring glutathione synthesis in the mdx mouse heart, as well as increased glutathione peroxidase-1 using glutathione. Oral administration from 10 weeks of age of the glutamate cysteine ligase inhibitor, l-buthionine(S,R)-sulfoximine (BSO, 5 mmol/L), led to a 33% and 50% drop in blood and cardiac glutathione, respectively, in 15- to 20-week-old mdx mice. Moreover, 20-week-old BSO-treated mdx mice displayed left ventricular hypertrophy associated with diastolic dysfunction, discontinuities in β-dystroglycan expression, micronecrosis and microangiopathic injuries. Examination of the glutathione status in four DMD patients showed that three displayed systemic glutathione deficiency as well. In conclusion, low glutathione resource hastens the onset of cardiomyopathy linked to a defect in dystrophin in mdx mice. This is relevant to the glutathione deficiency that DMD patients may suffer. PMID:20696779

  10. Glutathione redox cycle dysregulation in Huntington's disease knock-in striatal cells.

    PubMed

    Ribeiro, Márcio; Rosenstock, Tatiana R; Cunha-Oliveira, Teresa; Ferreira, Ildete L; Oliveira, Catarina R; Rego, A Cristina

    2012-11-15

    Huntington's disease (HD) is a CAG repeat disorder affecting the HD gene, which encodes for huntingtin (Htt) and is characterized by prominent cell death in the striatum. Oxidative stress was previously implicated in HD neurodegeneration, but the role of the major endogenous antioxidant system, the glutathione redox cycle, has been less studied following expression of full-length mutant Htt (FL-mHtt). Thus, in this work we analyzed the glutathione system in striatal cells derived from HD knock-in mice expressing mutant Htt versus wild-type cells. Mutant cells showed increased intracellular reactive oxygen species (ROS) and caspase-3 activity, which were significantly prevented following treatment with glutathione ethyl ester. Interestingly, mutant cells exhibited an increase in intracellular levels of both reduced and oxidized forms of glutathione, and enhanced activities of glutathione peroxidase (GPx) and glutathione reductase (GRed). Furthermore, glutathione-S-transferase (GST) and γ-glutamyl transpeptidase (γ-GT) activities were also increased in mutant cells. Nevertheless, glutamate-cysteine ligase (GCL) and glutathione synthetase (GS) activities and levels of GCL catalytic subunit were decreased in cells expressing FL-mHtt, highly suggesting decreased de novo synthesis of glutathione. Enhanced intracellular total glutathione, despite decreased synthesis, could be explained by decreased extracellular glutathione in mutant cells. This occurred concomitantly with decreased mRNA expression levels and activity of the multidrug resistance protein 1 (Mrp1), a transport protein that mediates cellular export of glutathione disulfide and glutathione conjugates. Additionally, inhibition of Mrp1 enhanced intracellular GSH in wild-type cells only. These data suggest that FL-mHtt affects the export of glutathione by decreasing the expression of Mrp1. Data further suggest that boosting of GSH-related antioxidant defense mechanisms induced by FL-mHtt is insufficient to

  11. Amodiaquine failure associated with erythrocytic glutathione in Plasmodium falciparum malaria

    PubMed Central

    Zuluaga, Lina; Pabón, Adriana; López, Carlos; Ochoa, Aleida; Blair, Silvia

    2007-01-01

    Objective To establish the relationship between production of glutathione and the therapeutic response to amodiaquine (AQ) monotherapy in Plasmodium falciparum non-complicated malaria patients. Methodology Therapeutic response to AQ was evaluated in 32 patients with falciparum malaria in two townships of Antioquia, Colombia, and followed-up for 28 days. For every patient, total glutathione and enzymatic activity (glutathione reductase, GR, and γ-glutamylcysteine synthetase, γ-GCS) were determined in parasitized erythrocytes, non-infected erythrocytes and free parasites, on the starting day (day zero, before ingestion of AQ) and on the day of failure (in case of occurrence). Results There was found an AQ failure of 31.25%. Independent of the therapeutic response, on the starting day and on the day of failure, lower total glutathione concentration and higher GR activities in parasitized erythrocytes were found, compared with non-infected erythrocytes (p < 0.003). In addition, only on the day of failure, γ-GCS activity of parasitized erythrocytes was higher, compared with that of healthy erythrocytes (p = 0.01). Parasitized and non-parasitized erythrocytes in therapeutic failure patients (TF) had higher total glutathione on the starting day compared with those of adequate clinical response (ACR) (p < 0.02). Parasitized erythrocytes of TF patients showed lower total glutathione on the failure day, compared with starting day (p = 0.017). No differences was seen in the GR and γ-GCS activities by compartment, neither between the two therapeutic response groups nor between the two treatment days. Conclusion This study is a first approach to explaining P. falciparum therapeutic failure in humans through differences in glutathione metabolism in TF and ACR patients. These results suggest a role for glutathione in the therapeutic failure to antimalarials. PMID:17451604

  12. Response of glutathione in mussels (Mytilus) exposed to common environmental contaminants

    SciTech Connect

    Inouye, L.S.; Casillas, E.

    1995-12-31

    Mussels (Mytilus sp.) were exposed to PCBs, a mixture of polycyclic aromatic hydrocarbons (PAHs), or extracts of contaminated sediments to determine the response of glutathione content in gill and digestive gland to chemicals contaminants. In addition, a field transplant investigation was conducted to determine if the differences observed in tissue glutathione levels of mussels from reference and contaminated sites were due to the presence of chemical contaminants rather than to population differences in basal glutathione concentrations. Exposure to PCBs or to sediment extracts from a contaminated site resulted in a decrease in glutathione content in the digestive gland, but an increase in glutathione content in gills. In contrast, no alterations in tissue glutathione were observed after exposure to PAHs. Transplant investigation results were consistent with those from the contaminated sediment extract exposure. Glutathione content in digestive glands was higher in mussels from a reference site compared to that found in mussels from the contaminated site, while the opposite trend was found in gill glutathione content of the same mussels. Eight weeks after being transplanted from the reference site to the contaminated site or alternatively from a contaminated site to a reference site, glutathione levels in the gland tissues matched those found in mussels native to the site to which they were transplanted. Although gill glutathione content was significantly different from that found at the site of origin, it did not match levels found in mussels native to the site to which they had been transplanted.

  13. Differences Between Distributed and Parallel Systems

    SciTech Connect

    Brightwell, R.; Maccabe, A.B.; Rissen, R.

    1998-10-01

    Distributed systems have been studied for twenty years and are now coming into wider use as fast networks and powerful workstations become more readily available. In many respects a massively parallel computer resembles a network of workstations and it is tempting to port a distributed operating system to such a machine. However, there are significant differences between these two environments and a parallel operating system is needed to get the best performance out of a massively parallel system. This report characterizes the differences between distributed systems, networks of workstations, and massively parallel systems and analyzes the impact of these differences on operating system design. In the second part of the report, we introduce Puma, an operating system specifically developed for massively parallel systems. We describe Puma portals, the basic building blocks for message passing paradigms implemented on top of Puma, and show how the differences observed in the first part of the report have influenced the design and implementation of Puma.

  14. Purification and Biochemical Characterization of Glutathione S-Transferase from Down Syndrome and Normal Children Erythrocytes: A Comparative Study

    ERIC Educational Resources Information Center

    Hamed, Ragaa R.; Maharem, Tahany M.; Abdel-Meguid, Nagwa; Sabry, Gilane M.; Abdalla, Abdel-Monem; Guneidy, Rasha A.

    2011-01-01

    Down syndrome (DS) is the phenotypic manifestation of trisomy 21. Our study was concerned with the characterization and purification of glutathione S-transferase enzyme (GST) from normal and Down syndrome (DS) erythrocytes to illustrate the difference in the role of this enzyme in the cell. Glutathione S-transferase and glutathione (GSH) was…

  15. The content of glutathione and glutathione S-transferases and the glutathione peroxidase activity in rat liver nuclei determined by a non-aqueous technique of cell fractionation.

    PubMed Central

    Soboll, S; Gründel, S; Harris, J; Kolb-Bachofen, V; Ketterer, B; Sies, H

    1995-01-01

    Hepatocellular nuclei require glutathione, glutathione S-transferases (GSTs) and Se-dependent glutathione peroxidase (GPx) for intranuclear protection against damage from electrophiles or products of active oxygen. Data so far available from the literature on nuclei isolated in aqueous systems range from glutathione, GSTs and GPx either being absent altogether to being present in quantities in excess of those in the cytoplasm. This paper describes a small-scale preparation of a nuclear fraction from rat liver by a non-aqueous technique, designed to retain nuclear water-soluble molecules in situ, since low-molecular-mass compounds can diffuse freely into other compartments during aqueous separation. This non-aqueous procedure shows the nucleus to contain glutathione at 8.4 mM and soluble GSTs at 38 micrograms/mg of protein, the enrichment over the homogenate being 1.2-1.4-fold. Se-dependent GPx activity was also present in the nucleus (56 m-units/mg), although with slightly lower activity than in the homogenate (0.7-fold). Images Figure 1 PMID:7487946

  16. Proteomic responses to lead-induced oxidative stress in Talinum triangulare Jacq. (Willd.) roots: identification of key biomarkers related to glutathione metabolisms.

    PubMed

    Kumar, Abhay; Majeti, Narasimha Vara Prasad

    2014-01-01

    In this study, Talinum triangulare Jacq. (Willd.) treated with different lead (Pb) concentrations for 7 days has been investigated to understand the mechanisms of ascorbate-glutathione metabolisms in response to Pb-induced oxidative stress. Proteomic study was performed for control and 1.25 mM Pb-treated plants to examine the root protein dynamics in the presence of Pb. Results of our analysis showed that Pb treatment caused a decrease in non-protein thiols, reduced glutathione (GSH), total ascorbate, total glutathione, GSH/oxidized glutathione (GSSG) ratio, and activities of glutathione reductase and γ-glutamylcysteine synthetase. Conversely, cysteine and GSSG contents and glutathione-S-transferase activity was increased after Pb treatment. Fourier transform infrared spectroscopy confirmed our metabolic and proteomic studies and showed that amino, phenolic, and carboxylic acids as well as alcoholic, amide, and ester-containing biomolecules had key roles in detoxification of Pb/Pb-induced toxic metabolites. Proteomic analysis revealed an increase in relative abundance of 20 major proteins and 3 new proteins (appeared only in 1.25 mM Pb). Abundant proteins during 1.25 mM Pb stress conditions have given a very clear indication about their involvement in root architecture, energy metabolism, reactive oxygen species (ROS) detoxification, cell signaling, primary and secondary metabolisms, and molecular transport systems. Relative accumulation patterns of both common and newly identified proteins are highly correlated with our other morphological, physiological, and biochemical parameters. PMID:24705950

  17. Glutathione production by recombinant Escherichia coli expressing bifunctional glutathione synthetase.

    PubMed

    Wang, Dezheng; Wang, Cheng; Wu, Hui; Li, Zhimin; Ye, Qin

    2016-01-01

    Glutathione (GSH) is an important bioactive substance applied widely in pharmaceutical and food industries. Due to the strong product inhibition in the GSH biosynthetic pathway, high levels of intracellular content, yield and productivity of GSH are difficult to achieve. Recently, a novel bifunctional GSH synthetase was identified to be less sensitive to GSH. A recombinant Escherichia coli strain expressing gshF encoding the bifunctional glutathione synthetase of Streptococcus thermophilus was constructed for GSH production. In this study, efficient GSH production using this engineered strain was investigated. The cultivation process was optimized by controlling dissolved oxygen (DO), amino acid addition and glucose feeding. 36.8 mM (11.3 g/L) GSH were formed at a productivity of 2.06 mM/h when the amino acid precursors (75 mM each) were added and glucose was supplied as the sole carbon and energy source. PMID:26586402

  18. Glutathione deficiency down-regulates hepatic lipogenesis in rats

    PubMed Central

    2010-01-01

    Background Oxidative stress is supposed to increase lipid accumulation by stimulation of hepatic lipogenesis at transcriptional level. This study was performed to investigate the role of glutathione in the regulation of this process. For that purpose, male rats were treated with buthionine sulfoximine (BSO), a specific inhibitor of γ-glutamylcysteine synthetase, for 7 days and compared with untreated control rats. Results BSO treatment caused a significant reduction of total glutathione in liver (-70%), which was attributable to diminished levels of reduced glutathione (GSH, -71%). Glutathione-deficient rats had lower triglyceride concentrations in their livers than the control rats (-23%), whereas the circulating triglycerides and the cholesterol concentrations in plasma and liver were not different between the two groups of rats. Livers of glutathione-deficient rats had lower mRNA abundance of sterol regulatory element-binding protein (SREBP)-1c (-47%), Spot (S)14 (-29%) and diacylglycerol acyltransferase 2 (DGAT-2, -27%) and a lower enzyme activity of fatty acid synthase (FAS, -26%) than livers of the control rats. Glutathione-deficient rats had also a lower hepatic activity of the redox-sensitive protein-tyrosine phosphatase (PTP)1B, and a higher concentration of irreversible oxidized PTP1B than control rats. No differences were observed in protein expression of total PTP1B and the mature mRNA encoding active XBP1s, a key regulator of unfolded protein and ER stress response. Conclusion This study shows that glutathione deficiency lowers hepatic triglyceride concentrations via influencing lipogenesis. The reduced activity of PTP1B and the higher concentration of irreversible oxidized PTP1B could be, at least in part, responsible for this effect. PMID:20482862

  19. Brain oxidative stress: detection and mapping of anti-oxidant marker 'Glutathione' in different brain regions of healthy male/female, MCI and Alzheimer patients using non-invasive magnetic resonance spectroscopy.

    PubMed

    Mandal, Pravat K; Tripathi, Manjari; Sugunan, Sreedevi

    2012-01-01

    Glutathione (GSH) serves as an important anti-oxidant in the brain by scavenging harmful reactive oxygen species that are generated during different molecular processes. The GSH level in the brain provides indirect information on oxidative stress of the brain. We report in vivo detection of GSH non-invasively from various brain regions (frontal cortex, parietal cortex, hippocampus and cerebellum) in bilateral hemispheres of healthy male and female subjects and from bi-lateral frontal cortices in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). All AD patients who participated in this study were on medication with cholinesterase inhibitors. Healthy young male (age 26.4±3.0) and healthy young female (age 23.6±2.1) subjects have higher amount of GSH in the parietal cortical region and a specific GSH distribution pattern (parietal cortex>frontal cortex>hippocampus ~ cerebellum) has been found. Overall mean GSH content is higher in healthy young female compared to healthy young male subjects and GSH is distributed differently in two hemispheres among male and female subjects. In both young female and male subjects, statistically significant (p=0.02 for young female and p=0.001 for young male) difference in mean GSH content is found when compared between left frontal cortex (LFC) and right frontal cortex (RFC). In healthy young female subjects, we report statistically significant positive correlation of GSH content between RFC and LFC (r=0.641, p=0.004) as well as right parietal cortex (RPC) and left parietal cortex (LPC) (r=0.797, p=0.000) regions. In healthy young male subjects, statistically significant positive correlation of GSH content was observed between LFC and LPC (r=0.481, p=0.032) regions. This statistical analysis implicates that in case of a high GSH content in LPC of a young male, his LFC region would also contain high GSH and vice versa. The difference in mean of GSH content between healthy young female control and female AD

  20. Dysregulation of Glutathione Homeostasis in Neurodegenerative Diseases

    PubMed Central

    Johnson, William M.; Wilson-Delfosse, Amy L.; Mieyal, John. J.

    2012-01-01

    Dysregulation of glutathione homeostasis and alterations in glutathione-dependent enzyme activities are increasingly implicated in the induction and progression of neurodegenerative diseases, including Alzheimer’s, Parkinson’s and Huntington’s diseases, amyotrophic lateral sclerosis, and Friedreich’s ataxia. In this review background is provided on the steady-state synthesis, regulation, and transport of glutathione, with primary focus on the brain. A brief overview is presented on the distinct but vital roles of glutathione in cellular maintenance and survival, and on the functions of key glutathione-dependent enzymes. Major contributors to initiation and progression of neurodegenerative diseases are considered, including oxidative stress, protein misfolding, and protein aggregation. In each case examples of key regulatory mechanisms are identified that are sensitive to changes in glutathione redox status and/or in the activities of glutathione-dependent enzymes. Mechanisms of dysregulation of glutathione and/or glutathione-dependent enzymes are discussed that are implicated in pathogenesis of each neurodegenerative disease. Limitations in information or interpretation are identified, and possible avenues for further research are described with an aim to elucidating novel targets for therapeutic interventions. The pros and cons of administration of N-acetylcysteine or glutathione as therapeutic agents for neurodegenerative diseases, as well as the potential utility of serum glutathione as a biomarker, are critically evaluated. PMID:23201762

  1. Changes of reduced glutathion, glutathion reductase, and glutathione peroxidase after radiation in guinea pigs

    SciTech Connect

    Erden, M.; Bor, N.M.

    1984-04-01

    In this series of experiments the protective action of reduced glutathion due to ionizing radiation has been studied. In the experimental group 18 guinea pigs were exposed to successive radiations of 150 rad 3 or 4 days apart. Total dose given amounted to 750 rad which is the LD50 for guinea pigs. Blood samples were taken 30 min after each exposure. The control series were sham radiated but otherwise treated identically. The cells of the removed blood samples were separated by centrifugation and were subjected to the reduced glutathion stability test. GSSGR, GPer, and LDH enzyme activities were also measured of which the latter served as a marked enzyme. It was found that LDH did not show any alteration after radiation. The reduced glutathion stability test showed a consistent but minor reduction (P greater than 0.05), in the experimental group. GSSGR enzyme activity on the other hand was reduced significantly (from 176.48 +/- 11.32 to 41.34 +/- 1.17 IU/ml of packed erythrocytes, P less than 0.001) in the same group. GPer activity showed a consistent but minor elevation during the early phase of the experimental group. It was later increased significantly beginning after 600 rad total radiation on the fourth session (P less than 0.050).

  2. Color analysis of different ceramic systems.

    PubMed

    Aladag, Akin; Gungor, Mehmet Ali; Artunc, Celal

    2010-01-01

    This study compared the color properties of three different ceramic systems. Three groups of 10 specimens each were prepared: Dental porcelain alloy was used as a framework for conventional and ProBOND metal-ceramic systems, while glass-ceramic ingots were used as a framework for 10 samples using an all-ceramic system. For the former, dentin porcelain was applied and a ceramic veneering material was applied to the ingot frameworks. Using a dental spectrophotometer, the pre- and post-glaze color compatibility between disc specimens and A3 shade was evaluated. The Kruskal-Wallis test was used to compare color differences among groups in this study, while the Mann-Whitney U test was used to make bilateral comparisons among the three different ceramic systems. The values obtained during the dentin stage revealed a significant difference in the all-ceramic group (p < 0.05). After glazing, there was no significant difference between ProBOND samples and all-ceramic samples (p > 0.05). These results suggest that ProBOND can yield esthetically superior results in clinical applications compared to conventional ceramic systems. PMID:20478787

  3. The photochemical thiol–ene reaction as a versatile method for the synthesis of glutathione S-conjugates targeting the bacterial potassium efflux system Kef† †Electronic supplementary information (ESI) available: Further experimental details and NMR spectra. See DOI: 10.1039/c5qo00436e Click here for additional data file.

    PubMed Central

    Rasmussen, Tim; Miller, Samantha; Booth, Ian R.

    2016-01-01

    The thiol–ene coupling reaction is emerging as an important conjugation reaction that is suitable for use in a biological setting. Here, we explore the utility of this reaction for the synthesis of glutathione-S-conjugates (GSX) and present a general, operationally simple, protocol with a wide substrate scope. The GSX afforded are an important class of compounds and provide invaluable molecular tools to study glutathione-binding proteins. In this study we apply the diverse library of GSX synthesised to further our understanding of the structural requirements for binding to the glutathione-binding protein, Kef, a bacterial K+ efflux system, found in many bacterial pathogens. This system is vital to the survival of bacteria upon exposure to electrophiles, and plays an essential role in the maintenance of intracellular pH and K+ homeostasis. Consequently, Kef is an appealing target for the development of novel antibacterial drugs. PMID:27110363

  4. Glutathione peroxidase 4 (Gpx4) and ferroptosis: what's so special about it?

    PubMed Central

    Conrad, Marcus; Friedmann Angeli, José Pedro

    2015-01-01

    The system XC−/glutathione/glutathione peroxidase 4 (Gpx4) axis pivotally controls ferroptosis, a recently described form of regulated non-apoptotic cell death. Compelling evidence has established that this route of cell death is not only of high relevance for triggering cancer cell death, but also proves to be amenable for therapeutic intervention to halt ischemia/reperfusion-related diseases. PMID:27308484

  5. Emerging regulatory paradigms in glutathione metabolism.

    PubMed

    Liu, Yilin; Hyde, Annastasia S; Simpson, Melanie A; Barycki, Joseph J

    2014-01-01

    One of the hallmarks of cancer is the ability to generate and withstand unusual levels of oxidative stress. In part, this property of tumor cells is conferred by elevation of the cellular redox buffer glutathione. Though enzymes of the glutathione synthesis and salvage pathways have been characterized for several decades, we still lack a comprehensive understanding of their independent and coordinate regulatory mechanisms. Recent studies have further revealed that overall central metabolic pathways are frequently altered in various tumor types, resulting in significant increases in biosynthetic capacity and feeding into glutathione synthesis. In this review, we will discuss the enzymes and pathways affecting glutathione flux in cancer and summarize current models for regulating cellular glutathione through both de novo synthesis and efficient salvage. In addition, we examine the integration of glutathione metabolism with other altered fates of intermediary metabolites and highlight remaining questions about molecular details of the accepted regulatory modes. PMID:24974179

  6. Emerging regulatory paradigms in glutathione metabolism

    PubMed Central

    Liu, Yilin; Hyde, Annastasia S.; Simpson, Melanie A.; Barycki, Joseph J.

    2015-01-01

    One of the hallmarks of cancer is the ability to generate and withstand unusual levels of oxidative stress. In part, this property of tumor cells is conferred by elevation of the cellular redox buffer glutathione. Though enzymes of the glutathione synthesis and salvage pathways have been characterized for several decades, we still lack a comprehensive understanding of their independent and coordinate regulatory mechanisms. Recent studies have further revealed that overall central metabolic pathways are frequently altered in various tumor types, resulting in significant increases in biosynthetic capacity, and feeding into glutathione synthesis. In this review, we will discuss the enzymes and pathways affecting glutathione flux in cancer, and summarize current models for regulating cellular glutathione through both de novo synthesis and efficient salvage. In addition, we examine the integration of glutathione metabolism with other altered fates of intermediary metabolites, and highlight remaining questions about molecular details of the accepted regulatory modes. PMID:24974179

  7. The Characterizations of Different Splicing Systems

    NASA Astrophysics Data System (ADS)

    Karimi, Fariba; Sarmin, Nor Haniza; Heng, Fong Wan

    The concept of splicing system was first introduced by Head in 1987 to model the biological process of DNA recombination mathematically. This model was made on the basis of formal language theory which is a branch of applied discrete mathematics and theoretical computer science. In fact, splicing system treats DNA molecule and the recombinant behavior by restriction enzymes and ligases in the form of words and splicing rules respectively. The notion of splicing systems was taken into account from different points of view by many mathematicians. Several modified definitions have been introduced by many researchers. In this paper, some properties of different kinds of splicing systems are presented and their relationships are investigated. Furthermore, these results are illustrated by some examples.

  8. Comparison of different Bacillus subtilis expression systems.

    PubMed

    Vavrová, Ludmila; Muchová, Katarína; Barák, Imrich

    2010-11-01

    Bacillus subtilis is considered to have great potential as a host for the production and secretion of recombinant proteins. Many different expression systems have been developed for B. subtilis. Here we compare two widely used expression systems, the IPTG-inducible derivative of spac system (hyper-spank) and the xylose-inducible (xyl) to the SURE (subtilin-regulated gene expression) system. Western blot analysis of the membrane protein SpoIISA together with its protein partner SpoIISB showed that the highest expression level of this complex is obtained using the SURE system. Measurement of β-galactosidase activities of the promoter-lacZ fusions in individual expression systems confirmed that the P(spaS) promoter of the SURE system is the strongest of those compared, although the induction/repression ratio reached only 1.84. Based on these results, we conclude that the SURE system is the most efficient of these three B. subtilis expression systems in terms of the amount of expressed product. Remarkably, the yield of the SpoIISA-SpoIISB complex obtained from B. subtilis was comparable to that normally obtained from the Escherichia coli arabinose-inducible expression system. PMID:20863884

  9. Exogenous IAA differentially affects growth, oxidative stress and antioxidants system in Cd stressed Trigonella foenum-graecum L. seedlings: Toxicity alleviation by up-regulation of ascorbate-glutathione cycle.

    PubMed

    Bashri, Gausiya; Prasad, Sheo Mohan

    2016-10-01

    In the present study, effect of exogenous indole-3-acetic acid at their different levels (i.e. low; IAAL, 10µM and high; IAAH, 100µM) were studied on growth, oxidative stress biomarkers and antioxidant enzymes (SOD, POD, CAT and GST), and metabolites (AsA and GSH) as well as enzymes (APX, GR and DHAR) of ascorbate-glutathione cycle in Trigonella foenum-graecum L. seedlings grown under cadmium (Cd1, 3mgCd kg(-1) soil and Cd2, 9mgCd kg(-1) soil) stress. Cadmium (Cd) at both doses caused reduction in growth which was correlated with enhanced lipid peroxidation and damage to membrane as a result of excess accumulation of O2(•-) and H2O2. Cd also enhanced the oxidation of AsA and GSH to DHA and GSSG, respectively which give a clear sign of oxidative stress, despite of accelerated activity of enzymatic antioxidants: SOD, CAT, POD, GST as well as APX, DHAR (except in Cd2 stress) and GR. Exogenous application of IAAL resulted further rise in the activities of these enzymes, and maintained the redox status (> ratios: AsA/DHA and GSH/GSSG) of cells. The maintained redox status of cells under IAAL treatment declined the level of ROS in Cd1 and Cd2 treated seedlings thereby alleviated the Cd toxicity and this effect was more pronounced under Cd1 stress. Contrary to this, exogenous IAAH suppressed the activity of DHAR and GR and disturbed the redox status (< ratios: AsA/DHA and GSH/GSSG) of cells, hence excess accumulation of ROS further aggravated the Cd induced damage. Thus, overall results suggest that IAA at low (IAAL) and high (IAAH) doses affected the Cd toxicity differently by regulating the ascorbate-glutathione cycle as well as activity of other antioxidants in Trigonella seedlings. PMID:27344401

  10. Roles for glutathione transferases in antioxidant recycling

    PubMed Central

    Dixon, David P; Steel, Patrick G

    2011-01-01

    Uniquely among the plant glutathione transferases, two classes possess a catalytic cysteine capable of performing glutathione-dependent reductions. These are the dehydroascorbate reductases (DHARs) and the lambda-class glutathione transferases (GSTLs). Using immobilized GSTLs probed with crude plant extracts we have identified flavonols as high affinity ligands and subsequently demonstrated a novel glutathione-dependent role for these enzymes in recycling oxidized quercetin. By comparing the activities of DHARs and GSTLs we now propose a unified catalytic mechanism that suggests oxidized anthocyanidins and tocopherols may be alternative polyphenolic substrates of GSTLs. PMID:21778824

  11. Human eye color difference threshold measurement system

    NASA Astrophysics Data System (ADS)

    Liu, Lin; Zhou, Taogeng

    2013-12-01

    The human eye has the ability to distinguish millions of colors, with this feature we can identify very subtle color differences, and the measurement of human eye color difference threshold can provide a visual function diagnosis for testee. In recent years, people begin to focus on studies on visual threshold diagnostic equipment. This paper proposes a human eye color difference threshold measurement system which is based on dual integrating sphere. The system includes two pairs of dual integrating sphere and color control module. Dual integrating sphere uses to mix and produce color, and palette unit which produces primary colors (red (R), green (G), blue (B)) is embedded in dual integrating sphere. At the same time, the embedded palette unit which produces cyan (C), magenta (M), and yellow (Y) expands color area that the system can generate. One optical path based on dual integrating sphere generates standard color, the other path produces the matching color which is similar to a standard color. In the high-precision closed-loop color control module, photoelectric switch records stepper motor's origin position and limits move displacement. Precision stepper motor pushes the light-blocking panel of the palette unit to a predetermined position, while real-time monitoring the position of the light-blocking panel and mixing the ideal controllable color. Two colors that the system generates are projected onto the same target area. Subjects make a judgment on color difference threshold by observing the target eventually.

  12. Systemic risk on different interbank network topologies

    NASA Astrophysics Data System (ADS)

    Lenzu, Simone; Tedeschi, Gabriele

    2012-09-01

    In this paper we develop an interbank market with heterogeneous financial institutions that enter into lending agreements on different network structures. Credit relationships (links) evolve endogenously via a fitness mechanism based on agents' performance. By changing the agent's trust on its neighbor's performance, interbank linkages self-organize themselves into very different network architectures, ranging from random to scale-free topologies. We study which network architecture can make the financial system more resilient to random attacks and how systemic risk spreads over the network. To perturb the system, we generate a random attack via a liquidity shock. The hit bank is not automatically eliminated, but its failure is endogenously driven by its incapacity to raise liquidity in the interbank network. Our analysis shows that a random financial network can be more resilient than a scale free one in case of agents' heterogeneity.

  13. Informational exchange between different highly organized systems

    NASA Astrophysics Data System (ADS)

    Panovkin, B. N.

    The conditions under which information exchange is possible between different highly organized systems are considered in relation to problems of establishing informational contact with extraterrestrial civilizations. It is pointed out that the basis for mutual understanding among terrestrial societies has been the commonality of the subject relationship to the material and social world, which influences both articulation and cognitive processes. A model of information exchange between highly organized systems (automata) making use of different schemes for the classification of the objects of activity is then examined. It is shown that, in the most favorable case, information exchange is possible between actively interacting systems in direct contact according to a high-rank reflexive game with verification.

  14. Fluorometric microplate assay to measure glutathione S-transferase activity in insects and mites using monochlorobimane.

    PubMed

    Nauen, Ralf; Stumpf, Natascha

    2002-04-15

    Elevated levels of glutathione S-transferases (GSTs) play a major role as a mechanism of resistance to insecticides and acaricides in resistant pest insects and mites, respectively. Such compounds are either detoxicated directly via phase I metabolism or detoxicated by phase II metabolism of metabolites as formed by microsomal monooxygenases. Here we used monochlorobimane (MCB) as an artificial substrate and glutathione to determine total GST activity in equivalents of single pest insects and spider mites in a sensitive 96-well plate-based assay system by measuring the enzymatic conversion of MCB to its fluorescent bimane-glutathione adduct. The differentiation by their GST activity between several strains of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), with different degrees of resistance to numerous acaricides was more sensitive with MCB compared to the commonly used substrate 1-chloro-2,4-dinitrobenzene (CDNB). Compared to an acaricide-susceptible reference strain, one field population of T. urticae showed a more than 10-fold higher GST activity measured with MCB, in contrast to a less than 2-fold higher activity when CDNB was used. Furthermore, we showed that GST activity can be sensitively assessed with MCB in homogenates of pest insects such as Heliothis virescens, Spodoptera frugiperda (Lepidoptera: Noctuidae), Plutella xylostella (Lepidoptera: Yponomeutidae), and Myzus persicae (Hemiptera: Aphididae). PMID:11950219

  15. Hemispheric differences in the mesostriatal dopaminergic system

    PubMed Central

    Molochnikov, Ilana; Cohen, Dana

    2014-01-01

    The mesostriatal dopaminergic system, which comprises the mesolimbic and the nigrostriatal pathways, plays a major role in neural processing underlying motor and limbic functions. Multiple reports suggest that these processes are influenced by hemispheric differences in striatal dopamine (DA) levels, DA turnover and its receptor activity. Here, we review studies which measured the concentration of DA and its metabolites to examine the relationship between DA imbalance and animal behavior under different conditions. Specifically, we assess evidence in support of endogenous, inter-hemispheric DA imbalance; determine whether the known anatomy provides a suitable substrate for this imbalance; examine the relationship between DA imbalance and animal behavior; and characterize the symmetry of the observed inter-hemispheric laterality in the nigrostriatal and the mesolimbic DA systems. We conclude that many studies provide supporting evidence for the occurrence of experience-dependent endogenous DA imbalance which is controlled by a dedicated regulatory/compensatory mechanism. Additionally, it seems that the link between DA imbalance and animal behavior is better characterized in the nigrostriatal than in the mesolimbic system. Nonetheless, a variety of brain and behavioral manipulations demonstrate that the nigrostriatal system displays symmetrical laterality whereas the mesolimbic system displays asymmetrical laterality which supports hemispheric specialization in rodents. The reciprocity of the relationship between DA imbalance and animal behavior (i.e., the capacity of animal training to alter DA imbalance for prolonged time periods) remains controversial, however, if confirmed, it may provide a valuable non-invasive therapeutic means for treating abnormal DA imbalance. PMID:24966817

  16. Balneotherapy and platelet glutathione metabolism in type II diabetic patients

    NASA Astrophysics Data System (ADS)

    Ohtsuka, Yoshinori; Yabunaka, Noriyuki; Watanabe, Ichiro; Noro, Hiroshi; Agishi, Yuko

    1996-09-01

    Effects of balneotherapy on platelet glutathione metabolism were investigated in 12 type II (non-insulin-dependent) diabetic patients. Levels of the reduced form of glutathione (GSH) on admission were well correlated with those of fasting plasma glucose (FPG; r=0.692, P<0.02). After 4 weeks of balneotherapy, the mean level of GSH showed no changes; however, in well-controlled patients (FPG <150 mg/dl), the level increased ( P<0.01) and in poorly controlled patients (FPG >150 mg/dl), the value decreased ( P<0.05). There was a negative correlation between glutathione peroxidase (GPX) activities and the levels of FPG ( r=-0.430, P<0.05). After balneotherapy, the activity increased in 5 patients, decreased in 3 patients and showed no changes (alteration within ±3%) in all the other patients. From these findings in diabetic patients we concluded: (1) platelet GSH synthesis appeared to be induced in response to oxidative stress; (2) lowered GPX activities indicated that the antioxidative defense system was impaired; and (3) platelet glutathione metabolism was partially improved by 4 weeks balneotherapy, an effect thought to be dependent on the control status of plasma glucose levels. It is suggested that balneotherapy is beneficial for patients whose platelet antioxidative defense system is damaged, such as those with diabetes mellitus and coronary heart disease.

  17. Genetics Home Reference: glutathione synthetase deficiency

    MedlinePlus

    ... PubMed Njålsson R. Glutathione synthetase deficiency. Cell Mol Life Sci. 2005 Sep;62(17):1938-45. Review. Citation on PubMed Ristoff E, Larsson A. Inborn errors in the metabolism of glutathione. Orphanet J Rare Dis. 2007 Mar 30;2:16. Review. Citation on PubMed or ...

  18. Storage of Heparinised Canine Whole Blood for the Measurement of Glutathione Peroxidase Activity.

    PubMed

    van Zelst, Mariëlle; Hesta, Myriam; Gray, Kerry; Janssens, Geert P J

    2016-08-01

    Glutathione peroxidase activity is used as a biomarker of selenium status in dogs. Freshly collected blood samples are usually measured, due to the lack of knowledge on the effect of storing the samples. This study investigated if the analysis of glutathione peroxidase activity in whole blood collected from dogs was affected by storage of between 5 and 164 days. Results indicated that glutathione peroxidase activity was more variable in the freshly analysed samples compared to the stored samples. Although the mean differences between fresh and stored samples were not always equal to zero, this is thought to be caused by the variability of reagent preparation rather than by storage, as no consistent increase or decrease in glutathione peroxidase activity was found. Therefore, it can be concluded that heparinised dog blood samples can be successfully stored up to 164 days before analysis of glutathione peroxidase activity. PMID:26701335

  19. Glutathione and GSH-dependent enzymes in bronchoalveolar lavage fluid cells in response to ozone

    SciTech Connect

    Boehme, D.S.; Hotchkiss, J.A.; Henderson, R.F. )

    1992-02-01

    The purpose of this study was to determine if in vivo ozone exposure results in elevations in the levels of glutathione and glutathione-dependent enzymes in cells derived from bronchoalveolar lavage fluid (BALF). Our hypothesis was that, as part of a defense mechanism against oxygen toxicity, such cells would have increased levels of glutathione (GSH) in response to an oxidant stress. Female F344/N rats were exposed to 0.8 ppm ozone, 6 hr/day, for 1, 3, or 7 days, after which cells were collected by lung lavage. The GSH and GSH-peroxidase activity per milligram of protein in the cellular fraction, both necessary for reducing cellular peroxides, were elevated after 3 days of ozone exposure. After 7 days of exposure, cellular GSH had returned to control values, but the activity of glutathione reductase, the enzyme that reduces oxidized glutathione to GSH, was increased. Extracellular GSH concentration and glutathione reductase activity in BALF were also increased after 7 days of exposure. The total glutathione equivalents (GSH and GSSG, both cellular and extracellular) in BALF increased throughout the 7-day exposure, with GSH increasing first in the cells, and then in the extracellular fluid. This study demonstrated that the glutathione anti-oxidant system of BALF cells is stimulated by exposure to ozone. This response may serve to protect cells from the toxic effects of oxidant stress.

  20. Prolonged fasting increases glutathione biosynthesis in postweaned northern elephant seals

    PubMed Central

    Vázquez-Medina, José Pablo; Zenteno-Savín, Tania; Forman, Henry Jay; Crocker, Daniel E.; Ortiz, Rudy M.

    2011-01-01

    SUMMARY Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin–angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH oxidase activity; however, these increases are not correlated with increased oxidative damage or inflammation. Glutathione (GSH) is a potent reductant and a cofactor for glutathione peroxidases (GPx), glutathione-S transferases (GST) and 1-cys peroxiredoxin (PrxVI) and thus contributes to the removal of hydroperoxides, preventing oxidative damage. The effects of prolonged food deprivation on the GSH system are not well described in mammals. To test our hypothesis that GSH biosynthesis increases with fasting in postweaned elephant seals, we measured circulating and muscle GSH content at the early and late phases of the postweaning fast in elephant seals along with the activity/protein content of glutamate-cysteine ligase [GCL; catalytic (GCLc) and modulatory (GCLm) subunits], γ-glutamyl transpeptidase (GGT), glutathione disulphide reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), GST and PrxVI, as well as plasma changes in γ-glutamyl amino acids, glutamate and glutamine. GSH increased two- to four-fold with fasting along with a 40–50% increase in the content of GCLm and GCLc, a 75% increase in GGT activity, a two- to 2.5-fold increase in GR, G6PDH and GST activities and a 30% increase in PrxVI content. Plasma γ-glutamyl glutamine, γ-glutamyl isoleucine and γ-glutamyl methionine also increased with fasting whereas glutamate and glutamine decreased. Results indicate that GSH biosynthesis increases with fasting and that GSH contributes to counteracting hydroperoxide production, preventing oxidative damage in fasting seals. PMID:21430206

  1. Glutathione level after long-term occupational elemental mercury exposure

    SciTech Connect

    Kobal, Alfred Bogomir Prezelj, Marija; Horvat, Milena; Krsnik, Mladen; Gibicar, Darija; Osredkar, Josko

    2008-05-15

    Many in vitro and in vivo studies have elucidated the interaction of inorganic mercury (Hg) and glutathione. However, human studies are limited. In this study, we investigated the potential effects of remote long-term intermittent occupational elemental Hg vapour (Hg{sup o}) exposure on erythrocyte glutathione levels and some antioxidative enzyme activities in ex-mercury miners in the period after exposure. The study included 49 ex-mercury miners divided into subgroups of 28 still active, Hg{sup o}-not-exposed miners and 21 elderly retired miners, and 41 controls, age-matched to the miners subgroup. The control workers were taken from 'mercury-free works'. Reduced glutathione (GSH) and oxidized disulphide glutathione (GSSG) concentrations in haemolysed erythrocytes were determined by capillary electrophoresis, while total glutathione (total GSH) and the GSH/GSSG ratio were calculated from the determined values. Catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities in erythrocytes were measured using commercially available reagent kits, while urine Hg (U-Hg) concentrations were determined by cold vapour atomic absorption (CVAAS). No correlation of present U-Hg levels, GSH, GSSG, and antioxidative enzymes with remote occupational biological exposure indices were found. The mean CAT activity in miners and retired miners was significantly higher (p<0.05) than in the controls. No differences in mean GPx activity among the three groups were found, whereas the mean GR activity was significantly higher (p<0.05) in miners than in retired miners. The mean concentrations of GSH (mmol/g Hb) in miners (13.03{+-}3.71) were significantly higher (p<0.05) than in the control group (11.68{+-}2.66). No differences in mean total GSH, GSSG levels, and GSH/GSSG ratio between miners and controls were found. A positive correlation between GSSG and present U-Hg excretion (r=0.41, p=0.001) in the whole group of ex-mercury miners was observed. The

  2. Antioxidant enzyme systems and the ascorbate-glutathione cycle as contributing factors to cadmium accumulation and tolerance in two oilseed rape cultivars (Brassica napus L.) under moderate cadmium stress.

    PubMed

    Wu, Zhichao; Zhao, Xiaohu; Sun, Xuecheng; Tan, Qiling; Tang, Yafang; Nie, Zhaojun; Qu, Chanjuan; Chen, Zuoxin; Hu, Chengxiao

    2015-11-01

    Oilseed rape (Brassica napus L.) with high tolerance to cadmium (Cd) may be used in the phytoremediation of Cd-contaminated fields. However, the mechanisms responsible for Cd accumulation and tolerance in oilseed rape are still poorly understood. Here, we investigated the physiological and molecular processes involved in Cd tolerance of two oilseed rape cultivars with different Cd accumulation abilities. The total Cd accumulation in cultivar L351 was higher than cultivar L338, particularly with increasing concentrations of Cd exposure. L338 was a more pronounced Cd-sensitive cultivar than L351, while higher activities of antioxidant enzymes (CAT, APX, GR, DHAR) as well as higher contents of GSH and AsA were all observed in L351 under Cd treatments, especially at high levels. No differences were found in SOD activities between the two cultivars under the same Cd treatments, suggesting that SOD was not the key factor in relation to the differences of Cd tolerance and accumulation between them. Gene expression levels of BnFe-SOD, BnCAT, BnAPX, BcGR and BoDHAR in roots of L351 were relatively higher than that in L338 under Cd exposure as well as BnCAT and BcGR in leaves. It is concluded that antioxidant enzymes and the ascorbate-glutathione cycle play important roles in oilseed rape Cd accumulation and tolerance. PMID:26207887

  3. Different approaches to contracting in health systems.

    PubMed Central

    Perrot, Jean

    2006-01-01

    Contracting is one of the tools increasingly being used to enhance the performance of health systems in both developed and developing countries; it takes different forms and cannot be limited to the mere purchase of services. Actors adopt contracting to formalize all kinds of relations established between them. A typology for this approach will demonstrate its diversity and provide a better understanding of the various issues raised by contracting. In recent years the way health systems are organized has changed significantly. To remedy the under-performance of their health systems, most countries have undertaken reforms that have resulted in major institutional overhaul, including decentralization of health and administrative services, autonomy for public service providers, separation of funding bodies and service providers, expansion of health financing options and the development of the profit or nonprofit private sector. These institutional reshuffles lead not only to multiplication and diversification of the actors involved, but also to greater separation of the service provision and administrative functions. Health systems are becoming more complex and can no longer operate in isolation. Actors are gradually realizing that they need to forge relations. The simplest way to do that is through dialogue, although some prefer a more formal commitment. Interaction between actors may take various forms and be on different scales. There are several types of contractual relations: some are based on the nature of the contract (public or private), others on the parties involved and yet others on the scope of the contract. Here they are classified into three categories according to the object of the contract: delegation of responsibility, act of purchase of services, or cooperation. PMID:17143459

  4. Functional analysis and localisation of a delta-class glutathione S-transferase from Sarcoptes scabiei.

    PubMed

    Pettersson, Eva U; Ljunggren, Erland L; Morrison, David A; Mattsson, Jens G

    2005-01-01

    The mite Sarcoptes scabiei causes sarcoptic mange, or scabies, a disease that affects both animals and humans worldwide. Our interest in S. scabiei led us to further characterise a glutathione S-transferase. This multifunctional enzyme is a target for vaccine and drug development in several parasitic diseases. The S. scabiei glutathione S-transferase open reading frame reported here is 684 nucleotides long and yields a protein with a predicted molecular mass of 26 kDa. Through phylogenetic analysis the enzyme was classified as a delta-class glutathione S-transferase, and our paper is the first to report that delta-class glutathione S-transferases occur in organisms other than insects. The recombinant S. scabiei glutathione S-transferase was expressed in Escherichia coli via three different constructs and purified for biochemical analysis. The S. scabiei glutathione S-transferase was active towards the substrate 1-chloro-2,4-dinitrobenzene, though the positioning of fusion partners influenced the kinetic activity of the enzyme. Polyclonal antibodies raised against S. scabiei glutathione S-transferase specifically localised the enzyme to the integument of the epidermis and cavities surrounding internal organs in adult parasites. However, some minor staining of parasite intestines was observed. No staining was seen in host tissues, nor could we detect any antibody response against S. scabiei glutathione S-transferase in sera from naturally S. scabiei infected dogs or pigs. Additionally, the polyclonal sera raised against recombinant S. scabiei glutathione S-transferase readily detected a protein from mites, corresponding to the predicted size of native glutathione S-transferase. PMID:15619514

  5. The biological functions of glutathione revisited in arabidopsis transgenic plants with altered glutathione levels.

    PubMed

    Xiang, C; Werner, B L; Christensen, E M; Oliver, D J

    2001-06-01

    A functional analysis of the role of glutathione in protecting plants from environmental stress was undertaken by studying Arabidopsis that had been genetically modified to have altered glutathione levels. The steady-state glutathione concentration in Arabidopsis plants was modified by expressing the cDNA for gamma-glutamyl-cysteine synthetase (GSH1) in both the sense and antisense orientation. The resulting plants had glutathione levels that ranged between 3% and 200% of the level in wild-type plants. Arabidopsis plants with low glutathione levels were hypersensitive to Cd due to the limited capacity of these plants to make phytochelatins. Plants with the lowest levels of reduced glutathione (10% of wild type) were sensitive to as little as 5 microM Cd, whereas those with 50% wild-type levels required higher Cd concentrations to inhibit growth. Elevating glutathione levels did not increase metal resistance. It is interesting that the plants with low glutathione levels were also less able to accumulate anthocyanins supporting a role for glutathione S-transferases for anthocyanin formation or for the vacuolar localization and therefore accumulation of these compounds. Plants with less than 5% of wild-type glutathione levels were smaller and more sensitive to environmental stress but otherwise grew normally. PMID:11402187

  6. The antioxidant master glutathione and periodontal health

    PubMed Central

    Bains, Vivek Kumar; Bains, Rhythm

    2015-01-01

    Glutathione, considered to be the master antioxidant (AO), is the most-important redox regulator that controls inflammatory processes, and thus damage to the periodontium. Periodontitis patients have reduced total AO capacity in whole saliva, and lower concentrations of reduced glutathione (GSH) in serum and gingival crevicular fluid, and periodontal therapy restores the redox balance. Therapeutic considerations for the adjunctive use of glutathione in management of periodontitis, in limiting the tissue damage associated with oxidative stress, and enhancing wound healing cannot be underestimated, but need to be evaluated further through multi-centered randomized controlled trials. PMID:26604952

  7. Alcoholism: the role of different motivational systems.

    PubMed Central

    Pihl, R O; Peterson, J B

    1995-01-01

    Individuals use and misuse alcohol (and other drugs) because of the pharmacologically mediated effects these substances have on the operation of 4 psychobiological systems, mediating response to motivationally relevant unconditioned and conditioned stimuli. These 4 systems have unique neuroanatomical structure, biochemical modes of operation, association with affect, behavior and cognition, and responsiveness to drugs of abuse. Individual variation in the operation of these systems determines individual susceptibility to initiation and maintenance of drug use and abuse. Sources of such variation differ, in a vitally important fashion, in various specific populations of individuals at heightened risk for drug abuse. Nonalcoholic sons of male alcoholics, with multigenerational family histories of male alcoholism, appear to be at heightened risk for the development of alcohol abuse because alcohol eliminates their heightened response to threat, and because they are hypersensitive to ethanol's psychomotor stimulant effects. Anxiety-sensitive individuals also appear attracted to alcohol for its anxiolytic properties. Many other important sources of idiosyncratic variability exist. Detailed analysis of such sources may lead to the development of more effective prevention and treatment programs. Images Figure 7 PMID:8527424

  8. Identification of Small-Molecule Frequent Hitters of Glutathione S-Transferase-Glutathione Interaction.

    PubMed

    Brenke, Jara K; Salmina, Elena S; Ringelstetter, Larissa; Dornauer, Scarlett; Kuzikov, Maria; Rothenaigner, Ina; Schorpp, Kenji; Giehler, Fabian; Gopalakrishnan, Jay; Kieser, Arnd; Gul, Sheraz; Tetko, Igor V; Hadian, Kamyar

    2016-07-01

    In high-throughput screening (HTS) campaigns, the binding of glutathione S-transferase (GST) to glutathione (GSH) is used for detection of GST-tagged proteins in protein-protein interactions or enzyme assays. However, many false-positives, so-called frequent hitters (FH), arise that either prevent GST/GSH interaction or interfere with assay signal generation or detection. To identify GST-FH compounds, we analyzed the data of five independent AlphaScreen-based screening campaigns to classify compounds that inhibit the GST/GSH interaction. We identified 53 compounds affecting GST/GSH binding but not influencing His-tag/Ni(2+)-NTA interaction and general AlphaScreen signals. The structures of these 53 experimentally identified GST-FHs were analyzed in chemoinformatic studies to categorize substructural features that promote interference with GST/GSH binding. Here, we confirmed several existing chemoinformatic filters and more importantly extended them as well as added novel filters that specify compounds with anti-GST/GSH activity. Selected compounds were also tested using different antibody-based GST detection technologies and exhibited no interference clearly demonstrating specificity toward their GST/GSH interaction. Thus, these newly described GST-FH will further contribute to the identification of FH compounds containing promiscuous substructures. The developed filters were uploaded to the OCHEM website (http://ochem.eu) and are publicly accessible for analysis of future HTS results. PMID:27044684

  9. Forward masking in different cochlear implant systems

    NASA Astrophysics Data System (ADS)

    Boëx, Colette; Kós, Maria-Izabel; Pelizzone, Marco

    2003-10-01

    The goal of this study was to evaluate, from a psychophysical standpoint, the neural spread of excitation produced by the stimulation of different types of intracochlear electrode arrays: the Ineraid™, the Clarion™ S-Series on its own or with the Electrode Positioning System (EPS), and the Clarion™ HiFocus-I with the EPS. The EPS is an independent silicone part designed to bring the electrode array close to the modiolus. Forward masking was evaluated in 12 adult subjects (3 Ineraid™, 4 Clarion™ S-Series, 3 Clarion™ S-Series+EPS, 3 HiFocus-I+EPS) by psychophysical experiments conducted using trains of biphasic stimuli (813 pulses per second, 307.6 μs/phase). Masker signals (+8 dB re: threshold, 300 ms) were applied to the most apical electrode. Probe signals (30 ms, 10-ms postmasker) were delivered to more basal electrodes. Masked and unmasked detection thresholds of probe signals were measured. For both Clarion™ HiFocus-I subjects, measurements were conducted in both monopolar and bipolar stimulus configurations. No major differences were found in forward masking between the different intracochlear electrode arrays tested in the monopolar configuration at suprathreshold levels equivalent to those used in speech-coding strategies, but significant differences were found between subjects. A significant negative correlation also was found between the level of forward masking and the consonant identification performance. These measurements showed that the neural spread of excitation was more restricted in the bipolar configuration than in the monopolar configuration for HiFocus-I subjects. It was found that CIS strategies implemented without using apical electrodes, which showed high levels of masking, could improve consonant identification.

  10. Noise effects in two different biological systems

    NASA Astrophysics Data System (ADS)

    Spagnolo, B.; Spezia, S.; Curcio, L.; Pizzolato, N.; Fiasconaro, A.; Valenti, D.; Lo Bue, P.; Peri, E.; Colazza, S.

    2009-05-01

    We investigate the role of the colored noise in two biological systems: (i) adults of Nezara viridula (L.) (Heteroptera: Pentatomidae), and (ii) polymer translocation. In the first system we analyze, by directionality tests, the response of N. viridula individuals to subthreshold signals plus noise in their mating behaviour. The percentage of insects that react to the subthreshold signal shows a nonmonotonic behaviour, characterized by the presence of a maximum, as a function of the noise intensity. This is the signature of the non-dynamical stochastic resonance phenomenon. By using a “soft” threshold model we find that the maximum of the input-output cross correlation occurs in the same range of noise intensity values for which the behavioural activation of the insects has a maximum. Moreover this maximum value is lowered and shifted towards higher noise intensities, compared to the case of white noise. In the second biological system the noise driven translocation of short polymers in crowded solutions is analyzed. An improved version of the Rouse model for a flexible polymer is adopted to mimic the molecular dynamics by taking into account both the interactions between adjacent monomers and the effects of a Lennard-Jones potential between all beads. The polymer dynamics is simulated in a two-dimensional domain by numerically solving the Langevin equations of motion in the presence of thermal fluctuations and a colored noise source. At low temperatures or for strong colored noise intensities the translocation process of the polymer chain is delayed. At low noise intensity, as the polymer length increases, we find a nonmonotonic behaviour for the mean first translocation time of the polymer centre of inertia. We show how colored noise influences the motion of short polymers, by inducing two different regimes of translocation in the dynamics of molecule transport.

  11. Glutathione S-transferase class {pi} polymorphism in baboons

    SciTech Connect

    Aivaliotis, M.J.; Cantu, T.; Gilligan, R.

    1995-02-01

    Glutathione S-transferase (GST) comprises a family of isozymes with broad substrate specificities. One or more GST isozymes are present in most animal tissues and function in several detoxification pathways through the conjugation of reduced glutathione with various electrophiles, thereby reducing their potential toxicity. Four soluble GST isozymes encoded by genes on different chromosomes have been identified in humans. The acidic class pi GST, GSTP (previously designated GST-3), is widely distributed in adult tissues and appears to be the only GST isozyme present in leukocytes and placenta. Previously reported electrophoretic analyses of erythrocyte and leukocyte extracts revealed single bands of activity, which differed slightly in mobility between the two cell types, or under other conditions, a two-banded pattern. To our knowledge, no genetically determined polymorphisms have previously been reported in GSTP from any species. We now report a polymorphism of GSTP in baboon leukocytes, and present family data that verifies autosomal codominant inheritance. 14 refs., 2 figs., 1 tab.

  12. [PATOGENETIC VALUE OF VIOLATIONS FROM GLUTATHIONE SYSTEM AT THE PATIENTS WITH NONALCOHOLIC STEATOHEPATITIS ON A BACKGROUND OF DIABETES MELLITUS TYPE II].

    PubMed

    Sotskaya, Ya A; Homutyanskaya, N I; Dolgopolova, E V; Salamekh, K A

    2015-01-01

    At the patients with nonalcoholic steatohepatitis on a background of diabetes mellitus type II, after completion of the generally accepted medical treatment there was no normalization of indexes of the glutation system (the level of recovered glutation and activity of enzymes the glutation redox-system was saved decreased), that in a clinical plan was represented in.a presence unstable clinical and biochemical remission of disease. PMID:27491150

  13. Sex differences in the cellular defence system against free radicals from oxygen or drug metabolites in rat.

    PubMed

    Julicher, R H; Sterrenberg, L; Haenen, G R; Bast, A; Noordhoek, J

    1984-12-01

    In this study, it was investigated whether sex-related differences in the protective mechanisms against oxygen radicals and free radical metabolites from drugs were present in rat liver, heart, and kidney. To that end, superoxide dismutase, catalase, the factors of the glutathione system and vitamin E were measured. In addition, NADPH-dependent cytochrome c-reductase activity was established, as this enzyme is involved in the formation of free radicals in the presence of many xenobiotics. The total capacity of the cellular systems that detoxify reactive oxygen species or free radical-drug metabolites seems to be higher in female liver as compared to male. No differences were found for heart and kidney tissue. It is hypothesized that female rats probably are less vulnerable for those drugs whose hepatotoxic action is induced by excessive formation of free radical species. PMID:6442559

  14. Evaluation of lenticular antioxidant and redox system components in the lenses of acetyl-L-carnitine treatment in BSO-induced glutathione deprivation

    PubMed Central

    Elanchezhian, R.; Sakthivel, M.; Isai, M.; Thomas, P.A.

    2009-01-01

    Purpose To investigate whether acetyl-L-carnitine (ALCAR) retards L-buthionine-(S,R)-sulfoximine (BSO)-induced cataractogenesis in Wistar rat pups. Methods On postpartum day 3, group I pups received intraperitoneal (ip) saline and group II and group III pups received i.p. injections of BSO once daily for three consecutive days. In addition, group III pups received ip ALCAR once daily from postpartum days 3–15. Both eyes of each pup were examined up from postpartum day 16 to day 30. After sacrifice, extricated pup lenses were analyzed for antioxidant and redox system components. Results There was dense lenticular opacification in all group II pups, minimal opacification in 40% of group III pups, and no opacification in 60% of group III pups and in all of group I pups. Group II lenses exhibited significantly lower values of antioxidant and redox system components and higher malondialdehyde concentrations than in group I or group III lenses. Conclusions ALCAR prevents cataractogenesis in the BSO-induced cataract model, possibly by inhibiting depleting antioxidant enzyme and redox system components and inhibiting lipid peroxidation. PMID:19649174

  15. Transport of Glutathione Diethyl Ester Into Human Cells

    NASA Astrophysics Data System (ADS)

    Levy, Ellen J.; Anderson, Mary E.; Meister, Alton

    1993-10-01

    Glutathione monoesters in which the carboxyl group of the glycine residue is esterified were previously found, in contrast to glutathione itself, to be effectively transported into various types of cells and to be converted intracellularly into glutathione. Glutathione monoesters are thus useful for prevention of oxidative stress, certain toxicities, and for treatment of glutathione deficiency. Glutathione diethyl ester is rapidly split to the glutathione monoethyl ester by mouse plasma glutathione diester α-esterase activity. Thus, as expected, glutathione mono- and diesters have similar effects on cellular glutathione levels in mice. However, human plasma lacks glutathione diester α-esterase thus, it became of interest to compare the transport properties of glutathione mono- and diesters in human cells. We found that human cells (erythrocytes, peripheral blood mononuclear cells, fibroblasts, ovarian tumor cells, and purified T cells) transport glutathione diethyl ester much more effectively than the corresponding monoethyl (glycyl) ester. Human cells rapidly convert glutathione diethyl ester to the monoester, whose intracellular levels rise to levels that are significantly higher than levels found after application of the monoester to the cells. High levels of the monoester provide the cells with a means of producing glutathione over a period of time. We conclude that glutathione diethyl ester is highly effective as a delivery agent for glutathione monoester, and thus for glutathione, in human cells and therefore could serve to decrease oxidative stress and toxicity. Hamster (and certain other animals) also lack plasma glutathione diester α-esterase and therefore would be suitable animal models. Previously reported toxicity of certain glutathione ester preparations appears to reflect the presence of impurities rather than effects of the esters.

  16. Study of Linkage between Glutathione Pathway and the Antibiotic Resistance of Escherichia coli from Patients’ Swabs

    PubMed Central

    Kominkova, Marketa; Michalek, Petr; Cihalova, Kristyna; Guran, Roman; Cernei, Natalia; Nejdl, Lukas; Smerkova, Kristyna; Dostalova, Simona; Chudobova, Dagmar; Heger, Zbynek; Vesely, Radek; Gumulec, Jaromir; Kynicky, Jindrich; Xhaxhiu, Kledi; Zitka, Ondrej; Adam, Vojtech; Kizek, Rene

    2015-01-01

    In this work, we focused on the differences between bacterial cultures of E. coli obtained from swabs of infectious wounds of patients compared to laboratory E. coli. In addition, blocking of the protein responsible for the synthesis of glutathione (γ-glutamylcysteine synthase—GCL) using 10 mM buthionine sulfoximine was investigated. Each E. coli showed significant differences in resistance to antibiotics. According to the determined resistance, E. coli were divided into experimental groups based on a statistical evaluation of their properties as more resistant and more sensitive. These groups were also used for finding the differences in a dependence of the glutathione pathway on resistance to antibiotics. More sensitive E. coli showed the same kinetics of glutathione synthesis while blocking GCL (Km 0.1 µM), as compared to non-blocking. In addition, the most frequent mutations in genes of glutathione synthetase, glutathione peroxidase and glutathione reductase were observed in this group compared to laboratory E.coli. The group of “more resistant” E. coli exhibited differences in Km between 0.3 and 0.8 µM. The number of mutations compared to the laboratory E. coli was substantially lower compared to the other group. PMID:25837469

  17. Study of linkage between glutathione pathway and the antibiotic resistance of Escherichia coli from patients' swabs.

    PubMed

    Kominkova, Marketa; Michalek, Petr; Cihalova, Kristyna; Guran, Roman; Cernei, Natalia; Nejdl, Lukas; Smerkova, Kristyna; Dostalova, Simona; Chudobova, Dagmar; Heger, Zbynek; Vesely, Radek; Gumulec, Jaromir; Kynicky, Jindrich; Xhaxhiu, Kledi; Zitka, Ondrej; Adam, Vojtech; Kizek, Rene

    2015-01-01

    In this work, we focused on the differences between bacterial cultures of E. coli obtained from swabs of infectious wounds of patients compared to laboratory E. coli. In addition, blocking of the protein responsible for the synthesis of glutathione (γ-glutamylcysteine synthase-GCL) using 10 mM buthionine sulfoximine was investigated. Each E. coli showed significant differences in resistance to antibiotics. According to the determined resistance, E. coli were divided into experimental groups based on a statistical evaluation of their properties as more resistant and more sensitive. These groups were also used for finding the differences in a dependence of the glutathione pathway on resistance to antibiotics. More sensitive E. coli showed the same kinetics of glutathione synthesis while blocking GCL (Km 0.1 µM), as compared to non-blocking. In addition, the most frequent mutations in genes of glutathione synthetase, glutathione peroxidase and glutathione reductase were observed in this group compared to laboratory E.coli. The group of "more resistant" E. coli exhibited differences in Km between 0.3 and 0.8 µM. The number of mutations compared to the laboratory E. coli was substantially lower compared to the other group. PMID:25837469

  18. Glyoxalase 1 and glutathione reductase 1 regulate anxiety in mice.

    PubMed

    Hovatta, Iiris; Tennant, Richard S; Helton, Robert; Marr, Robert A; Singer, Oded; Redwine, Jeffrey M; Ellison, Julie A; Schadt, Eric E; Verma, Inder M; Lockhart, David J; Barlow, Carrolee

    2005-12-01

    Anxiety and fear are normal emotional responses to threatening situations. In human anxiety disorders--such as panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, social phobia, specific phobias and generalized anxiety disorder--these responses are exaggerated. The molecular mechanisms involved in the regulation of normal and pathological anxiety are mostly unknown. However, the availability of different inbred strains of mice offers an excellent model system in which to study the genetics of certain behavioural phenotypes. Here we report, using a combination of behavioural analysis of six inbred mouse strains with quantitative gene expression profiling of several brain regions, the identification of 17 genes with expression patterns that correlate with anxiety-like behavioural phenotypes. To determine if two of the genes, glyoxalase 1 and glutathione reductase 1, have a causal role in the genesis of anxiety, we performed genetic manipulation using lentivirus-mediated gene transfer. Local overexpression of these genes in the mouse brain resulted in increased anxiety-like behaviour, while local inhibition of glyoxalase 1 expression by RNA interference decreased the anxiety-like behaviour. Both of these genes are involved in oxidative stress metabolism, linking this pathway with anxiety-related behaviour. PMID:16244648

  19. Lectin-Gated, Mesoporous, Photofunctionalized Glyconanoparticles for Glutathione-Responsive Drug Delivery

    PubMed Central

    Zhou, Juan; Hao, Nanjing; De Zoyza, Thareendra; Yan, Mingdi

    2015-01-01

    A stimuli-responsive drug delivery system based on fluorescent, lectin-gated, mesoporous glyconanoparticles has been developed and evaluated in normal- and cancer lung epithelial cells. The gating process proved efficient, exhibiting good sealing properties in the absence of the glutathione redox trigger, avoiding premature release in normal cells. In the presence of higher levels of glutathione in cancer cells, the lectin gate was rapidly opened and the anticancer drug released. PMID:25989158

  20. The Genetic Architecture of Murine Glutathione Transferases

    PubMed Central

    Lu, Lu; Pandey, Ashutosh K.; Houseal, M. Trevor; Mulligan, Megan K.

    2016-01-01

    Glutathione S-transferase (GST) genes play a protective role against oxidative stress and may influence disease risk and drug pharmacokinetics. In this study, massive multiscalar trait profiling across a large population of mice derived from a cross between C57BL/6J (B6) and DBA2/J (D2)—the BXD family—was combined with linkage and bioinformatic analyses to characterize mechanisms controlling GST expression and to identify downstream consequences of this variation. Similar to humans, mice show a wide range in expression of GST family members. Variation in the expression of Gsta4, Gstt2, Gstz1, Gsto1, and Mgst3 is modulated by local expression QTLs (eQTLs) in several tissues. Higher expression of Gsto1 in brain and liver of BXD strains is strongly associated (P < 0.01) with inheritance of the B6 parental allele whereas higher expression of Gsta4 and Mgst3 in brain and liver, and Gstt2 and Gstz1 in brain is strongly associated with inheritance of the D2 parental allele. Allele-specific assays confirmed that expression of Gsto1, Gsta4, and Mgst3 are modulated by sequence variants within or near each gene locus. We exploited this endogenous variation to identify coexpression networks and downstream targets in mouse and human. Through a combined systems genetics approach, we provide new insight into the biological role of naturally occurring variants in GST genes. PMID:26829228

  1. Interaction between vitamin B6 and source of selenium on the response of the selenium-dependent glutathione peroxidase system to oxidative stress induced by oestrus in pubertal pig.

    PubMed

    Dalto, Danyel Bueno; Roy, Mélanie; Audet, Isabelle; Palin, Marie-France; Guay, Frédéric; Lapointe, Jérôme; Matte, J Jacques

    2015-10-01

    This study aimed to assess the interaction between vitamin B6 and selenium (Se) for the flow of Se towards the Se-dependent glutathione peroxidase (GPX) system in response to oxidative stress naturally induced by oestrus in a pubertal pig model. At first oestrus, forty-five gilts were randomly assigned to the experimental diets (n=9/group): basal diet (CONT); CONT+0.3mg/kg of Na-selenite (MSeB60); MSeB60+10mg/kg of HCl-B6 (MSeB610); CONT+0.3mg/kg of Se-enriched yeast (OSeB60); and OSeB60+10mg/kg of HCl-B6 (OSeB610). Blood samples were collected at each oestrus (long-term profiles), and daily from day -4 to +3 (slaughter) of the fourth oestrus (peri-oestrus profiles) after which liver, kidneys, and ovaries were collected. For long-term profiles, CONT had lower blood Se than Se-supplemented gilts (p<0.01) and OSe was higher than MSe (p<0.01). Lower erythrocyte pyridoxal-5-phosphate was found in B60 than B610 (p<0.01). No treatment effect was observed on GPX activity. For peri-oestrus profiles, treatment effects were similar to long-term profiles. Treatment effects on liver Se were similar to those for long-term blood Se profiles and OSe had higher renal Se concentrations than MSe gilts (p<0.01). Gene expressions of GPX1, GPX3, GPX4, and selenocysteine lyase in liver and kidney were greatest in OSeB610 gilts (p<0.05). These results suggest that dietary B6 modulate the metabolic pathway of OSe towards the GPX system during the peri-oestrus period in pubertal pigs. PMID:26302908

  2. Hen welfare in different housing systems.

    PubMed

    Lay, D C; Fulton, R M; Hester, P Y; Karcher, D M; Kjaer, J B; Mench, J A; Mullens, B A; Newberry, R C; Nicol, C J; O'Sullivan, N P; Porter, R E

    2011-01-01

    Egg production systems have become subject to heightened levels of scrutiny. Multiple factors such as disease, skeletal and foot health, pest and parasite load, behavior, stress, affective states, nutrition, and genetics influence the level of welfare hens experience. Although the need to evaluate the influence of these factors on welfare is recognized, research is still in the early stages. We compared conventional cages, furnished cages, noncage systems, and outdoor systems. Specific attributes of each system are shown to affect welfare, and systems that have similar attributes are affected similarly. For instance, environments in which hens are exposed to litter and soil, such as noncage and outdoor systems, provide a greater opportunity for disease and parasites. The more complex the environment, the more difficult it is to clean, and the larger the group size, the more easily disease and parasites are able to spread. Environments such as conventional cages, which limit movement, can lead to osteoporosis, but environments that have increased complexity, such as noncage systems, expose hens to an increased incidence of bone fractures. More space allows for hens to perform a greater repertoire of behaviors, although some deleterious behaviors such as cannibalism and piling, which results in smothering, can occur in large groups. Less is understood about the stress that each system imposes on the hen, but it appears that each system has its unique challenges. Selective breeding for desired traits such as improved bone strength and decreased feather pecking and cannibalism may help to improve welfare. It appears that no single housing system is ideal from a hen welfare perspective. Although environmental complexity increases behavioral opportunities, it also introduces difficulties in terms of disease and pest control. In addition, environmental complexity can create opportunities for the hens to express behaviors that may be detrimental to their welfare. As a

  3. Maintaining good hearing: calorie restriction, Sirt3, and glutathione.

    PubMed

    Han, Chul; Someya, Shinichi

    2013-10-01

    Reducing calorie intake extends the lifespan of a variety of experimental models and delays progression of age-related hearing loss (AHL). AHL is a common feature of aging and is characterized by age-related decline of hearing associated with loss of sensory hair cells, spiral ganglion neurons, and/or stria vascularis degeneration in the cochlea. Sirtuins are a family of NAD(+)-dependent enzymes that regulate lifespan in lower organisms and have emerged as broad regulators of cellular fate. Our recent study indicated that mitochondrial Sirt3, a member of the sirtuin family, mediates the anti-aging effects of calorie restriction (CR) on AHL in mice. Interestingly, we also found that weight loss alone may not be sufficient for maintaining normal hearing. How does CR slow the progression of AHL through regulation of Sirt3? Here we review the evidence that during CR, Sirt3 slows the progression of AHL by promoting the glutathione-mediated mitochondrial antioxidant defense system in mice. A significant reduction in food consumption in one's daily life may not be a desirable and realistic option for most people. Therefore, identification/discovery of compounds that induce the activation of SIRT3 or glutathione reductase, or that increase mitochondrial glutathione levels has potential for maintaining good hearing through mimicking the anti-aging effects of CR in human inner ear cells. PMID:23454634

  4. A Glutathione-Nrf2-Thioredoxin Cross-Talk Ensures Keratinocyte Survival and Efficient Wound Repair

    PubMed Central

    Telorack, Michèle; Meyer, Michael; Ingold, Irina; Conrad, Marcus; Bloch, Wilhelm; Werner, Sabine

    2016-01-01

    The tripeptide glutathione is the most abundant cellular antioxidant with high medical relevance, and it is also required as a co-factor for various enzymes involved in the detoxification of reactive oxygen species and toxic compounds. However, its cell-type specific functions and its interaction with other cytoprotective molecules are largely unknown. Using a combination of mouse genetics, functional cell biology and pharmacology, we unraveled the function of glutathione in keratinocytes and its cross-talk with other antioxidant defense systems. Mice with keratinocyte-specific deficiency in glutamate cysteine ligase, which catalyzes the rate-limiting step in glutathione biosynthesis, showed a strong reduction in keratinocyte viability in vitro and in the skin in vivo. The cells died predominantly by apoptosis, but also showed features of ferroptosis and necroptosis. The increased cell death was associated with increased levels of reactive oxygen and nitrogen species, which caused DNA and mitochondrial damage. However, epidermal architecture, and even healing of excisional skin wounds were only mildly affected in the mutant mice. The cytoprotective transcription factor Nrf2 was strongly activated in glutathione-deficient keratinocytes, but additional loss of Nrf2 did not aggravate the phenotype, demonstrating that the cytoprotective effect of Nrf2 is glutathione dependent. However, we show that deficiency in glutathione biosynthesis is efficiently compensated in keratinocytes by the cysteine/cystine and thioredoxin systems. Therefore, our study highlights a remarkable antioxidant capacity of the epidermis that ensures skin integrity and efficient wound healing. PMID:26808544

  5. A Glutathione-Nrf2-Thioredoxin Cross-Talk Ensures Keratinocyte Survival and Efficient Wound Repair.

    PubMed

    Telorack, Michèle; Meyer, Michael; Ingold, Irina; Conrad, Marcus; Bloch, Wilhelm; Werner, Sabine

    2016-01-01

    The tripeptide glutathione is the most abundant cellular antioxidant with high medical relevance, and it is also required as a co-factor for various enzymes involved in the detoxification of reactive oxygen species and toxic compounds. However, its cell-type specific functions and its interaction with other cytoprotective molecules are largely unknown. Using a combination of mouse genetics, functional cell biology and pharmacology, we unraveled the function of glutathione in keratinocytes and its cross-talk with other antioxidant defense systems. Mice with keratinocyte-specific deficiency in glutamate cysteine ligase, which catalyzes the rate-limiting step in glutathione biosynthesis, showed a strong reduction in keratinocyte viability in vitro and in the skin in vivo. The cells died predominantly by apoptosis, but also showed features of ferroptosis and necroptosis. The increased cell death was associated with increased levels of reactive oxygen and nitrogen species, which caused DNA and mitochondrial damage. However, epidermal architecture, and even healing of excisional skin wounds were only mildly affected in the mutant mice. The cytoprotective transcription factor Nrf2 was strongly activated in glutathione-deficient keratinocytes, but additional loss of Nrf2 did not aggravate the phenotype, demonstrating that the cytoprotective effect of Nrf2 is glutathione dependent. However, we show that deficiency in glutathione biosynthesis is efficiently compensated in keratinocytes by the cysteine/cystine and thioredoxin systems. Therefore, our study highlights a remarkable antioxidant capacity of the epidermis that ensures skin integrity and efficient wound healing. PMID:26808544

  6. [Ascorbate-glutathione cycle enzymes activity in Zea mays leaves under salinity and treatment by adaptogenic compounds].

    PubMed

    Konturs'ka, O O; Palladina, T O

    2012-01-01

    The effect of different salinity levels and synthetic compounds treatments on ascorbate-glutathione cycle enzymes activity in maize leaves has been investigated. One-day seedlings exposition with 0.05 M NaCl increased ascorbate peroxidase activity, whereas 10-day exposition did not affect it. However the exposition with 0.1 M NaCl, which is extreme for maize, decreased ascorbate peroxidase activity in leaves during 10 days. On the other hand glutathione reductase activity in leaves increased under both salt concentrations. Seeds treatments with Methyure and Ivine increased ascorbate peroxidase activity in the leaves of seedlings under 0.1 M NaCl, but did not affect glutathione reductase activity as compared to the salt control. The results obtained have shown differences of ascorbate-glutathione cycle enzymes responses to salt exposition of seedlings and the effects of adaptogenic compounds on the ascorbate-glutathione cycle via ascorbate peroxidase activation. PMID:23387279

  7. Glutathione Metabolism and Parkinson’s Disease

    PubMed Central

    Smeyne, Michelle

    2013-01-01

    It has been established that oxidative stress, defined as the condition when the sum of free radicals in a cell exceeds the antioxidant capacity of the cell, contributes to the pathogenesis of Parkinson’s disease. Glutathione is a ubiquitous thiol tripeptide that acts alone, or in concert with enzymes within cells to reduce superoxide radicals, hydroxyl radicals and peroxynitrites. In this review, we examine the synthesis, metabolism and functional interactions of glutathione, and discuss how this relates to protection of dopaminergic neurons from oxidative damage and its therapeutic potential in Parkinson’s disease. PMID:23665395

  8. Synergy between different electromagnetic-protection systems

    NASA Astrophysics Data System (ADS)

    Boudenot, J. C.

    1990-04-01

    A new approach to electromagnetic-protection (EP) design is presented. The EP problem for large structures has been shown to be strongly dependent on the various types of electromagnetic constraints (NEMP, lightning, EMC, TEMPEST). Even though the types of protection systems that can be applied are limited, the characteristics of these systems show a potential for synergism in the treatment of the EP. It is shown that, in order to take advantange of this potential synergism and to achieve the best cost-effective design, an early analysis of the protection scenario is required.

  9. Hen Welfare in Different Housing Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, the public has begun to question the conditions under which intensively-managed livestock are housed. As a consequence of this concern, animal production practices, including egg production systems, have become subject to heightened levels of scrutiny. Animal welfare issues lie at the he...

  10. Hen Welfare in Different Housing Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Egg production systems have become subject to heightened levels of scrutiny due to animal welfare concerns. Multiple factors such as disease, skeletal and foot health, pest and parasite load, behavior, stress, affective states, nutrition, and genetics influence the level of welfare laying hens exper...

  11. Glutathione metabolism and its implications for health.

    PubMed

    Wu, Guoyao; Fang, Yun-Zhong; Yang, Sheng; Lupton, Joanne R; Turner, Nancy D

    2004-03-01

    Glutathione (gamma-glutamyl-cysteinyl-glycine; GSH) is the most abundant low-molecular-weight thiol, and GSH/glutathione disulfide is the major redox couple in animal cells. The synthesis of GSH from glutamate, cysteine, and glycine is catalyzed sequentially by two cytosolic enzymes, gamma-glutamylcysteine synthetase and GSH synthetase. Compelling evidence shows that GSH synthesis is regulated primarily by gamma-glutamylcysteine synthetase activity, cysteine availability, and GSH feedback inhibition. Animal and human studies demonstrate that adequate protein nutrition is crucial for the maintenance of GSH homeostasis. In addition, enteral or parenteral cystine, methionine, N-acetyl-cysteine, and L-2-oxothiazolidine-4-carboxylate are effective precursors of cysteine for tissue GSH synthesis. Glutathione plays important roles in antioxidant defense, nutrient metabolism, and regulation of cellular events (including gene expression, DNA and protein synthesis, cell proliferation and apoptosis, signal transduction, cytokine production and immune response, and protein glutathionylation). Glutathione deficiency contributes to oxidative stress, which plays a key role in aging and the pathogenesis of many diseases (including kwashiorkor, seizure, Alzheimer's disease, Parkinson's disease, liver disease, cystic fibrosis, sickle cell anemia, HIV, AIDS, cancer, heart attack, stroke, and diabetes). New knowledge of the nutritional regulation of GSH metabolism is critical for the development of effective strategies to improve health and to treat these diseases. PMID:14988435

  12. Five Decades with Glutathione and the GSTome

    PubMed Central

    Mannervik, Bengt

    2012-01-01

    Uncle Folke inspired me to become a biochemist by demonstrating electrophoresis experiments on butterfly hemolymph in his kitchen. Glutathione became the subject for my undergraduate project in 1964 and has remained a focal point in my research owing to its multifarious roles in the cell. Since the 1960s, the multiple forms of glutathione transferase (GST), the GSTome, were isolated and characterized, some of which were discovered in our laboratory. Products of oxidative processes were found to be natural GST substrates. Examples of toxic compounds against which particular GSTs provide protection include 4-hydroxynonenal and ortho-quinones, with possible links to the etiology of Alzheimer and Parkinson diseases and other degenerative conditions. The role of thioltransferase and glutathione reductase in the cellular reduction of disulfides and other oxidized forms of thiols was clarified. Glyoxalase I catalyzes still another glutathione-dependent detoxication reaction. The unusual steady-state kinetics of this zinc-containing enzyme initiated model discrimination by regression analysis. Functional properties of the enzymes have been altered by stochastic mutations based on DNA shuffling and rationally tailored by structure-based redesign. We found it useful to represent promiscuous enzymes by vectors or points in multidimensional substrate-activity space and visualize them by multivariate analysis. Adopting the concept “molecular quasi-species,” we describe clusters of functionally related enzyme variants that may emerge in natural as well as directed evolution. PMID:22247548

  13. Protective effect of sesamol against 3-nitropropionic acid-induced cognitive dysfunction and altered glutathione redox balance in rats.

    PubMed

    Kumar, Puneet; Kalonia, Harikesh; Kumar, Anil

    2010-07-01

    Sesamol (SML) (Sesamum indicum, Linn, Pedaliaceae) has been used traditionally as a health supplement in India and other countries for a long time. It is a well-known antioxidant, currently being tried against several neurological disorders. The present study was designed to evaluate the potential of sesamol treatment against 3-nitropropionic acid (3-NP)-induced cognitive impairment and oxidative damage in striatal, cortex and hippocampal regions of the rat. The memory performance was assessed by Morris water maze and elevated plus maze paradigms. The oxidative damage was assessed by estimating the total glutathione, reduced glutathione, oxidized glutathione levels and glutathione redox ratio. Glutathione-S-transferase and lactate dehydrogenase enzymes were also measured in different brain areas. 3-NP significantly impaired memory performance as assessed in Morris water maze and elevated plus maze, which was significantly attenuated by sesamol (5, 10 and 20 mg/kg) pre-treatment. On the other hand, 3-NP significantly induced oxidative stress and depleted total glutathione, reduced glutathione, glutathione-S-transferase, lactate dehydrogenase enzyme levels and redox ratio in the striatum, cortex and hippocampal regions as compared to the vehicle-treated group. Sesamol pre-treatment restored oxidative defence possibly by its free radical scavenging activity as compared to the 3NP-treated group. The present study suggests that sesamol could be used as an effective agent in the management of Huntington's disease. PMID:20102363

  14. The Ascorbate-glutathione-α-tocopherol Triad in Abiotic Stress Response

    PubMed Central

    Szarka, András; Tomasskovics, Bálint; Bánhegyi, Gábor

    2012-01-01

    The life of any living organism can be defined as a hurdle due to different kind of stresses. As with all living organisms, plants are exposed to various abiotic stresses, such as drought, salinity, extreme temperatures and chemical toxicity. These primary stresses are often interconnected, and lead to the overproduction of reactive oxygen species (ROS) in plants, which are highly reactive and toxic and cause damage to proteins, lipids, carbohydrates and DNA, which ultimately results in oxidative stress. Stress-induced ROS accumulation is counteracted by enzymatic antioxidant systems and non-enzymatic low molecular weight metabolites, such as ascorbate, glutathione and α-tocopherol. The above mentioned low molecular weight antioxidants are also capable of chelating metal ions, reducing thus their catalytic activity to form ROS and also scavenge them. Hence, in plant cells, this triad of low molecular weight antioxidants (ascorbate, glutathione and α-tocopherol) form an important part of abiotic stress response. In this work we are presenting a review of abiotic stress responses connected to these antioxidants. PMID:22605990

  15. The ascorbate-glutathione-α-tocopherol triad in abiotic stress response.

    PubMed

    Szarka, András; Tomasskovics, Bálint; Bánhegyi, Gábor

    2012-01-01

    The life of any living organism can be defined as a hurdle due to different kind of stresses. As with all living organisms, plants are exposed to various abiotic stresses, such as drought, salinity, extreme temperatures and chemical toxicity. These primary stresses are often interconnected, and lead to the overproduction of reactive oxygen species (ROS) in plants, which are highly reactive and toxic and cause damage to proteins, lipids, carbohydrates and DNA, which ultimately results in oxidative stress. Stress-induced ROS accumulation is counteracted by enzymatic antioxidant systems and non-enzymatic low molecular weight metabolites, such as ascorbate, glutathione and α-tocopherol. The above mentioned low molecular weight antioxidants are also capable of chelating metal ions, reducing thus their catalytic activity to form ROS and also scavenge them. Hence, in plant cells, this triad of low molecular weight antioxidants (ascorbate, glutathione and α-tocopherol) form an important part of abiotic stress response. In this work we are presenting a review of abiotic stress responses connected to these antioxidants. PMID:22605990

  16. Glutathione and gamma-glutamyl transferases are involved in the formation of cadmium-glutathione complex.

    PubMed

    Adamis, Paula Daniela Braga; Mannarino, Sérgio Cantú; Eleutherio, Elis Cristina Araújo

    2009-05-01

    In a wild-type strain of Saccharomyces cerevisiae, cadmium induces the activities of both gamma-glutamyl transferase (gamma-GT) and glutathione transferase 2 (Gtt2). However, Gtt2 activity did not increase under gamma-GT or Ycf1 deficiencies, suggesting that the accumulation of glutathione-cadmium in the cytosol inhibits Gtt2. On the other hand, the balance between the cytoplasmic and vacuolar level of glutathione seems to regulate gamma-GT activity, since this enzyme was not activated in a gtt2 strain. Taken together, these results suggest that gamma-GT and Gtt2 work together to remove cadmium from the cytoplasm, a crucial mechanism for metal detoxification that is dependent on glutathione. PMID:19345220

  17. Systemic Imidacloprid Affects Intraguild Parasitoids Differently

    PubMed Central

    Roe, R. Michael; Bacheler, Jack S.

    2015-01-01

    Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) and Campoletis sonorensis (Cameron) (Hymenoptera, Ichneumonidae) are solitary endoparasitoids of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). They provide biological control of H. virescens populations in Southeastern US agricultural production systems. Field and greenhouse experiments conducted from 2011–2014 compared parasitism rates of parasitoids that developed inside H. virescens larvae fed on tobacco plants treated with and without imidacloprid. The parasitoids in our study did not have a similar response. Toxoneuron nigriceps had reduced parasitism rates, but parasitism rates of C. sonorensis were unaffected. Preliminary data indicate that adult female lifespans of T. nigriceps are also reduced. ELISA was used to measure concentrations of neonicotinoids, imidacloprid and imidacloprid metabolites in H. virescens larvae that fed on imidacloprid-treated plants and in the parasitoids that fed on these larvae. Concentrations were detectable in the whole bodies of parasitized H. virescens larvae, T. nigriceps larvae and T. nigriceps adults, but not in C. sonorensis larvae and adults. These findings suggest that there are effects of imidacloprid on multiple trophic levels, and that insecticide use may differentially affect natural enemies with similar feeding niches. PMID:26658677

  18. Systemic Imidacloprid Affects Intraguild Parasitoids Differently.

    PubMed

    Taylor, Sally V; Burrack, Hannah J; Roe, R Michael; Bacheler, Jack S; Sorenson, Clyde E

    2015-01-01

    Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) and Campoletis sonorensis (Cameron) (Hymenoptera, Ichneumonidae) are solitary endoparasitoids of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). They provide biological control of H. virescens populations in Southeastern US agricultural production systems. Field and greenhouse experiments conducted from 2011-2014 compared parasitism rates of parasitoids that developed inside H. virescens larvae fed on tobacco plants treated with and without imidacloprid. The parasitoids in our study did not have a similar response. Toxoneuron nigriceps had reduced parasitism rates, but parasitism rates of C. sonorensis were unaffected. Preliminary data indicate that adult female lifespans of T. nigriceps are also reduced. ELISA was used to measure concentrations of neonicotinoids, imidacloprid and imidacloprid metabolites in H. virescens larvae that fed on imidacloprid-treated plants and in the parasitoids that fed on these larvae. Concentrations were detectable in the whole bodies of parasitized H. virescens larvae, T. nigriceps larvae and T. nigriceps adults, but not in C. sonorensis larvae and adults. These findings suggest that there are effects of imidacloprid on multiple trophic levels, and that insecticide use may differentially affect natural enemies with similar feeding niches. PMID:26658677

  19. Glutathione, glutathione disulfide, and S-glutathionylated proteins in cell cultures.

    PubMed

    Giustarini, Daniela; Galvagni, Federico; Tesei, Anna; Farolfi, Alberto; Zanoni, Michele; Pignatta, Sara; Milzani, Aldo; Marone, Ilaria M; Dalle-Donne, Isabella; Nassini, Romina; Rossi, Ranieri

    2015-12-01

    The analysis of the global thiol-disulfide redox status in tissues and cells is a challenging task since thiols and disulfides can undergo artificial oxido-reductions during sample manipulation. Because of this, the measured values, in particular for disulfides, can have a significant bias. Whereas this methodological problem has already been addressed in samples of red blood cells and solid tissues, a reliable method to measure thiols and disulfides in cell cultures has not been previously reported. Here, we demonstrate that the major artifact occurring during thiol and disulfide analysis in cultured cells is represented by glutathione disulfide (GSSG) and S-glutathionylated proteins (PSSG) overestimation, due to artificial oxidation of glutathione (GSH) during sample manipulation, and that this methodological problem can be solved by the addition of N-ethylmaleimide (NEM) immediately after culture medium removal. Basal levels of GSSG and PSSG in different lines of cultured cells were 3-5 and 10-20 folds higher, respectively, when the cells were processed without NEM. NEM pre-treatment also prevented the artificial reduction of disulfides that occurs during the pre-analytical phase when cells are exposed to an oxidant stimulus. In fact, in the absence of NEM, after medium removal, GSH, GSSG and PSSG levels restored their initial values within 15-30 min, due to the activity of reductases and the lack of the oxidant. The newly developed protocol was used to measure the thiol-disulfide redox status in 16 different line cells routinely used for biomedical research both under basal conditions and after treatment with disulfiram, a thiol-specific oxidant (0-200 μM concentration range). Our data indicate that, in most cell lines, treatment with disulfiram affected the levels of GSH and GSSG only at the highest concentration. On the other hand, PSSG levels increased significantly also at the lower concentrations of the drug, and the rise was remarkable (from 100 to 1000

  20. The comprehensive acid-base characterization of glutathione

    NASA Astrophysics Data System (ADS)

    Mirzahosseini, Arash; Somlyay, Máté; Noszál, Béla

    2015-02-01

    Glutathione in its thiol (GSH) and disulfide (GSSG) forms, and 4 related compounds were studied by 1H NMR-pH titrations and a case-tailored evaluation method. The resulting acid-base properties are quantified in terms of 128 microscopic protonation constants; the first complete set of such parameters for this vitally important pair of compounds. The concomitant 12 interactivity parameters were also determined. Since biological redox systems are regularly compared to the GSH-GSSG pair, the eight microscopic thiolate basicities determined this way are exclusive means for assessing subtle redox parameters in a wide pH range.

  1. Short-term effects of T-2 toxin exposure on some lipid peroxide and glutathione redox parameters of broiler chickens.

    PubMed

    Bócsai, A; Pelyhe, Cs; Zándoki, E; Ancsin, Zs; Szabó-Fodor, J; Erdélyi, M; Mézes, M; Balogh, K

    2016-06-01

    The purpose of this study was to investigate the short-term effects of T-2 toxin exposure (3.09 mg/kg feed) on lipid peroxidation and glutathione redox system of broiler chicken. A total of 54 Cobb 500 cockerels were randomly distributed to two experimental groups at 21 days of age. Samples (blood plasma, red blood cell, liver, kidney and spleen) were collected every 12 h during a 48-h period. The results showed that the initial phase of lipid peroxidation, as measured by conjugated dienes and trienes in the liver, was continuously, but not significantly higher in T-2 toxin-dosed birds than in control birds. The termination phase of lipid peroxidation, as measured by malondialdehyde, was significantly higher in liver and kidney as a result of T-2 toxin exposure at the end of the experimental period (48th hour). The glutathione redox system activated shortly after starting the T-2 toxin exposure, which is supported by the significantly higher concentration of reduced glutathione and glutathione peroxidase activity in blood plasma at 24 and 48 h, in liver at 12, 24 and 36 h, and in kidney and spleen at 24 h. These results suggest that T-2 toxin, or its metabolites, may be involved in the generation of reactive oxygen substances which causes an increase in lipid peroxidation, and consequently activates the glutathione redox system, namely synthesis of reduced glutathione and glutathione peroxidase. PMID:26412027

  2. Regiospecificity of placental metabolism by cytochromes P450 and glutathione S-transferase.

    PubMed

    McRobie, D J; Glover, D D; Tracy, T S

    1996-01-01

    The placenta possesses the ability to metabolize numerous xenobiotics and endogenous steroids. However, it is unknown whether regional differences in these enzymatic reactions exist in the human placenta. To this end, we undertook a study of four regions of the placenta, the chorionic plate, maternal surface, placental margin and whole tissue, to assess the activities of cytochrome P450 1A1 and 19A1 (aromatase) and glutathione S-stransferase in these fractions. No differences in either P450 1A1 or glutathione S-transferase activities were noted among any of the placental fractions. However, with respect to P450 19A1 activity, the placental margin differed significantly from all other fractions (p < 0.05). This study demonstrates that whole tissue samples of the human placenta are adequate for placental cytochrome P450 and glutathione S-transferase metabolism studies. PMID:8938464

  3. Artificial elevation of glutathione affects symptom development in ZYMV-infected Cucurbita pepo L. plants.

    PubMed

    Zechmann, B; Zellnig, G; Urbanek-Krajnc, A; Müller, M

    2007-01-01

    Styrian oil pumpkin seedlings (Cucurbita pepo L. subsp. pepo var. styriaca GREB: .) were treated for 48 h with 1 mM OTC (L-2-oxothiazolidine-4-carboxylic acid) in order to artificially increase cellular glutathione content. They were inoculated with zucchini yellow mosaic virus (ZYMV) 10 days later. The effects of OTC treatment and ZYMV infection on glutathione levels were examined at the subcellular level by immunogold labeling of glutathione using a transmission electron microscope (TEM). These effects were further tested at the whole-tissue level by high performance liquid chromatography (HPLC). Such tests were carried out a) on roots, cotyledons and the first true leaves immediately after OTC treatment in order to analyze to which extent OTC increases glutathione levels in different cell compartments as well as in the whole organ; and b) in older and younger leaves and in roots three weeks after ZYMV inoculation in order to study how possible effects of OTC on symptom development would correlate with glutathione levels at the subcellular level and in the whole organ. Immunocytological and biochemical investigations revealed that, 48 h after OTC treatment, glutathione content had increased in all investigated organs, up to 144% in peroxisomes of cotyledons. Three weeks after ZYMV inoculation, glutathione labeling density had significantly increased within intact cells of infected leaves, up to 124% in the cytosol of younger leaves. Roots showed decreased amounts of glutathione in the TEM. Biochemical studies revealed that OTC treatment resulted in 41 and 51% higher glutathione content in older and younger ZYMV-infected leaves, respectively, in comparison to untreated and ZYMV-infected plants. Evaluation of symptom development at this point revealed that all untreated ZYMV-infected plants had symptoms, whereas only 42% of OTC-treated ZYMV-infected plants showed signs of symptoms. Quantification of ZYMV particles revealed that all organs of OTC-treated and ZYMV

  4. Glutathione and redox signaling in substance abuse

    PubMed Central

    Uys, Joachim D.; Mulholland, Patrick J.; Townsend, Danyelle M.

    2015-01-01

    Throughout the last couple decades, the cause and consequences of substance abuse has expanded to identify the underlying neurobiological signaling mechanisms associated with addictive behavior. Chronic use of drugs, such as cocaine, methamphetamine and alcohol leads to the formation of oxidative or nitrosative stress (ROS/RNS) and changes in glutathione and redox homeostasis. Of importance, redox-sensitive post-translational modifications on cysteine residues, such as S-glutathionylation and S-nitrosylation could impact on the structure and function of addiction related signaling proteins. In this commentary, we evaluate the role of glutathione and redox signaling in cocaine-, methamphetamine- and alcohol addiction and conclude by discussing the possibility of targeting redox pathways for the therapeutic intervention of these substance abuse disorders. PMID:25027386

  5. Glutathione and redox signaling in substance abuse.

    PubMed

    Uys, Joachim D; Mulholland, Patrick J; Townsend, Danyelle M

    2014-07-01

    Throughout the last couple decades, the cause and consequences of substance abuse has expanded to identify the underlying neurobiological signaling mechanisms associated with addictive behavior. Chronic use of drugs, such as cocaine, methamphetamine and alcohol leads to the formation of oxidative or nitrosative stress (ROS/RNS) and changes in glutathione and redox homeostasis. Of importance, redox-sensitive post-translational modifications on cysteine residues, such as S-glutathionylation and S-nitrosylation could impact on the structure and function of addiction related signaling proteins. In this commentary, we evaluate the role of glutathione and redox signaling in cocaine-, methamphetamine- and alcohol addiction and conclude by discussing the possibility of targeting redox pathways for the therapeutic intervention of these substance abuse disorders. PMID:25027386

  6. Functional Systems and Culturally-Determined Cognitive Differences.

    ERIC Educational Resources Information Center

    Wiseman, Richard L.

    Noting that one means of better understanding the nature of cultural differences is to elucidate the cognitive differences between members of differing cultures, this paper examines Alexander Luria's sociohistorical theory of functional cognitive systems. The paper first describes Luria's notion of functional systems, the crux of which postulates…

  7. Synthesis, characterization and cytotoxicity of glutathione- and PEG-glutathione-superparamagnetic iron oxide nanoparticles for nitric oxide delivery

    NASA Astrophysics Data System (ADS)

    Santos, M. C.; Seabra, A. B.; Pelegrino, M. T.; Haddad, P. S.

    2016-03-01

    Superparamagnetic iron oxide nanoparticles (SPIONs), with appropriate surface coatings, are commonly used for biomedical applications, such as drug delivery. For the successful application of SPIONs, it is necessary that the nanoparticles have well-defined morphological, structural and magnetic characteristics, in addition to high stability and biocompatibility in biological environments. The present work is focused on the synthesis and characterization of SPIONs, which were prepared using the co-precipitation method and have great potential for drug delivery. The surfaces of the SPIONs were functionalized with the tripeptide glutathione (GSH) and poly(ethylene glycol) (PEG) to form GSH-SPIONs and PEG-GSH-SPIONs. The structural, morphological, magnetic properties and the cytotoxicity of the obtained nanoparticles were characterized using different techniques. The results showed that the nanoparticles have a mean diameter of 10 nm in the solid state and are superparamagnetic at room temperature. No cytotoxicity was observed for either nanoparticle (up to 500 μg L-1) on mouse normal fibroblasts (3T3 cell line) or acute T cell leukemia (Jurkat cell line) after 24 h of incubation. Free thiol groups (SH) on the surfaces of GSH-SPIONs and PEG-GSH-SPIONs were nitrosated, leading to the formation of S-nitrosated SPIONs, which act as a nitric oxide (NO) donor. The amounts of NO released from GSNO-SPIONs and PEG-GSNO-SPIONs were (124.0 ± 1.0) μmol and (33.2 ± 5.1) μmol of NO per gram, respectively. This study highlights the successful capping of the SPION surfaces with antioxidant GSH and biocompatible PEG, which improved the dispersion and biocompatibility of the NPs in aqueous/biological environments, thereby enhancing the potential uses of SPIONs as drug delivery systems, such as a NO donor vehicle, in biomedical applications.

  8. Lead(II) complex formation with glutathione.

    PubMed

    Mah, Vicky; Jalilehvand, Farideh

    2012-06-01

    A structural investigation of complexes formed between the Pb(2+) ion and glutathione (GSH, denoted AH(3) in its triprotonated form), the most abundant nonprotein thiol in biological systems, was carried out for a series of aqueous solutions at pH 8.5 and C(Pb(2+)) = 10 mM and in the solid state. The Pb L(III)-edge extended X-ray absorption fine structure (EXAFS) oscillation for a solid compound with the empirical formula [Pb(AH(2))]ClO(4) was modeled with one Pb-S and two short Pb-O bond distances at 2.64 ± 0.04 and 2.28 ± 0.04 Å, respectively. In addition, Pb···Pb interactions at 4.15 ± 0.05 Å indicate dimeric species in a network where the thiolate group forms an asymmetrical bridge between two Pb(2+) ions. In aqueous solution at the mole ratio GSH/Pb(II) = 2.0 (C(Pb(2+)) = 10 mM, pH 8.5), lead(II) complexes with two thiolate ligands form, characterized by a ligand-to-metal charge-transfer band (LMCT) S(-) → Pb(2+) at 317 nm in the UV-vis spectrum and mean Pb-S and Pb-(N/O) bond distances of 2.65 ± 0.04 and 2.51 ± 0.04 Å, respectively, from a Pb L(III)-edge EXAFS spectrum. For solutions with higher mole ratios, GSH/Pb(II) ≥ 3.0, electrospray ionization mass spectroscopy spectra identified a triglutathionyllead(II) complex, for which Pb L(III)-edge EXAFS spectroscopy shows a mean Pb-S distance of 2.65 ± 0.04 Å in PbS(3) coordination, (207)Pb NMR spectroscopy displays a chemical shift of 2793 ppm, and in the UV-vis spectrum, an S(-) → Pb(2+) LMCT band appears at 335 nm. The complex persists at high excess of GSH and also at ∼25 K in frozen glycerol (33%)/water glasses for GSH/Pb(II) mole ratios from 4.0 to 10 (C(Pb(2+)) = 10 mM) measured by Pb L(III)-edge EXAFS spectroscopy. PMID:22594853

  9. Effect of Glutathione on Phytochelatin Synthesis in Tomato Cells 1

    PubMed Central

    Mendum, Mary Lou; Gupta, Subhash C.; Goldsbrough, Peter B.

    1990-01-01

    Growth of cell suspension cultures of tomato, Lycopersicon esculentum Mill. cv VFNT-Cherry, in the presence of cadmium is inhibited by buthionine sulfoximine, an inhibitor of glutathione synthesis. Cell growth and phytochelatin synthesis are restored to cells treated with buthionine sulfoximine by the addition of glutathione to the medium. Glutathione stimulates the accumulation of phytochelatins in cadmium treated cells, indicating that availability of glutathione can limit synthesis of these peptides. Exogenous glutathione causes a disproportionate increase in the level of smaller phytochelatins, notably [γ-Glu-Cys]2-Gly. In the presence of buthionine sulfoximine and glutathione, phytochelatins that are produced upon exposure to cadmium incorporate little [35S]cysteine, indicating that these peptides are probably not synthesized by sequential addition of cysteine and glutamate to glutathione. PMID:16667492

  10. Systemic antioxidant properties of L-carnitine in two different models of arterial hypertension.

    PubMed

    Mate, Alfonso; Miguel-Carrasco, José L; Monserrat, María T; Vázquez, Carmen M

    2010-06-01

    In spite of a wide range of drugs being available in the market, treatment of arterial hypertension still remains a challenge, and new therapeutic strategies could be developed in order to improve the rate of success in controlling this disease. Since oxidative stress has gained importance in the last few years as one of the mechanisms involved in the origin and development of hypertension, and considering that L-carnitine (LC) is a useful compound in different pathologies characterized by increased oxidative status, the aim of the present study was to investigate the systemic antioxidant effect of LC and its correlation to blood pressure in two experimental models of hypertension: (1) spontaneously hypertensive rats (SHR) and (2) rats with hypertension induced by N(omega)-nitro-L-arginine methyl ester (L-NAME). Treatment with captopril was also performed in SHR in order to compare the antioxidant and antihypertensive effects of LC and captopril. The antioxidant defense capacity, in terms of antioxidant enzyme activity, glutathione system availability and plasma total antioxidant capacity, was measured in both animal models with or without an oral, chronic treatment with LC. All the antioxidant parameters studied were diminished in SHR and in L-NAME-treated animals, an alteration that was in general reversed after treatments with LC and captopril. In addition, LC produced a significant but not complete reduction of systolic and diastolic blood pressure levels in these two models of hypertension, whereas captopril was able to normalize blood pressure. Both LC and captopril prevented the reduction in nitric oxide (NO) levels observed in hypertensive animals. This suggests a decrease in the systemic oxidative stress and a higher availability of NO induced by LC in a similar way to captopril's effects, which could be relevant in the management of arterial hypertension eventually. PMID:20506010

  11. Radiographic changes and lung function in relation to activity of the glutathione transferases theta and mu among asbestos cement workers.

    PubMed

    Jakobsson, K; Rannug, A; Alexandrie, A K; Warholm, M; Rylander, L; Hagmar, L

    1995-05-01

    Experimental data indicate that active oxygen species may be casually involved in the development of asbestos-related disease. Thus, it was hypothesized that individual differences in glutathione transferase activity, which may affect the ability to inactivate molecules formed in relation to oxidative stress, could influence the biological response to asbestos exposure. We could, however, not demonstrate an increased risk for radiographic changes or reduced lung function among asbestos cement workers deficient for glutathione transferase theta (GSTT1), glutathione transferase mu (GSTM1), or having a combined deficiency of enzyme activity. PMID:7618163

  12. Fasciola gigantica thioredoxin glutathione reductase: Biochemical properties and structural modeling.

    PubMed

    Gupta, Ankita; Kesherwani, Manish; Velmurugan, Devadasan; Tripathi, Timir

    2016-08-01

    Platyhelminth thioredoxin glutathione reductase (TGR) is a multifunctional enzyme that crosstalk between the conventional thioredoxin (Trx) and glutathione (GSH) system. It has been validated as a potential drug target in blood flukes. In the present study, we have performed a biochemical study on Fasciola gigantica TGR with substrates DTNB and GSSG. The Michaelis constant (Km) with DTNB was found to be 4.34±0.12μM while it was 61.15±1.50μM with GSSG. The kinetic results were compared with the TGR activities of other helminths. FgTGR showed typical hysteretic behavior with GSSG as other TGRs. We also described a homology-based structure of FgTGR. The cofactors (NADPH and FAD) and substrates (GSSG and DTNB) were docked, and two possible binding sites for substrates were identified in a single chain. The substrates were found to bind more favorably in the second site of TrxR domains. We also presented the first report on binding interaction of DTNB with a TGR. DTNB forms H-bond with His204 and Arg450 of chain A, Sec597, and Gly598 from chain B, salt-bridge with Lys124, and numerous other hydrophobic interactions. Helminth TGR represents an important enzyme in the redox and antioxidant system; hence, its inhibition can be used as an effective strategy against liver flukes. PMID:27112978

  13. Involvement of salicylic acid, glutathione and protein S-thiolation in plant cell death-mediated defence response of Mesembryanthemum crystallinum against Botrytis cinerea.

    PubMed

    Kuźniak, Elżbieta; Kaźmierczak, Andrzej; Wielanek, Marzena; Głowacki, Rafał; Kornas, Andrzej

    2013-02-01

    The response of Mesembryanthemum crystallinum plants performing C3 photosynthesis and crassulacean acid metabolism (CAM) to the non-host necrotrophic pathogen Botrytis cinerea was analyzed at the local and systemic levels. The induction of programmed cell death, lignin and callose deposition, changes in salicylic acid, glutathione and cysteinylglycine pools as well as the content of thiolated proteins were studied. The infected C3 and CAM plants exhibited hypersensitive-like defence response, however fluorescence staining with acridine orange and ethidium bromide revealed programmed cell death events in C3 plants only. The local immune response was not related to callose and lignin deposition. In the infected plants, salicylic acid, glutathione and cysteinylglycine, the first product of glutathione catabolism, as well as protein S-thiolation, predominantly S-glutathionylation, contributed to local defence at sites of inoculation. They (except protein thiolation) were also active in the establishment of systemic acclimation response monitored in the non-treated upper leaves. The extent to which they were involved in the local and systemic responses induced by B. cinerea differed in C3 and CAM plants. The accumulation of free salicylic acid, both in treated and upper leaves of the infected plants, was much more pronounced in CAM plants. The results have been discussed with respect to redox regulations in defence against necrotrophic pathogens and to stress acclimation. PMID:23228550

  14. A glutathione reductase mutant of yeast accumulates high levels of oxidized glutathione and requires thioredoxin for growth.

    PubMed Central

    Muller, E G

    1996-01-01

    A glutathione reductase null mutant of Saccharomyces cerevisiae was isolated in a synthetic lethal genetic screen for mutations which confer a requirement for thioredoxin. Yeast mutants that lack glutathione reductase (glr1 delta) accumulate high levels of oxidized glutathione and have a twofold increase in total glutathione. The disulfide form of glutathione increases 200-fold and represents 63% of the total glutathione in a glr1 delta mutant compared with only 6% in wild type. High levels of oxidized glutathione are also observed in a trx1 delta, trx2 delta double mutant (22% of total), in a glr1 delta, trx1 delta double mutant (71% of total), and in a glr1 delta, trx2 delta double mutant (69% of total). Despite the exceptionally high ratio of oxidized/reduced glutathione, the glr1 delta mutant grows with a normal cell cycle. However, either one of the two thioredoxins is essential for growth. Cells lacking both thioredoxins and glutathione reductase are not viable under aerobic conditions and grow poorly anaerobically. In addition, the glr1 delta mutant shows increased sensitivity to the thiol oxidant diamide. The sensitivity to diamide was suppressed by deletion of the TRX2 gene. The genetic analysis of thioredoxin and glutathione reductase in yeast runs counter to previous studies in Escherichia coli and for the first time links thioredoxin with the redox state of glutathione in vivo. Images PMID:8930901

  15. Dorsal Anterior Cingulate Lactate and Glutathione Levels in Euthymic Bipolar I Disorder: 1H-MRS Study

    PubMed Central

    Pastorello, Bruno F.; Leite, Cláudia da Costa; Henning, Anke; Moreno, Ricardo A.; Garcia Otaduy, Maria Concepción

    2016-01-01

    Objective: Oxidative stress and mitochondrial dysfunction are 2 closely integrated processes implicated in the physiopathology of bipolar disorder. Advanced proton magnetic resonance spectroscopy techniques enable the measurement of levels of lactate, the main marker of mitochondrial dysfunction, and glutathione, the predominant brain antioxidant. The objective of this study was to measure brain lactate and glutathione levels in bipolar disorder and healthy controls. Methods: Eighty-eight individuals (50 bipolar disorder and 38 healthy controls) underwent 3T proton magnetic resonance spectroscopy in the dorsal anterior cingulate cortex (2x2x4.5cm3) using a 2-D JPRESS sequence. Lactate and glutathione were quantified using the ProFit software program. Results: Bipolar disorder patients had higher dorsal anterior cingulate cortex lactate levels compared with controls. Glutathione levels did not differ between euthymic bipolar disorder and controls. There was a positive correlation between lactate and glutathione levels specific to bipolar disorder. No influence of medications on metabolites was observed. Conclusion: This is the most extensive magnetic resonance spectroscopy study of lactate and glutathione in bipolar disorder to date, and results indicated that euthymic bipolar disorder patients had higher levels of lactate, which might be an indication of altered mitochondrial function. Moreover, lactate levels correlated with glutathione levels, indicating a compensatory mechanism regardless of bipolar disorder diagnosis. PMID:27207914

  16. Effect of selenium- and glutathione-enriched yeast supplementation on a combined atherosclerosis and diabetes hamster model.

    PubMed

    Agbor, Gabriel A; Vinson, Joe A; Patel, Shachi; Patel, Kunal; Scarpati, Jenyne; Shiner, Drew; Wardrop, Forbes; Tompkins, Thomas A

    2007-10-17

    Selenium has a central role in antioxidant pathways as a cofactor to glutathione peroxidase. The present study evaluated the effects of four different preparations of inactivated yeast containing various concentrations of selenium and glutathione on a combined atherosclerosis and diabetes hamster model. The hamsters were supplemented with the yeast products for three months. The enriched yeast with the highest selenium and glutathione levels reduced the weight loss induced by diabetes, inhibited an increase in plasma cholesterol and triglyceride caused by a high-cholesterol and high-fat diet, increased the time taken for oxidation of lower density lipoproteins (lag time), and inhibited the formation of atherosclerosis better than low selenium/glutathione yeast supplementation. It was concluded that the yeast prepared to provide high selenium and high glutathione was the best for effecting beneficial changes in glutathione, cholesterol, atherosclerosis, and for demonstrating an antioxidant effect. The high selenium and low glutathione yeast was the best for improving selenium and glucose levels. PMID:17880156

  17. In Vivo Magnetic Resonance Studies of Glycine and Glutathione Metabolism in a Rat Mammary Tumor

    PubMed Central

    Thelwall, Peter E.; Simpson, Nicholas E.; Rabbani, Zahid N.; Clark, M. Daniel; Pourdeyhimi, Roxana; Macdonald, Jeffrey M.; Blackband, Stephen J.; Gamcsik, Michael P.

    2011-01-01

    The metabolism of glycine into glutathione was monitored noninvasively in vivo in intact R3230Ac rat tumors by magnetic resonance imaging and spectroscopy. Metabolism was tracked by following the isotope label from intravenously infused [2-13C]-glycine into the glycinyl residue of glutathione. Signals from [2-13C]-glycine and γ-glutamylcysteinyl-[2-13C]-glycine (13C-glutathione) were detected by nonlocalized 13C spectroscopy as these resonances are distinct from background signals. In addition, using spectroscopic imaging methods, heterogeneity in the in vivo tumor distribution of glutathione was observed. In vivo spectroscopy also detected isotope incorporation from [2-13C]-glycine into both the 2- and 3-carbons of serine. Analyses of tumor tissue extracts show single and multiple label incorporation from [2-13C]-glycine into serine from metabolism through the serine hydroxymethyltransferase and glycine cleavage system pathways. Mass spectrometric analysis of extracts also shows that isotope-labeled serine is further metabolized via the transsulfuration pathway as the 13C-isotope labels appear in both the glycinyl- and the cysteinyl-residue of glutathione. Our studies demonstrate the use of magnetic resonance imaging and spectroscopy for monitoring tumor metabolic processes central to oxidative stress defense. PMID:21751272

  18. Glutathione reductase gsr-1 is an essential gene required for Caenorhabditis elegans early embryonic development.

    PubMed

    Mora-Lorca, José Antonio; Sáenz-Narciso, Beatriz; Gaffney, Christopher J; Naranjo-Galindo, Francisco José; Pedrajas, José Rafael; Guerrero-Gómez, David; Dobrzynska, Agnieszka; Askjaer, Peter; Szewczyk, Nathaniel J; Cabello, Juan; Miranda-Vizuete, Antonio

    2016-07-01

    Glutathione is the most abundant thiol in the vast majority of organisms and is maintained in its reduced form by the flavoenzyme glutathione reductase. In this work, we describe the genetic and functional analysis of the Caenorhabditis elegans gsr-1 gene that encodes the only glutathione reductase protein in this model organism. By using green fluorescent protein reporters we demonstrate that gsr-1 produces two GSR-1 isoforms, one located in the cytoplasm and one in the mitochondria. gsr-1 loss of function mutants display a fully penetrant embryonic lethal phenotype characterized by a progressive and robust cell division delay accompanied by an aberrant distribution of interphasic chromatin in the periphery of the cell nucleus. Maternally expressed GSR-1 is sufficient to support embryonic development but these animals are short-lived, sensitized to chemical stress, have increased mitochondrial fragmentation and lower mitochondrial DNA content. Furthermore, the embryonic lethality of gsr-1 worms is prevented by restoring GSR-1 activity in the cytoplasm but not in mitochondria. Given the fact that the thioredoxin redox systems are dispensable in C. elegans, our data support a prominent role of the glutathione reductase/glutathione pathway in maintaining redox homeostasis in the nematode. PMID:27117030

  19. Airway glutathione homeostasis is altered in children with severe asthma: Evidence for oxidant stress

    PubMed Central

    Fitzpatrick, Anne M.; Teague, W. Gerald; Holguin, Fernando; Yeh, Mary; Brown, Lou Ann S.

    2009-01-01

    Background Severe asthma is characterized by persistent airway inflammation and increased formation of reactive oxygen species. Objectives Glutathione (GSH) is an important antioxidant in the epithelial lining fluid (ELF). We hypothesized that airway GSH homeostasis was altered in children with severe asthma and was characterized by decreased GSH and increased glutathione disulfide (GSSG) concentrations. Methods Bronchoalveolar lavage was obtained from 65 children with severe asthma, including 35 children with baseline airway obstruction evidenced by FEV1 <80%. Control data were obtained from 6 children with psychogenic (habit) cough or vocal cord dysfunction undergoing diagnostic bronchoscopy and 35 healthy adult controls. GSH, GSSG, and other determinants of airway oxidative stress including glutathione S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), malondialdehyde, 8-isoprostane, and H2O2 were measured in the ELF. The ELF redox potential was calculated from GSH and GSSG by using the Nernst equation. Results: Compared with controls, subjects with severe asthma had lower airway GSH with increased GSSG despite no differences in GST, GR, and GPx activities between groups. This was accompanied by increased malondialdehyde, 8-isoprostane, and H2O2 concentrations in the ELF. GSH oxidation was most apparent in subjects with severe asthma with airway obstruction and was supported by an upward shift in the ELF GSH redox potential. Conclusion Children with severe asthma have increased biomarkers of oxidant stress in the ELF that are associated with increased formation of GSSG and a shift in the GSH redox potential toward the more oxidized state. PMID:19130935

  20. Purification and thermal dependence of glutathione reductase from two forage legume species.

    PubMed

    Kidambi, S P; Mahan, J R; Matches, A G

    1990-02-01

    Alfalfa (Medicago sativa L.) and sainfoin (Onobrychis viciifolia Scop.) are forage legumes that differ in their responses to high and low temperature stresses. Thermal limitations on the function of glutathione reductase (EC 1.6.4.2) could adversely affect the ability of the plant to cope with adverse temperatures. Our objectives were to (a) purify glutathione reductase from ;Cimarron' alfalfa and ;PI 212241' sainfoin and (b) investigate the intraspecies variation in the thermal dependency of glutathione reductase from each of three cultivars of alfalfa and two cultivars and an introduction of sainfoin. Glutathione reductase was purified 1222-and 1948-fold to a specific activity of 281 and 273 units per milligram of protein, from one species each of alfalfa and sainfoin, respectively. The relative molecular mass of the protein was approximately 140 kilodaltons with subunits of 57 and 37 kilodaltons under denaturing conditions. The activation energies were approximately 50 kilojoules per mole for both species. Over a 5 to 45 degrees C temperature gradient, large variation among species and genotypes within species was found for: (a) the minimum apparent Michaelis constant (0.6-2.1 micromoles of NADPH), (b) the temperature at which the minimum apparent Michaelis constant was observed (10-25 degrees C), and (c) the thermal kinetic windows (6-19 degrees C width). Future studies will focus on relating the thermal dependence of the Michaelis constant of the glutathione reductases and plant growth rates and forage quality of these species throughout the growing season. PMID:16667283

  1. Effect of transport on blood selenium and glutathione status in feeder lambs.

    PubMed

    Hall, J A; Bobe, G; Nixon, B K; Vorachek, W R; Hugejiletu; Nichols, T; Mosher, W D; Pirelli, G J

    2014-09-01

    Stress from transport may be linked to increased generation of reactive oxygen species, the removal of which requires reduced glutathione and selenium. The aim of this experiment was to examine the effect of transport on glutathione and Se status of feeder lambs. Recently weaned lambs (n = 40) were blocked by gender and BW on d 0 of the experiment and randomly assigned to 2 treatment groups: group 1, no transport and full access to feed and water (control), and group 2, 8-h road transport followed by another 16 h of feed deprivation (transport). After 24 h, both treatment groups were treated the same. All lambs were weighed, and blood samples were collected at 0, 8, 24, and 72 h and analyzed for whole-blood (WB) and serum Se concentrations, serum NEFA concentrations, and erythrocyte concentrations of glutathione. Transport of feeder lambs for 8 h followed by another 16 h of feed deprivation transiently (significant at 24 h but no longer different at 72 h) decreased BW and erythrocyte glutathione concentrations and increased serum NEFA and blood Se concentrations compared with control lambs. Our results suggest that 8 h of transport followed by another 16 h of feed deprivation results in fatty acid and Se mobilization from tissue stores with a coincident decrease in erythrocyte glutathione concentrations. PMID:25035242

  2. Gender Differences and Intra-Gender Differences amongst Management Information Systems Students

    ERIC Educational Resources Information Center

    Beyer, Sylvia

    2008-01-01

    Few women major in Management Information Systems (MIS). The purpose of this paper is to examine the reasons for women's underrepresentation in MIS. In addition to examining gender differences, an important and novel goal of this study is to examine intra-gender differences in undergraduate students, i.e., differences among female MIS majors and…

  3. Recombinant baculovirus vectors expressing glutathione-S-transferase fusion proteins.

    PubMed

    Davies, A H; Jowett, J B; Jones, I M

    1993-08-01

    Recombinant baculoviruses are a popular means of producing heterologous protein in eukaryotic cells. Purification of recombinant proteins away from the insect cell background can, however, remain an obstacle for many developments. Recently, prokaryotic fusion protein expression systems have been developed allowing single-step purification of the heterologous protein and specific proteolytic cleavage of the affinity tag moiety from the desired antigen. Here we report the introduction of these attributes to the baculovirus system. "Baculo-GEX" vectors enable baculovirus production of fusion proteins with the above advantages, but in a eukaryotic post-translational processing environment. Glutathione-S-transferase (GST) fusions are stable cytoplasmic proteins in insect cells and may therefore be released by sonication alone, avoiding the solubility problems and detergent requirements of bacterial systems. Thus large amounts of authentic antigen may be purified in a single, non-denaturing step. PMID:7763917

  4. Glutathione in metastases: From mechanisms to clinical applications.

    PubMed

    Estrela, José M; Ortega, Angel; Mena, Salvador; Sirerol, J Antoni; Obrador, Elena

    2016-08-01

    Metastatic spread, not primary tumors, is the leading cause of cancer death. Glutathione (γ-glutamyl-cysteinyl-glycine, GSH) is particularly relevant in cancer cells as it is involved in regulating carcinogenic mechanisms, growth and dissemination, and multidrug and radiation resistance. Upon interaction of metastatic cells with the vascular endothelium, a high percentage of metastatic cells with high GSH levels survive the combined nitrosative and oxidative stresses elicited by the vascular endothelium. GSH release from different organs, mainly the liver, and its interorgan transport through the blood circulation to metastatic foci, promote their growth. This review focuses on the relationship among GSH and different key mechanisms that facilitate metastatic cell survival and growth, i.e. adaptive responses to stress, cell death evasion and utilization of physiological neuroendocrine mechanisms. Different strategies that are aimed at sensitizing metastases to cancer therapy by depleting metastatic cell GSH are analyzed. PMID:26754151

  5. Glutathione and γ-glutamylcysteine in hydrogen peroxide detoxification.

    PubMed

    Quintana-Cabrera, Ruben; Bolaños, Juan P

    2013-01-01

    Hydrogen peroxide (H2O2) is an important regulator of cell redox status and signaling pathways. However, if produced in excess, it can trigger oxidative damage, which can be counteracted by the antioxidant systems. Amongst these, the glutathione (GSH) precursor, γ-glutamylcysteine (γGC), has recently been shown to detoxify H2O2 in a glutathione peroxidase-1 (GPx1)-dependent fashion. To analyze how both γGC and GSH reduce H2O2, we have taken advantage of a colorimetric assay that allows simple and reliable quantification of H2O2 in the micromolar range. Whereas most assays rely on coupled enzymatic reactions, this method determines the formation of a ferric thiocyanate derivative after direct Fe(2+) oxidation by H2O2. Here, we detail the procedure and considerations to determine H2O2 reduction by both γGC and GSH, either from cell samples or in vitro reactions with purified enzymes from GSH metabolism. PMID:23830629

  6. Bioavailability Study of an Innovative Orobuccal Formulation of Glutathione

    PubMed Central

    Buonocore, Daniela; Grosini, Matteo; Giardina, Silvana; Michelotti, Angela; Carrabetta, Mariaelena; Seneci, Antonio; Verri, Manuela; Dossena, Maurizia; Marzatico, Fulvio

    2016-01-01

    Alteration of the ubiquitous thiol tripeptide glutathione (GSH) is involved in oxidative stress, which plays a role in ageing; consequently, GSH is closely related to this process characterized by progressive decline in the efficiency of physiological function and increased susceptibility to disease. When circulating GSH decreases, oral administration might be considered a therapeutic benefit. Unfortunately, due to the hydrolysis of the tripeptide by intestinal γ-glutamyltransferase, dietary glutathione is not a major determinant for its increase. Aim of this work was to evaluate improvement of GSH systemic availability testing, in vitro and in vivo, an optimized orobuccal fast-slow release formulation tablet containing pure stabilized GSH. In vitro evaluation of the penetration capability of the innovative GSH-release formulation showed that GSH was well absorbed by the reconstructed oral epithelium and its absorption has features of time-dependence. In addition, in vivo results, obtained from 15 healthy volunteers, were in favor of GSH level improvement in blood showing fast (after 30 and 60 minutes) absorption through oral mucosa. In conclusion, the intake of GSH formulated through optimized orobuccal fast-slow release tablets gave positive results in raising GSH blood concentration. PMID:26649136

  7. Renal Clearance and Degradation of Glutathione-Coated Copper Nanoparticles

    PubMed Central

    Yang, Shengyang; Sun, Shasha; Zhou, Chen; Hao, Guiyang; Liu, Jinbin; Ramezani, Saleh; Yu, Mengxiao; Sun, Xiankai; Zheng, Jie

    2016-01-01

    Degradation of inorganic nanoparticles (NPs) into small molecular complexes is often observed in the physiological environment; however, how this process influences renal clearance of inorganic NPs is largely unknown. By systematically comparing renal clearance of degradable luminescent glutathione coated copper NPs (GS-CuNPs) and their dissociated products, Cu(II)-glutathione disulfide (GSSG) complexes (Cu(II)-GSSG), we found that GS-CuNPs were eliminated through the urinary system surprisingly faster and accumulated in the liver much less than their smaller dissociation counterparts. With assistance of radiochemistry and positron emission tomography (PET) imaging, we found that the observed “nano size” effect in enhancing renal clearance is attributed to the fact that GS-CuNPs are more resistant to serum protein adsorption than Cu(II)-GSSG. In addition, since dissociation of GS-CuNPs follows zero-order chemical kinetics, their renal clearance and biodistribution also depend on initial injection doses and their dissociation processes. Quantitative understanding of size effect and other factors involved in renal clearance and biodistribution of degradable inorganic NPs will lay down a foundation for further development of renal-clearable inorganic NPs with minimized nanotoxicity. PMID:25674666

  8. Increased efflux of glutathione conjugate in acutely diabetic cardiomyocytes.

    PubMed

    Ghosh, Sanjoy; Ting, Simon; Lau, Howard; Pulinilkunnil, Thomas; An, Ding; Qi, Dake; Abrahani, Mohammed A; Rodrigues, Brian

    2004-10-01

    In diabetes, cell death and resultant cardiomyopathy have been linked to oxidative stress and depletion of antioxidants like glutathione (GSH). Although the de novo synthesis and recycling of GSH have been extensively studied in the chronically diabetic heart, their contribution in modulating cardiac oxidative stress in acute diabetes has been largely ignored. Additionally, the possible contribution of cellular efflux in regulating GSH levels during diabetes is unknown. We used streptozotocin to make Wistar rats acutely diabetic and after 4 days examined the different processes that regulate cardiac GSH. Reduction in myocyte GSH in diabetic rats was accompanied by increased oxidative stress, excessive reactive oxygen species, and an elevated apoptotic cell death. The effect on GSH was not associated with any change in either synthesis or recycling, as both gamma-glutamylcysteine synthetase gene expression (responsible for bio syn thesis) and glutathione reductase activity (involved with GSH recycling) remained unchanged. However, gene expression of multidrug resistance protein 1, a transporter implicated in effluxing GSH during oxidative stress, was elevated. GSH conjugate efflux mediated by multidrug resistance protein 1 also increased in diabetic cardiomyocytes, an effect that was blocked using MK-571, a specific inhibitor of this transporter. As MK-571 also decreased oxidative stress in diabetic cardiomyocytes, an important role can be proposed for this transporter in GSH and reactive oxygen species homeostasis in the acutely diabetic heart. PMID:15573148

  9. Physical exercise intensity can be related to plasma glutathione levels.

    PubMed

    Gambelunghe, C; Rossi, R; Micheletti, A; Mariucci, G; Rufini, S

    2001-03-01

    The aim of the present study was to examine the effect of different kinds of physical exercise on plasma glutathione levels. Male Wistar rats were randomly divided into four groups: In walking group (W; n=6), rats were trained to walk 0.8 m/min for 45 min; slow running group (SR; n=6) were trained to run 4 m/min for 45 min; fast running group (FR; n=6) ran 8 m/min for 60 min and control rats (C; n=6) remained in their home cages. All animals were sacrificed after exercise and the levels of reduced glutathione (GSH) in plasma samples determined by high performance liquid chromatography (HPLC) with a fluorescent detector. Compared to controls, exercise did not change GSH plasma levels of the W group. A tendency to decrease blood GSH was observed in plasma samples of the SR group and in the FR group, physical exercise resulted in a dramatic decrease in GSH plasma levels. These data suggest that during light physical exercise there is a low production of reactive oxygen species (ROS) with a low request for antioxidant defence such as oxidation of GSH. The dramatic decrease observed in GSH levels in FR rats would indicate the presence of oxidative stress able to modify blood antioxidant profiles. Our results suggest that GSH plays a central antioxidant role in blood during intensive physical exercise and that its modifications are closely related to exercise intensity. PMID:11519887

  10. Physical exercise intensity can be related to plasma glutathione levels.

    PubMed

    Gambelunghe, C; Rossi, R; Micheletti, A; Mariucci, G; Rufini, S

    2001-03-01

    The aim of the present study was to examine the effect of different kinds of physical exercise on plasma glutathione levels. Male Wistar rats were randomly divided into four groups: In walking group (W; n=6), rats were trained to walk 0.8 m/min for 45 min; slow running group (SR; n=6) were trained to run 4 m/min for 45 min; fast running group (FR; n=6) ran 8m/min for 60 min and control rats (C; n=6) remained in their home cages. All animals were sacrificed after exercise and the levels of reduced glutathione (GSH) in plasma samples determined by high performance liquid chromatography (HPLC) with a fluorescent detector. Compared to controls, exercise did not change GSH plasma levels of the W group. A tendency to decrease blood GSH was observed in plasma samples of the SR group and in the FR group, physical exercise resulted in a dramatic decrease in GSH plasma levels. These data suggest that during light physical exercise there is a low production of reactive oxygen species (ROS) with a low request for antioxidant defence such as oxidation of GSH. The dramatic decrease observed in GSH levels in FR rats would indicate the presence of oxidative stress able to modify blood antioxidant profiles. Our results suggest that GSH plays a central antioxidant role in blood during intensive physical exercise and that its modifications are closely related to exercise intensity. PMID:11579999

  11. A Selective Glutathione Probe based on AIE Fluorogen and its Application in Enzymatic Activity Assay

    PubMed Central

    Lou, Xiaoding; Hong, Yuning; Chen, Sijie; Leung, Chris Wai Tung; Zhao, Na; Situ, Bo; Lam, Jacky Wing Yip; Tang, Ben Zhong

    2014-01-01

    In this work, we design and synthesize a malonitrile-functionalized TPE derivative (TPE-DCV), which can react with thiol group through thiol-ene click reaction, leading to the fluorescence change of the system. Combined with the unique AIE property, TPE-DCV can selectively detect glutathione (GSH) but not cysteine or homocysteine. As the cleavage of GSSG with the aid of glutathione reductase produces GSH, which turns on the fluorescence of TPE-DCV, the ensemble of TPE-DCV and GSSG can thus serve as a label-free sensor for enzymatic activity assay of glutathione reductase. We also apply TPE-DCV for the detection of intracellular GSH in living cells. PMID:24603274

  12. A Selective Glutathione Probe based on AIE Fluorogen and its Application in Enzymatic Activity Assay

    NASA Astrophysics Data System (ADS)

    Lou, Xiaoding; Hong, Yuning; Chen, Sijie; Leung, Chris Wai Tung; Zhao, Na; Situ, Bo; Lam, Jacky Wing Yip; Tang, Ben Zhong

    2014-03-01

    In this work, we design and synthesize a malonitrile-functionalized TPE derivative (TPE-DCV), which can react with thiol group through thiol-ene click reaction, leading to the fluorescence change of the system. Combined with the unique AIE property, TPE-DCV can selectively detect glutathione (GSH) but not cysteine or homocysteine. As the cleavage of GSSG with the aid of glutathione reductase produces GSH, which turns on the fluorescence of TPE-DCV, the ensemble of TPE-DCV and GSSG can thus serve as a label-free sensor for enzymatic activity assay of glutathione reductase. We also apply TPE-DCV for the detection of intracellular GSH in living cells.

  13. Influence of gender and season on reduced glutathione concentration and energy reserves of Gammarus roeseli.

    PubMed

    Gismondi, Eric; Beisel, Jean-Nicolas; Cossu-Leguille, Carole

    2012-10-01

    As biomarkers are known to be influenced by biotic and abiotic factors (e.g. gender, temperature), we investigated over a one-year long sampling period, the influence of season and gender on reduced glutathione concentrations and its synthesis in the crustacean amphipod Gammarus roeseli. At the same time, we assessed energy reserves and malondialdehyde levels as toxic biomarker. Results have shown that, in both genders, reduced glutathione concentrations were inversely correlated to water temperature, and higher in females than in males whatever the season. Total lipid and glycogen contents were higher in females than in males, allowing females to have enough energy to assume the reproductive period and maintain high GSH concentrations for detoxification processes. Conversely, females have lower cell damages than males. These differences between genders could induce differential sensitivity in a contamination context, and thus affect the population. Females could resist better than males in contaminated environments, especially in spring when reduced glutathione concentration is the highest. PMID:22769238

  14. Active synchronization between two different chaotic dynamical system

    SciTech Connect

    Maheri, M.; Arifin, N. Md; Ismail, F.

    2015-05-15

    In this paper we investigate on the synchronization problem between two different chaotic dynamical system based on the Lyapunov stability theorem by using nonlinear control functions. Active control schemes are used for synchronization Liu system as drive and Rossler system as response. Numerical simulation by using Maple software are used to show effectiveness of the proposed schemes.

  15. Active synchronization between two different chaotic dynamical system

    NASA Astrophysics Data System (ADS)

    Maheri, M.; Arifin, N. Md; Ismail, F.

    2015-05-01

    In this paper we investigate on the synchronization problem between two different chaotic dynamical system based on the Lyapunov stability theorem by using nonlinear control functions. Active control schemes are used for synchronization Liu system as drive and Rossler system as response. Numerical simulation by using Maple software are used to show effectiveness of the proposed schemes.

  16. A difference characteristic for one-dimensional deterministic systems

    NASA Astrophysics Data System (ADS)

    Shahverdian, A. Yu.; Apkarian, A. V.

    2007-06-01

    A numerical characteristic for one-dimensional deterministic systems reflecting its higher order difference structure is introduced. The comparison with Lyapunov exponent is given. A difference analogy for Eggleston theorem as well as an estimate for Hausdorff dimension of the difference attractor, formulated in terms of the new characteristic is proved.

  17. Comparing Different Fault Identification Algorithms in Distributed Power System

    NASA Astrophysics Data System (ADS)

    Alkaabi, Salim

    A power system is a huge complex system that delivers the electrical power from the generation units to the consumers. As the demand for electrical power increases, distributed power generation was introduced to the power system. Faults may occur in the power system at any time in different locations. These faults cause a huge damage to the system as they might lead to full failure of the power system. Using distributed generation in the power system made it even harder to identify the location of the faults in the system. The main objective of this work is to test the different fault location identification algorithms while tested on a power system with the different amount of power injected using distributed generators. As faults may lead the system to full failure, this is an important area for research. In this thesis different fault location identification algorithms have been tested and compared while the different amount of power is injected from distributed generators. The algorithms were tested on IEEE 34 node test feeder using MATLAB and the results were compared to find when these algorithms might fail and the reliability of these methods.

  18. The regulation of gelation of Phloem exudate from cucurbita fruit by dilution, glutathione, and glutathione reductase.

    PubMed

    Alosi, M C; Melroy, D L; Park, R B

    1988-04-01

    The average glutathione equivalent concentration in phloem exudate collected from squash fruit (Cucurbita moschata [Duchesne] Poir. var Butternut) and pumpkin fruit (Cucurbita pepo [L.] var Jack-o-lattern) was 1.02 and 0.60 millimolar, respectively. Glutathione reductase (EC 1.6.4.2) activity in phloem exudate from squash and pumpkin fruit averaged 0.48 and 1.74 micromole NADPH oxidized per minute per milliliter, respectively. Protein concentrations in fruit phloem exudates averaged 67 milligrams per milliliter for squash and 57 milligrams per milliliter for pumpkin. The phloem-specific P-proteins account for most of the protein content of exudate. Pure exudate from fruit does not gel for hours or days, but when diluted with neutral or alkaline aqueous solutions, exudate gels rapidly. Exudate solutions undergo biphasic pH changes with dilution. We suggest that P-protein undergoes conformational change upon dilution, exposing titratable groups and sulfhydryl residues. Oxidation of the latter forms the intermolecular disulfide bridges of the gel. The gelation of diluted exudate is regulated by factors (oxygen, pH, glutathione, NADPH) which affect the maintenance of reduced sulfhydryl residues and the activity of glutathione reductase. While these factors may also act in vivo to regulate redox conditions in phloem, their relationship to hypothetical sol/gel transitions or motile and nonmotile phases in the transport conduit is unknown. PMID:16666036

  19. Detection of glutathione transferase activity on polyacrylamide gels.

    PubMed

    Ricci, G; Lo Bello, M; Caccuri, A M; Galiazzo, F; Federici, G

    1984-12-01

    A simple and sensitive assay for glutathione transferase activity on polyacrylamide gel is described. The method is based on the fast reduction of nitroblue tetrazolium salt by glutathione. Blue insoluble formazan colors the gel except in the glutathione transferase area. The stable and defined colorless zone is still detectable with 0.005 unit enzyme. This technique has been successfully applied with enzyme preparations of human heart and other tissues. PMID:6532239

  20. Normal and quasinormal forms for systems of difference and differential-difference equations

    NASA Astrophysics Data System (ADS)

    Kashchenko, Ilya; Kaschenko, Sergey

    2016-09-01

    The local dynamics of systems of difference and singularly perturbed differential-difference equations is studied in the neighborhood of a zero equilibrium state. Critical cases in the problem of stability of its state of equilibrium have infinite dimension. Special nonlinear evolution equations, which act as normal forms, are set up. It is shown that their dynamics defines the behavior of solutions to the initial system.

  1. Basis difference method for orthogonal systems on a surface

    NASA Astrophysics Data System (ADS)

    Korobitsyn, V. A.

    2011-07-01

    The basis operator method intended for constructing systems of difference approximations to differential operators in vector and tensor analysis is extended to orthogonal systems on a surface. A class of completely conservative differential-difference schemes for continuum mechanics in Lagrangian variables is constructed. Basis operators are constructed using the finite volume equation, consistency conditions for discrete operators of the first derivative, and consistent projection operators for grid functions. A system of differential-difference continuum mechanics equations on a surface is obtained, which implies all conservation laws typical of the continuum case, including additional ones. A stability estimate is derived for discrete equations of an incompressible viscous fluid.

  2. Complement profile and activation mechanisms by different LDL apheresis systems.

    PubMed

    Hovland, Anders; Hardersen, Randolf; Nielsen, Erik Waage; Enebakk, Terje; Christiansen, Dorte; Ludviksen, Judith Krey; Mollnes, Tom Eirik; Lappegård, Knut Tore

    2012-07-01

    Extracorporeal removal of low-density lipoprotein (LDL) cholesterol by means of selective LDL apheresis is indicated in otherwise uncontrolled familial hypercholesterolemia. During blood-biomaterial interaction other constituents than the LDL particles are affected, including the complement system. We set up an ex vivo model in which human whole blood was passed through an LDL apheresis system with one of three different apheresis columns: whole blood adsorption, plasma adsorption and plasma filtration. The concentrations of complement activation products revealed distinctly different patterns of activation and adsorption by the different systems. Evaluated as the final common terminal complement complex (TCC) the whole blood system was inert, in contrast to the plasma systems, which generated substantial and equal amounts of TCC. Initial classical pathway activation was revealed equally for both plasma systems as increases in the C1rs-C1inh complex and C4d. Alternative pathway activation (Bb) was most pronounced for the plasma adsorption system. Although the anaphylatoxins (C3a and C5a) were equally generated by the two plasma separation systems, they were efficiently adsorbed to the plasma adsorption column before the "outlet", whereas they were left free in the plasma in the filtration system. Consequently, during blood-biomaterial interaction in LDL apheresis the complement system is modulated in different manners depending on the device composition. PMID:22373816

  3. [Selective N-heterylazimine inhibition of reactions catalyzed by rat liver glutathione transferase].

    PubMed

    Stulovskiĭ, A V; Voznyĭ, I V; Rozengart, E V; Suvorov, A A; Khovanskikh, A E

    1992-01-01

    Three reactions (nucleophile substitution, thiolysis and N-deoxygenation) catalyzed by rat liver glutathione transferase have been studied using several N-heterylazimine inhibitors. The inhibitors are sharply different in their effectiveness in the transferase reactions. Their efficiency depends on their structure. The mechanism which underlies the found regularities is suggested. PMID:1413125

  4. Measurement of glutathione in activated sludges.

    PubMed

    Dziurla, M A; Leroy, P; Strünkmann, G W; Salhi, M; Lee, D U; Camacho, P; Heinz, V; Müller, J A; Paul, E; Ginestet, Ph; Audic, J M; Block, J C

    2004-01-01

    Thermal, electric, mechanical or oxidative stress seem a promising way to reduce the production of excess activated sludge during biological wastewater treatment. However, the adaptation and the resistance of the sludge microbial ecosystem to stress conditions is a major question as it may definitively limit the effect of some treatments. Defence mechanisms developed by aerobic organisms, in particular, in response to oxidative stress involve various antioxidant activities and compounds such as glutathione. An HPLC method was developed for measuring reduced and total glutathione (GSH and GSHt) in perchloric acid sludge extracts. The method was sensitive, highly specific and validated for linearity, precision and recovery. Considering the extraction yield and the oxidation of GSH during extract storage, the measured GSH concentration was estimated to represent 60% of the GSH content from activated sludges. GSHt ranged from 0.32 to 3.34micromolg(-1) volatile solids and the GSH/GSHt ratio ranged from 32% to 91%. Measurements performed on sludges stressed in precise conditions selected to reach a reduction of sludge production showed a decrease of GSH and GSHt concentrations with thermal, mechanical, electric and ozone stress. PMID:14630122

  5. Manipulation of glutathione metabolism in transgenic plants.

    PubMed

    Creissen, G; Broadbent, P; Stevens, R; Wellburn, A R; Mullineaux, P

    1996-05-01

    There is clear potential for the genetic manipulation of key enzymes involved in stress metabolism in transgenic plants. However, the data emerging so far from such experiments are equivocal. The detailed analysis of stress responses in progeny of primary transgenics, coupled with comparisons with control transgenic plants that do not contain the GR transgene, allows us to take into account the possible variation in response to stress associated with regeneration of plants from tissue culture. The picture that is now beginning to emerge with respect to the role of GR in stress protection is that, although there are clearly benefits to be had from overexpression of the enzymes, there is no direct correlation between enzyme levels and stress tolerance. It may be that overexpression of the cytosolic isoform (gor2) will prove to be of greater benefit. Furthermore, the types of stresses to which transgenic plants have been exposed in order to assess the consequences of oxidative stress tolerance cannot reproduce those that will experienced in field conditions. Only when plants with higher GR levels and increased glutathione synthesis capacity are grown in field trials will it be possible to make a full assessment of the benefits of engineering plants with altered glutathione metabolism. PMID:8736785

  6. Plasma cysteine, cystine, and glutathione in cirrhosis.

    PubMed

    Chawla, R K; Lewis, F W; Kutner, M H; Bate, D M; Roy, R G; Rudman, D

    1984-10-01

    Plasma contains three forms of cyst(e)ine: cysteine, cystine, and protein-bound cysteine. The former is a thiol and the latter two are disulfides. The levels of all three types of cyst(e)ine, as well as the cysteinyl tripeptide glutathione, were measured in the plasma of 14 normal and 10 cirrhotic individuals. All subjects ate mixed foods. Some cirrhotic patients were studied during nasogastric hyperalimentation with Vivonex (Norwich Eaton Pharmaceuticals, Norwich, N.Y.) as well as during total parenteral nutrition with FreAmine III (American McGaw, Irvine, Calif.); neither formula contains cyst(e)ine. Regardless of the nature of the diet, cirrhotic patients had significantly subnormal values for cysteine, glutathione, and albumin. In addition, the following significant changes were found to be diet-dependent: (a) elevated methionine during Vivonex, (b) subnormal taurine during mixed foods and total parenteral nutrition, (c) depressed protein-bound cysteine during total parenteral nutrition, (d) depressed cyst(e)ine thiol/disulfide ratio during mixed foods, and (e) depressed total thiol during Vivonex and total parenteral nutrition. The data indicate multiple abnormalities in sulfur metabolism in cirrhosis. PMID:6468868

  7. Targeting brain cells with glutathione-modulated nanoliposomes: in vitro and in vivo study

    PubMed Central

    Salem, Heba F; Ahmed, Sayed M; Hassaballah, Ashraf E; Omar, Mahmoud M

    2015-01-01

    Background The blood–brain barrier prevents many drug moieties from reaching the central nervous system. Therefore, glutathione-modulated nanoliposomes have been engineered to enhance the targeting of flucytosine to the brain. Methods Glutathione-modulated nanoliposomes were prepared by thin-film hydration technique and evaluated in the primary brain cells of rats. Lecithin, cholesterol, and span 65 were mixed at 1:1:1 molar ratio. The molar percentage of PEGylated glutathione varied from 0 mol% to 0.75 mol%. The cellular binding and the uptake of the targeted liposomes were both monitored by epifluorescent microscope and flow cytometry techniques. A biodistribution and a pharmacokinetic study of flucytosine and flucytosine-loaded glutathione–modulated liposomes was carried out to evaluate the in vivo brain-targeting efficiency. Results The size of glutathione-modulated nanoliposomes was <100 nm and the zeta potential was more than −65 mV. The cumulative release reached 70% for certain formulations. The cellular uptake increased as molar percent of glutathione increased to reach the maximum at 0.75 mol%. The uptake of the targeted liposomes by brain cells of the rats was three times greater than that of the nontargeted liposomes. An in vivo study showed that the relative efficiency was 2.632±0.089 and the concentration efficiency was 1.590±0.049, and also, the drug-targeting index was 3.670±0.824. Conclusion Overall, these results revealed that glutathione-PEGylated nanoliposomes enhance the effective delivery of flucytosine to brain and could become a promising new therapeutic option for the treatment of the brain infections. PMID:26229435

  8. Glutathione as a skin whitening agent: Facts, myths, evidence and controversies.

    PubMed

    Sonthalia, Sidharth; Daulatabad, Deepashree; Sarkar, Rashmi

    2016-01-01

    Glutathione is a low molecular weight thiol-tripeptide that plays a prominent role in maintaining intracellular redox balance. In addition to its remarkable antioxidant properties, the discovery of its antimelanogenic properties has led to its promotion as a skin-lightening agent. It is widely used for this indication in some ethnic populations. However, there is a dichotomy between evidence to support its efficacy and safety. The hype around its depigmentary properties may be a marketing gimmick of pharma-cosmeceutical companies. This review focuses on the various aspects of glutathione: its metabolism, mechanism of action and the scientific evidence to evaluate its efficacy as a systemic skin-lightening agent. Glutathione is present intracellularly in its reduced form and plays an important role in various physiological functions. Its skin-lightening effects result from direct as well as indirect inhibition of the tyrosinase enzyme and switching from eumelanin to phaeomelanin production. It is available in oral, parenteral and topical forms. Although the use of intravenous glutathione injections is popular, there is no evidence to prove its efficacy. In fact, the adverse effects caused by intravenous glutathione have led the Food and Drug Administration of Philippines to issue a public warning condemning its use for off-label indications such as skin lightening. Currently, there are three randomized controlled trials that support the skin-lightening effect and good safety profile of topical and oral glutathione. However, key questions such as the duration of treatment, longevity of skin-lightening effect and maintenance protocols remain unanswered. More randomized, double-blind, placebo-controlled trials with larger sample size, long-term follow-up and well-defined efficacy outcomes are warranted to establish the relevance of this molecule in disorders of hyperpigmentation and skin lightening. PMID:27088927

  9. Glutathione depletion sensitizes cisplatin- and temozolomide-resistant glioma cells in vitro and in vivo

    PubMed Central

    Rocha, C R R; Garcia, C C M; Vieira, D B; Quinet, A; de Andrade-Lima, L C; Munford, V; Belizário, J E; Menck, C F M

    2014-01-01

    Malignant glioma is a severe type of brain tumor with a poor prognosis and few options for therapy. The main chemotherapy protocol for this type of tumor is based on temozolomide (TMZ), albeit with limited success. Cisplatin is widely used to treat several types of tumor and, in association with TMZ, is also used to treat recurrent glioma. However, several mechanisms of cellular resistance to cisplatin restrict therapy efficiency. In that sense, enhanced DNA repair, high glutathione levels and functional p53 have a critical role on cisplatin resistance. In this work, we explored several mechanisms of cisplatin resistance in human glioma. We showed that cellular survival was independent of the p53 status of those cells. In addition, in a host-cell reactivation assay using cisplatin-treated plasmid, we did not detect any difference in DNA repair capacity. We demonstrated that cisplatin-treated U138MG cells suffered fewer DNA double-strand breaks and DNA platination. Interestingly, the resistant cells carried higher levels of intracellular glutathione. Thus, preincubation with the glutathione inhibitor buthionine sulfoximine (BSO) induced massive cell death, whereas N-acetyl cysteine, a precursor of glutathione synthesis, improved the resistance to cisplatin treatment. In addition, BSO sensitized glioma cells to TMZ alone or in combination with cisplatin. Furthermore, using an in vivo model the combination of BSO, cisplatin and TMZ activated the caspase 3–7 apoptotic pathway. Remarkably, the combined treatment did not lead to severe side effects, while causing a huge impact on tumor progression. In fact, we noted a remarkable threefold increase in survival rate compared with other treatment regimens. Thus, the intracellular glutathione concentration is a potential molecular marker for cisplatin resistance in glioma, and the use of glutathione inhibitors, such as BSO, in association with cisplatin and TMZ seems a promising approach for the therapy of such devastating

  10. Glutathione depletion sensitizes cisplatin- and temozolomide-resistant glioma cells in vitro and in vivo.

    PubMed

    Rocha, C R R; Garcia, C C M; Vieira, D B; Quinet, A; de Andrade-Lima, L C; Munford, V; Belizário, J E; Menck, C F M

    2014-01-01

    Malignant glioma is a severe type of brain tumor with a poor prognosis and few options for therapy. The main chemotherapy protocol for this type of tumor is based on temozolomide (TMZ), albeit with limited success. Cisplatin is widely used to treat several types of tumor and, in association with TMZ, is also used to treat recurrent glioma. However, several mechanisms of cellular resistance to cisplatin restrict therapy efficiency. In that sense, enhanced DNA repair, high glutathione levels and functional p53 have a critical role on cisplatin resistance. In this work, we explored several mechanisms of cisplatin resistance in human glioma. We showed that cellular survival was independent of the p53 status of those cells. In addition, in a host-cell reactivation assay using cisplatin-treated plasmid, we did not detect any difference in DNA repair capacity. We demonstrated that cisplatin-treated U138MG cells suffered fewer DNA double-strand breaks and DNA platination. Interestingly, the resistant cells carried higher levels of intracellular glutathione. Thus, preincubation with the glutathione inhibitor buthionine sulfoximine (BSO) induced massive cell death, whereas N-acetyl cysteine, a precursor of glutathione synthesis, improved the resistance to cisplatin treatment. In addition, BSO sensitized glioma cells to TMZ alone or in combination with cisplatin. Furthermore, using an in vivo model the combination of BSO, cisplatin and TMZ activated the caspase 3-7 apoptotic pathway. Remarkably, the combined treatment did not lead to severe side effects, while causing a huge impact on tumor progression. In fact, we noted a remarkable threefold increase in survival rate compared with other treatment regimens. Thus, the intracellular glutathione concentration is a potential molecular marker for cisplatin resistance in glioma, and the use of glutathione inhibitors, such as BSO, in association with cisplatin and TMZ seems a promising approach for the therapy of such devastating

  11. Correction of glutathione deficiency in the lower respiratory tract of HIV seropositive individuals by glutathione aerosol treatment.

    PubMed Central

    Holroyd, K. J.; Buhl, R.; Borok, Z.; Roum, J. H.; Bokser, A. D.; Grimes, G. J.; Czerski, D.; Cantin, A. M.; Crystal, R. G.

    1993-01-01

    BACKGROUND--Concentrations of glutathione, a ubiquitous tripeptide with immune enhancing and antioxidant properties, are decreased in the blood and lung epithelial lining fluid of human immunodeficiency virus (HIV) seropositive individuals. Since the lung is the most common site of infection in those who progress to AIDS it is rational to consider whether it is possible to safely augment glutathione levels in the epithelial lining fluid of HIV seropositive individuals, thus potentially improving local host defence. METHODS--Purified reduced glutathione was delivered by aerosol to HIV seropositive individuals (n = 14) and the glutathione levels in lung epithelial lining fluid were compared before and at one, two, and three hours after aerosol administration. RESULTS--Before treatment total glutathione concentrations in the epithelial lining fluid were approximately 60% of controls. After three days of twice daily doses each of 600 mg reduced glutathione, total glutathione levels in the epithelial lining fluid increased and remained in the normal range for at least three hours after treatment. Strikingly, even though > 95% of the glutathione in the aerosol was in its reduced form, the percentage of oxidised glutathione in epithelial lining fluid increased from 5% before treatment to about 40% three hours after treatment, probably reflecting the use of glutathione as an antioxidant in vivo. No adverse effects were observed. CONCLUSIONS--It is feasible and safe to use aerosolised reduced glutathione to augment the deficient glutathione levels of the lower respiratory tract of HIV seropositive individuals. It is rational to evaluate further the efficacy of this tripeptide in improving host defence in HIV seropositive individuals. PMID:8256245

  12. Proteomic Profiling of Cytosolic Glutathione Transferases from Three Bivalve Species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea

    PubMed Central

    Martins, José Carlos; Campos, Alexandre; Osório, Hugo; da Fonseca, Rute; Vasconcelos, Vítor

    2014-01-01

    Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs), in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST) were surveyed in three bivalves with different habitats and life strategies: Corbicula fluminea, Anodonta cygnea and Mytilus galloprovincialis. GSTs were purified by glutathione-agarose affinity chromatography, and the collection of expressed cGST classes of each bivalve were identified using a proteomic approach. All the purified extracts were also characterized kinetically. Results reveal variations in cGST subunits collection (diversity and properties) between the three tested bivalves. Using proteomics, four pi-class and two sigma-class GST subunits were identified in M. galloprovincialis. C. fluminea also yielded four pi-class and one sigma-class GST subunits. For A. cygnea, two mu-class and one pi-class GST subunits were identified, these being the first record of GSTs from these freshwater mussels. The affinity purified extracts also show differences regarding enzymatic behavior among species. The variations found in cGST collection and kinetics might justify diverse selective advantages for each bivalve organism. PMID:24473139

  13. Proteomic profiling of cytosolic glutathione transferases from three bivalve species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea.

    PubMed

    Martins, José Carlos; Campos, Alexandre; Osório, Hugo; da Fonseca, Rute; Vasconcelos, Vítor

    2014-01-01

    Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs), in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST) were surveyed in three bivalves with different habitats and life strategies: Corbicula fluminea, Anodonta cygnea and Mytilus galloprovincialis. GSTs were purified by glutathione-agarose affinity chromatography, and the collection of expressed cGST classes of each bivalve were identified using a proteomic approach. All the purified extracts were also characterized kinetically. Results reveal variations in cGST subunits collection (diversity and properties) between the three tested bivalves. Using proteomics, four pi-class and two sigma-class GST subunits were identified in M. galloprovincialis. C. fluminea also yielded four pi-class and one sigma-class GST subunits. For A. cygnea, two mu-class and one pi-class GST subunits were identified, these being the first record of GSTs from these freshwater mussels. The affinity purified extracts also show differences regarding enzymatic behavior among species. The variations found in cGST collection and kinetics might justify diverse selective advantages for each bivalve organism. PMID:24473139

  14. Habitual consumption of fruits and vegetables: associations with human rectal glutathione S-transferase.

    PubMed

    Wark, Petra A; Grubben, Marina J A L; Peters, Wilbert H M; Nagengast, Fokko M; Kampman, Ellen; Kok, Frans J; van 't Veer, Pieter

    2004-11-01

    The glutathione (GSH)/glutathione S-transferase (GST) system is an important detoxification system in the gastrointestinal tract. A high activity of this system may benefit cancer prevention. The aim of the study was to assess whether habitual consumption of fruits and vegetables, especially citrus fruits and brassica and allium vegetables, is positively associated with parameters reflecting the activity of the GSH/GST enzyme system in human rectal mucosa. GST enzyme activity, GST isoenzyme levels of GST-alpha (A1-1, A1-2 and A2-2), -mu (M1-1) and -pi (P1-1), and GSH levels were measured in rectal biopsies from 94 subjects. Diet, lifestyle, GSTM1 and GSTT1 null polymorphisms were assessed. Mean GST enzyme activity was 237 nmol/min/mg protein (SD = 79). Consumption of citrus fruits was positively associated with GST enzyme activity [difference between high and low consumption: 28.9 (95% confidence interval (CI) = 9.3-48.6) nmol/min/mg protein], but was not associated with the other parameters. A positive association with brassica vegetables was found among carriers of the GSTM1-plus genotype [difference between high and low consumption: 22.6 (95% CI = 0.2-45.0) nmol/min/mg protein], but not among GSTM1-null individuals (-25.8 nmol/min/mg protein, 95% CI = -63.3-11.8). This is in line with a positive association between consumption of brassica vegetables and GSTM isoenzyme level [difference between high and low consumption: 67.5%, 95% CI = (6.8-162.7)]. Consumption of allium vegetables was not associated with GST enzyme activity, but negatively with GSTP1-1 levels [difference between high and low consumption: -23.3%, 95% CI = (-35.5; -8.6)]. Associations were similar among those with the GSTT1-plus and GSTT1-null genotype. In conclusion, variations in habitual consumption of fruits, particularly citrus fruits, and of vegetables, in particular brassica vegetables, among those with the GSTM1-plus genotype, may contribute to variations in human rectal GST enzyme

  15. Assessing System Thinking through Different Concept-Mapping Practices

    ERIC Educational Resources Information Center

    Brandstadter, Kristina; Harms, Ute; Grossschedl, Jorg

    2012-01-01

    System thinking is usually investigated by using questionnaires, video analysis, or interviews. Recently, concept-mapping (CM) was suggested as an adequate instrument for analysing students' system thinking. However, there are different ways with which to use this method. Therefore, the purpose of this study was to examine whether particular…

  16. Contextualizing Learning Scenarios According to Different Learning Management Systems

    ERIC Educational Resources Information Center

    Drira, R.; Laroussi, M.; Le Pallec, X.; Warin, B.

    2012-01-01

    In this paper, we first demonstrate that an instructional design process of Technology Enhanced Learning (TEL) systems based on a Model Driven Approach (MDA) addresses the limits of Learning Technology Standards (LTS), such as SCORM and IMS-LD. Although these standards ensure the interoperability of TEL systems across different Learning Management…

  17. Retention mechanism of technetium-99m-HM-PAO: intracellular reaction with glutathione

    SciTech Connect

    Neirinckx, R.D.; Burke, J.F.; Harrison, R.C.; Forster, A.M.; Andersen, A.R.; Lassen, N.A.

    1988-12-01

    Preparations of d,l- and meso-hexamethylpropyleneamine oxime (HM-PAO) labeled with technetium-99m were added to rat brain homogenates diluted with phosphate buffer (1:10). The conversion of d,l-HM-PAO to hydrophilic forms took place with an initial rate constant of 0.12 min-1. Incubation of the brain homogenate with 2% diethyl maleate for 5 h decreased the homogenate's measured glutathione (GSH) concentration from 160 to 16 microM and decreased the conversion rate to 0.012 min-1. Buffered aqueous solutions of glutathione rapidly converted the HM-PAO tracers to hydrophilic forms having the same chromatographic characteristics as found in the brain homogenates. The rate constant for the conversion reaction of d,l-HM-PAO in GSH aqueous solution was 208 and 317 L/mol/min in two different assay systems and for meso-HM-PAO the values were 14.7 and 23.2 L/mol/min, respectively. Rat brain has a GSH concentration of about 2.3 mM and the conversion of the d,l-HM-PAO due to GSH alone should proceed with a rate constant of 0.48 to 0.73 min-1 and be correspondingly 14-fold slower for meso-HM-PAO. In human brain, the in vivo data of Lassen et al. show a conversion rate constant of 0.80 min-1. This correspondence of values supports the notion that GSH may be important for the in vivo conversion of 99mTc-labeled HM-PAO to hydrophilic forms and may be the mechanism of trapping in brain and other cells. A kinetic model for the trapping of d,l- and meso-HM-PAO in tissue is developed that is based on data of GSH concentration in various organs.

  18. Potential role of glutathione in evolution of thiol-based redox signaling sites in proteins

    PubMed Central

    Mohanasundaram, Kaavya A.; Haworth, Naomi L.; Grover, Mani P.; Crowley, Tamsyn M.; Goscinski, Andrzej; Wouters, Merridee A.

    2015-01-01

    Cysteine is susceptible to a variety of modifications by reactive oxygen and nitrogen oxide species, including glutathionylation; and when two cysteines are involved, disulfide formation. Glutathione-cysteine adducts may be removed from proteins by glutaredoxin, whereas disulfides may be reduced by thioredoxin. Glutaredoxin is homologous to the disulfide-reducing thioredoxin and shares similar binding modes of the protein substrate. The evolution of these systems is not well characterized. When a single Cys is present in a protein, conjugation of the redox buffer glutathione may induce conformational changes, resulting in a simple redox switch that effects a signaling cascade. If a second cysteine is introduced into the sequence, the potential for disulfide formation exists. In favorable protein contexts, a bistable redox switch may be formed. Because of glutaredoxin's similarities to thioredoxin, the mutated protein may be immediately exapted into the thioredoxin-dependent redox cycle upon addition of the second cysteine. Here we searched for examples of protein substrates where the number of redox-active cysteine residues has changed throughout evolution. We focused on cross-strand disulfides (CSDs), the most common type of forbidden disulfide. We searched for proteins where the CSD is present, absent and also found as a single cysteine in protein orthologs. Three different proteins were selected for detailed study—CD4, ERO1, and AKT. We created phylogenetic trees, examining when the CSD residues were mutated during protein evolution. We posit that the primordial cysteine is likely to be the cysteine of the CSD which undergoes nucleophilic attack by thioredoxin. Thus, a redox-active disulfide may be introduced into a protein structure by stepwise mutation of two residues in the native sequence to Cys. By extension, evolutionary acquisition of structural disulfides in proteins can potentially occur via transition through a redox-active disulfide state. PMID

  19. Potential role of glutathione in evolution of thiol-based redox signaling sites in proteins.

    PubMed

    Mohanasundaram, Kaavya A; Haworth, Naomi L; Grover, Mani P; Crowley, Tamsyn M; Goscinski, Andrzej; Wouters, Merridee A

    2015-01-01

    Cysteine is susceptible to a variety of modifications by reactive oxygen and nitrogen oxide species, including glutathionylation; and when two cysteines are involved, disulfide formation. Glutathione-cysteine adducts may be removed from proteins by glutaredoxin, whereas disulfides may be reduced by thioredoxin. Glutaredoxin is homologous to the disulfide-reducing thioredoxin and shares similar binding modes of the protein substrate. The evolution of these systems is not well characterized. When a single Cys is present in a protein, conjugation of the redox buffer glutathione may induce conformational changes, resulting in a simple redox switch that effects a signaling cascade. If a second cysteine is introduced into the sequence, the potential for disulfide formation exists. In favorable protein contexts, a bistable redox switch may be formed. Because of glutaredoxin's similarities to thioredoxin, the mutated protein may be immediately exapted into the thioredoxin-dependent redox cycle upon addition of the second cysteine. Here we searched for examples of protein substrates where the number of redox-active cysteine residues has changed throughout evolution. We focused on cross-strand disulfides (CSDs), the most common type of forbidden disulfide. We searched for proteins where the CSD is present, absent and also found as a single cysteine in protein orthologs. Three different proteins were selected for detailed study-CD4, ERO1, and AKT. We created phylogenetic trees, examining when the CSD residues were mutated during protein evolution. We posit that the primordial cysteine is likely to be the cysteine of the CSD which undergoes nucleophilic attack by thioredoxin. Thus, a redox-active disulfide may be introduced into a protein structure by stepwise mutation of two residues in the native sequence to Cys. By extension, evolutionary acquisition of structural disulfides in proteins can potentially occur via transition through a redox-active disulfide state. PMID

  20. Sex Differences in Circadian Timing Systems: Implications for Disease

    PubMed Central

    Bailey, Matthew; Silver, Rae

    2014-01-01

    Virtually every eukaryotic cell has an endogenous circadian clock and a biological sex. These cell-based clocks have been conceptualized as oscillators whose phase can be reset by internal signals such as hormones, and external cues such as light. The present review highlights the inter-relationship between circadian clocks and sex differences. In mammals, the suprachiasmatic nucleus (SCN) serves as a master clock synchronizing the phase of clocks throughout the body. Gonadal steroid receptors are expressed in almost every site that receives direct SCN input. Here we review sex differences in the circadian timing system in the hypothalamic-pituitary-gonadal axis (HPG), the hypothalamicadrenal-pituitary (HPA) axis, and sleep-arousal systems. We also point to ways in which disruption of circadian rhythms within these systems differs in the sexes and is associated with dysfunction and disease. Understanding sex differentiated circadian timing systems can lead to improved treatment strategies for these conditions. PMID:24287074

  1. Withanolide A prevents neurodegeneration by modulating hippocampal glutathione biosynthesis during hypoxia.

    PubMed

    Baitharu, Iswar; Jain, Vishal; Deep, Satya Narayan; Shroff, Sabita; Sahu, Jayanta Kumar; Naik, Pradeep Kumar; Ilavazhagan, Govindasamy

    2014-01-01

    Withania somnifera root extract has been used traditionally in ayurvedic system of medicine as a memory enhancer. Present study explores the ameliorative effect of withanolide A, a major component of withania root extract and its molecular mechanism against hypoxia induced memory impairment. Withanolide A was administered to male Sprague Dawley rats before a period of 21 days pre-exposure and during 07 days of exposure to a simulated altitude of 25,000 ft. Glutathione level and glutathione dependent free radicals scavenging enzyme system, ATP, NADPH level, γ-glutamylcysteinyl ligase (GCLC) activity and oxidative stress markers were assessed in the hippocampus. Expression of apoptotic marker caspase 3 in hippocampus was investigated by immunohistochemistry. Transcriptional alteration and expression of GCLC and Nuclear factor (erythroid-derived 2)-related factor 2 (Nrf2) were investigated by real time PCR and immunoblotting respectively. Exposure to hypobaric hypoxia decreased reduced glutathione (GSH) level and impaired reduced gluatathione dependent free radical scavenging system in hippocampus resulting in elevated oxidative stress. Supplementation of withanolide A during hypoxic exposure increased GSH level, augmented GSH dependent free radicals scavenging system and decreased the number of caspase and hoescht positive cells in hippocampus. While withanolide A reversed hypoxia mediated neurodegeneration, administration of buthionine sulfoximine along with withanolide A blunted its neuroprotective effects. Exogenous administration of corticosterone suppressed Nrf2 and GCLC expression whereas inhibition of corticosterone synthesis upregulated Nrf2 as well as GCLC. Thus present study infers that withanolide A reduces neurodegeneration by restoring hypoxia induced glutathione depletion in hippocampus. Further, Withanolide A increases glutathione biosynthesis in neuronal cells by upregulating GCLC level through Nrf2 pathway in a corticosterone dependenet manner. PMID

  2. Withanolide A Prevents Neurodegeneration by Modulating Hippocampal Glutathione Biosynthesis during Hypoxia

    PubMed Central

    Baitharu, Iswar; Jain, Vishal; Deep, Satya Narayan; Shroff, Sabita; Sahu, Jayanta Kumar; Naik, Pradeep Kumar; Ilavazhagan, Govindasamy

    2014-01-01

    Withania somnifera root extract has been used traditionally in ayurvedic system of medicine as a memory enhancer. Present study explores the ameliorative effect of withanolide A, a major component of withania root extract and its molecular mechanism against hypoxia induced memory impairment. Withanolide A was administered to male Sprague Dawley rats before a period of 21 days pre-exposure and during 07 days of exposure to a simulated altitude of 25,000 ft. Glutathione level and glutathione dependent free radicals scavenging enzyme system, ATP, NADPH level, γ-glutamylcysteinyl ligase (GCLC) activity and oxidative stress markers were assessed in the hippocampus. Expression of apoptotic marker caspase 3 in hippocampus was investigated by immunohistochemistry. Transcriptional alteration and expression of GCLC and Nuclear factor (erythroid-derived 2)–related factor 2 (Nrf2) were investigated by real time PCR and immunoblotting respectively. Exposure to hypobaric hypoxia decreased reduced glutathione (GSH) level and impaired reduced gluatathione dependent free radical scavenging system in hippocampus resulting in elevated oxidative stress. Supplementation of withanolide A during hypoxic exposure increased GSH level, augmented GSH dependent free radicals scavenging system and decreased the number of caspase and hoescht positive cells in hippocampus. While withanolide A reversed hypoxia mediated neurodegeneration, administration of buthionine sulfoximine along with withanolide A blunted its neuroprotective effects. Exogenous administration of corticosterone suppressed Nrf2 and GCLC expression whereas inhibition of corticosterone synthesis upregulated Nrf2 as well as GCLC. Thus present study infers that withanolide A reduces neurodegeneration by restoring hypoxia induced glutathione depletion in hippocampus. Further, Withanolide A increases glutathione biosynthesis in neuronal cells by upregulating GCLC level through Nrf2 pathway in a corticosterone dependenet manner

  3. Differences in Systemic Oxidative Stress Based on Race and the Metabolic Syndrome: The Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) Study

    PubMed Central

    Zhao, Liping; Patel, Riyaz S.; Jones, Dean P.; Ahmed, Yusuf; Stoyanova, Neli; Gibbons, Gary H.; Vaccarino, Viola; Din-Dzietham, Rebecca; Quyyumi, Arshed A.

    2012-01-01

    Abstract Background Classification schema such as metabolic syndrome may underestimate cardiovascular disease (CVD) risk in African Americans, despite a higher burden of CVD in African Americans. Oxidative stress results from an imbalance of prooxidants and antioxidants and leads to endothelial dysfunction that promotes vascular inflammation and atherosclerosis. Aminothiol markers of oxidative stress are associated with CVD risk factors and metabolic syndrome; however, little is known about racial differences in levels of oxidative stress. We sought to investigate whether oxidative stress would be higher in African Americans compared to whites independently of traditional risk factor burden. Methods We assessed oxidative stress in a biracial, community-based cohort. In 620 subjects (59% female, 52% African American) in the Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) study, we measured plasma levels of glutathione, an intracellular antioxidant, and its redox potential as a ratio of reduced and oxidized glutathione (Eh glutathione). Results African Americans had lower glutathione levels (P<0.001) compared to whites. There was a trend toward more oxidized Eh glutathione (P=0.07) in African Americans; however, this did not reach statistical significance. After adjustment for demographics and CVD risk factors, African-American race remained a significant correlate of lower glutathione levels (P<0.001) and a more oxidized Eh glutathione (P=0.04). After further adjustment for high-sensitivity C-reactive protein (hsCRP), glutathione remained significantly lower in African Americans (P=0.001). African Americans with or without metabolic syndrome had lower glutathione levels compared to whites with or without metabolic syndrome, respectively (both P≤0.001), and African Americans without metabolic syndrome had a more oxidized Eh glutathione compared to whites without metabolic syndrome (P=0.003). Conclusions African Americans have higher levels

  4. Analysis of Arabidopsis glutathione-transferases in yeast.

    PubMed

    Krajewski, Matthias P; Kanawati, Basem; Fekete, Agnes; Kowalski, Natalie; Schmitt-Kopplin, Philippe; Grill, Erwin

    2013-07-01

    The genome of Arabidopsis thaliana encodes 54 functional glutathione transferases (GSTs), classified in seven clades. Although plant GSTs have been implicated in the detoxification of xenobiotics, such as herbicides, extensive redundancy within this large gene family impedes a functional analysis in planta. In this study, a GST-deficient yeast strain was established as a system for analyzing plant GSTs that allows screening for GST substrates and identifying substrate preferences within the plant GST family. To this end, five yeast genes encoding GSTs and GST-related proteins were simultaneously disrupted. The resulting yeast quintuple mutant showed a strongly reduced conjugation of the GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl). Consistently, the quintuple mutant was hypersensitive to CDNB, and this phenotype was complemented by the inducible expression of Arabidopsis GSTs. The conjugating activity of the plant GSTs was assessed by in vitro enzymatic assays and via analysis of exposed yeast cells. The formation of glutathione adducts with dinitrobenzene was unequivocally verified by stable isotope labeling and subsequent accurate ultrahigh-resolution mass spectrometry (ICR-FTMS). Analysis of Arabidopsis GSTs encompassing six clades and 42 members demonstrated functional expression in yeast by using CDNB and NBD-Cl as model substrates. Subsequently, the established yeast system was explored for its potential to screen the Arabidopsis GST family for conjugation of the fungicide anilazine. Thirty Arabidopsis GSTs were identified that conferred increased levels of glutathionylated anilazine. Efficient anilazine conjugation was observed in the presence of the phi, tau, and theta clade GSTs including AtGSTF2, AtGSTF4, AtGSTF6, AtGSTF8, AtGSTF10, and AtGSTT2, none of which had previously been known to contribute to fungicide detoxification. ICR-FTMS analysis of yeast extracts allowed the simultaneous detection and

  5. A comparative study of two different clear aligner systems

    PubMed Central

    2014-01-01

    Background This study aims to compare the ‘Nuvola®’ system with ‘Fantasmino®’ system, examine their material properties, and define the indications for use of the aligners. Methods Two groups of patients were selected and were respectively treated with Nuvola® aligner and Fantasmino® system. Results The goal of treatment has been achieved with the two systems. Conclusions The two types of aligners have shown differences during the treatment. Fantasmino® system has elastic properties of high performance, but its size does not encourage compliance throughout the day. Nuvola® system determines good tooth movement and its size facilitates the patient’s collaboration. In both aligner systems, difficulties were found in the correction of torque information and rotations. PMID:24934094

  6. Quantification of Glutathione in Caenorhabditis elegans

    PubMed Central

    Caito, Samuel W.; Aschner, Michael

    2015-01-01

    Glutathione (GSH) is the most abundant intracellular thiol with diverse functions from redox signaling, xenobiotic detoxification, and apoptosis. The quantification of GSH is an important measure for redox capacity and oxidative stress. This protocol quantifies total GSH from Caenorhabditis elegans, an emerging model organism for toxicology studies. GSH is measured using the 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) cycling method originally created for cell and tissue samples but optimized for whole worm extracts. DTNB reacts with GSH to from a 5′-thio-2-nitrobenzoic acid (TNB) chromophore with maximum absorbance of 412 nm. This method is both rapid and sensitive, making it ideal for studies involving a large number of transgenic nematode strains. PMID:26309452

  7. Nomenclature for mammalian soluble glutathione transferases.

    PubMed

    Mannervik, Bengt; Board, Philip G; Hayes, John D; Listowsky, Irving; Pearson, William R

    2005-01-01

    The nomenclature for human soluble glutathione transferases (GSTs) is extended to include new members of the GST superfamily that have been discovered, sequenced, and shown to be expressed. The GST nomenclature is based on primary structure similarities and the division of GSTs into classes of more closely related sequences. The classes are designated by the names of the Greek letters: Alpha, Mu, Pi, etc., abbreviated in Roman capitals: A, M, P, and so on. (The Greek characters should not be used.) Class members are distinguished by Arabic numerals and the native dimeric protein structures are named according to their subunit composition (e.g., GST A1-2 is the enzyme composed of subunits 1 and 2 in the Alpha class). Soluble GSTs from other mammalian species can be classified in the same manner as the human enzymes, and this chapter presents the application of the nomenclature to the rat and mouse GSTs. PMID:16399376

  8. Glutathione depletion and acute exercise increase O-GlcNAc protein modification in rat skeletal muscle.

    PubMed

    Peternelj, Tina Tinkara; Marsh, Susan A; Strobel, Natalie A; Matsumoto, Aya; Briskey, David; Dalbo, Vincent J; Tucker, Patrick S; Coombes, Jeff S

    2015-02-01

    Post-translational modification of intracellular proteins with O-linked β-N-acetylglucosamine (O-GlcNAc) profoundly affects protein structure, function, and metabolism. Although many skeletal muscle proteins are O-GlcNAcylated, the modification has not been extensively studied in this tissue, especially in the context of exercise. This study investigated the effects of glutathione depletion and acute exercise on O-GlcNAc protein modification in rat skeletal muscle. Diethyl maleate (DEM) was used to deplete intracellular glutathione and rats were subjected to a treadmill run. White gastrocnemius and soleus muscles were analyzed for glutathione status, O-GlcNAc and O-GlcNAc transferase (OGT) protein levels, and mRNA expression of OGT, O-GlcNAcase and glutamine:fructose-6-phosphate amidotransferase. DEM and exercise both reduced intracellular glutathione and increased O-GlcNAc. DEM upregulated OGT protein expression. The effects of the interventions were significant 4 h after exercise (P < 0.05). The changes in the mRNA levels of O-GlcNAc enzymes were different in the two muscles, potentially resulting from different rates of oxidative stress and metabolic demands between the muscle types. These findings indicate that oxidative environment promotes O-GlcNAcylation in skeletal muscle and suggest an interrelationship between cellular redox state and O-GlcNAc protein modification. This could represent one mechanism underlying cellular adaptation to oxidative stress and health benefits of exercise. PMID:25416863

  9. Identification and characterization of a selenium-dependent glutathione peroxidase in Setaria cervi

    SciTech Connect

    Singh, Anchal; Rathaur, Sushma . E-mail: sushmarathaur@yahoo.com

    2005-06-17

    Setaria cervi a bovine filarial parasite secretes selenium glutathione peroxidase during in vitro cultivation. A significant amount of enzyme activity was detected in the somatic extract of different developmental stages of the parasite. Among different stages, microfilariae showed a higher level of selenium glutathione peroxidase activity followed by males then females. However, when the activity was compared in excretory secretory products of these stages males showed higher activity than microfilariae and female worms. The enzyme was purified from female somatic extract using a combination of glutathione agarose and gel filtration chromatography, which migrated as a single band of molecular mass {approx}20 kDa. Selenium content of purified enzyme was estimated by atomic absorption spectroscopy and found to be 3.5 ng selenium/{mu}g of protein. Further, inhibition of enzyme activity by potassium cyanide suggested the presence of selenium at the active site of enzyme. This is the first report of identification of selenium glutathione peroxidase from any filarial parasite.

  10. Carbon dot cluster as an efficient "off-on" fluorescent probe to detect Au(III) and glutathione.

    PubMed

    Gu, Jiangjiang; Hu, Donghua; Wang, Weina; Zhang, Qiuhong; Meng, Zhen; Jia, Xudong; Xi, Kai

    2015-06-15

    In this paper, we reported for the first time that Au(III) decorated carbon dot cluster (Au(III)/CDC) was synthesized to detect glutathione through fluorescence "off-on" approach. The "off" process was realized by the introduction of Au(III) on luminescent carbon dots (CDs), which formed the complex of Au(III)/CDC and quenched the fluorescence of CDs efficiently. This "off" process was used to detect Au(III) with the selectivity among 21 metal ions and the limitation was 0.48 μM (S/N=3). Au(III) could be removed from the complex by biothiol in the solution, which restored the fluorescence of CDC to achieve the "on" process. This process was selective for biothiols (especially for glutathione) among saccharides, dopamine and amino acids and the limit of detection was 2.02 μM (S/N=3). Due to the dependence of the fluorescence restoration on the concentration of glutathione, Au(III)/CDC was applied as the fluorescence sensor for detection of glutathione in the solution and cellular cytosol. By referring to the fluorescence change in the solution, the intracellular glutathione with/without oxygen stress was evaluated. As compared with the commercial assay, our Au(III)/CDC based assay was simple, facile and low cost, which would be useful to measure intracellular glutathione at different cellular states. PMID:25558871