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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.

  2. Genetic variability of glutathione S-transferase enzymes in human populations: functional inter-ethnic differences in detoxification systems.

    PubMed

    Polimanti, Renato; Carboni, Cinzia; Baesso, Ilenia; Piacentini, Sara; Iorio, Andrea; De Stefano, Gian Franco; Fuciarelli, Maria

    2013-01-01

    Glutathione S-Transferase enzymes (GSTs) constitute the principal Phase II superfamily which plays a key role in cellular detoxification and in other biological processes. Studies of GSTs have revealed that genetic polymorphisms are present in these enzymes and that some of these are Loss-of-Function (LoF) variants, which affect enzymatic functions and are related to different aspects of human health. The aim of this study was to analyze functional genetic differences in GST enzymes among human populations. Attention was focused on LoF polymorphisms of GSTA1, GSTM1, GSTO1, GSTO2, GSTP1 and GSTT1 genes. These LoF variants were analyzed in 668 individuals belonging to six human groups with different ethnic backgrounds: Amhara and Oromo from Ethiopia; Colorado and Cayapa Amerindians and African Ecuadorians from Ecuador; and one sample from central Italy. The HapMap database was used to compare our data with reference populations and to analyze the haplotype and Linkage Disequilibrium diversity in different ethnic groups. Our results highlighted that ethnicity strongly affects the genetic variability of GST enzymes. In particular, GST haplotypes/variants with functional impact showed significant differences in human populations, according to their ethnic background. These data underline that human populations have different structures in detoxification genes, suggesting that these ethnic differences influence disease risk or response to drugs and therefore have implications for genetic association studies involving GST enzymes. In conclusion, our investigation provides data about the distribution of important LoF variants in GST genes in human populations. This information may be useful for designing and interpreting genetic association studies.

  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. 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

  5. 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

  6. 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

  7. 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 §...

  8. 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 §...

  9. Interaction between glutathione and Apoptosis in Systemic Lupus Erythematosus

    PubMed Central

    Shah, Dilip; Sah, Sangita; Nath, Swapan K.

    2013-01-01

    Systemic lupus erythematosus (SLE) is characterized by imbalance redox state and increased apoptosis. The activation, proliferation and cell death of lymphocytes are dependent on intracellular levels of glutathione and controlled production of reactive oxygen species (ROS). Changes in the intracellular redox environment of cells, through oxygen-derived free radical production known as oxidative stress, have been reported to be critical for cellular immune dysfunction, activation of apoptotic enzymes and apoptosis. The shift in the cellular GSH-to-GSSG redox balance in favor of the oxidized species, GSSG, constitutes an important signal that can decide the fate of the abnormal apoptosis in the disease. The current review will focus on four main areas: (1) general description of oxidative stress markers in SLE, (2) alteration of redox state and complication of disease (3) role of redox mechanisms in the initiation and execution phases of apoptosis, and (4) intracellular glutathione and its checkpoints with lymphocyte apoptosis represent novel targets for pharmacological intervention in SLE. PMID:23279845

  10. Naegleria fowleri: a free-living highly pathogenic amoeba contains trypanothione/trypanothione reductase and glutathione/glutathione reductase systems.

    PubMed

    Ondarza, Raúl N; Hurtado, Gerardo; Tamayo, Elsa; Iturbe, Angélica; Hernández, Eva

    2006-11-01

    This paper presents definitive data showing that the thiol-bimane compound isolated and purified by HPLC from Naegleria fowleri trophozoites unequivocally corresponds by matrix assisted laser-desorption ionization-time-of-flight MS, to the characteristic monoprotonated ion of trypanothione-(bimane)(2) [M(+)H(+)] of m/z 1104.57 and to the trypanothione-(bimane) of m/z 914.46. The trypanothione disulfide T(S)(2) was also found to have a molecular ion of m/z 723.37. Additionally HPLC demonstrated that thiol-bimane compounds corresponding to cysteine and glutathione were present in Naegleria. The ion patterns of the thiol-bimane compounds prepared from commercial trypanothione standard, Entamoeba histolytica and Crithidia luciliae are identical to the Naegleria thiol-bimane compound. Partially purified extracts from N. fowleri showed the coexistence of glutathione and trypanothione reductases activities. There is not doubt that the thiol compound trypanothione, which was previously thought to occur only in Kinetoplastida, is also present in the human pathogens E. histolytica and N. fowleri, as well as in the non-pathogenic euglenozoan E. gracilis. The presence of the trypanothione/trypanothione reductase system in N. fowleri creates the possibility of using this enzyme as a new "drug target" for rationally designed drugs to eliminate the parasite, without affecting the human host.

  11. 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

  12. [Study on color reaction of copper(II)-neocuprine-glutathione-alcohol system].

    PubMed

    Guo, L; Liu, G; Zhang, Z; Liu, S; Wang, L

    2000-06-01

    The colour reaction of glutathione with copper(II)-neocuproine-alcohol was investigated in the present paper. The absorbance increased distinctly by about 13.8% when alcohol was added to the system. The maximum absorption wavelength lambda max of [Cu (neocuproine)2]+ was at 456 nm and the apparent molar absorptivity was 1.2 x 10(4) L.mol-1.cm-1 in the selected system. Linear dynamic relationship was obtained in the concentration range of 2-24 micrograms.mL-1 for glutathione. The regression equation was as following: A = 0.0104 + 0.0385c. The correlation coefficients was 0.9998. The recoveries obtained were between 98.5% and 99.9%. The relative standard deviations were less than 0.9% for all analyses. This method was used to determine glutathione in soybean extracts by the electromagnetic field technique and satisfactory results were obtained.

  13. [Glutathione redox system, immune status, antioxidant enzymes and metabolism of purine nucleotides in hypothyroidism].

    PubMed

    Tapbergenov, S O; Sovetov, B S; Bekbosynova, R B; Bolysbekova, S M

    2015-01-01

    The immune status, components of the glutathione redox system, the activity of antioxidant enzymes and metabolism of purine nucleotides have been investigated in animals with experimental hypothyroidism. On day 8 after an increase in the number of leukocytes, lymphocytes, T-helpers and T-suppressors as well as increased number of B-lymphocytes was found in blood of thyroidectomized rats. This was accompanied by decreased activity of adenosine deaminase (AD), AMP-deaminase (AMPD), and 5'-nucleotidase (5'N) in blood, but the ratio of enzyme activity AD/AMPD increased. These changes in the activity of enzymes, involved in purine catabolism can be regarded as increased functional relationships between T and B lymphocytes in hypothyroidism. The functional changes of immune system cells were accompanied by increased activity of glutathione peroxidase (GPx), a decrease in the activity of superoxide dismutase (SOD), glutathione reductase (GR) and the ratio GH/GPx. Thyroidectomized rats had increased amounts of total, oxidized (GSSG) and reduced glutathione (GSH), but the ratio GSH/GSSG decerased as compared with control animals. In the liver, hypothyroidism resulted in activation of SOD, GPx, decreased activity of GR and decreased ratio GR/GPx. At the same time, the levels of total, oxidized, and reduced glutathione increased, but the ratio GSH/GSSG as well as activities of enzymes involved in purine nucleotide metabolism ratio (and their ratio 5'N/AD + AMPD) decreased. All these data suggest a functional relationship of the glutathione redox system not only with antioxidant enzymes, but also activity of enzymes involved purine nucleotide metabolism and immune status.

  14. Martial art training enhances the glutathione antioxidant system in middle-aged adults.

    PubMed

    Douris, Peter C; Elokda, Ahmed S; Handrakis, John P; Principal, Suze; Rondo, Eleni; Bovell, Juan; Coughlin, William P; Mastroianni, Charles N; Wong, Michael J; Zimmerman, Thomas

    2009-08-01

    The purpose of this study was to compare the antioxidant capacity of physically active middle-aged martial artists to age-matched sedentary controls. Nine sedentary subjects (mean age 52.9 yr) and 9 martial artists (mean age 51.8 yr) who practice Soo Bahk Do, a Korean martial art and were age- and sex-matched performed a graded exercise test (GXT) using a modified Bruce protocol. Ages ranged from 41 to 58 years. A GXT has been shown to be an effective technique for inducing oxidative stress. Glutathione (GSH) is the body's most highly concentrated antioxidant, is the central component of the antioxidant system, and plays an essential role in protecting tissues against oxidative stress. Free radical oxidation leads to the transformation of GSH to glutathione disulfide (GSSG). Venous blood samples for GSH and GSSG were collected before and immediately after the GXT. Repeated measures analysis of variance were performed on the resting baseline values and immediate post-GXT values of GSH, GSSG, and GSH:GSSG to compare groups. The blood GSH, GSSG, and GSH:GSSG levels were significantly different (p < 0.001) between the 2 groups at rest and after the GXT. The Soo Bahk Do practitioners had higher resting levels of GSH and lower levels of GSSG and responded more effectively to acute oxidative stress than the age-matched sedentary controls. Soo Bahk Do appears to enhance the antioxidant defense system and may be an effective intervention for improving overall health by protecting against the adverse effects of oxidative stress that is associated with the free radical theory of aging. Health professionals should be aware of alternative methods of training, conditioning, and exercise that can improve the general adaptation response to oxidative stress.

  15. 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

  16. A study of gender, strain and age differences in mouse liver glutathione-S-transferase.

    PubMed

    Egaas, E; Falls, J G; Dauterman, W C

    1995-01-01

    The hepatic cytosolic glutathione S-transferase (GST) activity in four strains of the mouse and one strain of the rat was studied with the substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethachrynic acid (ETHA), cumene hydroperoxide (CU) and atrazine as the in vitro substrates. In the mouse, significant gender, strain and age-related differences in the GST activity towards CDNB and atrazine were found between adolescent and sexually mature males and females of the CD-1, C57BL/6, DBA/2 and Swiss-Webster strains, and the differences were larger with atrazine as the substrate. With DCNB and CU a similar tendency was observed, however not significant for all strains. The GST activity towards ETHA was also gender and strain specific, but revealed no age-related differences. The herbicide atrazine seems to be a useful substrate in the study of strain and age-related differences in the mouse GST class Pi.

  17. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862... I (general controls). The device is exempt from the premarket notification procedures in subpart...

  18. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862... I (general controls). The device is exempt from the premarket notification procedures in subpart...

  19. 21 CFR 862.1365 - Glutathione test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862... I (general controls). The device is exempt from the premarket notification procedures in subpart...

  20. Systems toxicology: modelling biomarkers of glutathione homeostasis and paracetamol metabolism.

    PubMed

    Stahl, Simone H; Yates, James W; Nicholls, Andrew W; Kenna, J Gerry; Coen, Muireann; Ortega, Fernando; Nicholson, Jeremy K; Wilson, Ian D

    2015-08-01

    One aim of systems toxicology is to deliver mechanistic, mathematically rigorous, models integrating biochemical and pharmacological processes that result in toxicity to enhance the assessment of the risk posed to humans by drugs and other xenobiotics. The benefits of such 'in silico' models would be in enabling the rapid and robust prediction of the effects of compounds over a range of exposures, improving in vitro-in vivo correlations and the translation from preclinical species to humans. Systems toxicology models of organ toxicities that result in high attrition rates during drug discovery and development, or post-marketing withdrawals (e.g., drug-induced liver injury (DILI)) should facilitate the discovery of safe new drugs. Here, systems toxicology as applied to the effects of paracetamol (acetaminophen, N-acetyl-para-aminophenol (APAP)) is used to exemplify the potential of the approach. PMID:26464084

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. The biological importance of glutathione peroxidase and peroxiredoxin backup systems in bivalves during peroxide exposure.

    PubMed

    Trevisan, Rafael; Mello, Danielle Ferraz; Uliano-Silva, Marcela; Delapedra, Gabriel; Arl, Miriam; Dafre, Alcir Luiz

    2014-10-01

    Organic peroxide elimination in eukaryotes essentially depends on glutathione peroxidase (GPx) and peroxiredoxin (Prx) enzymes, which are supported by their respective electron donors, glutathione (GSH) and thioredoxin (Trx). This system depends on the ancillary enzymes glutathione reductase (GR) and thioredoxin reductase (TrxR) to maintain GSH and Trx in their reduced state. This study discusses the biological importance of GR and TrxR in supporting GPx and Prx during cumene hydroperoxide (CHP) exposure in brown mussel Perna perna. ZnCl2 or 1-chloro-2,4-dinitrobenze (CDNB) was used to decrease GR and TrxR activities in gills, as already reported with mammals and bivalves. ZnCl2 exposure lowered GR activity (28%), impaired the in vivo CHP decomposition and decreased the survival rates under CHP exposure. CDNB decreased GR (54%) and TrxR (73%) activities and induced glutathione depletion (99%), promoting diminished peroxide elimination and survival rates at a greater extent than ZnCl2. CDNB also increased the susceptibility of hemocytes to CHP toxicity. Despite being toxic and causing mortality at longer exposures, short (2 h) exposure to CHP promoted an up regulation of GSH (50 and 100 μM CHP) and protein-thiol (100 μM CHP) levels, which was blocked by ZnCl2 or CDNB pre-exposure. Results highlight the biological importance of GSH, GR and TrxR in supporting GPx and Prx activities, contributing to organic peroxides elimination and mussel survival under oxidative challenges. To our knowledge, this is the first work that demonstrates, albeit indirectly, the biological importance of GPx/GR/GSH and Prx/TrxR/Trx systems on in vivo organic peroxide elimination in bivalves.

  6. Selectivity of silymarin on the increase of the glutathione content in different tissues of the rat.

    PubMed

    Valenzuela, A; Aspillaga, M; Vial, S; Guerra, R

    1989-10-01

    Silymarin, a flavonoid extracted from the seeds of the milk thistle, Silybum marianum, increases the redox state and the total glutathione content of the liver, intestine, and stomach of the rat. The same treatment does not affect the levels of the tripeptides in the kidney, lung, and spleen. This selective effect of the flavonoid on the digestive organs is ascribed to its pharmacokinetics on the digestive track, where the biliary concentration of silymarin is increased and maintained via the entero-hepatic circulation.

  7. [GLUTATHIONE SYSTEM ACTIVITY IN RAT TISSUES UNDER PHENYLETHYL BIGUANIDE ACTION ON THE BACKGROUND OF EXPERIMENTAL BRAIN ISCHEMIA/REPERFUSION DEVELOPMENT].

    PubMed

    Safonova, O A; Popova, T N; Kryl'skii, D V

    2016-01-01

    It was studied the total antioxidant activity, content of primary lipid peroxidation (LPO) products and reduced glutathione, and the activity of glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and NADP-isocitrate dehydrogenase in rat tissues under phenylethyl biguanide (phenfor- min) action on the background of experimental brain ischemia/reperfusion development. It is stablished the analyzed parameters, increasing under ischemia/reperfusion conditions in the brain and blood serum of animals, exhibit a decrease upon the introduction of this biguanide derivative. The obtained data can be explained by a decrease in degree of mobilization of the antioxidant system--in particular, of its glutathione chain--in the pathologic state. Hence, there is a need in NADPH supply for the system functioning compared with the pathology. Thus, phenylethyl biguanide demonstrates its antioxidant and protective properties under oxidative stress development that is accompanied by accumulation of the products of free radical oxidation of biomolecules during the ischemic brain injury. PMID:27159954

  8. Selenium and glutathione peroxidases in blood of patients with different stages of chronic renal failure.

    PubMed

    Zachara, Bronislaw A; Salak, Anna; Koterska, Dominika; Manitius, Jacek; Wasowicz, Wojciech

    2004-01-01

    In patients with chronic renal failure (CRF) Se concentration in blood components is usually lower as compared with healthy controls. One of the five known forms of Se-dependent glutathione peroxidases (GSH-Px), the plasma GSH-Px, is synthesized primarily in the kidney. In CRF patients, plasma GSH-Px activity is reduced and the reduction increases with the progress of the disease. The Se concentration in blood components was measured spectrofluorometrically with 2,3-diaminonaphthalene as complexing reagent. Activities of GSH-Px in red cells and in plasma were assayed by the coupled method with t-butyl hydroperoxide as substrate. The study group consisted of 150 patients in different stages of CRF. The results were compared with the values for 30 healthy subjects. Se concentrations in whole blood and plasma of the entire group of patients were significantly lower (p < 0.01) as compared with the healthy subjects. In the incipient stage, however, the Se levels in all blood components were non-significantly lower. In whole blood and plasma the Se levels gradually decreased, reaching in the end stage values that were lower by 29 to 32% (p < 0.0001) as compared with the control group. Total protein and albumin levels in plasma of patients were significantly lower (p < 0.0001) as compared with healthy subjects and they decreased linearly with the progress of the disease. Positive and highly significant correlations were noted between total plasma protein and plasma Se concentrations (p < 0.0001) as well as between plasma albumin and plasma Se concentrations (p < 0.0001). Red cell GSH-Px activity in the entire group of patients was lower (p < 0.05) than in the control group and did not change significantly with the progress of the disease. In plasma, however, GSH-Px activity of the entire group was lower by 33% (p < 0.0001) as compared with healthy subjects and decreased gradually with increasing renal failure. Highly significant, inverse correlations were seen between

  9. Preferential regeneration of thioredoxin from parasitic flatworm Fasciola gigantica using glutathione system.

    PubMed

    Gupta, Ankita; Pandey, Tripti; Kumar, Bijay; Tripathi, Timir

    2015-11-01

    The maintenance of cellular redox homeostasis is a crucial adaptive problem faced by parasites, and its disruption can shift the biochemical balance toward the host. The thioredoxin (Trx) system plays a key role in redox metabolism and defense against oxidative stress. In this study, biochemical experiments were performed on Fasciola gigantica Thioredoxin1 (FgTrx1). The recombinant FgTrx1 exists as a monomer and catalyzes the reduction of insulin. FgTrx1 is preferentially regenerated by the glutathione (GSH) system using glutathione reductase (GR). The regeneration of FgTrx1 by the conventional Trx system is much less as compared to the GSH system, suggesting that FgTrx1 could be acting as glutaredoxin (Grx). DNA nicking and hydroperoxide assay suggests that it protects the DNA from radical-induced oxidative damage. Thus, FgTrx1 might play a role in parasite survival as it can regenerate itself even in the absence of the canonical Trx system and also protect the cells from ROS induced damage. Further, we propose that the GR activity of FgTrx1 is not restricted to -CXXC- motif but is regulated by residues present in close proximity to the -CXXC- motif, through manipulation of the redox potential or the pKa of the active site Cys residues.

  10. 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

  11. E6* oncoprotein expression of human papillomavirus type-16 determines different ultraviolet sensitivity related to glutathione and glutathione peroxidase antioxidant defence.

    PubMed

    Mouret, Stéphane; Sauvaigo, Sylvie; Peinnequin, André; Favier, Alain; Beani, Jean-Claude; Leccia, Marie-Thérèse

    2005-06-01

    Clinical observations of non-melanoma skin cancer in immunocompromised patients, such as organ transplant recipients, suggest co-operative effects of human papillomavirus (HPV) and ultraviolet (UV) radiation. The aim of the present study is to evaluate UV sensitivity and DNA damage formation according to antioxidant status in HPV16-infected keratinocytes. We used SKv cell lines, infected with HPV16 and well characterized for their proliferative and tumorigenic capacities. We showed that SKv cell lines presented various E6* (a truncated form of E6) RNA levels. We demonstrated that the higher oncoprotein RNA expression level was associated with a higher resistance to solar-simulated radiation, more specifically to UVB radiation and to hydrogen peroxide. Moreover, this high resistance was associated with a low oxidative DNA damage formation after UV radiation and was related to high glutathione content and glutathione peroxidase activities. Therefore, the results of our study suggest that E6* levels could modulate the glutathione/glutathione peroxidase pathway providing a mechanism to protect HPV-infected keratinocytes against an environmental oxidative stress, such as UV radiation.

  12. 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.

  13. Glutathione Production in Yeast

    NASA Astrophysics Data System (ADS)

    Bachhawat, Anand K.; Ganguli, Dwaipayan; Kaur, Jaspreet; Kasturia, Neha; Thakur, Anil; Kaur, Hardeep; Kumar, Akhilesh; Yadav, Amit

    Glutathione, γ -glutamyl-cysteinyl-glycine, is the most abundant non-protein thiol found in almost all eukaryotic cells (and in some prokaryotes). The tripeptide, which is synthesized non-ribosomally by the consecutive action of two soluble enzymes, is needed for carrying out numerous functions in the cell, most important of which is the maintenance of the redox buffer. The cycle of glutathione biosynthesis and degradation forms part of the γ -glutamyl cycle in most organisms although the latter half of the pathway has not been demonstrated in yeasts. Our current understanding of how glutathione levels are controlled at different levels in the cell is described. Several different routes and processes have been attempted to increase commercial production of glutathione using both yeast and bacteria. In this article we discuss the history of glutathione production in yeast. The current bottlenecks for increased glutathione production are presented based on our current understanding of the regulation of glutathione homeostasis, and possible strategies for overcoming these limitations for further enhancing and improving glutathione production are discussed

  14. 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

  15. 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

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

    PubMed

    Stringari, James; Nunes, Adriana K C; Franco, Jeferson L; Bohrer, Denise; Garcia, Solange C; Dafre, Alcir L; Milatovic, Dejan; Souza, Diogo O; Rocha, João 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(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(2)-isoprostanes levels at all time points. Significant negative correlations were found between F(2)-isoprostanes and GSH, as well as between F(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 mercury at

  17. 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

  18. 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

  19. Effects of glutathione modulation on oxidative stress and enzymatic antioxidant defence in yeast Pachysolen tannophilus.

    PubMed

    Saharan, Rajesh K; Sharma, Sukesh C

    2011-03-01

    The aim of this study was to explore the relationship of intracellular glutathione with various oxidative stress markers and the stress protectant marker trehalose. In the first group of yeast cells, diethyl maleate was used for depletion of glutathione. A second group of yeast cells were incubated with amino acids constituting glutathione (GIu, Cys, Gly) to increase glutathione level. Increased level of oxidative stress marker like ROS, protein carbonyl formation and lipid peroxidation and decreased viability in glutathione-depleted cells were observed in the present study. The increased activity of antioxidant enzymes SOD and CAT in the glutathione depleted group suggests the interaction of different antioxidant defence system in Pachysolen tannophilus. Furthermore, the increased levels of trehalose in glutathione-depleted group shows that trehalose acts as a stress reducer in glutathione depleted Pachysolen tannophilus.

  20. Antiaging effect of dietary chitosan supplementation on glutathione-dependent antioxidant system in young and aged rats.

    PubMed

    Anandan, R; Ganesan, B; Obulesu, T; Mathew, S; Asha, K K; Lakshmanan, P T; Zynudheen, A A

    2013-01-01

    Aging has been defined as the changes that occur in living organisms with the passage of time that lead to functional impairment and ultimately to death. Free radical-induced oxidative damage has long been thought to be the most important consequence of the aging process. In the present study, an attempt has been made to study the salubrious effects of dietary supplementation of chitosan on glutathione-dependent antioxidant defense system in young and aged rats. The dietary supplementation of chitosan significantly reduced the age-associated dyslipidemic abnormalities noted in the levels of total cholesterol, HDL-cholesterol, and LDL-cholesterol in plasma and heart tissue. Its administration significantly (P < 0.05) attenuated the oxidative stress in the heart tissue of aged rats through the counteraction of free radical formation by maintaining the enzymatic [glutathione peroxidase (GPx) and glutathione reductase (GR)] and non-enzymatic [reduced glutathione (GSH)] status at levels comparable to that of normal young rats. Our results conclude that dietary intake of chitosan restores the depleted myocardial antioxidant status and suggest that it could be an effective therapeutic agent in treatment of age-associated disorders where hypercholesterolemia and oxidative stress are the major causative factors.

  1. Control of oxidative reactions of hemoglobin in the design of blood substitutes: role of the ascorbate-glutathione antioxidant system.

    PubMed

    Simoni, Jan; Villanueva-Meyer, Javier; Simoni, Grace; Moeller, John F; Wesson, Donald E

    2009-02-01

    Uncontrolled oxidative reactions of hemoglobin (Hb) are still the main unresolved problem for Hb-based blood substitute developers. Spontaneous oxidation of acellular ferrous Hb into a nonfunctional ferric Hb generates superoxide anion. Hydrogen peroxide, formed after superoxide anion dismutation, may react with ferrous/ferric Hb to produce toxic ferryl Hb, fluorescent heme degradation products, and/or protein-based free radicals. In the presence of free iron released from heme, superoxide anion and hydrogen peroxide might react via the Haber-Weiss and Fenton reactions to generate the hydroxyl radical. These highly reactive oxygen and heme species may not only be involved in shifting the cellular redox balance to the oxidized state that facilitates signal transduction and pro-inflammatory gene expression, but could also be involved in cellular and organ injury, and generation of vasoactive compounds such as isoprostanes and angiotensins. It is believed that these toxic species may be formed after administration of Hb-based blood substitutes, particularly in ischemic patients with a diminished ability to control oxidative reactions. Although varieties of antioxidant strategies have been suggested, this in vitro study examined the ability of the ascorbate-glutathione antioxidant system in preventing Hb oxidation and formation of its ferryl intermediate. The results suggest that although ascorbate is effective in reducing the formation of ferryl Hb, glutathione protects heme against excessive oxidation. Ascorbate without glutathione failed to protect the red blood cell membranes against Hb/hydrogen peroxide-mediated peroxidation. This study provides evidence that the ascorbate-glutathione antioxidant system is essential in attenuation of the pro-oxidant potential of redox active acellular Hbs, and superior to either ascorbate or glutathione alone. PMID:19178455

  2. Control of oxidative reactions of hemoglobin in the design of blood substitutes: role of the ascorbate-glutathione antioxidant system.

    PubMed

    Simoni, Jan; Villanueva-Meyer, Javier; Simoni, Grace; Moeller, John F; Wesson, Donald E

    2009-02-01

    Uncontrolled oxidative reactions of hemoglobin (Hb) are still the main unresolved problem for Hb-based blood substitute developers. Spontaneous oxidation of acellular ferrous Hb into a nonfunctional ferric Hb generates superoxide anion. Hydrogen peroxide, formed after superoxide anion dismutation, may react with ferrous/ferric Hb to produce toxic ferryl Hb, fluorescent heme degradation products, and/or protein-based free radicals. In the presence of free iron released from heme, superoxide anion and hydrogen peroxide might react via the Haber-Weiss and Fenton reactions to generate the hydroxyl radical. These highly reactive oxygen and heme species may not only be involved in shifting the cellular redox balance to the oxidized state that facilitates signal transduction and pro-inflammatory gene expression, but could also be involved in cellular and organ injury, and generation of vasoactive compounds such as isoprostanes and angiotensins. It is believed that these toxic species may be formed after administration of Hb-based blood substitutes, particularly in ischemic patients with a diminished ability to control oxidative reactions. Although varieties of antioxidant strategies have been suggested, this in vitro study examined the ability of the ascorbate-glutathione antioxidant system in preventing Hb oxidation and formation of its ferryl intermediate. The results suggest that although ascorbate is effective in reducing the formation of ferryl Hb, glutathione protects heme against excessive oxidation. Ascorbate without glutathione failed to protect the red blood cell membranes against Hb/hydrogen peroxide-mediated peroxidation. This study provides evidence that the ascorbate-glutathione antioxidant system is essential in attenuation of the pro-oxidant potential of redox active acellular Hbs, and superior to either ascorbate or glutathione alone.

  3. 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

  4. The glutathione-dependent system of antioxidant defense is not modulated by temperature acclimation in muscle tissues from striped bass, Morone saxatilis.

    PubMed

    Grim, Jeffrey M; Simonik, Elizabeth A; Semones, Molly C; Kuhn, Donald E; Crockett, Elizabeth L

    2013-02-01

    Cold temperature generally induces an enhancement of oxidative capacities, a greater content of intracellular lipids, and a remodeling of lipids in biological membranes. These physiological responses may pose a heightened risk of lipid peroxidation (LPO), while warm temperature could result in greater risk of LPO since rates involving reactive oxygen species and LPO will be elevated. The current study examines responses of the glutathione system of antioxidant defense after temperature acclimation. We measured total glutathione (tGSH), and protein levels of GPx1, GPx4, and GST (cardiac and skeletal muscles), and enzymatic activity (skeletal muscle) of glutathione-dependent antioxidants (GPx, GPx4, and GST) in tissues from striped bass (Morone saxatilis) acclimated for six weeks to 7 °C or 25 °C. tGSH of cardiac muscle from cold-acclimated animals was 1.2-times higher than in warm-bodied counterparts, but unchanged with temperature acclimation in skeletal muscle. A second low molecular weight antioxidant, ascorbate was 1.4- and 1.5-times higher in cardiac and skeletal muscle, respectively in warm- than cold-acclimated animals. Despite 1.2-times higher oxidative capacities (as indicated by citrate synthase activity), in skeletal muscle from cold- versus warm-acclimated fish, levels and activities of antioxidant enzymes were similar between acclimation groups. Lipid peroxidation products (as indicated by TBARS), normalized to tissue wet weight, were more than 2-times higher in skeletal muscle from cold- than warm-acclimated animals, however, when normalized to phospholipid content there was no statistical difference between acclimation groups. Our results demonstrate that the physiological changes, associated with acclimation to low temperature in the eurythermal striped bass, are not accompanied by an enhanced antioxidant defense in the glutathione-dependent system. PMID:23202656

  5. The glutathione-dependent system of antioxidant defense is not modulated by temperature acclimation in muscle tissues from striped bass, Morone saxatilis.

    PubMed

    Grim, Jeffrey M; Simonik, Elizabeth A; Semones, Molly C; Kuhn, Donald E; Crockett, Elizabeth L

    2013-02-01

    Cold temperature generally induces an enhancement of oxidative capacities, a greater content of intracellular lipids, and a remodeling of lipids in biological membranes. These physiological responses may pose a heightened risk of lipid peroxidation (LPO), while warm temperature could result in greater risk of LPO since rates involving reactive oxygen species and LPO will be elevated. The current study examines responses of the glutathione system of antioxidant defense after temperature acclimation. We measured total glutathione (tGSH), and protein levels of GPx1, GPx4, and GST (cardiac and skeletal muscles), and enzymatic activity (skeletal muscle) of glutathione-dependent antioxidants (GPx, GPx4, and GST) in tissues from striped bass (Morone saxatilis) acclimated for six weeks to 7 °C or 25 °C. tGSH of cardiac muscle from cold-acclimated animals was 1.2-times higher than in warm-bodied counterparts, but unchanged with temperature acclimation in skeletal muscle. A second low molecular weight antioxidant, ascorbate was 1.4- and 1.5-times higher in cardiac and skeletal muscle, respectively in warm- than cold-acclimated animals. Despite 1.2-times higher oxidative capacities (as indicated by citrate synthase activity), in skeletal muscle from cold- versus warm-acclimated fish, levels and activities of antioxidant enzymes were similar between acclimation groups. Lipid peroxidation products (as indicated by TBARS), normalized to tissue wet weight, were more than 2-times higher in skeletal muscle from cold- than warm-acclimated animals, however, when normalized to phospholipid content there was no statistical difference between acclimation groups. Our results demonstrate that the physiological changes, associated with acclimation to low temperature in the eurythermal striped bass, are not accompanied by an enhanced antioxidant defense in the glutathione-dependent system.

  6. 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.

  7. 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.

  8. 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.

  9. [Effect of Arnica montana on the state of lipid peroxidation and protective glutathione system of rat liver in experimental toxic hepatitis].

    PubMed

    Iamemiĭ, I M; Grygor'iea, N P; Meshchyshen, I F

    1998-01-01

    Effects of Tinctura Arnica on lipids peroxidation and on the protective glutathions system of liver in rats in case of experimental toxic hepatitis have been studied. Toxic hepatitis is accompanied by deep alterations of the oxidant-antioxidant status of the body. Intoxication of the body by CCl4 results in intensification of the free radicals formation particularly in liver: accumulation of lipids peroxidation molecular products, glutathione system enzyme activity inhibition in early terms and its partial restoration in remote terms has been seen. Our studies revealed that Arnica montana infusion inhibits the rate of lipids perioxidation products formation, affects the glutathione system enzymes activity.

  10. Subnormothermic Perfusion in the Isolated Rat Liver Preserves the Antioxidant Glutathione and Enhances the Function of the Ubiquitin Proteasome System

    PubMed Central

    Alva, Norma; Sanchez-Nuño, Sergio; Dewey, Shannamar; Gomes, Aldrin V.

    2016-01-01

    The reduction of oxidative stress is suggested to be one of the main mechanisms to explain the benefits of subnormothermic perfusion against ischemic liver damage. In this study we investigated the early cellular mechanisms induced in isolated rat livers after 15 min perfusion at temperatures ranging from normothermia (37°C) to subnormothermia (26°C and 22°C). Subnormothermic perfusion was found to maintain hepatic viability. Perfusion at 22°C raised reduced glutathione levels and the activity of glutathione reductase; however, lipid and protein oxidation still occurred as determined by malondialdehyde, 4-hydroxynonenal-protein adducts, and advanced oxidation protein products. In livers perfused at 22°C the lysosomal and ubiquitin proteasome system (UPS) were both activated. The 26S chymotrypsin-like (β5) proteasome activity was significantly increased in the 26°C (46%) and 22°C (42%) groups. The increased proteasome activity may be due to increased Rpt6 Ser120 phosphorylation, which is known to enhance 26S proteasome activity. Together, our results indicate that the early events produced by subnormothermic perfusion in the liver can induce oxidative stress concomitantly with antioxidant glutathione preservation and enhanced function of the lysosomal and UPS systems. Thus, a brief hypothermia could trigger antioxidant mechanisms and may be functioning as a preconditioning stimulus. PMID:27800122

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. FK506 Neuroprotection after Cavernous Nerve Injury is Mediated by Thioredoxin and Glutathione Redox Systems

    PubMed Central

    Lagoda, Gwen; Xie, Yi; Sezen, Sena F.; Hurt, K. Joseph; Liu, Limin; Musicki, Biljana; Burnett, Arthur L.

    2015-01-01

    Introduction Immunophilin ligands such as FK506 (FK) preserve erectile function (EF) following cavernous nerve injury (CNI), although the precise mechanisms are unclear. We examined whether the thioredoxin (Trx) and glutathione (GSH) redox systems mediate this effect after CNI. Aim Investigate the roles of Trx reductase 2 (TrxR2) and S-Nitrosoglutathione reductase (GSNOR) as antioxidative/nitrosative and antiapoptotic mediators of the neuroprotective effect of FK in the penis after CNI. Methods Adult male rats, wild-type (WT) mice, and GSNOR deficient (GSNOR −/−) mice were divided into four groups: sham surgery (CN exposure only) + vehicle; sham surgery + FK (5mg/kg/day/rat or 2mg/kg/day/mouse, for 2 days, subcutaneous); CNI + vehicle; and CNI + FK. At day 4 after injury, electrically stimulated changes in intracavernosal pressure (ICP) were measured. Penes were collected for Western blot analysis of TrxR2, GSNOR and Bcl-2 and for immunolocalization of TrxR2 and GSNOR. Main Outcome Measures EF assessment represented by maximal ICP and total ICP in response to electrical stimulation. Evaluation of protein expression levels and distribution patterns of antioxidative/nitrosative and antiapoptotic factors in penile tissue. Results EF decreased after CNI compared with sham surgery values in both rats (p<0.01) and WT and GSNOR −/− mice (p<0.05). FK treatment preserved EF after CNI compared with vehicle treatment in rats (p<0.01) and WT mice (p<0.05) but not in GSNOR −/− mice. In rats, GSNOR (p<0.01) and Bcl-2 (p<0.05) expressions were significantly decreased after CNI. FK treatment in CN-injured rats restored expression of GSNOR and upregulated TrxR2 (p<0.001) and Bcl-2 (p<0.001) expressions compared with vehicle treatment. Localizations of proteins in the penis were observed for: TrxR2 (endothelium, smooth muscle) and for GSNOR (nerves, endothelium, smooth muscle). Conclusions The neuroprotective effect of FK in preserving EF after CNI involves antioxidative

  16. Transcriptional differences in gene families of the ascorbate-glutathione cycle in wheat during mild water deficit.

    PubMed

    Secenji, Maria; Hideg, Eva; Bebes, Attila; Györgyey, János

    2010-01-01

    When comparing the responses of two wheat (Triticum aestivum L.) genotypes, the drought-tolerant Plainsman V and the drought-sensitive Cappelle Desprez, to reduced amounts of irrigation water, we found differences in ascorbate metabolism: both ascorbate oxidation and transcription levels of enzymes processing ascorbate were changed. Relative transcript levels of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) isoenzymes, predicted to localize in distinct subcellular organelles, showed different transcriptional changes in the two genotypes. Among APX coding mRNAs, expression levels of two cytosolic (cAPX I, II) and a thylakoid-bound (tAPX) variants increased significantly in Plainsman V while a cytosolic (cAPX I) and a stromal (sAPX II) APX coding transcripts were found to be higher in Cappelle Desprez after a 4-week-long water-deficit stress. Examining the MDARs, two cytosolic isoforms (cMDAR I, II) displayed significant up-regulation of mRNA levels in the sensitive genotype, whereas only one of them (cMDAR II) did in the tolerant cultivar. We found an up-regulated chloroplastic DHAR (chlDHAR) mRNA only in the sensitive Cappelle Desprez. However, increased expression levels of a cytosolic GR (cGR) and a chloroplastic GR (chlGR) were detected only in the tolerant Plainsman V. After 4 weeks of reduced irrigation, a significantly lower ascorbate/dehydroascorbate ratio was detected in leaves of the sensitive Cappelle Desprez than in the tolerant Plainsman V. Our results indicate that more robust transcription of ascorbate-based detoxification machinery may prevent an adverse shift of the cellular redox balance.

  17. Modeling the acid-base properties of glutathione in different ionic media, with particular reference to natural waters and biological fluids.

    PubMed

    Cigala, Rosalia Maria; Crea, Francesco; De Stefano, Concetta; Lando, Gabriele; Milea, Demetrio; Sammartano, Silvio

    2012-08-01

    The acid-base properties of γ-L-glutamyl-L-cysteinyl-glycine (glutathione, GSH) were determined by potentiometry (ISE-H(+), glass electrode) in pure NaI((aq)) and in NaCl((aq))/MgCl(2(aq)), and NaCl((aq))/CaCl(2(aq)) mixtures, at T = 298.15 K and different ionic strengths (up to I(c) ~ 5.0 mol L(-1)). In addition, the activity coefficients of glutathione were also determined by the distribution method at the same temperature in various ionic media (LiCl((aq)), NaCl((aq)), KCl((aq)), CsCl((aq)), MgCl(2(aq)), CaCl(2(aq)), NaI((aq))). The results obtained were also used to calculate the Specific ion Interaction Theory (SIT) and Pitzer coefficients for the dependence on medium and ionic strength of glutathione species, as well as the formation constants of weak Mg(j)H( i )(GSH)((i+2j-3)) and Ca(j)H(i)(GSH)((i+2j-3)) complexes. Direct calorimetric titrations were also carried out in pure NaCl((aq)) and in NaCl((aq))/CaCl(2(aq)) mixtures at different ionic strengths (0.25 ≤ I (c )/mol L(-1) ≤ 5.0) in order to determine the enthalpy changes for the protonation and complex formation equilibria in these media at T = 298.15 K. Results obtained are useful for the definition of glutathione speciation in any aqueous media containing the main cations of natural waters and biological fluids, such as Na(+), K(+), Mg(2+), and Ca(2+). Finally, this kind of systematic studies, where a series of ionic media (e.g., all alkali metal chlorides) is taken into account in the determination of various thermodynamic parameters, is useful for the definition of some trends in the thermodynamic behavior of glutathione in aqueous solution. PMID:21997535

  18. Modeling the acid-base properties of glutathione in different ionic media, with particular reference to natural waters and biological fluids.

    PubMed

    Cigala, Rosalia Maria; Crea, Francesco; De Stefano, Concetta; Lando, Gabriele; Milea, Demetrio; Sammartano, Silvio

    2012-08-01

    The acid-base properties of γ-L-glutamyl-L-cysteinyl-glycine (glutathione, GSH) were determined by potentiometry (ISE-H(+), glass electrode) in pure NaI((aq)) and in NaCl((aq))/MgCl(2(aq)), and NaCl((aq))/CaCl(2(aq)) mixtures, at T = 298.15 K and different ionic strengths (up to I(c) ~ 5.0 mol L(-1)). In addition, the activity coefficients of glutathione were also determined by the distribution method at the same temperature in various ionic media (LiCl((aq)), NaCl((aq)), KCl((aq)), CsCl((aq)), MgCl(2(aq)), CaCl(2(aq)), NaI((aq))). The results obtained were also used to calculate the Specific ion Interaction Theory (SIT) and Pitzer coefficients for the dependence on medium and ionic strength of glutathione species, as well as the formation constants of weak Mg(j)H( i )(GSH)((i+2j-3)) and Ca(j)H(i)(GSH)((i+2j-3)) complexes. Direct calorimetric titrations were also carried out in pure NaCl((aq)) and in NaCl((aq))/CaCl(2(aq)) mixtures at different ionic strengths (0.25 ≤ I (c )/mol L(-1) ≤ 5.0) in order to determine the enthalpy changes for the protonation and complex formation equilibria in these media at T = 298.15 K. Results obtained are useful for the definition of glutathione speciation in any aqueous media containing the main cations of natural waters and biological fluids, such as Na(+), K(+), Mg(2+), and Ca(2+). Finally, this kind of systematic studies, where a series of ionic media (e.g., all alkali metal chlorides) is taken into account in the determination of various thermodynamic parameters, is useful for the definition of some trends in the thermodynamic behavior of glutathione in aqueous solution.

  19. [Structure and functions of glutathione transferases].

    PubMed

    Fedets, O M

    2014-01-01

    Data about classification, nomenclature, structure, substrate specificity and role of many glutathione transferase's isoenzymes in cell functions have been summarised. The enzyme has been discovered more than 50 years ago. This family of proteins is updated continuously. It has very different composition and will have demand for system analysis for many years.

  20. Glutathione transferase gene family from the housefly Musca domestica.

    PubMed

    Syvanen, M; Zhou, Z H; Wang, J Y

    1994-10-17

    Three new glutathione transferase (GST) genes from the housefly Musca domestica are described. These genes, identified as MdGST-2, -3, and -4, were from cDNA clones obtained from a cDNA bank in phage lambda. The bank was prepared using poly(A)+ RNA from a housefly that is highly resistant to organophosphate insecticides because of enhanced expression of multiple members of the glutathione transferase gene family. The DNA sequence of each is reported and has a complete open reading frame that specified an amino acid sequence similar to other dipteran glutathione transferases. Based on phylogenetic analysis, we can conclude that the insect glutathione transferase gene family falls into two groups, each of which evolves at a different rate, presumably due to differences in functional constraints. We show that MdGST-1 (and their homologues from Drosophila and Lucilia) evolve at a significantly slower rate than the other members of the gene family. Each housefly GST cDNA was inserted into a bacterial plasmid expression system and a glutathione transferase activity was expressed in Escherichia coli. The transcription pattern of each of these glutathione transferases was examined in a variety of different housefly strains that are known to differ in their resistance to organophosphate insecticides due to different patterns of glutathione transferase expression. We found that the level of transcription for two of our clones was positively correlated with the level of organophosphate resistance.

  1. 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

  2. Glutathione transferases and neurodegenerative diseases.

    PubMed

    Mazzetti, Anna Paola; Fiorile, Maria Carmela; Primavera, Alessandra; Lo Bello, Mario

    2015-03-01

    There is substantial agreement that the unbalance between oxidant and antioxidant species may affect the onset and/or the course of a number of common diseases including Parkinson's and Alzheimer's diseases. Many studies suggest a crucial role for oxidative stress in the first phase of aging, or in the pathogenesis of various diseases including neurological ones. Particularly, the role exerted by glutathione and glutathione-related enzymes (Glutathione Transferases) in the nervous system appears more relevant, this latter tissue being much more vulnerable to toxins and oxidative stress than other tissues such as liver, kidney or muscle. The present review addresses the question by focusing on the results obtained by specimens from patients or by in vitro studies using cells or animal models related to Parkinson's and Alzheimer's diseases. In general, there is an association between glutathione depletion and Parkinson's or Alzheimer's disease. In addition, a significant decrease of glutathione transferase activity in selected areas of brain and in ventricular cerebrospinal fluid was found. For some glutathione transferase genes there is also a correlation between polymorphisms and onset/outcome of neurodegenerative diseases. Thus, there is a general agreement about the protective effect exerted by glutathione and glutathione transferases but no clear answer about the mechanisms underlying this crucial role in the insurgence of neurodegenerative diseases.

  3. Growth hormone alters the glutathione S-transferase and mitochondrial thioredoxin systems in long-living Ames dwarf mice.

    PubMed

    Rojanathammanee, Lalida; Rakoczy, Sharlene; Brown-Borg, Holly M

    2014-10-01

    Ames dwarf mice are deficient in growth hormone (GH), prolactin, and thyroid-stimulating hormone and live significantly longer than their wild-type (WT) siblings. The lack of GH is associated with stress resistance and increased longevity. However, the mechanism underlying GH's actions on cellular stress defense have yet to be elucidated. In this study, WT or Ames dwarf mice were treated with saline or GH (WT saline, Dwarf saline, and Dwarf GH) two times daily for 7 days. The body and liver weights of Ames dwarf mice were significantly increased after 7 days of GH administration. Mitochondrial protein levels of the glutathione S-transferase (GST) isozymes, K1 and M4 (GSTK1 and GSTM4), were significantly higher in dwarf mice (Dwarf saline) when compared with WT mice (WT saline). GH administration downregulated the expression of GSTK1 proteins in dwarf mice. We further investigated GST activity from liver lysates using different substrates. Substrate-specific GST activity (bromosulfophthalein, dichloronitrobenzene, and 4-hydrox-ynonenal) was significantly reduced in GH-treated dwarf mice. In addition, GH treatment attenuated the activity of thioredoxin and glutaredoxin in liver mitochondria of Ames mice. Importantly, GH treatment suppressed Trx2 and TrxR2 mRNA expression. These data indicate that GH has a role in stress resistance by altering the functional capacity of the GST system through the regulation of specific GST family members in long-living Ames dwarf mice. It also affects the regulation of thioredoxin and glutaredoxin, factors that regulate posttranslational modification of proteins and redox balance, thereby further influencing stress resistance.

  4. Growth hormone alters the glutathione S-transferase and mitochondrial thioredoxin systems in long-living Ames dwarf mice.

    PubMed

    Rojanathammanee, Lalida; Rakoczy, Sharlene; Brown-Borg, Holly M

    2014-10-01

    Ames dwarf mice are deficient in growth hormone (GH), prolactin, and thyroid-stimulating hormone and live significantly longer than their wild-type (WT) siblings. The lack of GH is associated with stress resistance and increased longevity. However, the mechanism underlying GH's actions on cellular stress defense have yet to be elucidated. In this study, WT or Ames dwarf mice were treated with saline or GH (WT saline, Dwarf saline, and Dwarf GH) two times daily for 7 days. The body and liver weights of Ames dwarf mice were significantly increased after 7 days of GH administration. Mitochondrial protein levels of the glutathione S-transferase (GST) isozymes, K1 and M4 (GSTK1 and GSTM4), were significantly higher in dwarf mice (Dwarf saline) when compared with WT mice (WT saline). GH administration downregulated the expression of GSTK1 proteins in dwarf mice. We further investigated GST activity from liver lysates using different substrates. Substrate-specific GST activity (bromosulfophthalein, dichloronitrobenzene, and 4-hydrox-ynonenal) was significantly reduced in GH-treated dwarf mice. In addition, GH treatment attenuated the activity of thioredoxin and glutaredoxin in liver mitochondria of Ames mice. Importantly, GH treatment suppressed Trx2 and TrxR2 mRNA expression. These data indicate that GH has a role in stress resistance by altering the functional capacity of the GST system through the regulation of specific GST family members in long-living Ames dwarf mice. It also affects the regulation of thioredoxin and glutaredoxin, factors that regulate posttranslational modification of proteins and redox balance, thereby further influencing stress resistance. PMID:24285747

  5. [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

  6. Sensorially important aldehyde production from amino acids in model wine systems: impact of ascorbic acid, erythorbic acid, glutathione and sulphur dioxide.

    PubMed

    Grant-Preece, Paris; Fang, Hongjuan; Schmidtke, Leigh M; Clark, Andrew C

    2013-11-01

    The efficiency of different white wine antioxidant systems in preventing aldehyde production from amino acids by oxidative processes is not well understood. The aim of this study was to assess the efficiency of sulphur dioxide alone and in combination with either glutathione, ascorbic acid or its stereoisomer erythorbic acid, in preventing formation of the sensorially important compounds methional and phenylacetaldehyde from methionine and phenylalanine in model white wine. UHPLC, GC-MS/MS, LC-MS/MS, flow injection analysis and luminescence sensors determined both compositional changes during storage, and sulphur dioxide-aldehyde apparent equilibrium constants. Depending on temperature (25 or 45°C) or extent of oxygen supply, sulphur dioxide was equally or more efficient in impeding the production of methional compared to the other antioxidant systems. For phenylacetaldehyde, erythorbic acid or glutathione with sulphur dioxide provided improved inhibition compared to sulphur dioxide alone, in conditions of limited oxygen consumption. The results also demonstrate the extent to which sulphur dioxide addition can lower the free aldehyde concentrations to below their aroma thresholds.

  7. Comparison of age-related differences in expression of phospholipid hydroperoxide glutathione peroxidase mRNA and activity in various tissues of pigs.

    PubMed

    Lei, X G; Ross, D A; Roneker, K R

    1997-05-01

    Phospholipid hydroperoxide glutathione peroxidase (PHGPX) is the second identified Se-dependent intracellular glutathione peroxidase (PHGPX) that reduces phospholipid hydroperoxides. The objective of this study was to determine the developmental regulation of PHGPX expression in tissues of neonatal, weanling and finishing pigs (Sus scrofa) compared with the expression of the classic Se-dependent cellular glutathione peroxidase (GPX) and the Se-independent enzyme, glutathione S-transferase (GST). Eight different tissues were collected from Se-adequate male pigs aged 1, 28 and 180 days, and supernatant of the tissue homogenate was assayed for PHGPX, GPX and GST activities by using phosphatidylcholine hydroperoxide, hydrogen peroxide and 1-chloro-2,4-dinitrobenzene as substrate, respectively. Total RNA was isolated from four tissues and assayed for PHGPX mRNA expression. Both mRNA and activity expression of PHGPX in most assayed tissues was increased as pigs became older (P < 0.05), but increases in PHGPX mRNA levels between ages did not fully account for all changes in activity. Expression of GPX activity was increased more than that of PHGPX between day 1 and day 28 (P < 0.0001). Expression of GST activity in various tissues was also affected by age (P < 0.01) but lacked a consistent relationship with the changes in GPX and PHGPX activity. Tissue-specific patterns of developmental expression of these enzymes may be related to the susceptibility of organs to pro-oxidant injuries. In conclusion, expression of PHGPX mRNA and activity in various tissues of pigs is developmentally increased over ages, and the pattern is somewhat different from that of GPX.

  8. GLUTATHIONE SYNTHESIS

    PubMed Central

    Lu, Shelly C.

    2012-01-01

    BACKGROUND Glutathione (GSH) is present in all mammalian tissues as the most abundant non-protein thiol that defends against oxidative stress. GSH is also a key determinant of redox signaling, vital in detoxification of xenobiotics, regulates cell proliferation, apoptosis, immune function, and fibrogenesis. Biosynthesis of GSH occurs in the cytosol in a tightly regulated manner. Key determinants of GSH synthesis are the availability of the sulfur amino acid precursor, cysteine, and the activity of the rate-limiting enzyme, glutamate cysteine ligase (GCL), which is composed of a catalytic (GCLC) and a modifier (GCLM) subunit. The second enzyme of GSH synthesis is GSH synthetase (GS). SCOPE OF REVIEW This review summarizes key functions of GSH and focuses on factors that regulate the biosynthesis of GSH, including pathological conditions where GSH synthesis is dysregulated. MAJOR CONCLUSIONS GCL subunits and GS are regulated at multiple levels and often in a coordinated manner. Key transcription factors that regulate the expression of these genes include NF-E2 related factor 2 (Nrf2) via the antioxidant response element (ARE), AP-1, and nuclear factor kappa B (NFκB). There is increasing evidence that dysregulation of GSH synthesis contributes to the pathogenesis of many pathological conditions. These include diabetes mellitus, pulmonary and liver fibrosis, alcoholic liver disease, cholestatic liver injury, endotoxemia and drug-resistant tumor cells. GENERAL SIGNIFICANCE GSH is a key antioxidant that also modulates diverse cellular processes. A better understanding of how its synthesis is regulated and dysregulated in disease states may lead to improvement in the treatment of these disorders. PMID:22995213

  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. Exogenous glutathione improves high root-zone temperature tolerance by modulating photosynthesis, antioxidant and osmolytes systems in cucumber seedlings

    PubMed Central

    Ding, Xiaotao; Jiang, Yuping; He, Lizhong; Zhou, Qiang; Yu, Jizhu; Hui, Dafeng; Huang, Danfeng

    2016-01-01

    To investigate the physiological responses of plants to high root-zone temperature (HT, 35 °C) stress mitigated by exogenous glutathione (GSH), cucumber (Cucumis sativus L.) seedlings were exposed to HT with or without GSH treatment for 4 days and following with 4 days of recovery. Plant physiological variables, growth, and gene expression related to antioxidant enzymes and Calvin cycle were quantified. The results showed that HT significantly decreased GSH content, the ratio of reduced to oxidized glutathione (GSH/GSSG), chlorophyll content, photosynthesis and related gene expression, shoot height, stem diameter, as well as dry weight. The exogenous GSH treatment clearly lessened the HT stress by increasing the above variables. Meanwhile, HT significantly increased soluble protein content, proline and malondialdehyde (MDA) content as well as O2•− production rate, the gene expression and activities of antioxidant enzymes. The GSH treatment remarkably improved soluble protein content, proline content, antioxidant enzymes activities, and antioxidant enzymes related gene expression, and reduced the MDA content and O2•− production rate compared to no GSH treatment in the HT condition. Our results suggest that exogenous GSH enhances cucumber seedling tolerance of HT stress by modulating the photosynthesis, antioxidant and osmolytes systems to improve physiological adaptation. PMID:27752105

  11. Heterogeneous Role of the Glutathione Antioxidant System in Modulating the Response of ESFT to Fenretinide in Normoxia and Hypoxia

    PubMed Central

    Magwere, Tapiwanashe; Burchill, Susan A.

    2011-01-01

    Glutathione (GSH) is implicated in drug resistance mechanisms of several cancers and is a key regulator of cell death pathways within cells. We studied Ewing's sarcoma family of tumours (ESFT) cell lines and three mechanistically distinct anticancer agents (fenretinide, doxorubicin, and vincristine) to investigate whether the GSH antioxidant system is involved in the reduced sensitivity to these chemotherapeutic agents in hypoxia. Cell viability and death were assessed by the trypan blue exclusion assay and annexin V-PI staining, respectively. Hypoxia significantly decreased the sensitivity of all ESFT cell lines to fenretinide-induced death, whereas the effect of doxorubicin or vincristine was marginal and cell-line-specific. The response of the GSH antioxidant system in ESFT cell lines to hypoxia was variable and also cell-line-specific, although the level of GSH appeared to be most dependent on de novo biosynthesis rather than recycling. RNAi-mediated knockdown of key GSH regulatory enzymes γ-glutamylcysteine synthetase or glutathione disulfide reductase partially reversed the hypoxia-induced resistance to fenretinide, and increasing GSH levels using N-acetylcysteine augmented the hypoxia-induced resistance in a cell line-specific manner. These observations are consistent with the conclusion that the role of the GSH antioxidant system in modulating the sensitivity of ESFT cells to fenretinide is heterogeneous depending on environment and cell type. This is likely to limit the value of targeting GSH as a therapeutic strategy to overcome hypoxia-induced drug resistance in ESFT. Whether targeting the GSH antioxidant system in conjunction with other therapeutics may benefit some patients with ESFT remains to be seen. PMID:22174837

  12. 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

  13. Effects of heavy metals (Cd, Cu, Cr, Pb, Zn) on fish glutathione metabolism.

    PubMed

    Eroglu, A; Dogan, Z; Kanak, E G; Atli, G; Canli, M

    2015-03-01

    The glutathione metabolism contains crucial antioxidant molecules to defend the organisms against oxidants. Thus, the aim of this study was to investigate the response of the glutathione metabolism in the liver of freshwater fish Oreochromis niloticus exposed to metals (Cu, Cd, Cr, Pb, Zn) in different periods. Fish were exposed to metals (as 1 μg/mL) individually for 1, 7, and 14 days and subsequently antioxidant enzymes (glutathione peroxidase, GPX; glutathione reductase, GR and glutathione S-transferase, GST) and glutathione levels (total glutathione, tGSH; reduced glutathione, rGSH; oxidized glutathione, GSSG and GSH/GSSG ratios) in the liver were measured. There was no fish mortality during the experiments, except Cu exposure. The antioxidant enzymes responded differently to metal exposures depending on metal types and exposure durations. GPX activity increased only after Cd exposure, while GST activity increased following 7 days of all metal exposures. However, GR activity did not alter in most cases. Total GSH and GSH/GSSG levels generally decreased, especially after 7 days. Data showed that metal exposures significantly altered the response of antioxidant system parameters, particularly at day 7 and some recovery occurred after 14 days. This study suggests that the response of antioxidant system could help to predict metal toxicity in the aquatic environments and be useful as an "early warning tool" in natural monitoring studies.

  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. 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

    2010-01-20

    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.

  17. 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

  18. Modulation of glutathione-related antioxidant defense system of fish chronically treated by the fungicide propiconazole.

    PubMed

    Li, Zhi-Hua; Zlabek, Vladimir; Grabic, Roman; Li, Ping; Randak, Tomas

    2010-09-01

    Recently, residual fungicides are generally recognized as relevant sources of aquatic environmental pollutants. However, the toxicological effects of these contaminants have not been adequately researched. In this study, the chronic effect of PCZ, a triazole-containing fungicide commonly present in aquatic environment, on GSH-related antioxidant system and oxidative stress indices of rainbow trout (Oncorhynchus mykiss) were investigated. Fish were exposed at sub-lethal concentrations of PCZ (0.2, 50 and 500 microg/L) for 7, 20 and 30 days. GSH levels and GSH-related enzyme activities, including GPx, GR and GST, were quantified in three tissues-liver, gill and muscle. The levels of LPO and CP were also measured as makers of oxidative damage. In addition, the correlations of the measured parameters in various tissues were evaluated by using PCA. The results of this study indicate that chronic exposure of PCZ has resulted in different responses in various tissues and the gill was the most sensitive tissue; however, before these parameters are used as potential biomarkers for monitoring residual fungicides in aquatic environment, more detailed experiments in laboratory need to be performed in the future.

  19. 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.

  20. Glutathione transferase activity and expression patterns during grain filling in flag leaves of wheat genotypes differing in drought tolerance: Response to water deficit.

    PubMed

    Gallé, Agnes; Csiszár, Jolán; Secenji, Maria; Guóth, Adrienn; Cseuz, László; Tari, Irma; Györgyey, János; Erdei, László

    2009-11-15

    Total glutathione S-transferase (GST, EC 2.5.1.18) and glutathione peroxidase (GPOX) activity were measured spectrophotometrically in Triticum aestivum cv. MV Emese and cv. Plainsman (drought tolerant) and cv. GK Elet and Cappelle Desprez (drought-sensitive) flag leaves under control and drought stress conditions during the grain-filling period, in order to reveal possible roles of different GST classes in the senescence of flag leaves. Six wheat GSTs, members of 3 GST classes, were selected and their regulation by drought and senescence was investigated. High GPOX activity (EC 1.11.1.9) was observed in well-watered controls of the drought-tolerant Plainsman cultivar. At the same time, TaGSTU1B and TaGSTF6 sequences, investigated by real-time PCR, showed high-expression levels that increased with time, indicating that the gene products of these genes may play important roles in monocarpic senescence of wheat. Expression of these genes was also induced by drought stress in all of the four investigated cultivars, but extremely high transcript amounts were detected in cv. Plainsman. Our data indicate genotypic variations of wheat GSTs. Expression levels and early induction of two senescence-associated GSTs under drought during grain filling in flag leaves correlated with high yield stability.

  1. Drug repurposing: sulfasalazine sensitizes gliomas to gamma knife radiosurgery by blocking cystine uptake through system Xc-, leading to glutathione depletion.

    PubMed

    Sleire, L; Skeie, B S; Netland, I A; Førde, H E; Dodoo, E; Selheim, F; Leiss, L; Heggdal, J I; Pedersen, P-H; Wang, J; Enger, P Ø

    2015-12-01

    Glioblastomas (GBMs) are aggressive brain tumors that always recur after radiotherapy. Cystine, mainly provided by the system X(c)(-) antiporter, is a requirement for glioma cell synthesis of glutathione (GSH) which has a critical role in scavenging free radicals, for example, after radiotherapy. Thus, we hypothesized that the X(c)(-)-inhibitor sulfasalazine (SAS) could potentiate the efficacy of radiotherapy against gliomas. Here, we show that the catalytic subunit of system X(c)(-), xCT, was uniformly expressed in a panel of 30 human GBM biopsies. SAS treatment significantly reduced cystine uptake and GSH levels, whereas it significantly increased the levels of reactive oxygen species (ROS) in glioma cells in vitro. Furthermore, SAS and radiation synergistically increased DNA double-strand breaks and increased glioma cell death, whereas adding the antioxidant N-acetyl-L-cysteine (NAC) reversed cell death. Moreover, SAS and gamma knife radiosurgery (GKRS) synergistically prolonged survival in nude rats harboring human GBM xenografts, compared with controls or either treatment alone. In conclusion, SAS effectively blocks cystine uptake in glioma cells in vitro, leading to GSH depletion and increased ROS levels, DNA damage and cell death. Moreover, it potentiates the anti-tumor efficacy of GKRS in rats with human GBM xenografts, providing a survival benefit. Thus, SAS may have a role as a radiosensitizer to enhance the efficacy of current radiotherapies for glioma patients.

  2. The balance between 4-hydroxynonenal and intrinsic glutathione/glutathione S-transferase A4 system may be critical for the epidermal growth factor receptor phosphorylation of human esophageal squamous cell carcinomas.

    PubMed

    Uno, Kaname; Kato, Katsuaki; Kusaka, Gen; Asano, Naoki; Iijima, Katsunori; Shimosegawa, Tooru

    2011-10-01

    Oxidative stress might participate in the carcinogenesis of human esophageal squamous cell carcinomas (hESCC). 4-Hydroxynonenal (HNE) is a major product of membrane lipid peroxidation with short life. It might act as an important mediator through the generation of adducts and activate epidermal growth factor receptor (EGFR) signaling. It is mainly trapped with glutathione (GSH) and catalyzed by glutathione S-transferases (GSTs). This study aimed to elucidate the possible participation of HNE, GSH/GST system, and EGFR signaling in hESCC development. Immunohistochemistry of HNE adducts, EGFR, and phosphorylated EGFR (pEGFR) was performed with hESCC specimens. The effect of HNE on the phosphorylation of EGFR and its downstream PhospholipaseCγ1 (PLCγ1) was investigated with KYSE30 cell-line. Pretreatment with GSH inducer N-acetylcysteine (NAC) or GSH inhibitor Buthionine sulfoximine (BSO) and mandatory transfection of hGSTA4 gene in KYSE30 were conducted to investigate the relationship between HNE and GSH/GST system. Immunoreactants of HNE adducts, EGFR, and pEGFR were increased in hESCC compared to non-cancerous epithelium with positive correlations. The treatment of HNE ligand-independently induced the phosphorylation of EGFR and PLCγ1 accompanying the diminishment of intracellular GSH level. NAC increased GSH contents but BSO decreased in dose-dependent manners. Reflecting changes in GSH, HNE-induced EGFR phosphorylation was suppressed by NAC, whereas it was promoted by BSO. Mandatory expression of hGSTA4 suppressed HNE-induced events. We first demonstrated that the ligand-independent activation of EGFR by the balance between the stimulation of HNE and the prevention of intrinsic GSH/GST system might participate in the development of hESCC.

  3. The Glutathione/Glutaredoxin System Is Essential for Arsenate Reduction in Synechocystis sp. Strain PCC 6803▿ †

    PubMed Central

    López-Maury, Luis; Sánchez-Riego, Ana María; Reyes, José Carlos; Florencio, Francisco J.

    2009-01-01

    Arsenic resistance in Synechocystis sp. strain PCC 6803 is mediated by an operon of three genes in which arsC codes for an arsenate reductase with unique characteristics. Here we describe the identification of two additional and nearly identical genes coding for arsenate reductases in Synechocystis sp. strain PCC 6803, which we have designed arsI1 and arsI2, and the biochemical characterization of both ArsC (arsenate reductase) and ArsI. Functional analysis of single, double, and triple mutants shows that both ArsI enzymes are active arsenate reductases but that their roles in arsenate resistance are essential only in the absence of ArsC. Based on its biochemical properties, ArsC belongs to a family that, though related to thioredoxin-dependent arsenate reductases, uses the glutathione/glutaredoxin system for reduction, whereas ArsI belongs to the previously known glutaredoxin-dependent family. We have also analyzed the role in arsenate resistance of the three glutaredoxins present in Synechocystis sp. strain PCC 6803 both in vitro and in vivo. Only the dithiolic glutaredoxins, GrxA (glutaredoxin A) and GrxB (glutaredoxin B), are able to donate electrons to both types of reductases in vitro, while GrxC (glutaredoxin C), a monothiolic glutaredoxin, is unable to donate electrons to either type. Analysis of glutaredoxin mutant strains revealed that only those lacking the grxA gene have impaired arsenic resistance. PMID:19304854

  4. Measurement of malondialdehyde, glutathione, and glutathione peroxidase in SLE patients.

    PubMed

    Gheita, Tamer A; Kenawy, Sanaa A

    2014-01-01

    Oxidative stress contributes to chronic inflammation of tissues and plays a central role in immunomodulation, which may lead to autoimmune diseases such as systemic lupus erythematosus (SLE) and antiphospholipid syndrome. Markers of oxidative damage include malondialdehyde (MDA), antioxidant scavengers as glutathione (GSH), and glutathione peroxidase (GSH Px), which all correlate well with SLE disease activity. Amelioration of some clinical manifestations of SLE may be expected by targeting lipid peroxidation with dietary or pharmacological antioxidants. Here, we describe the detection of the key players of oxidant/antioxidant imbalance in SLE.

  5. Relevance of the glutathione system in temporal lobe epilepsy: evidence in human and experimental models.

    PubMed

    Cárdenas-Rodríguez, Noemí; Coballase-Urrutia, Elvia; Pérez-Cruz, Claudia; Montesinos-Correa, Hortencia; Rivera-Espinosa, Liliana; Sampieri, Aristides; Carmona-Aparicio, Liliana

    2014-01-01

    Oxidative stress, which is a state of imbalance in the production of reactive oxygen species and nitrogen, is induced by a wide variety of factors. This biochemical state is associated with diseases that are systemic as well as diseases that affect the central nervous system. Epilepsy is a chronic neurological disorder, and temporal lobe epilepsy represents an estimated 40% of all epilepsy cases. Currently, evidence from human and experimental models supports the involvement of oxidative stress during seizures and in the epileptogenesis process. Hence, the aim of this review was to provide information that facilitates the processing of this evidence and investigate the therapeutic impact of the biochemical status for this specific pathology.

  6. Relevance of the Glutathione System in Temporal Lobe Epilepsy: Evidence in Human and Experimental Models

    PubMed Central

    Cárdenas-Rodríguez, Noemí; Coballase-Urrutia, Elvia; Pérez-Cruz, Claudia; Montesinos-Correa, Hortencia; Rivera-Espinosa, Liliana; Sampieri, Aristides; Carmona-Aparicio, Liliana

    2014-01-01

    Oxidative stress, which is a state of imbalance in the production of reactive oxygen species and nitrogen, is induced by a wide variety of factors. This biochemical state is associated with diseases that are systemic as well as diseases that affect the central nervous system. Epilepsy is a chronic neurological disorder, and temporal lobe epilepsy represents an estimated 40% of all epilepsy cases. Currently, evidence from human and experimental models supports the involvement of oxidative stress during seizures and in the epileptogenesis process. Hence, the aim of this review was to provide information that facilitates the processing of this evidence and investigate the therapeutic impact of the biochemical status for this specific pathology. PMID:25538816

  7. Unusual production of glutathione in Actinobacteria

    PubMed Central

    Johnson, Todd; Newton, Gerald; Fahey, R.C.; Rawat, Mamta

    2008-01-01

    Most Actinobacteria produce mycothiol as the major thiol. In addition to mycothiol Rhodococcus AD45 generates a substantial level of glutathione possibly using genes acquired in a lateral transfer. Instead of mycothiol, Rubrobacter radiotolerans and Rubrobacter xylanophilus produce glutathione, whose synthesis appears to involve enzymes substantially different from those in other organisms. PMID:18719892

  8. Regulation of the system x(C)- cystine/glutamate exchanger by intracellular glutathione levels in rat astrocyte primary cultures.

    PubMed

    Seib, Todd Michael; Patel, Sarjubhai Amratbhai; Bridges, Richard James

    2011-10-01

    The system x(C)- (Sx(C)-) transporter functions to mediate the exchange of extracellular cystine (L-Cys(2)) and intracellular glutamate (L-Glu). Internalized L-Cys(2) serves as a rate-limiting precursor for the biosynthesis of glutathione (GSH), while the externalized L-Glu can contribute to either excitatory signaling or excitotoxicity. In the present study the influence of culture conditions (with and without dibutyryl-cAMP) and GSH levels on the expression of Sx(C)- were investigated in primary rat astrocyte cultures. Sx(C)- activity in dbcAMP-treated cells was nearly sevenfold greater than in untreated astrocytes and increased further (∼threefold) following the depletion of intracellular GSH with buthionine sulfoximine. This increase in Sx(C)- triggered by GSH depletion was only observed in the dbcAMP-treated phenotype and was distinct from the Nrf2-mediated response initiated by exposure to electrophiles. Changes in Sx(C)- activity correlated with increases in both protein and mRNA levels of the xCT subunit of the Sx(C)- heterodimer, an increase in the V(max) for L-Glu uptake and was linked temporally to GSH levels. This induction of Sx(C)- was not mimicked by hydrogen peroxide nor attenuated by nonspecific antioxidants but was partially prevented by the co-administration of the cell-permeant thiols GSH-ethyl ester and N-acetylcysteine. These findings demonstrate that the expression of Sx(C)- on astrocytes is dynamically regulated by intracellular GSH levels in a cell- and phenotype-dependent manner. The presence of this pathway likely reflects the inherent vulnerability of the CNS to oxidative damage and raises interesting questions as to the functional consequences of changes in Sx(C)- activity in CNS injury and disease.

  9. 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.

  10. 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

  11. Comparison of in vivo effect of inorganic lead and cadmium on glutathione reductase system and delta-aminolevulinate dehydratase in human erythrocytes.

    PubMed Central

    Roels, H A; Buchet, J P; Lauwerys, R R; Sonnet, J

    1975-01-01

    The activity of delta-aminolevulinate dehydratase (ALAD) of erythrocytes, the lead (Pb-B) and cadmium (Cd-B) concentration in whole blood, the content of reduced glutathion (GSH) in erythrocytes, and the regeneration rate of GSH by intact erythrocytes were measured during an epidemiological survey of 84 men employed in a Belgian cadmium and lead producing plant. A control group of 26 persons (students and laboratory staff) was also examined. The logarithm of the ALAD activity is highly inversely correlated with log Pb-B (r = -0.760) but no correlation was found with log Cd-B. There exists a significant negative correlation between GSH and log Pb-B (r = -0.423) but not between GSH AND LOG Cd-B. The apparently good relationship between log ALAD and GSH disappeared completely by holding log Pb-B constant, but log ALAD remained highly inversely correlated with log Pb-B when standardized for GSH concentration (r = -0.748). In vivo investigation of the GSH regeneration rate of intact erythrocytes demonstrated clearly that the overall activity of the glutathione oxidation-reduction pathways is not impaired in Pb and Cd-exposed workers with significantly increased Pb-B and Cd-B, since their initial GSH regeneration rate (first 15 minutes) was identical with that of the control group. Results of similar in vitro experiments in which control whole blood was incubated before-hand with Pb2+ or Cd2+, or both, reinforce this conclusion. Since increased Cd-B and Pb-B do not influence the glutathione reductase system of erythrocytes, and since endogenous erythrocyte GSH is not correlated with Cd-B, the moderate decrease in endogenous erythrocyte Gsh found in Pb-exposed workers might result from a Pb-induced impairment for the erythrocyte mechanism for glutathione synthesis. PMID:1156566

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. Modulation of exogenous glutathione in phytochelatins and photosynthetic performance against cd stress in the two rice genotypes differing in Cd tolerance.

    PubMed

    Cai, Yue; Cao, Fangbin; Cheng, Wangda; Zhang, Guoping; Wu, Feibo

    2011-11-01

    Greenhouse hydroponic experiments were conducted using Cd-sensitive (Xiushui63) and tolerant (Bing97252) rice genotypes to evaluate genotypic differences in response of photosynthesis and phytochelatins to Cd toxicity in the presence of exogenous glutathione (GSH). Plant height, chlorophyll content, net photosynthetic rate (Pn), and biomass decreased in 5 and 50 μM Cd treatments, and Cd-sensitive genotype showed more severe reduction than the tolerant one. Cadmium stress caused decrease in maximal photochemical efficiency of PSII (Fv/Fm) and effective PSII quantum yield [Y(II)] and increase in quantum yield of regulated energy dissipation [Y(NPQ)], with changes in Cd-sensitive genotype being more evident. Cadmium-induced phytochelatins (PCs), GSH, and cysteine accumulation was observed in roots of both genotypes, with markedly higher level in PCs and GSH on day 5 in Bing97252 compared with that measured in Xiushui63. Exogenous GSH significantly alleviated growth inhibition in Xiushui63 under 5 μM Cd and in both genotypes in 50 μM Cd. External GSH significantly increased chlorophyll content, Pn, Fv/Fm, and Y(II) of plants exposed to Cd, but decreased Y(NPQ) and the coefficient of non-photochemical quenching (qN). GSH addition significantly increased root GSH content in plants under Cd exposure (except day 5 of 50 μM Cd) and induced up-regulation in PCs of 5 μM-Cd-treated Bing97252 throughout the 15-day and Xiushui63 of 5-day exposure. The results suggest that genotypic difference in the tolerance to Cd stress was positively linked to the capacity in elevation of GSH and PCs, and that alleviation of Cd toxicity by GSH is related to significant improvement in chlorophyll content, photosynthetic performance, and root GSH levels.

  19. 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.

  20. 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

  1. A pH/glutathione double responsive drug delivery system using molecular imprint technique for drug loading

    NASA Astrophysics Data System (ADS)

    Zhang, Kelin; Guan, Xiujuan; Qiu, Yanxin; Wang, Dongdong; Zhang, Xiaoyu; Zhang, Haixia

    2016-12-01

    A surface molecular imprinting polymer (SMIP) with doxorubicin (DOX) as the template was prepared on the surface of mesoporous silica nanoparticles (MSNs), which were further used as DOX carriers. The loading amount of DOX was calculated as 10.5 ± 0.2 wt% with loading efficiency of 70 ± 8%. The DOX release was controlled because the monomer molecule used in polymerization of SMIP containing sulfur-sulfur bonding, which could be decomposed with an acidic pH and glutathione (GSH). Under an acidic pH and high concentration of GSH, there was greater release of DOX than under normal physiological conditions, which induced less damage to normal cells than to cancer cells. Confocal laser scanning microscopy studies verified the invasion of the DOX within SMIP into TCA8113 cancer cells. These results indicate that the prepared SMIP was an effective nanocarrier.

  2. 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

  3. 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

  4. Immunocal® and preservation of glutathione as a novel neuroprotective strategy for degenerative disorders of the nervous system.

    PubMed

    Ross, Erika K; Gray, Josie J; Winter, Aimee N; Linseman, Daniel A

    2012-12-01

    Oxidative stress and glutathione (GSH) depletion are both recognized as significant contributors to the pathogenesis of many devastating neurodegenerative diseases. In particular, mitochondrial dysfunction leads to the aberrant production and accumulation of reactive oxygen species (ROS), which are capable of oxidizing key cellular proteins, lipids, and DNA, ultimately triggering cell death. In addition to other roles that it plays in the cell, GSH functions as a critical scavenger of these ROS. Therefore, GSH depletion exacerbates cell damage due to free radical generation. Strategies that increase or preserve the levels of intracellular GSH have been shown to act in a neuroprotective manner, suggesting that augmentation of the available GSH pool may be a promising therapeutic target for neurodegeneration. This review discusses the capacity of a cystine-rich, whey protein supplement (Immunocal®) to enhance the de novo synthesis of GSH in neurons, and highlights its potential as a novel therapeutic approach to mitigate the oxidative damage that underlies the pathogenesis of various neurodegenerative diseases. Additionally, this review discusses various patents from 1993 to 2012 both with Immunocal® and other methods that modulate GSH in neurodegeneration.

  5. 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.

  6. 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

  7. Role of glutathione, glutathione transferase, and glutaredoxin in regulation of redox-dependent processes.

    PubMed

    Kalinina, E V; Chernov, N N; Novichkova, M D

    2014-12-01

    Over the last decade fundamentally new features have been revealed for the participation of glutathione and glutathione-dependent enzymes (glutathione transferase and glutaredoxin) in cell proliferation, apoptosis, protein folding, and cell signaling. Reduced glutathione (GSH) plays an important role in maintaining cellular redox status by participating in thiol-disulfide exchange, which regulates a number of cell functions including gene expression and the activity of individual enzymes and enzyme systems. Maintaining optimum GSH/GSSG ratio is essential to cell viability. Decrease in the ratio can serve as an indicator of damage to the cell redox status and of changes in redox-dependent gene regulation. Disturbance of intracellular GSH balance is observed in a number of pathologies including cancer. Consequences of inappropriate GSH/GSSG ratio include significant changes in the mechanism of cellular redox-dependent signaling controlled both nonenzymatically and enzymatically with the participation of isoforms of glutathione transferase and glutaredoxin. This review summarizes recent data on the role of glutathione, glutathione transferase, and glutaredoxin in the regulation of cellular redox-dependent processes.

  8. A spectrofluorimetric method for cysteine and glutathione using the fluorescence system of Zn(II)-8-hydroxyquinoline-5-sulphonic acid complex.

    PubMed

    Wang, H; Wang, W S; Zhang, H S

    2001-10-01

    The addition of thiol compounds to the fluorescence system of Zn(II)-8-hydroxyquinoline-5-sulphonic acid complex (Zn(II)-HQS) in H3BO3-Na2B4O7 buffer (pH 8.50) solution led to immediate fluorescence inhibition, which was proportional to their amounts. Based on this finding, a novel spectrofluorimetric method for the determination of cysteine (Cys) and reduced glutathione (GSH) has been developed. The detection limits were 17 ng ml(-1) and 0.6 microg ml(-1), respectively. Most amino acids had no interference at high concentrations. The proposed method has been applied to the determination of Cys in protein hydrolysate and cystine electrolyte, and GSH in human blood serum with recoveries of 95.6-104.5%.

  9. 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.

  10. 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

  11. 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

  12. Antioxidant N-Acetylcysteine and Glutathione Increase the Viability and Proliferation of MG63 Cells Encapsulated in the Gelatin Methacrylate/VA-086/Blue Light Hydrogel System.

    PubMed

    Lin, Chih-Hsin; Lin, Kai-Fung; Mar, Kwei; Lee, Shyh-Yuan; Lin, Yuan-Min

    2016-08-01

    Photoencapsulation of cells inside a hydrogel system can provide a suitable path to establish a gel in situ for soft tissue regeneration applications. However, the presence of photoinitiators and blue or UV light irradiation can result in cell damage and an increase of reactive oxygen species. We here evaluate the benefits of an antioxidant pretreatment on the photoencapsulated cells. We study this by evaluating proliferation and viability of MG63 cells, which we combined with a gelatin methacrylate (GelMA) hydrogel system, using the photoinitiator, VA-086, cured with 440 nm blue light. We found that blue light irradiation as well as the presence of 1% VA-086 reduced MG63 cell proliferation rates. Adding a short pretreatment step to the MG63 cells, consisting of the antioxidant molecules N-acetylcysteine (NAC) and reduced glutathione (GSH), and optimizing the GelMA encapsulation steps, we found that both NAC and GSH pretreatments of MG63 cells significantly increased both proliferation and viability of the cells, when using a 15% GelMA hydrogel, 1% VA-086, and 1-min blue light exposure. These findings suggest that the use of antioxidant pretreatment can counteract the negative presence of the photoinitiators and blue light exposure and result in a suitable environment for photoencapsulating cells in situ for tissue engineering and soft tissue applications.

  13. Fisetin attenuates hydrogen peroxide-induced cell damage by scavenging reactive oxygen species and activating protective functions of cellular glutathione system.

    PubMed

    Kang, Kyoung Ah; Piao, Mei Jing; Kim, Ki Cheon; Cha, Ji Won; Zheng, Jian; Yao, Cheng Wen; Chae, Sungwook; Hyun, Jin Won

    2014-01-01

    Hydrogen peroxide (H2O2) can induce cell damage by generating reactive oxygen species (ROS), resulting in DNA damage and cell death. The aim of this study is to elucidate the protective effects of fisetin (3,7,3',4',-tetrahydroxy flavone) against H2O2-induced cell damage. Fisetin reduced the level of superoxide anion, hydroxyl radical in cell free system, and intracellular ROS generated by H2O2. Moreover, fisetin protected against H2O2-induced membrane lipid peroxidation, cellular DNA damage, and protein carbonylation, which are the primary cellular outcomes of H2O2 treatment. Furthermore, fisetin increased the level of reduced glutathione (GSH) and expression of glutamate-cysteine ligase catalytic subunit, which is decreased by H2O2. Conversely, a GSH inhibitor abolished the cytoprotective effect of fisetin against H2O2-induced cells damage. Taken together, our results suggest that fisetin protects against H2O2-induced cell damage by inhibiting ROS generation, thereby maintaining the protective role of the cellular GSH system.

  14. Allocation of cysteine for glutathione production in caterpillars with different antioxidant defense strategies: a comparison of Lymantria dispar and Malacosoma disstria.

    PubMed

    Barbehenn, Raymond V; Kochmanski, Joseph; Menachem, Brandon; Poirier, Lisa M

    2013-10-01

    Sulfur amino acids [cysteine (Cys) and methionine (Met)] play two major roles during animal development: protein synthesis for growth and glutathione synthesis for defense. For caterpillars, the levels of sulfur amino acids found in foliar protein can be especially low relative to their nutritional needs. Previous work has measured concentrations of glutathione (GSH; containing Cys) in specific animal tissues, but has not examined whole-body levels to ascertain the costliness of this defense in terms of Cys allocation. This study examined whether the production of GSH varies between species and within individuals in accordance with an insect's need for antioxidant defense. Secondly, we quantified the allocation of total Cys (peptide-bound plus free Cys) to GSH in caterpillars as an estimate of its cost. Two contrasting species were compared: Lymantria dispar (Lymantriidae), a species that is highly defended, and Malacosoma disstria (Lasiocampidae), a species that is less defended. As expected, GSH levels were significantly higher in L. dispar than in M. disstria. Consistent with the function of the midgut as a first line of defense against ingested toxins, GSH levels were significantly higher in these tissues than in the whole bodies of both species. A major finding in this study was that a large fraction of total Cys is used to produce GSH: GSH in the midguts of L. dispar and M. disstria contained 23 and 21%, respectively, of the total Cys in these tissues, and the GSH in their remaining body tissues contained 19 and 17% of the total Cys in these tissues. Levels of total Cys in caterpillar tissues followed the same pattern of distribution as did GSH, producing a strong association between GSH and total Cys (R(2) = 0.794). We conclude that GSH is a costly defense, especially in generalist tree-feeding species such as L. dispar. These results further suggest that the large allocation of Cys to GSH in highly defended species might produce a tradeoff by limiting the

  15. 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

  16. 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

  17. 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.

  18. Effects of Cyanobacterial Lipopolysaccharides from Microcystis on Glutathione-Based Detoxification Pathways in the Zebrafish (Danio rerio) Embryo

    PubMed Central

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

    2012-01-01

    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

  19. Glutathione peroxidase and catalase modulate the genotoxicity of arsenite.

    PubMed

    Wang, T S; Shu, Y F; Liu, Y C; Jan, K Y; Huang, H

    1997-09-01

    The X-ray hypersensitive Chinese hamster ovary (CHO) cells, xrs-5, are also more sensitive to sodium arsenite in terms of cell growth and micronucleus induction than CHO-K1 cells. Since reactive oxygen species are suggested to be involved in arsenic toxicity, we have measured antioxidant mechanisms in xrs-5 as well as CHO-K1 cells. There were no apparent differences in the activities of superoxide dismutase, glutathione S-transferase, glutathione reductase, and the levels of glutathione between xrs-5 and CHO-K1 cells. However, the activities of glutathione peroxidase and catalase were 5.4- and 5.8-fold lower, respectively, in xrs-5 cells. The addition of catalase or glutathione peroxidase to cultures reduced the arsenite-induced micronuclei in xrs-5 cells. Whereas, simultaneous treatment with mercaptosuccinate, an inhibitor of glutathione peroxidase, and 3-aminotriazole, an inhibitor of catalase, synergistically increased the arsenite-induced micronuclei. These results suggest that both catalase and glutathione peroxidase are involved in defense against arsenite genotoxicity. The xrs-6 cells, another line of x-ray hypersensitive CHO cells, which had 1.6-fold higher catalase activity and 2.5-fold higher glutathione peroxidase activity than xrs-5 cells, were also more sensitive than CHO-K1 cells but were less sensitive than xrs-5 cells to cell growth inhibition of arsenite. Moreover, a 1.6-fold increase of glutathione peroxidase activity by selenite adaptation effectively removed the arsenite-induced micronuclei in CHO-K1 cells. These results suggest that glutathione peroxidase is more important than catalase in defending against arsenite toxicity. Our results also suggest that increasing the intracellular antioxidant level may have preventive or therapeutic effects in arsenic poisoning.

  20. Investigation of acetaminophen toxicity in HepG2/C3a microscale cultures using a system biology model of glutathione depletion.

    PubMed

    Leclerc, Eric; Hamon, Jeremy; Claude, Isabelle; Jellali, Rachid; Naudot, Marie; Bois, Frederic

    2015-06-01

    We have integrated in vitro and in silico information to investigate acetaminophen (APAP) and its metabolite N-acetyl-p-benzoquinone imine (NAPQI) toxicity in liver biochip. In previous works, we observed higher cytotoxicity of HepG2/C3a cultivated in biochips when exposed to 1 mM of APAP for 72 h as compared to Petri cultures. We complete our investigation with the present in silico approach to extend the mechanistic interpretation of the intracellular kinetics of the toxicity process. For that purpose, we propose a mathematical model based on the coupling of a drug pharmacokinetic model (PK) with a systemic biology model (SB) describing the reactive oxygen species (ROS) production by NAPQI and the subsequent glutathione (GSH) depletion. The SB model was parameterized using (i) transcriptomic data, (ii) qualitative results of time lapses ROS fluorescent curves for both control and 1-mM APAP-treated experiments, and (iii) additional GSH literature data. The PK model was parameterized (i) using the in vitro kinetic data (at 160 μM, 1 mM, 10 mM), (ii) using the parameters resulting from a physiologically based pharmacokinetic (PBPK) literature model for APAP, and (iii) by literature data describing NAPQI formation. The PK-SB model predicted a ROS increase and GSH depletion due to the NAPQI formation. The transition from a detoxification phase and NAPQI and ROS accumulation was predicted for a NAPQI concentration ranging between 0.025 and 0.25 μM in the cytosol. In parallel, we performed a dose response analysis in biochips that shows a reduction of the final hepatic cell number appeared in agreement with the time and doses associated with the switch of the NAPQI detoxification/accumulation. As a result, we were able to correlate in vitro extracellular APAP exposures with an intracellular in silico ROS accumulation using an integration of a coupled mathematical and experimental liver on chip approach.

  1. 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

  2. Comparison of inhibitory effects between acetaminophen-glutathione conjugate and reduced glutathione in human glutathione reductase.

    PubMed

    Nýdlová, Erika; Vrbová, Martina; Cesla, Petr; Jankovičová, Barbora; Ventura, Karel; Roušar, Tomáš

    2014-09-01

    Acetaminophen overdose is the most frequent cause of acute liver injury. The main mechanism of acetaminophen toxicity has been attributed to oxidation of acetaminophen. The oxidation product is very reactive and reacts with glutathione generating acetaminophen-glutathione conjugate (APAP-SG). Although this conjugate has been recognized to be generally nontoxic, we have found recently that APAP-SG could produce a toxic effect. Therefore, the aim of our study was to estimate the toxicity of purified APAP-SG by characterizing the inhibitory effect in human glutathione reductase (GR) and comparing that to the inhibitory effect of the natural inhibitor reduced glutathione. We used two types of human GR: recombinant and freshly purified from red blood cells. Our results show that GR was significantly inhibited in the presence of both APAP-SG and reduced glutathione. For example, the enzyme activity of recombinant and purified GR was reduced in the presence of 4 mm APAP-SG (with 0.5 mm glutathione disulfide) by 28% and 22%, respectively. The type of enzyme inhibition was observed to be competitive in the cases of both APAP-SG and glutathione. As glutathione inhibits GR activity in cells under physiological conditions, the rate of enzyme inhibition ought to be weaker in the case of glutathione depletion that is typical of acetaminophen overdose. Notably, however, enzyme activity likely remains inhibited due to the presence of APAP-SG, which might enhance the pro-oxidative status in the cell. We conclude that our finding could reflect some other pathological mechanism that may contribute to the toxicity of acetaminophen.

  3. Glutathione-dependent peroxidative metabolism in the alveolar macrophage

    PubMed Central

    Vogt, Molly T.; Thomas, Catherine; Vassallo, Charles L.; Basford, R. E.; Gee, J. Bernard L.

    1971-01-01

    Phagocytosis by rabbit alveolar macrophages (AM) is accompanied by increases in O2 consumption, glucose oxidation, and H2O2 formation. Two aspects of the interrelations between these metabolic features of phagocytosis have been studied. First, the following evidence indicates that glutathione, glutathione reductase, and peroxidase serve as a cytoplasmic shuttle between H2O2 and NADPH-dependent glucose oxidation: (a) AM contain 5.9 mμmoles of reduced glutathione per 106 cells and exhibit glutathione peroxidase and NADPH-specific glutathione reductase activity; (b) oxidized glutathione potentiates NADP stimulation of glucose oxidation; (c) an artificial H2O2-generating system stimulates glucose oxidation; (d) the cell penetrating thiol inhibitor, N-ethylmaleimide diminishes glucose oxidation. This effect largely depends on inhibition of the glutathione system rather than on inhibition of either H2O2 formation or enzymes directly subserving glucose oxidation. Second, three potential H2O2-generating oxidases have been sought. No cyanide-insensitive NADH or NADPH oxidase activity could be detected. D-amino acid oxidase activity was 0.48 ±0.07 U/106 cells with D-alanine as substrate. PMID:4395562

  4. 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

  5. Selenium regulation of glutathione peroxidase in human hepatoma cell line Hep3B.

    PubMed

    Baker, R D; Baker, S S; LaRosa, K; Whitney, C; Newburger, P E

    1993-07-01

    Glutathione peroxidase is an important enzyme in cellular antioxidant defense systems, detoxifying peroxides and hydroperoxides. As a component of the glutathione cycle, it protects the liver from reactive oxygen metabolites. Selenocysteine is present at the catalytic site of glutathione peroxidase, and selenium availability regulates glutathione peroxidase enzyme activity. Hep3B cells, a well-differentiated human hepatoma-derived cell line, exhibited time-dependent decrease in glutathione peroxidase activity (nmol NADPH oxidized/min/mg protein, mean +/- SE) when incubated in selenium-free medium for 10 days (Day 0, 21.8 +/- 7.3; Day 2, 10.9 +/- 1.2; Day 4, 7.9 +/- 0.8; Day 6, 4.0 +/- 0.7; Day 8, 4.5 +/- 0.6; Day 10, 1.6 +/- 0.4). With the reintroduction of selenium, glutathione peroxidase activity returned. A second human hepatoma cell line, HepG2, demonstrated a similar pattern when depleted of and then repleted with selenium. To assess protein synthesis, glutathione peroxidase activity was measured in deficient and replete Hep3B cells incubated with and without selenium and with and without cycloheximide. Deficient cells (mean +/- SE) (4.9 +/- 0.2) showed an increase in glutathione peroxidase activity after 24 h in selenium-containing medium (11.6 +/- 0.2), but not when cycloheximide was included in the medium (6.9 +/- 0.5) or when cycloheximide and no selenium was included (5.3 +/- 0.8). Replete Hep3B cells (40.1 +/- 1.1) demonstrated decreased glutathione peroxidase after 24 h in medium without selenium (34.0 +/- 1.4), medium with both cycloheximide and selenium (34.0 +/- 2.6), and medium without selenium and containing cycloheximide (37.6 +/- 1.3). These data suggest that protein synthesis is needed for selenium repletion to exert control on glutathione peroxidase activity. Using a cDNA for human glutathione peroxidase (GPx1), selenium-deficient and replete Hep3B cell RNA was analyzed by Northern blot. mRNA for GPx was quantified by densitometry. The steady

  6. Plant glutathione peroxidases: emerging role of the antioxidant enzymes in plant development and stress responses.

    PubMed

    Bela, Krisztina; Horváth, Edit; Gallé, Ágnes; Szabados, László; Tari, Irma; Csiszár, Jolán

    2015-03-15

    The plant glutathione peroxidase (GPX) family consists of multiple isoenzymes with distinct subcellular locations which exhibit different tissue-specific expression patterns and environmental stress responses. Contrary to most of their counterparts in animal cells, plant GPXs contain cysteine instead of selenocysteine in their active site and while some of them have both glutathione peroxidase and thioredoxin peroxidase functions, the thioredoxin regenerating system is much more efficient in vitro than the glutathione system. At present, the function of these enzymes in plants is not completely understood. The occurrence of thiol-dependent activities of plant GPX isoenzymes suggests that - besides detoxification of H2O2 and organic hydroperoxides - they may be involved in regulation of the cellular redox homeostasis by maintaining the thiol/disulfide or NADPH/NADP(+) balance. GPXs may represent a link existing between the glutathione- and the thioredoxin-based system. The various thiol buffers, including Trx, can affect a number of redox reactions in the cells most probably via modulation of thiol status. It is still required to identify the in vivo reductant for particular GPX isoenzymes and partners that GPXs interact with specifically. Recent evidence suggests that plant GPXs does not only protect cells from stress induced oxidative damage but they can be implicated in plant growth and development. Following a more general introduction, this study summarizes present knowledge on plant GPXs, highlighting the results on gene expression analysis, regulation and signaling of Arabidopsis thaliana GPXs and also suggests some perspectives for future research.

  7. 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

  8. 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.

  9. Glutathione redox system, GSH-Px activity and lipid peroxidation (LPO) levels in tadpoles of R.r.ridibunda and B.viridis.

    PubMed

    Cavas, Levent; Tarhan, Leman

    2003-03-01

    Total glutathione (t-GSH), reduced glutathione (GSH), glutathione disulphide (GSSG) levels, t-GSH/GSSG ratio, glutathione peroxidase (GSH-Px) activity and lipid peroxidation (LPO) levels were investigated during the development period of a predominantly aquatic amphibian R.r.ridibunda and a predominantly terrestrial amphibian B. viridis. While t-GSH and GSH showed a similar trend, GSSG concentration increased significantly (p<0.05) during the larval stages in R.r.ridibunda larvae. In contrast to R.r.ridibunda larvae, there was no significant (p>0.05) change between 1 and 5 weeks in the t-GSH and GSH concentrations of B. viridis. t-GSH and GSH concentrations of B. viridis larvae became sharply elevated after the fifth week, GSSG levels increased 3.25-fold during the metamorphosis. The t-GSH/GSSG ratio fluctuated and the lowest t-GSH/GSSG ratios were observed at the third week for both species. GSH-Px activities for both species increased significantly (p<0.05) during the growing period. The highest GSH-Px activities in R.r.ridibunda and B.viridis were observed at the eighth week and they were 3.45 +/- 0.17 and 4.1 +/- 0.21 IU mg(-1), respectively. The membrane LPO levels in the R.r.ridibunda and B. viridis tadpoles significantly (p<0.001) decreased from 206 +/- 10.3 to 146 +/- 7.3 and from 198 +/- 9.9 to 23 +/- 1.15 nmol MDA g(-1) w.w., respectively.

  10. Glutamine attenuates post-traumatic glutathione depletion in human muscle.

    PubMed

    Fläring, U B; Rooyackers, O E; Wernerman, J; Hammarqvist, F

    2003-03-01

    Glutathione is quantitatively the most important endogenous scavenger system. Glutathione depletion in skeletal muscle is pronounced following major trauma and sepsis in intensive care unit patients. Also, following elective surgery, glutathione depletion occurs in parallel with a progressive decline in muscle glutamine concentration. The present study was designed to test the hypothesis that glutamine supplementation may counteract glutathione depletion in a human trauma model. A homogeneous group of patients (n = 17) undergoing a standardized surgical procedure were prospectively randomly allocated to receive glutamine (0.56 g x day(-1) x kg(-1)) or placebo as part of isonitrogenous and isocaloric nutrition. Percutaneous muscle biopsies and blood samples were taken pre-operatively and at 24 and 72 h after surgery. The concentrations of muscle glutathione and related amino acids were determined in muscle tissue and plasma. In the control (unsupplemented) subjects, total muscle glutathione had decreased by 47+/-8% and 37+/-11% and reduced glutathione had decreased by 53+/-10% and 45+/-16% respectively at 24 and 72 h after surgery (P < 0.05). In contrast, in the glutamine-supplemented group, no significant post-operative decreases in total or reduced glutathione were seen following surgery. Muscle free glutamine had decreased at 72 h after surgery in both groups, by 41.4+/-14.8% (P < 0.05) in the glutamine-supplemented group and by 46.0+/-14.3% (P < 0.05) in the control group. In conclusion, the present study demonstrates that intravenous glutamine supplementation attenuates glutathione depletion in skeletal muscle in humans following standardized surgical trauma.

  11. Glutathione in Cancer Cell Death

    PubMed Central

    Ortega, Angel L.; Mena, Salvador; Estrela, Jose M.

    2011-01-01

    Glutathione (L-γ-glutamyl-L-cysteinyl-glycine; GSH) in cancer cells is particularly relevant in the regulation of carcinogenic mechanisms; sensitivity against cytotoxic drugs, ionizing radiations, and some cytokines; DNA synthesis; and cell proliferation and death. The intracellular thiol redox state (controlled by GSH) is one of the endogenous effectors involved in regulating the mitochondrial permeability transition pore complex and, in consequence, thiol oxidation can be a causal factor in the mitochondrion-based mechanism that leads to cell death. Nevertheless GSH depletion is a common feature not only of apoptosis but also of other types of cell death. Indeed rates of GSH synthesis and fluxes regulate its levels in cellular compartments, and potentially influence switches among different mechanisms of death. How changes in gene expression, post-translational modifications of proteins, and signaling cascades are implicated will be discussed. Furthermore, this review will finally analyze whether GSH depletion may facilitate cancer cell death under in vivo conditions, and how this can be applied to cancer therapy. PMID:24212662

  12. Glutathione analogue sorbents selectively bind glutathione S-transferase isoenzymes.

    PubMed

    Castro, V M; Kelley, M K; Engqvist-Goldstein, A; Kauvar, L M

    1993-06-01

    Novel affinity sorbents for glutathione S-transferases (GSTs) were created by binding glutathione (GSH) analogues to Sepharose 6B. The GSH molecule was modified at the glycine moiety and at the group attached to the sulphur of cysteine. When tested by affinity chromatography in a flow-through microplate format, several of these sorbents selectively bound GST isoenzymes. gamma E-C(Hx)-phi G (glutathione with a hexyl moiety bound to cysteine and phenylglycine substituted for glycine) specifically bound rat GST 7-7, the Pi-class isoenzyme, from liver, kidney and small intestine. gamma E-C(Bz)-beta A (benzyl bound to cysteine and beta-alanine substituted for glycine) was highly selective for rat subunits 3 and 4, which are Mu-class isoenzymes. By allowing purification of the isoenzymes under mild conditions that preserve activity, the novel sorbents should be useful in characterizing the biological roles of GSTs in both normal animal and cancer tissues.

  13. Effect of N-acetylcysteine on the spinal-cord glutathione system and nitric-oxide metabolites in rats with neuropathic pain.

    PubMed

    Horst, Andréa; Kolberg, Carolina; Moraes, Maira S; Riffel, Ana Paula K; Finamor, Isabela A; Belló-Klein, Adriane; Pavanato, Maria Amália; Partata, Wania A

    2014-05-21

    Since N-acetylcysteine (NAC) is a donor of cysteine, we studied the relationship between NAC and concentration of oxidized and reduced glutathione (GSH/GSSG ratio), and glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities in the lumbosacral spinal cord of rats with chronic constriction injury (CCI) of the sciatic nerve that received NAC (150mg/kg/day, i.p.) or 0.9% saline solution for 3 or 10 days. Hydrogen peroxide (H2O2) and nitric-oxide (NO) metabolites were also measured. Von Frey hair and hot-plate tests showed hyperalgesia at day 1 in CCI rats. Hyperalgesia persisted at all other times in saline-treated CCI rats, but returned to pre-injury values in NAC-treated CCI rats after 3 postoperative days. GST activity and the GSH/GSSG ratio increased in saline-treated CCI rats, while the NAC treatment increased GST and GPx activities at day 10, with no significant change in the GSH/GSSG ratio. NAC treatment did not affect H2O2 levels, but it reduced NO metabolites in CCI rats 3 days after the surgery. Thus, the anti-hyperalgesic effect of NAC appears not to involve its action as a cysteine precursor for GSH synthesis, but involves a decrease in NO. PMID:24704379

  14. Neural Systems and Individual Differences

    ERIC Educational Resources Information Center

    Posner, Michael I.

    2004-01-01

    Howard Garner's book Multiple Intelligences was important in psychology because it sought to relate a neuropsychological theory of common mental processes with a view of individual differences implicit in the term intelligences. New developments in imaging and genetics may make these connections more realistic.

  15. Glutathione transferases: a structural perspective.

    PubMed

    Oakley, Aaron

    2011-05-01

    The glutathione transferases (GSTs) are one of the most important families of detoxifying enzymes in nature. The classic activity of the GSTs is conjugation of compounds with electrophilic centers to the tripeptide glutathione (GSH), but many other activities are now associated with GSTs, including steroid and leukotriene biosynthesis, peroxide degradation, double-bond cis-trans isomerization, dehydroascorbate reduction, Michael addition, and noncatalytic "ligandin" activity (ligand binding and transport). Since the first GST structure was determined in 1991, there has been an explosion in structural data across GSTs of all three families: the cytosolic GSTs, the mitochondrial GSTs, and the membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG family). In this review, the major insights into GST structure and function will be discussed.

  16. Delayed cardiomyopathy in dystrophin deficient mdx mice relies on intrinsic glutathione resource.

    PubMed

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

    2010-09-01

    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 beta-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.

  17. 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

  18. 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

  19. Role of glutathione in cancer pathophysiology and therapeutic interventions.

    PubMed

    Singh, Simendra; Khan, Amir R; Gupta, Alok K

    2012-01-01

    Glutathione (GSH) is an important intracellular antioxidant that instills several vital roles within a cell including maintenance of the redox state, drug detoxification, and cellular protection from damage by free radicals, peroxides and toxins. Molecular alterations in the components of the GSH system in various tumors can lead to increased survival and enhanced tumor drug resistance. Early identification of the importance of intracellular GSH to detoxification reactions has now led to investigating the potential importance that GSH chemistry has on signal transduction, molecular regulation of cellular physiology and regulation of apoptosis pathway. Several therapeutic agents that target this system have been developed and used experimentally and clinically in an attempt to improve cancer chemotherapy. This review highlights different roles played by GSH that finally regulate tumor growth and advances in the use of GSH-based drugs to specifically target this detoxifying system in cancer treatment as a means to increase therapeutic response and decrease chemotherapeutic drug resistance.

  20. Effect of different Thai traditional processing of various hot chili peppers on urethane-induced somatic mutation and recombination in Drosophila melanogaster: assessment of the role of glutathione transferase activity.

    PubMed

    Laohavechvanich, P; Kangsadalampai, K; Tirawanchai, N; Ketterman, A J

    2006-08-01

    Four different Thai traditional chili peppers, namely bird pepper (Capsicum frutescens), red chili spur peppers (Capsicum annuum), green bell peppers and sweet pepper (C. annuum) were investigated for their antimutagenic properties. Each chili was prepared in three formulations commonly used for chili food processing; raw paste (chili ground in water), pickled in vinegar or stir-fried in palm oil. Each sample was tested for its antimutagenic effect against urethane by using the somatic mutation and recombination of wing hair of Drosophila melanogaster as an indicator. Three-day-old larvae, trans-heterozygous for two genetic markers, multiple wing hairs mwh and orrigon (ORR;flr3), were exposed to urethane alone or in combination with each chili formulation. The various processing methods for chilies differentially extracted the antimutagenic chili components. The specific chili as well as the method of processing influenced the observed antimutagenic properties against urethane. This suggested each chili contains a unique complex mixture of many antimutagens. Co-treatment and pre-treatment experiments showed that both direct and indirect protective mechanisms are involved in an 'activation' process to give antimutagenesis effects. An association between antigenotoxicity and glutathione transferase activity could not be established.

  1. 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.

  2. Glutathione Utilization by Candida albicans Requires a Functional Glutathione Degradation (DUG) Pathway and OPT7, an Unusual Member of the Oligopeptide Transporter Family

    PubMed Central

    Desai, Prashant Ramesh; Thakur, Anil; Ganguli, Dwaipayan; Paul, Sanjoy; Morschhäuser, Joachim; Bachhawat, Anand K.

    2011-01-01

    Candida albicans lacks the ability to survive within its mammalian host in the absence of endogenous glutathione biosynthesis. To examine the ability of this yeast to utilize exogenous glutathione, we exploited the organic sulfur auxotrophy of C. albicans met15Δ strains. We observed that glutathione is utilized efficiently by the alternative pathway of glutathione degradation (DUG pathway). The major oligopeptide transporters OPT1–OPT5 of C. albicans that were most similar to the known yeast glutathione transporters were not found to contribute to glutathione transport to any significant extent. A genomic library approach to identify the glutathione transporter of C. albicans yielded OPT7 as the primary glutathione transporter. Biochemical studies on OPT7 using radiolabeled GSH uptake revealed a Km of 205 μm, indicating that it was a high affinity glutathione transporter. OPT7 is unusual in several aspects. It is the most remote member to known yeast glutathione transporters, lacks the two highly conserved cysteines in the family that are known to be crucial in trafficking, and also has the ability to take up tripeptides. The transporter was regulated by sulfur sources in the medium. OPT7 orthologues were prevalent among many pathogenic yeasts and fungi and formed a distinct cluster quite remote from the Saccharomyces cerevisiae HGT1 glutathione transporter cluster. In vivo experiments using a systemic model of candidiasis failed to detect expression of OPT7 in vivo, and strains disrupted either in the degradation (dug3Δ) or transport (opt7Δ) of glutathione failed to show a defect in virulence. PMID:21994941

  3. 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

  4. 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

  5. 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…

  6. The influence of reduced glutathione on chromosome damage induced by X-rays or heavy ion beams of different LETs and on the interaction of DNA lesions induced by radiations and bleomycin.

    PubMed

    Pujari, Geetanjali; Sarma, A; Chatterjee, A

    2010-02-01

    It is thought that high linear energy transfer (LET) radiation induces more complex DNA damage than low-LET particles, specifically clustered DNA damage that causes cells to repair DNA double strand breaks (DSB) more slowly and leads to severe biological consequences. The present study aimed to investigate the role of exogenously added glutathione (GSH) on (12)C-beam (287keV/mum) and (7)Li-beam (60keV/mum) induced chromosome aberration (CA) formation, particularly on exchange aberration formation. In order to characterize the role of GSH in the joining of DNA DSBs, we induced DNA lesions with bleomycin (Blem) in conjunction with either high- or low-LET radiation (X-rays) since the chemistry of the free DNA ends created by Blem and X-rays is similar. CHO cells were exposed to reduced GSH at a concentration of 2mM for 3h before radiation. Treatment with Blem (20mug/ml) was carried out for 2h before the cells were exposed to radiation. Our results show that the frequency of chromosomal aberration increases with increased LET. Heavy ion exposed cells show a higher frequency of CA over time than do X-irradiated cells. An analysis of the first post-irradiation mitosis of exposed CHO cells shows that high-LET radiation induces more breaks than exchange-type aberrations and exogenous GSH has no influence on high-LET radiation-induced DNA damage. The DNA lesions induced by low-LET radiation interact relatively strongly with Blem-induced lesions whereas interaction between Blem and high-LET radiations was poor. This could be attributed to differences in repair kinetics and qualitative differences in the DNA lesions induced by Blem and high-LET radiation.

  7. Making recombinant proteins in animals--different systems, different applications.

    PubMed

    Dyck, Michael K; Lacroix, Dan; Pothier, François; Sirard, Marc-André

    2003-09-01

    Transgenic animal bioreactors represent a powerful tool to address the growing need for therapeutic recombinant proteins. The ability of transgenic animals to produce complex, biologically active recombinant proteins in an efficient and economic manner has stimulated a great deal of interest in this area. As a result, genetically modified animals of several species, expressing foreign proteins in various tissues, are currently being developed. However, the generation of transgenic animals is a cumbersome process and remains problematic in the application of this technology. The advantages and disadvantages of different transgenic systems in relation to other bioreactor systems are discussed.

  8. 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

  9. Ageing of glutathione reductase in the lens.

    PubMed

    Zhang, W Z; Augusteyn, R C

    1994-07-01

    The distribution of glutathione reductase activity in concentric layers from the lens has been determined as a function of age for 16 species. Primate lenses have almost ten times the level of glutathione reductase found in other species. Comparison with the activity of hexokinase revealed that this is not due to a higher overall rate of metabolism in these lenses. By contrast, the higher activity found in bird and fish lenses reflects a higher metabolic activity in these tissues. In all species, a gradient of activity was observed with the highest specific activity in the outermost cortical fibres, decreasing to virtually no activity in the inner parts of the tissue. No alterations were found in this gradient with increasing age, other than an increase in the amount of nuclear tissue essentially devoid of activity. The maximum activity in the outer cortical fibres was the same, regardless of the age of the lens. The time taken, in different species, for the specific activity to decrease by half, was estimated from the rate of protein accumulation. This time was found to vary from a few days to several years, indicating that the decrease in activity is not due to ageing but rather, it is related to the maturation of fibre cells. These observations are discussed in terms of current concepts of lens ageing and cataract formation. PMID:7835401

  10. Hemolytic anemia and metabolic acidosis: think about glutathione synthetase deficiency.

    PubMed

    Ben Ameur, Salma; Aloulou, Hajer; Nasrallah, Fehmi; Kamoun, Thouraya; Kaabachi, Naziha; Hachicha, Mongia

    2015-02-01

    Glutathione synthetase deficiency (GSSD) is a rare disorder of glutathione metabolism with varying clinical severity. Patients may present with hemolytic anemia alone or together with acidosis and central nervous system impairment. Diagnosis is made by clinical presentation and detection of elevated concentrations of 5-oxoproline in urine and low glutathione synthetase activity in erythrocytes or cultured skin fibroblasts. The prognosis seems to depend on early diagnosis and treatment. We report a 4 months old Tunisian male infant who presented with severe metabolic acidosis with high anion gap and hemolytic anemia. High level of 5-oxoproline was detected in her urine and diagnosis of GSSD was made. Treatment consists of the correction of acidosis, blood transfusion, and supplementation with antioxidants. He died of severe metabolic acidosis and sepsis at the age of 15 months.

  11. Glutathione peroxidase and iron-thiol dependent lipid peroxidation.

    PubMed

    Punekar, N S; Lardy, H A

    1989-12-01

    Role of glutathione peroxidase in iron-thiol-mediated lipid peroxidation was examined. The enzyme was unable to prevent peroxidation of extracted rat liver microsomal lipids. In contrast, when arachidonic acid was the substrate, glutathione peroxidase did decrease the formation of thiobarbituric acid-reactive material. Superoxide dismutase produced a consistent but partial inhibition of peroxidation and catalase was without effect. Our results suggest that iron-thiol-dependent lipid peroxidation cannot be completely blocked by protective enzymes that are effective in other systems. PMID:2635868

  12. 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

  13. 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

  14. 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

  15. Sex differences in the vomeronasal system.

    PubMed

    Guillamón, A; Segovia, S

    1997-01-01

    In the early eighties we found sex differences in the vomeronasal organ (VNO) and hypothesized that the vomeronasal system (VNS), a complex neural network involved in the control of reproductive behavior, might be sexually dimorphic. At that time sex differences had already been described for some structures that receive VNO input, such as the medial amygdala, the medial preoptic area, the ventromedial hypothalamic nucleus, and the ventral region of the premammillary nucleus. Since then, we have shown sex differences in the accessory olfactory bulb (AOB), the bed nucleus of the accessory olfactory tract (BAOT), and the bed nucleus of the stria terminalis (BST). When new VNS connections were found, all of them ended in nuclei that present sex differences. In general, sex differences in the olfactory system show two morphological patterns: one in which males present greater morphological measures than females, and just the opposite. To explain the morphometric measures of males in the latter, it has been hypothesized that androgens serve as inhibitors. Our work on the involvement of the GABA(A) receptor in the development of AOB and maternal behavior sex differences also suggests that neonatal changes in neuronal membrane permeability to the ion Cl- differences. This might be the first animal model to help us to understand the situation in which human genetic and gonadal sex do not agree with brain and behavioral sex. Finally, we stress that sex differences in the VNS constitute a neurofunctional model for understanding sex differences in reproductive behaviors.

  16. 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.

  17. Methods for the determination of plasma or tissue glutathione levels.

    PubMed

    Tipple, Trent E; Rogers, Lynette K

    2012-01-01

    We present two different methods for determining levels of glutathione in complex biological samples and plasma. The DTNB/GR enzyme recycling method is sensitive and requires no specialized equipment. The HPLC method is particularly useful for situations in which sample amounts are limited. Detailed instructions for performing each method as well as the advantages and disadvantages of each are discussed in this chapter.

  18. Effect of aluminium metal on glutathione (GSH) level in plasma and cytosolic fraction of human blood.

    PubMed

    Khan, Haroon; Khan, M Farid; Jan, Syed Umer; Ullah, Naseem

    2011-01-01

    Aluminium is being used in the medicines in the form of antacids. The Aluminium metal can be leached from our utensils and can harm the body for its side effects, if become available to the systemic circulation. So it is important to check the effect of Aluminum on the Glutathione in vivo condition. Ellman method was used to determine the effect of Aluminum on GSH level in whole blood spectrophotometerically. 5,5-Dithiobis, 2-Nitrobenzoic Acid, Glutathione, Aluminium sulphate, phosphate buffer, HCl (Hydrochloric acid) and other laboratory instruments were used to conduct the research work. Time dependent effect of Aluminum on Glutathione level in whole blood was also checked and decrease was observed. This study also shows the effect of Aluminum as helping agent for the Glutathione to enhance the antioxidant system of the body or a cause for depletion of reduced Glutathione.

  19. 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.

  20. 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

  1. Biliary transport of glutathione S-conjugate by rat liver canalicular membrane vesicles.

    PubMed

    Inoue, M; Akerboom, T P; Sies, H; Kinne, R; Thao, T; Arias, I M

    1984-04-25

    Transport of S-dinitrophenyl glutathione, a model compound of glutathione S-conjugates, was studied in isolated rat liver canalicular membrane vesicles by a rapid filtration technique. The membrane vesicles exhibited time-dependent uptake of [2-3H]glycine-glutathione conjugate into an osmotically sensitive intravesicular space. Inactivation of vesicle-associated gamma-glutamyltransferase by affinity labeling with L-(alpha-S,5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazole-acetic acid had no effect on the initial rate of transport. Chemical analysis revealed that the intact glutathione conjugate accounted for most vesicle-associated radioactivity, reflecting the low transferase activity in the liver and membrane vesicles. The initial rate of transport followed saturation kinetics with respect to conjugate concentrations; an apparent Km of 1.0 mM and Vmax of 1.7 nmol/mg of protein X 20 s were calculated. These results indicate that transport of the glutathione S-conjugate across the canalicular membranes is a carrier-mediated process. Sodium chloride in the transport medium could be replaced by KCl, LiCl, or choline chloride without any changes in transport activity. The rate of conjugate transport was enhanced by a valinomycin-induced K+ diffusion potential (vesicle-inside-positive). The rate of conjugate uptake was enhanced by replacing KCl in the transport medium with K gluconate, providing a less permeant anion, and was reduced by replacing KCl with KSCN, providing a more permeant anion. These data indicate that conjugate transport is electrogenic and involves the transfer of negative charge. Transport of S-dinitrophenyl glutathione was inhibited by S-benzyl glutathione, oxidized glutathione, or reduced glutathione. This transport system in canalicular membranes may function in biliary secretion of glutathione S-conjugates of xenobiotics whose synthesis in hepatocytes requires glutathione S-transferases.

  2. 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 ...

  3. 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.

  4. Response of the ascorbate-glutathione cycle to re-aeration following hypoxia in lupine roots.

    PubMed

    Garnczarska, Małgorzata

    2005-06-01

    The response of the enzymes and metabolites of the ascorbate-glutathione pathway to oxidative stress caused by re-aeration following hypoxia was studied in roots of hydroponically grown lupine (Lupinus luteus L. cv. Juno) seedlings. Lupine roots were deprived of oxygen by subjecting them to hypoxia for 48 and 72 h and then re-aerated for up to 4 h. An increased content of total ascorbate was observed in lupine roots immediately after hypoxia, whereas total glutathione level decreased. However, a significant increase in the reduced forms of both metabolites was found directly after hypoxia. Re-admission of oxygen caused the decrease of the ratios of reduced to oxidized forms of ascorbate and glutathione, indicating oxidative stress. While monodehydroascorbate reductase (MDHAR, EC 1.6.5.4) activity remained unaltered during re-aeration the increase in activities of ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) was observed 30 min after transfer from hypoxic condition. Dehydroascorbate reductase (DHAR, EC 1.8.5.1) activity approached the control level during a whole re-aeration period. Native gel electrophoresis combined with specific activity staining revealed seven isoforms of APX, five isoforms of GR and three different proteins with DHA reductase activity in roots extracts. However, immediately after hypoxic treatment APX-5 isoform and GR-1 isoform were not observed in roots. This experimental system was also used to investigate superoxide anion level in roots utilizing the superoxide anion-specific indicator dihydroethidium (DHE). Intense DHE-derived fluorescence was found in re-aerated root tips as compared to control roots, indicating that re-aeration induced superoxide anion production in hypoxically pretreated roots.

  5. Evaluation of different lining/cooling systems

    SciTech Connect

    Tijhuis, G.; Laar, K. van

    1995-07-01

    For blast furnace linings and cooling systems, different systems are used around the world. Most furnaces have either staves or plate coolers as a cooling system. Some furnaces have an externally cooled shell using sprays or panel cooling. Refractories applied include alumina, silicon-carbide, carbon and semigraphite. The performance of a lining/cooling system does not only depend on the design as such, but also on the way the furnace is operated, the burden composition, raw material quality, production level, fuel injection, etc. To compare one lining/cooling system with another requires that all these factors re taken into account to make a good comparison. A refractory lining and/or cooling system may fail due to several mechanisms. As reported earlier, the attack mechanism may be related to temperature, stress, chemical reactions, abrasion, or a combination of these factors. To make it even more complicated, in every furnace zone another attack mechanism may be present. Experience with modern blast furnace operations has shown that failure due to temperature fluctuations is most important. The paper focuses on the behavior of lining/cooling systems under several conditions. In particular, the consequences of high temperatures and severe temperatures fluctuations will be discussed.

  6. Glutathione, glutathione-related enzymes, and oxidative stress in individuals with subacute occupational exposure to lead.

    PubMed

    Dobrakowski, Michał; Pawlas, Natalia; Hudziec, Edyta; Kozłowska, Agnieszka; Mikołajczyk, Agnieszka; Birkner, Ewa; Kasperczyk, Sławomir

    2016-07-01

    The aim of the study was to investigate the influence of subacute exposure to lead on the glutathione-related antioxidant defense and oxidative stress parameters in 36 males occupationally exposed to lead for 40±3.2days. Blood lead level in the examined population increased significantly by 359% due to lead exposure. Simultaneously, erythrocyte glutathione level decreased by 16%, whereas the activity of glutathione-6-phosphate dehydrogenase in erythrocytes and leukocytes decreased by 28% and 10%, respectively. Similarly, the activity of glutathione-S-transferase in erythrocytes decreased by 45%. However, the activity of glutathione reductase in erythrocytes and leukocytes increased by 26% and 6%, respectively, whereas the total oxidant status value in leukocytes increased by 37%. Subacute exposure to lead results in glutathione pool depletion and accumulation of lipid peroxidation products; however, it does not cause DNA damage. Besides, subacute exposure to lead modifies the activity of glutathione-related enzymes. PMID:27331344

  7. 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

  8. Glutathione determination by the Tietze enzymatic recycling assay and its relationship to cellular radiation response.

    PubMed Central

    Eady, J. J.; Orta, T.; Dennis, M. F.; Stratford, M. R.; Peacock, J. H.

    1995-01-01

    Large fluctuations in glutathione content were observed on a daily basis using the Tietze enzyme recycling assay in a panel of six human cell lines of varying radiosensitivity. Glutathione content tended to increase to a maximum during exponential cell proliferation, and then decreased at different rates as the cells approached plateau phase. By reference to high-performance liquid chromatography and flow cytometry of the fluorescent bimane derivative we were able to verify that these changes were real. However, the Tietze assay was occasionally unable to detect glutathione in two of our cell lines (MGH-U1 and AT5BIVA), although the other methods indicated its presence. The existence of an inhibitory activity responsible for these anomalies was confirmed through spiking our samples with known amounts of glutathione. We were unable to detect a direct relationship between cellular glutathione concentration and aerobic radiosensitivity in our panel of cell lines. PMID:7577452

  9. 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.

  10. 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

  11. 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

  12. Role of reduced glutathione in the amelioration of nicotine-induced oxidative stress.

    PubMed

    Dey, S K; Roy, S

    2010-04-01

    Nicotine, a major toxic component of cigarette smoke has been identified as a major risk factor for different diseases. This study investigates the role of reduce glutathione (GSH) against nicotine treated liver and kidney toxicity. Results showed that the application of 80 mg GSH per kg body weight per day exert protective effect against nicotine-induced liver and kidney toxicity by modulating the biochemical marker enzyme LDH, lipid peroxidation and augmenting antioxidant defense system. To our knowledge, this is the first finding of this sort. PMID:20221824

  13. 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

  14. 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

  15. 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

  16. Different approaches to contracting in health systems.

    PubMed

    Perrot, Jean

    2006-11-01

    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.

  17. 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

  18. [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

  19. [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.

  20. 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

  1. [Microleakage of four different amalgam binding systems].

    PubMed

    Oberholzer, T G; Grobler, S R; Rossouw, R J; van Wyk Kotze, T J; Grobler-Rabie, A

    2001-02-01

    This-study was undertaken to evaluate and compare microleakage in class V cavities in human teeth which were lined with Amalgambond Plus with HPA (Parkell, USA), Optibond Solo (Kerr, U.S.A.), Fuji Plus (GC Corporation, Japan) and Prime & Bond 2.1 (Dentsply, Switzerland), and then restored with Logic amalgam (SDI Australia). The restored teeth were thermocycled in basic fuchsin dye, sectioned, and evaluated for dye penetration. The interdiffusion zones were viewed in a confocal laser scanning microscope (CLSM). The results showed that no bonding system could totally eliminate microleakage. Statistical analysis revealed significant differences between Amalgambond Plus with HPA and Prime & Bond 2.1, Fuji Plus as well as Optibond Solo, for both the enamel and dentine sides. No significant differences were found between Prime & Bond 2.1, Fuji Plus and Optibond Solo, for both the enamel and dentine sides. Amalgambond Plus showed significantly more leakage at dentine sides while Prime & Bond 2.1 showed significantly more leakage at enamel sides. The CLSM revealed hybrid layers of different thicknesses, resin penetration into tubules, as well as resin incorporation within the spherical particles of the amalgam. Optibond Solo, Fuji Plus and Prime & Bond 2.1 can serve to improve the marginal seal of amalgam restorations.

  2. 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.

  3. High Performance Liquid Chromatography Coupled with Pre-column Derivatization for Determination of Oxidized Glutathione Level in Rats Exposed to Paraquat.

    PubMed

    Hami, Zahra; Amini, Mohsen; Kiani, Amir; Ghazi-Khansari, Mahmoud

    2013-01-01

    Glutathione (GSH) is one of the most important antioxidants that plays an essential role in detoxification of reactive oxygen species (ROS) which oxidizes to glutathione disulfide (GSSG). Paraquat (PQ), awidely used herbicide, causes pulmonary injury with the productionof ROS. Excessive ROS accumulation as a consequence of PQ exposure are frequently targeted by GSH thereby oxidative stress leads to depletion of cellular GSH by transforming of GSH to glutathione disulfide (GSSG). A precise method of measuring of GSSG concentration in plasma as indicator of oxidative stress is needed. Some analytical techniques such as high-performance liquid chromatography (HPLC), gas chromatography and capillary electrophoresis have been used for determination of GSSG concentration. In the present study, a new HPLC method with fluorescence detection based on derivatization of the amine group of glutathione with 9-fluorenylmethyl chloroformate (FMOC-Cl) was developed. Male Wistar albino rats exposed to different doses of PQ (20-60 mg/kg) and control group were used and after protein precipitation, their plasma was subjected to derivatization with FMOC in the presence of borate buffer. The derivatized samples were injected to HPLC system with C18 column, mobile phase consisting of methanol and phosphate buffer, λem= 315 nm, λex= 260 nm. Among all experimental groups, the rats which received 60 mg/kg PQ, showed a significant increase in the amount of oxidized glutathione (GSSG) compared to the control group. In this study, the applied derivatization and HPLC method made it possible to measure small amounts of glutathione in plasma using a precise and sensitive technique.

  4. Enzymes of glutathione synthesis in dog skeletal muscles and their response to training.

    PubMed

    Marin, E; Kretzschmar, M; Arokoski, J; Hänninen, O; Klinger, W

    1993-04-01

    The glutathione synthesizing enzymes, gamma-glutamyl cysteinyl synthetase and glutathione synthetase, were found in all skeletal muscles studied in dogs. Both occurred also in the liver, but only the former in the lung. The influence of physical training on these enzyme activities was also investigated. For 30 weeks the dogs ran 5 days week-1 on a treadmill at a 15 degrees uphill grade. A 1.5- to 2-fold increase in the gamma-glutamyl cysteinyl synthetase and 3-fold increase in the glutathione synthetase activities was observed in muscles affected by the training procedure (m. triceps, m. extensor carpi radialis and m. gastrocnemius). No training effect could be observed in the splenius and longissimus dorsi muscles or in the liver. The training increased total glutathione levels in the lung and gastrocnemius muscle as well as in the plasma. Glutathione disulfide levels were not altered. Acute physical exercise significantly decreased the plasma total glutathione concentrations in the trained dogs. The results indicate a training responsive adaptation of glutathione system in skeletal muscle.

  5. 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

  6. 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.

  7. 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

  8. Association between glutathione, haemoglobin and transferrin in finnsheep.

    PubMed

    Atroshi, F; Osterberg, S; Lindström, U B

    1980-04-01

    Haemoglobin (Hb) and transferrin (Tf) types were determined in 760 Finnsheep and correlated with the reduced glutathione (GSH) levels of packed erythrocytes. The gene frequencies of the two haemoglobin alleles A and B were: HbA = 0.748 and HbB = 0.252. Five transferrin alleles were found: A, B, C, D and E, with gene frequencies of 0.056, 0.226, 0.620, 0.075 and 0.023, respectively. The Hb B group had significantly higher GSH levels and lower haematocrit values than heterozygotes (Hb AB) and homozygote (Hb AA). There was no significant difference in GSH concentration among the haemoglobin types in lambs. Erythrocyte glutathione levels of Tf BC ewes were significantly higher than the levels in sheep with other transferrin types, whereas young lambs of Tf AB types had the highest GSH levels. The significance of these findings is discussed.

  9. Effects of glutathione on the in vivo metabolism and oxidative stress of arsenic in mice.

    PubMed

    Wang, Da; Lin, Lin; Li, Xin; Sun, Gui-Fan

    2015-01-01

    In this study, we investigated the in vivo effects of exogenous glutathione and buthionine sulfoximine on arsenic methylation and antioxidant capacity in mice exposed to arsenic via drinking water. Thirty-six female albino mice were randomly divided into six groups. All groups were given free access to drinking water that contained arsenic continuously except the control group. After ten days, mice were treated with different levels of glutathione or buthionine sulfoximine. The levels of the metabolites of arsenic were determined in the liver and urine. The levels of glutathione and total antioxidant capacity were determined in the whole blood and liver. Our results showed that the increase of arsenic species in the liver as well as the decrease of blood and hepatic glutathione and total antioxidant capacity, were all relieved by exogenous glutathione consistently. We also observed the involvement of glutathione in promoting arsenic methylation and urinary elimination in vivo. Increase of total arsenic in the urine was mainly due to the increase of dimethylated arsenic. Furthermore, administration of glutathione increased the first methylation ratio and secondary methylation ratio in the liver and urine, which resulted in the consequent increase of dimethylated arsenic percent and decrease of inorganic arsenic percent in the urine. Opposite effects appeared with the administration of buthionine sulfoximine, a scavenger of glutathione. Our study indicated that exogenous glutathione not only accelerated the methylation and the excretion of arsenic, but also relieve the arsenic-induced oxidative stress. This provides a potential useful chemopreventive dietary component for human populations being at risk of arsenic exposure.

  10. Effects of glutathione on the in vivo metabolism and oxidative stress of arsenic in mice.

    PubMed

    Wang, Da; Lin, Lin; Li, Xin; Sun, Gui-Fan

    2015-01-01

    In this study, we investigated the in vivo effects of exogenous glutathione and buthionine sulfoximine on arsenic methylation and antioxidant capacity in mice exposed to arsenic via drinking water. Thirty-six female albino mice were randomly divided into six groups. All groups were given free access to drinking water that contained arsenic continuously except the control group. After ten days, mice were treated with different levels of glutathione or buthionine sulfoximine. The levels of the metabolites of arsenic were determined in the liver and urine. The levels of glutathione and total antioxidant capacity were determined in the whole blood and liver. Our results showed that the increase of arsenic species in the liver as well as the decrease of blood and hepatic glutathione and total antioxidant capacity, were all relieved by exogenous glutathione consistently. We also observed the involvement of glutathione in promoting arsenic methylation and urinary elimination in vivo. Increase of total arsenic in the urine was mainly due to the increase of dimethylated arsenic. Furthermore, administration of glutathione increased the first methylation ratio and secondary methylation ratio in the liver and urine, which resulted in the consequent increase of dimethylated arsenic percent and decrease of inorganic arsenic percent in the urine. Opposite effects appeared with the administration of buthionine sulfoximine, a scavenger of glutathione. Our study indicated that exogenous glutathione not only accelerated the methylation and the excretion of arsenic, but also relieve the arsenic-induced oxidative stress. This provides a potential useful chemopreventive dietary component for human populations being at risk of arsenic exposure. PMID:26354374

  11. 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

  12. Oral supplementation with whey proteins increases plasma glutathione levels of HIV-infected patients.

    PubMed

    Micke, P; Beeh, K M; Schlaak, J F; Buhl, R

    2001-02-01

    HIV infection is characterized by an enhanced oxidant burden and a systemic deficiency of the tripeptide glutathione (GSH), a major antioxidant. The semi-essential amino acid cysteine is the main source of the free sulfhydryl group of GSH and limits its synthesis. Therefore, different strategies to supplement cysteine supply have been suggested to increase glutathione levels in HIV-infected individuals. The aim of this study was to evaluate the effect of oral supplementation with two different cysteine-rich whey protein formulas on plasma GSH levels and parameters of oxidative stress and immune status in HIV-infected patients. In a prospective double blind clinical trial, 30 patients (25 male, 5 female; mean age (+/- SD) 42 +/- 9.8 years) with stable HIV infection (221 +/- 102 CD4 + lymphocytes L-1) were randomized to a supplemental diet with a daily dose of 45 g whey proteins of either Protectamin (Fresenius Kabi, Bad Hamburg, Germany) or Immunocal (Immunotec, Vandreuil, Canada) for two weeks. Plasma concentrations of total, reduced and oxidized GSH, superoxide anion (O2-) release by blood mononuclear cells, plasma levels of TNF-alpha and interleukins 2 and 12 were quantified with standard methods at baseline and after therapy. Pre-therapy, plasma GSH levels (Protectamin: 1.92 +/- 0.6 microM; Immunocal: 1.98 +/- 0.9 microM) were less than normal (2.64 +/- 0.7 microM, P = 0.03). Following two weeks of oral supplementation with whey proteins, plasma GSH levels increased in the Protectamin group by 44 +/- 56% (2.79 +/- 1.2 microM, P = 0.004) while the difference in the Immunocal group did not reach significance (+ 24.5 +/- 59%, 2.51 +/- 1.48 microM, P = 0.43). Spontaneous O2- release by blood mononuclear cells was stable (20.1 +/- 14.2 vs. 22.6 +/- 16.1 nmol h-1 10-6 cells, P = 0.52) whereas PMA-induced O2- release decreased in the Protectamin group (53.7 +/- 19 vs. 39.8 +/- 18 nmol h-1 10-6 cells, P = 0.04). Plasma concentrations of TNF-alpha and interleukins 2 and

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. Comparative modeling of thioredoxin glutathione reductase from Schistosoma mansoni: a multifunctional target for antischistosomal therapy.

    PubMed

    Sharma, Monika; Khanna, Smriti; Bulusu, Gopalakrishnan; Mitra, Abhijit

    2009-02-01

    Schistosoma mansoni, a trematode parasite, which causes schistosomiasis and affects more than 200 million people worldwide, lives in an aerobic environment and therefore needs an effective redox mechanism for surviving reactive oxygen species from its host. Although, the host has two different redox systems: glutaredoxin and thioredoxin, the parasite has only one unique multifunctional enzyme, thioredoxin glutathione reductase (TGR) involving a fusion of two proteins, glutaredoxin (Grx) and thioredoxin reductase (TR), for performing all the redox activities. This dependence of S. mansoni on a single protein, TGR, for its protection from oxidative stress, makes it a promising drug target. Here, we describe a suitably validated, homology model for S. mansoni TGR (SmTGR), developed using both TR and Grx templates, functionally complete in the dimeric form with cofactors NADP(H) and FAD. Comparative analysis of substrate and inhibitor binding pockets of our model with crystal structures of parent TR as well as with that of glutathione reductase (GR), which is an essential component of the Grx system, appears to provide greater insight into the functioning of TGR. This also augments recent observations reported on the basis of X-ray structure data on SmTGR monomer lacking the C-terminal selenocysteine tail. PMID:19070522

  19. Acute toxicity and responses of antioxidant systems to 1-methyl-3-octylimidazolium bromide at different developmental stages of goldfish.

    PubMed

    Li, Xiao-Yu; Zeng, Shi-Hu; Dong, Xiang-Yi; Ma, Jun-Guo; Wang, Jian-Ji

    2012-01-01

    Acute toxicity of 1-methyl-3-octylimidazolium bromide ([C(8)mim]Br) to goldfish at different developmental stages and responses of the antioxidant system in adult goldfish were evaluated in the present study. The results indicate that post-embryonic developmental toxicity of [C(8)mim]Br on goldfish is developmental-stage dependent. The juvenile and larva goldfish are more sensitive to [C(8)mim]Br-toxicity than the adult fish. Histological observations in adult goldfish reveal that acute [C(8)mim]Br exposure damages the hepatopancreas, intestines, and kidneys, indicating that these are possible target organs of [C(8)mim]Br toxicity in goldfish. Subsequent biochemical assays in adult goldfish show that [C(8)mim]Br also induces changes in the activities of the superoxide dismutase, catalase, glutathione peroxidase, and glutathione content of fish hepatopancreas. These results suggest that [C(8)mim]Br exposure may induce oxidant stress and lipid peroxidation in hepatopancreas of adult goldfish. In addition, we also find that [C(8)mim]Br causes a remarkable increase in malondialdehyde (MDA) levels in the hepatopancreas of adult goldfish, and thus we think that the MDA level change can be a biomarker of [C(8)mim]Br toxicity in goldfish. The present study indicates that ionic liquids can be a threat to the survival, growth, and development of the fish population once they are accidentally leaked into aquatic ecosystems.

  20. Binding properties of ferrocene-glutathione conjugates as inhibitors and sensors for glutathione S-transferases.

    PubMed

    Martos-Maldonado, Manuel C; Casas-Solvas, Juan M; Téllez-Sanz, Ramiro; Mesa-Valle, Concepción; Quesada-Soriano, Indalecio; García-Maroto, Federico; Vargas-Berenguel, Antonio; García-Fuentes, Luís

    2012-02-01

    The binding properties of two electroactive glutathione-ferrocene conjugates that consist in glutathione attached to one or both of the cyclopentadienyl rings of ferrocene (GSFc and GSFcSG), to Schistosoma japonica glutathione S-transferase (SjGST) were studied by spectroscopy fluorescence, isothermal titration calorimetry (ITC) and differential pulse voltammetry (DPV). Such ferrocene conjugates resulted to be competitive inhibitors of glutathione S-transferase with an increased binding affinity relative to the natural substrate glutathione (GSH). We found that the conjugate having two glutathione units (GSFcSG) exhibits an affinity for SjGST approximately two orders of magnitude higher than GSH. Furthermore, it shows negative cooperativity with the affinity for the second binding site two orders of magnitude lower than that for the first one. We propose that the reason for such negative cooperativity is steric since, i) the obtained thermodynamic parameters do not indicate profound conformational changes upon GSFcSG binding and ii) docking studies have shown that, when bound, part of the first bound ligand invades the second site due to its large size. In addition, voltammetric measurements show a strong decrease of the peak current upon binding of ferrocene-glutathione conjugates to SjGST and provide very similar K values than those obtained by ITC. Moreover, the sensing ability, expressed by the sensitivity parameter shows that GSFcSG is much more sensitive than GSFc, for the detection of SjGST.

  1. Comparison of Different Commercial Wireless Keypad Systems

    NASA Astrophysics Data System (ADS)

    Burnstein, Ray A.; Lederman, Leon M.

    2003-05-01

    Wireless keypad systems have been in limited use for the past 10 years in the classroom.1,2 Such systems can be used to quiz students in real time during the class, thus engaging students more directly in the lecture.3 Nonetheless, until recently widespread use of such keypad systems has been limited for several reasons. First, the original systems were relatively expensive but perhaps more important was the reluctance on the part of faculty to change the existing passive lecture format.4,5 However, problems associated with large lecture classes6 and the validation of the concept of "interactive engagement" from the high-statistics study of Hake7 has changed the opinions of many. In addition the desirability of peer learning,8 which is enhanced with a response system, has also been accepted. At the present time a number of commercial systems are available. The purpose of this paper is to present a comparison and summary of what is commercially available9 and a reminder that keypads are a dramatically effective teaching and learning tool.

  2. Glutathione-binding site of a bombyx mori theta-class glutathione transferase.

    PubMed

    Hossain, M D Tofazzal; Yamada, Naotaka; Yamamoto, Kohji

    2014-01-01

    The glutathione transferase (GST) superfamily plays key roles in the detoxification of various xenobiotics. Here, we report the isolation and characterization of a silkworm protein belonging to a previously reported theta-class GST family. The enzyme (bmGSTT) catalyzes the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy)-propane, and 4-nitrophenethyl bromide. Mutagenesis of highly conserved residues in the catalytic site revealed that Glu66 and Ser67 are important for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTT and into the metabolism of exogenous chemical agents.

  3. Effect of glutathione on oxymyoglobin oxidation.

    PubMed

    Tang, Jiali; Faustman, Cameron; Lee, Seok; Hoagland, Thomas A

    2003-03-12

    The oxidation of oxymyoglobin (OxyMb) to metmyoglobin (MetMb) is responsible for fresh meat discoloration. Glutathione (GSH) is an important tripeptide reductant that can protect lipid and protein from oxidation. The objective of this research was to investigate the effect of GSH on MetMb formation in vitro and in bovine skeletal muscle cytosol. Equine MetMb formation was greater in the presence of GSH than controls at pH 5.6 or 7.2 and 25 or 37 degrees C (p < 0.05); GSH addition to purified bovine OxyMb solution also resulted in more MetMb formation at pH 7.2 and 25 or 37 degrees C (p < 0.05). This effect on MetMb formation was partly or completely inhibited by EDTA or catalase in the GSH-equine OxyMb system (p < 0.05). The addition of GSH to bovine muscle cytosol inhibited MetMb formation at pH 5.6 or 7.2 and 4 or 25 degrees C (p < 0.05); the effect was concentration-dependent. The inhibitory effect was observed in a high molecular weight (HMW) but not low molecular weight fraction of cytosol at pH 7.2 and 25 degrees C (p < 0.05); there was no effect when HMW was heated at 90 degrees C for 15 min. These results suggest the antioxidant effect of GSH on bovine OxyMb is dependent on heat-sensitive HMW cytosolic component(s).

  4. Intracellular glutathione and cytotoxicity of platinum complexes.

    PubMed

    Pendyala, L; Creaven, P J; Perez, R; Zdanowicz, J R; Raghavan, D

    1995-01-01

    Although there have been a number of reports correlating cellular GSH levels with cytotoxicity of platinum agents, none has examined the relationship between GSH concentrations and cytotoxicity. In this study, using a highly specific HPLC method for measuring GSH and expressing GSH as concentration and also per cell number, we evaluated the correlation between GSH levels and the cytotoxicity to five agents in ten human tumor cell lines. The five platinum agents included the platinum(II) complexes cisplatin, carboplatin and oxaliplatin and platinum(IV) complexes iproplatin and tetraplatin. The correlation between intracellular GSH concentration and cytotoxicity was highly significant only for iproplatin (P = 0.002) followed by tetraplatin, which demonstrated a trend toward statistical significance (P = 0.06). Cytotoxicity of the other platinum complexes showed no relation to GSH concentration, cisplatin itself showing a P-value of 0.09. In contrast, the GSH levels normalized to cell number showed a statistically significant correlation with the cytotoxicity of four of the five platinum agents, the exception being carboplatin; the strongest correlation observed was that for iproplatin and tetraplatin. Glutathione-S-transferase (GST) activity in these cell lines showed no correlation with cytotoxicity of any of the platinum complexes. Our results, from the analyses of both GSH concentration as well as GSH per cell number, suggest a significantly higher interaction between GSH and iproplatin compared with the other platinum agents. Moreover, our data suggest that relationships between cytotoxicity and GSH levels on a per-cell basis may not persist when differences in cell volume are taken into account.

  5. Five decades with glutathione and the GSTome.

    PubMed

    Mannervik, Bengt

    2012-02-24

    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.

  6. Cadmium induced changes in subcellular glutathione contents within glandular trichomes of Cucurbita pepo L.

    PubMed

    Kolb, Dagmar; Müller, Maria; Zellnig, Günther; Zechmann, Bernd

    2010-07-01

    Plants cope with cadmium (Cd) stress by complexation with phytochelatins (Pc), metallothioneins and glutathione and sequestration within vacuoles. Especially glutathione was found to play a major role in Cd detoxification as Cd shows a high binding affinity towards thiols and as glutathione is a precursor for Pc synthesis. In the present study, we have used an immunohistochemical approach combined with computer-supported transmission electron microscopy in order to measure changes in the subcellular distribution of glutathione during Cd-stress in mesophyll cells and cells of different glandular trichomes (long and short stalked) of Cucurbita pepo L. subsp. pepo var. styriaca GREB: . Even though no ultrastructural alterations were observed in leaf and glandular trichome cells after the treatment of plants with 50 microM cadmium chloride (CdCl(2)) for 48 h, all cells showed a large decrease in glutathione contents. The strongest decrease was found in nuclei and the cytosol (up to 76%) in glandular trichomes which are considered as a major side of Cd accumulation in leaves. The ratio of glutathione between the cytosol and nuclei and the other cell compartments was strongly decreased only in glandular trichomes (more than 50%) indicating that glutathione in these two cell compartments is especially important for the detoxification of Cd in glandular trichomes. Additionally, these data indicate that large amounts of Cd are withdrawn from nuclei during Cd exposure. The present study gives a detailed insight into the compartment-specific importance of glutathione during Cd exposure in mesophyll cells and glandular trichomes of C. pepo L. plants.

  7. 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

  8. 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

  9. 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.

  10. 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

  11. Redox regulation of ascorbate and glutathione by a chloroplastic dehydroascorbate reductase is required for high-light stress tolerance in Arabidopsis.

    PubMed

    Noshi, Masahiro; Hatanaka, Risa; Tanabe, Noriaki; Terai, Yusuke; Maruta, Takanori; Shigeoka, Shigeru

    2016-05-01

    Chloroplasts are a significant site for reactive oxygen species production under illumination and, thus, possess a well-organized antioxidant system involving ascorbate. Ascorbate recycling occurs in different manners in this system, including a dehydroascorbate reductase (DHAR) reaction. We herein investigated the physiological significance of DHAR3 in photo-oxidative stress tolerance in Arabidopsis. GFP-fused DHAR3 protein was targeted to chloroplasts in Arabidopsis leaves. A DHAR3 knockout mutant exhibited sensitivity to high light (HL). Under HL, the ascorbate redox states were similar in mutant and wild-type plants, while total ascorbate content was significantly lower in the mutant, suggesting that DHAR3 contributes, at least to some extent, to ascorbate recycling. Activation of monodehydroascorbate reductase occurred in dhar3 mutant, which might compensate for the lack of DHAR3. Interestingly, glutathione oxidation was consistently inhibited in dhar3 mutant. These findings indicate that DHAR3 regulates both ascorbate and glutathione redox states to acclimate to HL.

  12. Conjugate products of pyocyanin-glutathione reactions.

    PubMed

    Cheluvappa, Rajkumar; Eri, Rajaraman

    2015-08-01

    This "Letter to the Editor" is a "gentle but purposeful rejoinder" to specific comments made in pages 36-37 of your Muller and Merrett (2015) publication regarding the data presented in our Cheluvappa et al. (2008) paper. Our rebuttal topics include the effect of oxygen on the pyocyanin-glutathione reaction, relevance of reaction-duration to pathophysiology, rationale of experiments, veracity of statements germane to molecular-structure construction, and correction of hyperbole. PMID:26079058

  13. 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.

  14. Effect of glutathione depletion on Ifosfamide nephrotoxicity in rats.

    PubMed

    Garimella-Krovi, Sudha; Springate, James E

    2008-09-01

    Kidney injury is an important side effect of the chemotherapeutic agent ifosfamide in humans. Previous studies have shown that treatment with ifosfamide reduces kidney glutathione and that the toxicity of ifosfamide is enhanced in glutathione-depleted renal tubule cells in vitro. In this study, we examined the effect of glutathione depletion on ifosfamide nephrotoxicity in vivo using rats treated with the glutathione-depleting agent buthionine sulfoximine. Animals received 80 mg/kg ifosfamide intraperitoneally daily for three days with or without buthionine sulfoximine in drinking water. Buthionine sulfoximine produced a significant fall in renal glutathione content but did not affect kidney function. Ifosfamide-treated rats developed low-grade glucosuria, phosphaturia and proteinuria that worsened with concomitant buthionine sulfoximine therapy. These findings indicate that glutathione depletion exacerbates ifosfamide nephrotoxicity in rats and suggest that pharmacological methods for replenishing intracellular glutathione may be effective in ameliorating ifosfamide-induced renal injury.

  15. The Roles of Glutathione Peroxidases during Embryo Development.

    PubMed

    Ufer, Christoph; Wang, Chi Chiu

    2011-01-01

    Embryo development relies on the complex interplay of the basic cellular processes including proliferation, differentiation, and apoptotic cell death. Precise regulation of these events is the basis for the establishment of embryonic structures and the organ development. Beginning with fertilization of the oocyte until delivery the developing embryo encounters changing environmental conditions such as varying levels of oxygen, which can give rise to reactive oxygen species (ROS). These challenges are met by the embryo with metabolic adaptations and by an array of anti-oxidative mechanisms. ROS can be deleterious by modifying biological molecules including lipids, proteins, and nucleic acids and may induce abnormal development or even embryonic lethality. On the other hand ROS are vital players of various signaling cascades that affect the balance between cell growth, differentiation, and death. An imbalance or dysregulation of these biological processes may generate cells with abnormal growth and is therefore potentially teratogenic and tumorigenic. Thus, a precise balance between processes generating ROS and those decomposing ROS is critical for normal embryo development. One tier of the cellular protective system against ROS constitutes the family of selenium-dependent glutathione peroxidases (GPx). These enzymes reduce hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. Of special interest within this protein family is the moonlighting enzyme glutathione peroxidase 4 (Gpx4). This enzyme is a scavenger of lipophilic hydroperoxides on one hand, but on the other hand can be transformed into an enzymatically inactive cellular structural component. GPx4 deficiency - in contrast to all other GPx family members - leads to abnormal embryo development and finally produces a lethal phenotype in mice. This review is aimed at summarizing the current knowledge on GPx isoforms during embryo development and tumor development with an emphasis on

  16. 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…

  17. Inhibition of glutathione synthesis distinctly alters mitochondrial and cytosolic redox poise

    PubMed Central

    Hanafin, William P; Beaudoin, Jessica N; Bica, Denisa E; DiLiberto, Stephen J; Kenis, Paul JA; Gaskins, H Rex

    2014-01-01

    The glutathione couple GSH/GSSG is the most abundant cellular redox buffer and is not at equilibrium among intracellular compartments. Perturbation of glutathione poise has been associated with tumorigenesis; however, due to analytical limitations, the underlying mechanisms behind this relationship are poorly understood. In this regard, we have implemented a ratiometric, genetically encoded redox-sensitive green fluorescent protein fused to human glutaredoxin (Grx1-roGFP2) to monitor real-time glutathione redox potentials in the cytosol and mitochondrial matrix of tumorigenic and non-tumorigenic cells. First, we demonstrated that recovery time in both compartments depended upon the length of exposure to oxidative challenge with diamide, a thiol-oxidizing agent. We then monitored changes in glutathione poise in cytosolic and mitochondrial matrices following inhibition of glutathione (GSH) synthesis with L-buthionine sulphoximine (BSO). The mitochondrial matrix showed higher oxidation in the BSO-treated cells indicating distinct compartmental alterations in redox poise. Finally, the contributory role of the p53 protein in supporting cytosolic redox poise was demonstrated. Inactivation of the p53 pathway by expression of a dominant-negative p53 protein sensitized the cytosol to oxidation in BSO-treated tumor cells. As a result, both compartments of PF161-T + 53DD cells were equally oxidized ≈20 mV by inhibition of GSH synthesis. Conversely, mitochondrial oxidation was independent of p53 status in GSH-deficient tumor cells. Taken together, these findings indicate different redox requirements for the glutathione thiol/disulfide redox couple within the cytosol and mitochondria of resting cells and reveal distinct regulation of their redox poise in response to inhibition of glutathione biosynthesis. PMID:24586100

  18. 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

  19. Crystal structure of Glycine max glutathione transferase in complex with glutathione: investigation of the mechanism operating by the Tau class glutathione transferases.

    PubMed

    Axarli, Irene; Dhavala, Prathusha; Papageorgiou, Anastassios C; Labrou, Nikolaos E

    2009-08-13

    Cytosolic GSTs (glutathione transferases) are a multifunctional group of enzymes widely distributed in Nature and involved in cellular detoxification processes. The three-dimensional structure of GmGSTU4-4 (Glycine max GST Tau 4-4) complexed with GSH was determined by the molecular replacement method at 2.7 A (1 A=0.1 nm) resolution. The bound GSH is located in a region formed by the beginning of alpha-helices H1, H2 and H3 in the N-terminal domain of the enzyme. Significant differences in the G-site (GSH-binding site) as compared with the structure determined in complex with Nb-GSH [S-(p-nitrobenzyl)-glutathione] were found. These differences were identified in the hydrogen-bonding and electrostatic interaction pattern and, consequently, GSH was found bound in two different conformations. In one subunit, the enzyme forms a complex with the ionized form of GSH, whereas in the other subunit it can form a complex with the non-ionized form. However, only the ionized form of GSH may form a productive and catalytically competent complex. Furthermore, a comparison of the GSH-bound structure with the Nb-GSH-bound structure shows a significant movement of the upper part of alpha-helix H4 and the C-terminal. This indicates an intrasubunit modulation between the G-site and the H-site (electrophile-binding site), suggesting that the enzyme recognizes the xenobiotic substrates by an induced-fit mechanism. The reorganization of Arg111 and Tyr107 upon xenobiotic substrate binding appears to govern the intrasubunit structural communication between the G- and H-site and the binding of GSH. The structural observations were further verified by steady-state kinetic analysis and site-directed mutagenesis studies.

  20. Permanence and global attractivity for Lotka-Volterra difference systems.

    PubMed

    Lu, Z; Wang, W

    1999-09-01

    The permanence and global attractivity for two-species difference systems of Lotka-Volterra type are considered. It is proved that a cooperative system cannot be permanent. For a permanent competitive system, the explicit expression of the permanent set E is obtained and sufficient conditions are given to guarantee the global attractivity of the positive equilibrium of the system.

  1. 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.

  2. Efflux of glutathione and glutathione complexes from human erythrocytes in response to inorganic arsenic exposure.

    PubMed

    Yildiz, Deniz; Cakir, Yeliz

    2012-12-01

    The objective of the present study was to investigate if arsenic exposure results in glutathione efflux from human erythrocytes. Arsenite significantly depleted intracellular nonprotein thiol level in a time- and concentration-dependent manner. The intracellular nonprotein thiol level was decreased to 0.767 ± 0.0017 μmol/ml erythrocyte following exposure to 10 mM of arsenite for 4 h. Extracellular nonprotein thiol level was increased concomitantly with the intracellular decrease and reached to 0.481 ± 0.0005 μmol/ml erythrocyte in 4 h. In parallel with the change in extracellular nonprotein thiol levels, significant increases in extracellular glutathione levels were detected. Extracellular glutathione levels reached to 0.122 ± 0.0013, 0.226 ± 0.003, and 0.274 ± 0.004 μmol/ml erythrocyte with 1, 5, and 10 mM of arsenite, respectively. Dimercaptosuccinic acid treatment of supernatants significantly increased the glutathione levels measured in the extracellular media. Utilization of MK571 and verapamil, multidrug resistance-associated protein 1 and Pgp inhibitors, decreased the rate of glutathione efflux from erythrocytes suggesting a role for these membrane transporters in the process. The results of the present study indicate that human erythrocytes efflux glutathione in reduced free form and in conjugated form or forms that can be recovered with dimercaptosuccinic acid when exposed to arsenite. PMID:22890881

  3. Reassessing cellular glutathione homoeostasis: novel insights revealed by genetically encoded redox probes.

    PubMed

    Morgan, Bruce

    2014-08-01

    Glutathione is the most abundant small molecule thiol in nearly all eukaryotes. Whole-cell levels of oxidized (GSSG) and reduced (GSH) glutathione are variable and responsive to genetic and chemical manipulations, which has led to their relative levels being widely used as a marker of the 'cellular redox state' and to indicate the level of 'oxidative stress' experienced by cells, tissues and organisms. However, the applicability of glutathione as a marker for a generalized 'cellular redox state' is questionable, especially in the light of recent observations in yeast cells. In yeast, whole-cell GSSG changes are almost completely dependent upon the activity of an ABC-C (ATP-binding cassette-C) transporter, Ycf1 (yeast cadmium factor 1), which mediates sequestration of GSSG to the vacuole. In the absence of Ycf1 whole-cell GSSG content is strongly decreased and extremely robust to perturbation. These observations are consistent with highly specific redox-sensitive GFP probe-based measurements of the cytosolic glutathione pool and indicate that cytosolic GSSG reductive systems are easily able to reduce nearly all GSSG formed, even following treatment with large concentrations of oxidant. In the present paper, I discuss the consequences of these new findings for our understanding of glutathione homoeostasis in the eukaryotic cell.

  4. 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

  5. Comparison of oxidized and reduced glutathione in the bread-making qualities of rice batter.

    PubMed

    Yano, Hiroyuki

    2012-02-01

    The demand for gluten-free bread is growing as the recognition of celiac disease and wheat allergy has increased worldwide. In our previous study, reduced glutathione (GSH) was found to improve the gas-retaining properties of rice batter used for gluten-free bread. In this article, oxidized glutathione (GSSG) was shown to have the same effect. Moreover, sensory tests revealed that GSSG bread had a significantly reduced sulfurous odor. Analyses by a gas chromatography-flame photometric detector demonstrated the presence of hydrogen sulfide and methyl mercaptan in the headspace of GSH bread, and also their significant reduction in GSSG bread. The viscoelastic properties and microstructures of GSSG and GSH bread did not noticeably differ. These observations suggest the usefulness of GSSG in making gluten-free rice bread and extend our knowledge of the use of glutathione in food processing. Practical Application: Glutathione, a widely-distributed peptide in cells, improves the bread-making quality of gluten-free rice batter. While both the reduced (GSH) and oxidized (GSSG) glutathione are effective, GSSG-bread has significantly reduced sulfurous odor compared to GSH-bread.

  6. Thalidomide resistance is based on the capacity of the glutathione-dependent antioxidant defense.

    PubMed

    Knobloch, Jürgen; Reimann, Kerstin; Klotz, Lars-Oliver; Rüther, Ulrich

    2008-01-01

    Thalidomide as an effective treatment for multiple myeloma and leprosy has also caused birth defects in thousands of children five decades ago particularly in Europe. Thus its use in humans remains limited. The rapid and fatal approval of thalidomide at that time ultimately was a consequence of the sole use of thalidomide-insensitive species in animal toxicity tests. Here, we aimed at elucidating the molecular basis for the resistance of mice to thalidomide teratogenicity. By using hydroethidine staining we demonstrate that thalidomide induces the formation of superoxide in embryonic fibroblasts of thalidomide-sensitive species but not in those of mice. As determined by trypan blue staining, scavenging of superoxide prevents thalidomide-induced apoptosis, a marker for thalidomide teratogenicity. Mouse embryonic fibroblasts are found to have higher glutathione levels than those of sensitive species and can be sensitized for thalidomide by glutathione depletion with diethyl maleate or diamide. Accordingly, experimental increase of glutathione levels in human embryonic fibroblasts by adding N-acetyl cysteine or glutathione ethyl ester to the culture medium counteracts thalidomide-induced apoptosis. Finally, we show that thalidomide-induced molecular pathology downstream of superoxide is essentially identical in human and sensitized mouse embryonic fibroblasts. In conclusion, thalidomide-resistance is based on the capacity of the glutathione-dependent antioxidant defense. We provide a basis to pharmacologically overcome the limitations of thalidomide use at humans and describe substantial differences between human and mouse embryonic cells regarding the protection against oxidative stress.

  7. 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

  8. Change in metabolic status of glutathione by palladium nitrate in blood components.

    PubMed

    Mukhtiar, Muhammad; Khan, Muhammad Farid; Jan, Syed Umer; Khan, Haroon; Ullah, Naseem; Badshah, Amir

    2013-01-01

    This piece of research work present the toxicological impact of varied concentrations of palladium nitrate [Pd (NO3)2] by changing the chemical status of glutathione and the way how glutathione plays its role in detoxification and conjugation processes of [Pd (NO(3))(2))] in whole blood components (plasma and cytosolic fraction). The impact of different concentration of [Pd (NO3)2] on reduced glutathione level in whole blood component (plasma and cytosolic fraction) were measured spectrophotometrically following Standard Ellman's method. Compared with control sample, significant decrease in the GSH content in whole blood components (plasma and cytosolic fraction) was obtained with various concentrations (100µM-1000µM) of palladium nitrate. Depleted GSH level was more pronounced with time incubation period (0-90) minutes. These finding shows that changes in the GSH status produced by palladium nitrate could either be due to palladium nitrate and glutathione( Pd-SG) complex formation or by conversion of reduce glutathione (2GSH + Pd(+2) - GSSG). This change in the GSH metabolic status provides information regarding the mechanism of palladium, in blood components.

  9. Protective role of glutathione in buck semen cryopreservation.

    PubMed

    Noei Razliqi, R; Zhandi, M; Shakeri, M; Towhidi, A; Sharafi, M; Emamverdi, M; Khodaei Motlagh, M

    2015-01-01

    The aim of this study was to determine the effect of low levels of glutathione on post-thawed buck sperm quality. In this experiment, different concentrations of glutathione [0 (LG-0), 0.5 (LG-0.5), 1 (LG-1), 1.5 (LG-1.5), and 2 (LG-2) mM] were added in a soybean lecithin-based extender. A total of 16 ejaculates from four bucks were collected and pooled. Each pooled sample was divided into five equal parts and each part was diluted by one of the above mentioned groups. After freeze-thawing process, motility and velocity, plasma membrane integrity and functionality, and apoptosis features of spermatozoa were evaluated. The results of this experiment showed that total motility (50.75 ± 2.33), plasma membrane integrity (55.75 ± 3.01) and functionality (46.75 ± 2.79) were higher in LG-1 extender compared to other extenders (P<0.05). The percentage of live spermatozoa (53.23 ± 3.26) was higher in LG-1 extender compared to other extenders, with the exception of LG-1.5 extender (P<0.05). Also, the percentage of late apoptotic spermatozoa (21.33 ± 1.63) was lower in LG-1 extender compared to other extenders (P<0.05). In conclusion, our results showed that GL-1 extender resulted in higher post-thawed buck sperm quality compared to other extenders.

  10. Glutathione and cysteine biosynthesis in two varieties of Abelmoschus esculentus in response to mine spoil.

    PubMed

    Arya, Shashi K; Khalique, Shaista; Kumar, Sanjay; Roy, B K

    2008-01-01

    The extent of accumulation of some heavy metals and glutathione and cysteine levels in the roots and aerial plant parts in two genotypically different varieties of A. esculentus (KS404 and BO2) exposed to mine spoil were investigated. Glutathione (GSH) level in both the varieties on control sites increased from basal level to 155.15 nmol g(-1) dry weight (d.wt.), almost 1.5 fold on 30 day and attained a plateau within 60 day Mine spoil exposure of both the varieties decreased glutathione 1.13 fold (89.2 nmol g(-1) dry weight) during 60 day from its basal level. GSH concentration in shoots of these varieties increased accompanying growth contrary to roots where it finally declined 2 fold. Cysteine content in control plants increased 2 fold (31.6 nmol g(-1) dry weight) on 30 day and finally declined 1.38 fold (22.35 nmol g(-1) dry weight, at 60 day). Both the varieties, when exposed to mine spoil, showed enhanced cysteine content almost 2 fold during 30 day (50.95 nmol g(-1) dry weight) but failed to increase further Forshoots in both the varieties challenged with mine spoil, cysteine maxima reached late (15.2 nmol g(-1) dry weight, at 40 day) relative to control but the levels declined subsequently (11.85 nmol g(-l) dry weight). Contrary to GSH, cysteine content in roots of both the varieties responded positively to mine spoil as apparent from the 2.23 fold increase during 30 d than basal level although it lowered to a level of 12.85 nmol g(-1) dry weight finally at 60 day. Both the varieties accumulated almost maximum level of selected cations (Fe > Mn> Zn> Cu > Ni) during 30 day, but BO2 variety was significantly superior in this regard. Invariably high accumulation of such cations in roots over shoots indicated accumulation, retention or restricted translocation from root to shoot. The metal share of the edible part was just 6% of the plant load. Thus, present work reflects a genotypic differences in metal accumulation and that affected the major non

  11. Crystal and solution structural studies of mouse phospholipid hydroperoxide glutathione peroxidase 4

    PubMed Central

    Janowski, Robert; Scanu, Sandra; Niessing, Dierk; Madl, Tobias

    2016-01-01

    The mammalian glutathione peroxidase (GPx) family is a key component of the cellular antioxidative defence system. Within this family, GPx4 has unique features as it accepts a large class of hydroperoxy lipid substrates and has a plethora of biological functions, including sperm maturation, regulation of apoptosis and cerebral embryogenesis. In this paper, the structure of the cytoplasmic isoform of mouse phospholipid hydroperoxide glutathione peroxidase (O70325-2 GPx4) with selenocysteine 46 mutated to cysteine is reported solved at 1.8 Å resolution using X-ray crystallography. Furthermore, solution data of an isotope-labelled GPx protein are presented. PMID:27710939

  12. Probing the binding of trypsin to glutathione-stabilized gold nanoparticles in aqueous solution.

    PubMed

    Wang, Gongke; Liu, Xingbing; Yan, Changling; Bai, Guangyue; Lu, Yan

    2015-11-01

    We investigate the interaction of trypsin with glutathione-stabilized Au nanoparticles (NPs) using fluorescence, synchronous fluorescence and ultraviolet (UV) absorption spectroscopy. We find that trypsin binds strongly to the Au NPs with a static quenching mechanism, and that the interaction is characteristic of positive cooperative binding. Furthermore, we determine the binding constants and the thermodynamic parameters, which suggest that the main binding forces between the glutathione-stabilized Au NPs and trypsin are electrostatic interactions and hydrogen bonding. Analysis of UV-vis absorption spectra suggests that aggregation of the Au NPs occurs in the trypsin/Au NPs system, which significantly alters the conformation of the protein.

  13. 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…

  14. The three-dimensional structure of class pi glutathione S-transferase in complex with glutathione sulfonate at 2.3 A resolution.

    PubMed Central

    Reinemer, P; Dirr, H W; Ladenstein, R; Schäffer, J; Gallay, O; Huber, R

    1991-01-01

    The three-dimensional structure of class pi glutathione S-transferase from pig lung, a homodimeric enzyme, has been solved by multiple isomorphous replacement at 3 A resolution and preliminarily refined at 2.3 A resolution (R = 0.24). Each subunit (207 residues) is folded into two domains of different structure. Domain I (residues 1-74) consists of a central four-stranded beta-sheet flanked on one side by two alpha-helices and on the other side, facing the solvent, by a bent, irregular helix structure. The topological pattern resembles the bacteriophage T4 thioredoxin fold, in spite of their dissimilar sequences. Domain II (residues 81-207) contains five alpha-helices. The dimeric molecule is globular with dimensions of about 55 A x 52 A x 45 A. Between the subunits and along the local diad, is a large cavity which could possibly be involved in the transport of nonsubstrate ligands. The binding site of the competitive inhibitor, glutathione sulfonate, is located on domain I, and is part of a cleft formed between intrasubunit domains. Glutathione sulfonate is bound in an extended conformation through multiple interactions. Only three contact residues, namely Tyr7, Gln62 and Asp96 are conserved within the family of cytosolic glutathione S-transferases. The exact location of the binding site(s) of the electrophilic substrate is not clear. Catalytic models are discussed on the basis of the molecular structure. Images PMID:2065650

  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. 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.

  17. The role of skeletal muscle in liver glutathione metabolism during acetaminophen overdose.

    PubMed

    Bilinsky, L M; Reed, M C; Nijhout, H F

    2015-07-01

    Marked alterations in systemic glutamate-glutamine metabolism characterize the catabolic state, in which there is an increased breakdown and decreased synthesis of skeletal muscle protein. Among these alterations are a greatly increased net release of glutamine (Gln) from skeletal muscle into blood plasma and a dramatic depletion of intramuscular Gln. Understanding the catabolic state is important because a number of pathological conditions with very different etiologies are characterized by its presence; these include major surgery, sepsis, trauma, and some cancers. Acetaminophen (APAP) overdose is also accompanied by dramatic changes in systemic glutamate-glutamine metabolism including large drops in liver glutathione (for which glutamate is a precursor) and plasma Gln. We have constructed a mathematical model of glutamate and glutamine metabolism in rat which includes liver, blood plasma and skeletal muscle. We show that for the normal rat, the model solutions fit experimental data including the diurnal variation in liver glutathione (GSH). We show that for the rat chronically dosed with dexamethasone (an artificial glucocorticoid which induces a catabolic state) the model can be used to explain empirically observed facts such as the linear decline in intramuscular Gln and the drop in plasma glutamine. We show that for the Wistar rat undergoing APAP overdose the model reproduces the experimentally observed rebound of liver GSH to normal levels by the 24-h mark. We show that this rebound is achieved in part by the action of the cystine-glutamate antiporter, an amino acid transporter not normally expressed in liver but induced under conditions of oxidative stress. Finally, we explain why supplementation with Gln, a Glu precursor, assists in the preservation of liver GSH during APAP overdose despite the fact that under normal conditions only Cys is rate-limiting for GSH formation.

  18. Functions and Cellular Compartmentation of the Thioredoxin and Glutathione Pathways in Yeast

    PubMed Central

    Delaunay-Moisan, Agnès; Outten, Caryn E.; Igbaria, Aeid

    2013-01-01

    Abstract Significance: The thioredoxin (TRX) and glutathione (GSH) pathways are universally conserved thiol-reductase systems that drive an array of cellular functions involving reversible disulfide formation. Here we consider these pathways in Saccharomyces cerevisiae, focusing on their cell compartment-specific functions, as well as the mechanisms that explain extreme differences of redox states between compartments. Recent Advances: Recent work leads to a model in which the yeast TRX and GSH pathways are not redundant, in contrast to Escherichia coli. The cytosol possesses full sets of both pathways, of which the TRX pathway is dominant, while the GSH pathway acts as back up of the former. The mitochondrial matrix also possesses entire sets of both pathways, in which the GSH pathway has major role in redox control. In both compartments, GSH has also nonredox functions in iron metabolism, essential for viability. The endoplasmic reticulum (ER) and mitochondrial intermembrane space (IMS) are sites of intense thiol oxidation, but except GSH lack thiol-reductase pathways. Critical Issues: What are the thiol-redox links between compartments? Mitochondria are totally independent, and insulated from the other compartments. The cytosol is also totally independent, but also provides reducing power to the ER and IMS, possibly by ways of reduced and oxidized GSH entering and exiting these compartments. Future Directions: Identifying the mechanisms regulating fluxes of GSH and oxidized glutathione between cytosol and ER, IMS, and possibly also peroxisomes, vacuole is needed to establish the proposed model of eukaryotic thiol-redox homeostasis, which should facilitate exploration of this system in mammals and plants. Antioxid. Redox Signal. 18, 1699–1711. PMID:23198979

  19. Chronic uranium exposure dose-dependently induces glutathione in rats without any nephrotoxicity.

    PubMed

    Poisson, C; Stefani, J; Manens, L; Delissen, O; Suhard, D; Tessier, C; Dublineau, I; Guéguen, Y

    2014-10-01

    Uranium is a heavy metal naturally found in the earth's crust that can contaminate the general public population when ingested. The acute effect and notably the uranium nephrotoxicity are well known but knowledge about the effect of chronic uranium exposure is less clear. In a dose-response study we sought to determine if a chronic exposure to uranium is toxic to the kidneys and the liver, and what the anti-oxidative system plays in these effects. Rats were contaminated for 3 or 9 months by uranium in drinking water at different concentrations (0, 1, 40, 120, 400, or 600 mg/L). Uranium tissue content in the liver, kidneys, and bones was linear and proportional to uranium intake after 3 and 9 months of contamination; it reached 6 μg per gram of kidney tissues for the highest uranium level in drinking water. Nevertheless, no histological lesions of the kidney were observed, nor any modification of kidney biomarkers such as creatinine or KIM-1. After 9 months of contamination at and above the 120-mg/L concentration of uranium, lipid peroxidation levels decreased in plasma, liver, and kidneys. Glutathione concentration increased in the liver for the 600-mg/L group, in the kidney it increased dose dependently, up to 10-fold, after 9 months of contamination. Conversely, chronic uranium exposure irregularly modified gene expression of antioxidant enzymes and activities in the liver and kidneys. In conclusion, chronic uranium exposure did not induce nephrotoxic effects under our experimental conditions, but instead reinforced the antioxidant system, especially by increasing glutathione levels in the kidneys.

  20. Diallyl disulphide depletes glutathione in Candida albicans

    PubMed Central

    Lemar, Katey M.; Aon, Miguel A.; Cortassa, Sonia; O’Rourke, Brian; T. Müller, Carsten; Lloyd, David

    2008-01-01

    Using two-photon scanning laser microscopy, we investigated the effect of an Allium sativum (garlic) constituent, diallyl disulphide (DADS), on key physiological functions of the opportunistic pathogen Candida albicans. A short 30 min exposure to 0.5 mm DADS followed by removal induced 70% cell death (50% necrotic, 20% apoptotic) within 2 h, increasing to 75% after 4 h. The early intracellular events associated with DADS-induced cell death were monitored with two-photon fluorescence microscopy to track mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS) and NADH or reduced glutathione (GSH) under aerobic conditions. DADS treatment decreased intracellular GSH and elevated intracellular ROS levels. Additionally, DADS induced a marked decrease of ΔΨm and lowered respiration in cell suspensions and isolated mitochondria. In vitro kinetic experiments in cell-free extracts suggest that glutathione-S-transferase (GST) is one of the intracellular targets of DADS. Additional targets were also identified, including inhibition of a site or sites between complexes II-IV in the electron transport chain, as well as the mitochondrial ATP-synthase. The results indicate that DADS is an effective antifungal agent able to trigger cell death in Candida, most probably by eliciting oxidative stress as a consequence of thiol depletion and impaired mitochondrial function. PMID:17534841

  1. 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

  2. A Chaotic System with Different Families of Hidden Attractors

    NASA Astrophysics Data System (ADS)

    Pham, Viet-Thanh; Volos, Christos; Jafari, Sajad; Vaidyanathan, Sundarapandian; Kapitaniak, Tomasz; Wang, Xiong

    The presence of hidden attractors in dynamical systems has received considerable attention recently both in theory and applications. A novel three-dimensional autonomous chaotic system with hidden attractors is introduced in this paper. It is exciting that this chaotic system can exhibit two different families of hidden attractors: hidden attractors with an infinite number of equilibrium points and hidden attractors without equilibrium. Dynamical behaviors of such system are discovered through mathematical analysis, numerical simulations and circuit implementation.

  3. Regional differences in spatial frame of reference systems for people in different areas of China.

    PubMed

    Li, Jing; Zhang, Kan

    2009-04-01

    Levinson defined spatial frame of reference systems into three types and found that people who spoke different languages all over the world had different habits in the use of these systems. Some quasi-experimental designed research in China suggested that Chinese people in various areas had different preferences for frame of reference systems in nonlinguistic spatial tasks. In this study, a newly designed and strictly controlled laboratory experiment was conducted to measure performance on linguistic spatial tasks. Response times of two groups of participants, respectively selected from the north (10 men and 12 women; M age = 24 yr., SD = 4) and south (11 men and 12 women; M age = 24 yr., SD = 3) of China, were compared on processing of spatial terms used in different systems: absolute (e.g., east) versus relative (e.g., right). To reduce the effect of living experience, the Northern participants with less than 4 yr. living experience in the south of China were included, and vice versa. Analysis showed that Southerners, but not Northerners, differed in response times to terms between absolute and relative systems. This finding suggests that speed of processing spatial terms differs among people who speak the uniform language Mandarin but live in geographically distinct home areas in China and use different frame of reference systems.

  4. Age-Specific Effects on Rat Lung Glutathione and Antioxidant Enzymes after Inhaling Ultrafine Soot

    PubMed Central

    Chan, Jackie K. W.; Kodani, Sean D.; Charrier, Jessie G.; Morin, Dexter; Edwards, Patricia C.; Anderson, Donald S.; Anastasio, Cort

    2013-01-01

    Vehicle exhaust is rich in polycyclic aromatic hydrocarbons (PAHs) and is a dominant contributor to urban particulate pollution (PM). Exposure to PM is linked to respiratory and cardiovascular morbidity and mortality in susceptible populations, such as children. PM can contribute to the development and exacerbation of asthma, and this is thought to occur because of the presence of electrophiles in PM or through electrophile generation via the metabolism of PAHs. Glutathione (GSH), an abundant intracellular antioxidant, confers cytoprotection through conjugation of electrophiles and reduction of reactive oxygen species. GSH-dependent phase II detoxifying enzymes glutathione peroxidase and glutathione S-transferase facilitate metabolism and conjugation, respectively. Ambient particulates are highly variable in composition, which complicates systematic study. In response, we have developed a replicable ultrafine premixed flame particle (PFP)-generating system for in vivo studies. To determine particle effects in the developing lung, 7–day-old neonatal and adult rats inhaled 22 μg/m3 PFP during a single 6-hour exposure. Pulmonary GSH and related phase II detoxifying gene and protein expression were evaluated 2, 24, and 48 hours after exposure. Neonates exhibited significant depletion of GSH despite higher initial baseline levels of GSH. Furthermore, we observed attenuated induction of phase II enzymes (glutamate cysteine ligase, glutathione reductase, glutathione S-transferase, and glutathione peroxidase) in neonates compared with adult rats. We conclude that developing neonates have a limited ability to deviate from their normal developmental pattern that precludes adequate adaptation to environmental pollutants, which results in enhanced cytotoxicity from inhaled PM. PMID:23065132

  5. 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

  6. 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

  7. 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.

  8. Glutathione-induced aggregation of gold nanoparticles: electromagnetic interactions in a closely packed assembly.

    PubMed

    Basu, Soumen; Pal, Tarasankar

    2007-06-01

    Gold nanoparticles of variable sizes have been prepared by reducing HAuCl4 with trisodium citrate by Frens' method. The synthesized gold particles show intense surface plasmon band in the visible region. The optical resonances in the visible are due to the surface plasmon oscillation, which is a function of geometry of the particles. The work reported here describes the interaction between nanoscale gold particles and a biomolecule, glutathione at low pH. Glutathione, which is a major cellular antioxidant and consists of amino acids glutamic acid, cysteine, and glycine, has been used as a molecular linker between the gold nanoparticles. In glutathione, the reactivity of the a-amines (adjacent to -COOH) is found to be pH-dependent. Linking via the a-amines are activated at low pH but suppressed at high pH due to electrostatic repulsive forces between the gold surfaces and the charged carboxylate groups. In colloidal solutions, the colour of gold nanoparticles may range from red to purple to blue, depending on the degree of aggregation as well as orientation of the individual particles within the aggregates. The citrate-functionalized gold nanoparticles with glutathione in variable acidic pH condition produce different but well-ordered aggregates. It is observed that a new peak appearing at a longer wavelength intensifies and shifts further to the red from the original peak position depending on the particle size, concentration of glutathione, and pH of the solution. The aggregates have been characterized by UV/Vis, FTIR, XRD, and TEM. On the basis of the first appearance of a clearly defined new peak at longer wavelength, a higher sensitivity of glutathione detection has been achieved with gold nanoparticles of larger dimension.

  9. 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

  10. 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

  11. 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.

  12. Insights into the catalytic mechanism of synthetic glutathione peroxidase mimetics.

    PubMed

    Bhowmick, Debasish; Mugesh, Govindasamy

    2015-11-01

    Glutathione Peroxidase (GPx) is a key selenoenzyme that protects biomolecules from oxidative damage. Extensive research has been carried out to design and synthesize small organoselenium compounds as functional mimics of GPx. While the catalytic mechanism of the native enzyme itself is poorly understood, the synthetic mimics follow different catalytic pathways depending upon the structures and reactivities of various intermediates formed in the catalytic cycle. The steric as well as electronic environments around the selenium atom not only modulate the reactivity of these synthetic mimics towards peroxides and thiols, but also the catalytic mechanisms. The catalytic cycle of small GPx mimics is also dependent on the nature of peroxides and thiols used in the study. In this review, we discuss how the catalytic mechanism varies with the substituents attached to the selenium atom.

  13. 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

  14. 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

  15. Maintenance of glutathione content is isolated hepatocyctes.

    PubMed Central

    Nińa, J; Hems, R; Krebs, H A

    1978-01-01

    1. During the standard procedure for the preparation of rat hepatocytes, about half of the cellular GSH (reduced glutathione) is lost. 2. This loss is prevented by the addition of 0.1 mM-EGTA (but no EDTA) to the perfusion medium. 3. On incubation with and without EGTA, isolated hepatocytes prepared in the presence of EGTA lose GSH. This loss is prevented by near-physiological concentrations of methionine or homocysteine, but not of cysteine. 4. Cysteine, at concentrations above 0.2 mM, causes a loss of GSH probably by non-enzymic formation of a mixed disulphide. 5. Serine together with methionine or homocystein increases GSH above the value in cells from starved rats in vivo. This is taken to suggest that cystathionine may be a cysteine donor in the synthesis of gamma-glutamylcysteine, the precursor of GSH. PMID:646804

  16. 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.

  17. 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…

  18. 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…

  19. Glutathione transferases in the bioactivation of azathioprine.

    PubMed

    Modén, Olof; Mannervik, Bengt

    2014-01-01

    The prodrug azathioprine is primarily used for maintaining remission in inflammatory bowel disease, but approximately 30% of the patients suffer adverse side effects. The prodrug is activated by glutathione conjugation and release of 6-mercaptopurine, a reaction most efficiently catalyzed by glutathione transferase (GST) A2-2. Among five genotypes of GST A2-2, the variant A2*E has threefold-fourfold higher catalytic efficiency with azathioprine, suggesting that the expression of A2*E could boost 6-mercaptopurine release and adverse side effects in treated patients. Structure-activity studies of the GST A2-2 variants and homologous alpha class GSTs were made to delineate the determinants of high catalytic efficiency compared to other alpha class GSTs. Engineered chimeras identified GST peptide segments of importance, and replacing the corresponding regions in low-activity GSTs by these short segments produced chimeras with higher azathioprine activity. By contrast, H-site mutagenesis led to decreased azathioprine activity when active-site positions 208 and 213 in these favored segments were mutagenized. Alternative substitutions indicated that hydrophobic residues were favored. A pertinent question is whether variant A2*E represents the highest azathioprine activity achievable within the GST structural framework. This issue was addressed by mutagenesis of H-site residues assumed to interact with the substrate based on molecular modeling. The mutants with notably enhanced activities had small or polar residues in the mutated positions. The most active mutant L107G/L108D/F222H displayed a 70-fold enhanced catalytic efficiency with azathioprine. The determination of its structure by X-ray crystallography showed an expanded H-site, suggesting improved accommodation of the transition state for catalysis.

  20. 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

  1. Glutathione peroxidase and phospholipid hydroperoxide glutathione peroxidase in tissues of Balb/C mice

    SciTech Connect

    Spallholz, J.E.; Roveri, A.; Yan, L.; Boylan, L.M.; Kang, C.R.; Ursini, F. Univ. of Padua )

    1991-03-11

    The two selenium (Se) enzymes glutathione peroxidase (GPx) and phospholipid hydroperoxide glutathione peroxide (PHGPx) were assayed in tissues and organ homogenates of female Balb/C mice fed torula yeast diets containing 0.008, 0.2 and 1.0 ug/g Se as selenite for nine months. GPx activity was detected in all tissues and organs whereas PHGPx activity was not detectable in lung, large intestine, eye or thymus tissue. GPx activity nearly always exceeded PHGPx activity when tissues or organs contained both enzymes irrespective of dietary Se treatment. GPx activity in tissues was generally more susceptible to the dietary Se deficiency than was PHGPx activity when expressed as a percentage of the activity found in tissues and organs of mice fed supplemented Se diets. This limited study suggests that dietary Se may be more valued in supporting PHGPx activity than GPx activity in the course of a protracted dietary Se deficiency.

  2. Enteric glial cells protect neurons from oxidative stress in part via reduced glutathione.

    PubMed

    Abdo, Hind; Derkinderen, Pascal; Gomes, Priya; Chevalier, Julien; Aubert, Philippe; Masson, Damien; Galmiche, Jean-Paul; Vanden Berghe, Pieter; Neunlist, Michel; Lardeux, Bernard

    2010-04-01

    Enteric glial cells (EGCs) are essential in the control of gastrointestinal functions. Although lesions of EGCs are associated with neuronal degeneration in animal models, their direct neuroprotective role remains unknown. Therefore, the aims of this study were to demonstrate the direct neuroprotective effects of EGCs and to identify putative glial mediators involved. First, viral targeted ablation of EGCs in primary cultures of enteric nervous system increased neuronal death both under basal conditions and in the presence of oxidative stress (dopamine, hydrogen peroxide). Second, direct or indirect coculture experiments of EGC lines with primary cultures of enteric nervous system or neuroblastoma cell lines (SH-SY5Y) prevented neurotoxic effects induced by oxidative stress (increased membrane permeability, release of neuronal specific enolase, caspase-3 immunoreactivity, changes in [Ca(2+)](i) response). Finally, combining pharmacological inhibition and mRNA silencing methods, we demonstrated that neuroprotective effects of EGCs were mediated in part by reduced glutathione but not by oxidized glutathione or by S-nitrosoglutathione. Our study identified the neuroprotective effects of EGCs via their release of reduced glutathione, extending their critical role in physiological contexts and in enteric neuropathies.-Abdo, H., Derkinderen, P., Gomes, P., Chevalier, J., Aubert, P., Masson, D., Galmiche, J.-P., Vanden Berghe, P., Neunlist, M., Lardeux, B. Enteric glial cells protect neurons from oxidative stress in part via reduced glutathione.

  3. 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

  4. Sex differences in circadian timing systems: implications for disease.

    PubMed

    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 hypothalamic-adrenal-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.

  5. Sex differences in circadian timing systems: implications for disease.

    PubMed

    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 hypothalamic-adrenal-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

  6. 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

  7. 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.

  8. Substrate profiling of glutathione S-transferase with engineered enzymes and matched glutathione analogues.

    PubMed

    Feng, Shan; Zhang, Lei; Adilijiang, Gulishana; Liu, Jieyuan; Luo, Minkui; Deng, Haiteng

    2014-07-01

    The identification of specific substrates of glutathione S-transferases (GSTs) is important for understanding drug metabolism. A method termed bioorthogonal identification of GST substrates (BIGS) was developed, in which a reduced glutathione (GSH) analogue was developed for recognition by a rationally engineered GST to label the substrates of the corresponding native GST. A K44G-W40A-R41A mutant (GST-KWR) of the mu-class glutathione S-transferases GSTM1 was shown to be active with a clickable GSH analogue (GSH-R1) as the cosubstrate. The GSH-R1 conjugation products can react with an azido-based biotin probe for ready enrichment and MS identification. Proof-of-principle studies were carried to detect the products of GSH-R1 conjugation to 1-chloro-2,4-dinitrobenzene (CDNB) and dopamine quinone. The BIGS technology was then used to identify GSTM1 substrates in the Chinese herbal medicine Ganmaocongji.

  9. 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

  10. Difference between Chitosan Hydrogels via Alkaline and Acidic Solvent Systems

    PubMed Central

    Nie, Jingyi; Wang, Zhengke; Hu, Qiaoling

    2016-01-01

    Chitosan (CS) has generated considerable interest for its desirable properties and wide applications. Hydrogel has been proven to be a major and vital form in the applications of CS materials. Among various types of CS hydrogels, physical cross-linked CS hydrogels are popular, because they avoided the potential toxicity and sacrifice of intrinsic properties caused by cross-linking or reinforcements. Alkaline solvent system and acidic solvent system are two important solvent systems for the preparation of physical cross-linked CS hydrogels, and also lay the foundations of CS hydrogel-based materials in many aspects. As members of physical cross-linked CS hydrogels, gel material via alkaline solvent system showed significant differences from that via acidic solvent system, but the reasons behind are still unexplored. In the present work, we studied the difference between CS hydrogel via alkaline system and acidic system, in terms of gelation process, hydrogel structure and mechanical property. In-situ/pseudo in-situ studies were carried out, including fluorescent imaging of gelation process, which provided dynamic visualization. Finally, the reasons behind the differences were explained, accompanied by the discussion about design strategy based on gelation behavior of the two systems. PMID:27786262

  11. Characterization of bifunctional L-glutathione synthetases from Actinobacillus pleuropneumoniae and Actinobacillus succinogenes for efficient glutathione biosynthesis.

    PubMed

    Yang, Jianhua; Li, Wei; Wang, Dezheng; Wu, Hui; Li, Zhimin; Ye, Qin

    2016-07-01

    Glutathione (GSH), an important bioactive substance, is widely applied in pharmaceutical and food industries. In this work, two bifunctional L-glutathione synthetases (GshF) from Actinobacillus pleuropneumoniae (GshFAp) and Actinobacillus succinogenes (GshFAs) were successfully expressed in Escherichia coli BL-21(DE3). Similar to the GshF from Streptococcus thermophilus (GshFSt), GshFAp and GshFAs can be applied for high titer GSH production because they are less sensitive to end-product inhibition (Ki values 33 and 43 mM, respectively). The active catalytic forms of GshFAs and GshFAp are dimers, consistent with those of GshFPm (GshF from Pasteurella multocida) and GshFSa (GshF from Streptococcus agalactiae), but are different from GshFSt (GshF from S. thermophilus) which is an active monomer. The analysis of the protein sequences and three dimensional structures of GshFs suggested that the binding sites of GshFs for substrates, L-cysteine, L-glutamate, γ-glutamylcysteine, adenosine-triphosphate, and glycine are highly conserved with only very few differences. With sufficient supply of the precursors, the recombinant strains BL-21(DE3)/pET28a-gshFas and BL-21(DE3)/pET28a-gshFap were able to produce 36.6 and 34.1 mM GSH, with the molar yield of 0.92 and 0.85 mol/mol, respectively, based on the added L-cysteine. The results showed that GshFAp and GshFAs are potentially good candidates for industrial GSH production. PMID:26996628

  12. Quantitation of protein S-glutathionylation by liquid chromatograph-tandem mass spectrometry: Correction for contaminating glutathione and glutathione disulfide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protein S-glutathionylation is a posttranslational modification that links oxidative stimuli to reversible changes in cellular function. Protein-glutathione mixed disulfides (PSSG) are commonly quantified by the reduction of the disulfide and detection of the resultant glutathione species. This met...

  13. Predicting differences in gene regulatory systems by state space models.

    PubMed

    Yamaguchi, Rui; Imoto, Seiya; Yamauchi, Mai; Nagasaki, Masao; Yoshida, Ryo; Shimamura, Teppei; Hatanaka, Yosuke; Ueno, Kazuko; Higuchi, Tomoyuki; Gotoh, Noriko; Miyano, Satoru

    2008-01-01

    We propose a statistical strategy to predict differentially regulated genes of case and control samples from time-course gene expression data by leveraging unpredictability of the expression patterns from the underlying regulatory system inferred by a state space model. The proposed method can screen out genes that show different patterns but generated by the same regulations in both samples, since these patterns can be predicted by the same model. Our strategy consists of three steps. Firstly, a gene regulatory system is inferred from the control data by a state space model. Then the obtained model for the underlying regulatory system of the control sample is used to predict the case data. Finally, by assessing the significance of the difference between case and predicted-case time-course data of each gene, we are able to detect the unpredictable genes that are the candidate as the key differences between the regulatory systems of case and control cells. We illustrate the whole process of the strategy by an actual example, where human small airway epithelial cell gene regulatory systems were generated from novel time courses of gene expressions following treatment with(case)/without(control) the drug gefitinib, an inhibitor for the epidermal growth factor receptor tyrosine kinase. Finally, in gefitinib response data we succeeded in finding unpredictable genes that are candidates of the specific targets of gefitinib. We also discussed differences in regulatory systems for the unpredictable genes. The proposed method would be a promising tool for identifying biomarkers and drug target genes.

  14. Glutathione transferase classes alpha, pi, and mu: GSH activation mechanism.

    PubMed

    Dourado, Daniel F A R; Fernandes, Pedro Alexandrino; Ramos, Maria João

    2010-10-14

    Since the early 1960s, glutathione transferases (GSTs) have been described as detoxification enzymes. In fact, GSTs are the most important enzymes involved in the metabolism of electrophilic xenobiotic/endobiotic compounds. These enzymes are able to catalyze the nucleophilic addition of glutathione (GSH) sulfur thiolate to a wide range of electrophilic substrates, building up a less toxic and more soluble compound. Cytosolic classes alpha, pi, and mu are the most extensively studied GSTs. However, many of the catalytic events are still poorly understood. In the present work, we have resorted to density functional theory (DFT) and to potential of mean force (PMF) calculations to determine the GSH activation mechanism of GSTP1-1 and GSTM1-1 isoenzymes. For the GSTP1-1 enzyme, we have demonstrated that a water molecule, after an initial conformational rearrangement of GSH, can assist a proton transfer between the GSH cysteine thiol (GSH-SH) and the GSH glutamate alpha carboxylate (GSH-COO(-)) groups. The energy barrier associated with the proton transfer is 11.36 kcal·mol(-1). The GSTM1-1 enzyme shows a completely different behavior from the previous isoenzyme. In this case, two water molecules, positioned between the GSH-SH and the ξ N atom of His107, working like a bridge, are able to promote the proton transfer between these two active groups with an energy barrier of 7.98 kcal·mol(-1). All our results are consistent with all the enzymes kinetics and mutagenesis experimental studies.

  15. Kinetic analysis of the intracellular conjugation of monochlorobimane by IC-21 murine macrophage glutathione-S-transferase.

    PubMed

    Young, P R; ConnorsWhite, A L; Dzido, G A

    1994-12-15

    Monochlorobimane (MCB) reacts with glutathione (GSH) in a reaction catalyzed by the glutathione-S-transferase (GST) isozymes. The diffusion of MCB through cell membranes is rapid and the fluorescence conjugates are relatively insensitive to quenching and to pH effects, and are expelled slowly from the cell, allowing the rate of fluorescence increase to be used to probe the dynamics of the intracellular reaction. Using low-light microscopic cytometry to monitor the initial rates of fluorescence increase for the GST-catalyzed reaction within IC-21 macrophages yields Vmax = 8.4 x 10(-16) mol s-1 cell-1 and KMCBm = 65 microM. Combining these data with an integrated Michaelis analysis of the reaction course yields KIP approximately 1.5 x 10(-5) M, and KmGSH approximately 3.0 x 10(-4) M (at [MCB] = 50 microM). The values of Vmax and KMCBm for the cell-free (extracellular) GST-catalyzed conjugation reaction are 1.2 x 10(-18) mol s-1 cell-1 and 3.1 microM, respectively. The values of Vmax for the intra- and extracellular conjugation reactions differ by 700-fold, suggesting the presence of an intracellular activator for this enzyme system. PMID:7803478

  16. The role of glutathione detoxification pathway in MCLR-induced hepatotoxicity in SD rats.

    PubMed

    Li, Shangchun; Chen, Jun; Xie, Ping; Guo, Xiaochun; Fan, Huihui; Yu, Dezhao; Zeng, Cheng; Chen, Liang

    2015-12-01

    In the present study, we investigated the role of glutathione (GSH) and its related enzymes in Sprague Dawley (SD) rats subjected to microcystin-leucine-arginine (MCLR)-induced hepatotoxicity. SD rats were intraperitoneally (i.p.) injected with MCLR after pretreating with or without buthionine-(S,R)-sulfoximine (BSO), an inhibitor of GSH synthesis. The depletion of GSH with BSO enhanced MCLR-induced oxidative stress, resulting in more severe liver damage and higher MCLR accumulation. Similarly, the contents of malondialdehyde (MDA), total GSH (T-GSH), oxidized GSH (GSSG) and GSH were significantly enhanced in BSO pretreated rats following MCLR treatment. The study showed that the transcription of GSH-related enzymes such as glutathione-S-transferase (GST), γ-glutamylcysteine synthetase (γ-GCS), glutathione reductase (GR) varied in different ways (expect for glutathione peroxidase (GPx), whose gene expression was induced in all treated groups) with or without BSO pretreatment before MCLR exposure, suggesting an adaptative response of GSH-related enzymes at transcription level to combat enhancement of oxidative stress induced by MCLR when pretreated with BSO. These data suggested the tissues with low GSH concentration are highly vulnerable to MCLR toxicity and GSH was critical for the detoxification in MCLR-induced hepatotoxicity in vivo.

  17. Ethanol induced attenuation of oxidative stress is unable to alter mRNA expression pattern of catalase, glutathione reductase, glutathione-S- transferase (GST1A), and superoxide dismutase (SOD3) enzymes in Japanese rice fish (Oryzias latipes) embryogenesis

    PubMed Central

    Wu, Minghui; Shariat-Madar, Bahbak; Haron, Mona H.; Wu, Mengmeng; Khan, Ikhlas A.; Dasmahapatra, Asok K.

    2010-01-01

    Although the mechanism of ethanol toxicity during embryogenesis is unknown, our earlier studies on Japanese rice fish (Oryzias latipes) embryos indicated that the effects might be mediated through oxidative stress. In this study we have determined the oxidative stress and the mRNA content of four antioxidant enzymes (catalase, glutathione reductase, glutathione-S-transferase, and superoxide dismutase) during Japanese rice fish embryogenesis (from 0 day post-fertilization to hatching) and after exposing the embryos to ethanol (100 and 300 mM) for 48 h at three stages (0–2, 1–3 and 4–6 day post fertilization, dpf) of organogenesis. We observed that oxidative stress was minimal in blastula, gastrula or neurula stages, increased gradually with the advancement of morphogenesis and reached its maximum level in hatchlings. The antioxidant enzyme mRNAs were constitutively expressed throughout development; however, the expression pattern was not identical among the enzymes. Catalase and superoxide dismutase (SOD) mRNAs were minimal in the fertilized eggs, but increased significantly in 1 dpf and then either sharply dropped (SOD) or maintained a steady-state (catalase). Glutathione S-transferase (GST) was very high in fertilized eggs and sharply dropped 1 dpf and then gradually increased thereafter. Glutathione reductase (GR) maintained a steady-state throughout the development. Ethanol was able to attenuate oxidative stress in embryos exposed only to 300 mM 1–3 dpf; no significant difference with controls was observed in other ethanol-treated groups. The antioxidant enzyme mRNAs also remained unaltered after ethanol treatment. From these data we conclude that the attenuation of oxidative stress by ethanol is probably due to the inhibition of normal growth of the embryos rather than by inhibiting catalase, GST, GR or SOD- dependent activities. PMID:20965276

  18. Distinguishing different sedimentary facies in a deltaic system

    NASA Astrophysics Data System (ADS)

    Purkait, Barendra; Majumdar, Dipanjan Das

    2014-07-01

    An attempt has been made to differentiate sedimentary facies in a modern deltaic system by means of grain-size characteristics of the Ganga alluvial plain of West Bengal, India. Three main energy environments (marine, mixed and riverine) comprising the delta were considered. Sand samples were collected from rivers (both tidal and non-tidal), coastal dunes, beaches and tidal flats of the deltaic plain. The grain-size distribution patterns were compared with the two model distributions of log-normal and log-skew-Laplace. Different sedimentary facies were identified by discriminant functions. The analytical results indicate that the energy gradient of the different sedimentary facies of the deltaic system is well reflected by the grain-size characteristics of the individual facies. While critically analyzing the role of different textural parameters in discriminating the individual facies associations, it is observed that the mean size, alpha (slope of coarser fractions of Laplace model) and skewness have greater potential to distinguish different sedimentary facies of the deltaic system. The results of discriminant analysis might be applicable to paleo-environmental interpretation of a deltaic system by distinguishing the individual facies associations.

  19. Exploring Individual Differences in Attitudes toward Audience Response Systems

    ERIC Educational Resources Information Center

    Kay, Robin H.; Knaack, Liesel

    2009-01-01

    The purpose of this study was to examine individual differences in attitudes toward Audience Response Systems (ARSs) in secondary school classrooms. Specifically, the impact of gender, grade, subject area, computer comfort level, participation level, and type of use were examined in 659 students. Males had significantly more positive attitudes…

  20. Fluorescein-labeled glutathione to study protein S-glutathionylation.

    PubMed

    Landino, Lisa M; Brown, Carolyn M; Edson, Carolyn A; Gilbert, Laura J; Grega-Larson, Nathan; Wirth, Anna Jean; Lane, Kelly C

    2010-07-01

    Numerous studies of S-glutathionylation of cysteine thiols indicate that this protein modification plays a key role in redox regulation of proteins. To facilitate the study of protein S-glutathionylation, we developed a synthesis and purification to produce milligram quantities of fluorescein-labeled glutathione. The amino terminus of the glutathione tripeptide reacted with fluorescein isothiocyanate readily in ammonium bicarbonate. Purification by solid phase extraction on C8 and C18 columns separated excess reactants from desired products. Both oxidized and reduced fluorescein-labeled glutathione reacted with a variety of thiol-containing proteins to yield fluorescent proteins. PMID:20156418

  1. Fluorescein-labeled glutathione to study protein S-glutathionylation.

    PubMed

    Landino, Lisa M; Brown, Carolyn M; Edson, Carolyn A; Gilbert, Laura J; Grega-Larson, Nathan; Wirth, Anna Jean; Lane, Kelly C

    2010-07-01

    Numerous studies of S-glutathionylation of cysteine thiols indicate that this protein modification plays a key role in redox regulation of proteins. To facilitate the study of protein S-glutathionylation, we developed a synthesis and purification to produce milligram quantities of fluorescein-labeled glutathione. The amino terminus of the glutathione tripeptide reacted with fluorescein isothiocyanate readily in ammonium bicarbonate. Purification by solid phase extraction on C8 and C18 columns separated excess reactants from desired products. Both oxidized and reduced fluorescein-labeled glutathione reacted with a variety of thiol-containing proteins to yield fluorescent proteins.

  2. Glutathione redox dynamics and expression of glutathione-related genes in the developing embryo

    PubMed Central

    Timme-Laragy, Alicia R.; Goldstone, Jared V.; Imhoff, Barry R.; Stegeman, John J.; Hahn, Mark E.; Hansen, Jason M.

    2013-01-01

    Embryonic development involves dramatic changes in cell proliferation and differentiation that must be highly coordinated and tightly regulated. Cellular redox balance is critical for cell fate decisions, but it is susceptible to disruption by endogenous and exogenous sources of oxidative stress. The most abundant endogenous non-protein antioxidant defense molecule is the tri-peptide glutathione (γ-glutamyl-cysteinylglycine, GSH), but the ontogeny of GSH concentration and redox state during early life stages is poorly understood. Here, we describe the GSH redox dynamics during embryonic and early larval development (0–5 days post-fertilization) in the zebrafish (Danio rerio), a model vertebrate embryo. We measured reduced and oxidized glutathione (GSH, GSSG) using HPLC, and calculated the whole embryo total glutathione (GSHT) concentrations and redox potentials (Eh) over 0–120 hours of zebrafish development (including mature oocytes, fertilization, mid-blastula transition, gastrulation, somitogenesis, pharyngula, pre-hatch embryos, and hatched eleutheroembryos). GSHT concentration doubled between 12 hours post fertilization (hpf) and hatching. The GSH Eh increased, becoming more oxidizing during the first 12 h, and then oscillated around −190 mV through organogenesis, followed by a rapid change, associated with hatching, to a more negative (more reducing) Eh (−220 mV). After hatching, Eh stabilized and remained steady through 120 hpf. The dynamic changes in GSH redox status and concentration defined discrete windows of development: primary organogenesis, organ differentiation, and larval growth. We identified the set of zebrafish genes involved in the synthesis, utilization, and recycling of GSH, including several novel paralogs, and measured how expression of these genes changes during development. Ontogenic changes in the expression of GSH-related genes support the hypothesis that GSH redox state is tightly regulated early in development. This study

  3. Quantitation of protein S-glutathionylation by liquid chromatography-tandem mass spectrometry: correction for contaminating glutathione and glutathione disulfide.

    PubMed

    Bukowski, Michael R; Bucklin, Christopher; Picklo, Matthew J

    2015-01-15

    Protein S-glutathionylation is a posttranslational modification that links oxidative stimuli to reversible changes in cellular function. Protein-glutathione mixed disulfide (PSSG) is commonly quantified by reduction of the disulfide and detection of the resultant glutathione species. This methodology is susceptible to contamination by free unreacted cellular glutathione (GSH) species, which are present in 1000-fold greater concentration. A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method was developed for quantification of glutathione and glutathione disulfide (GSSG), which was used for the determination of PSSG in biological samples. Analysis of rat liver samples demonstrated that GSH and GSSG coprecipitated with proteins similar to the range for PSSG in the sample. The use of [(13)C2,(5)N]GSH and [(13)C4,(5)N2]GSSG validated these results and demonstrated that the release of GSH from PSSG did not occur during sample preparation and analysis. These data demonstrate that GSH and GSSG contamination must be accounted for when determining PSSG content in cellular/tissue preparations. A protocol for rinsing samples to remove the adventitious glutathione species is demonstrated. The fragmentation patterns for glutathione were determined by high-resolution mass spectrometry, and candidate ions for detection of PSSG on protein and protein fragments were identified.

  4. Effects of mercury and selenium on glutathione metabolism and oxidative stress in mallard ducks

    USGS Publications Warehouse

    Hoffman, D.J.; Heinz, G.H.

    1998-01-01

    Earlier studies reported on the toxicity and related oxidative stress of different forms of Se, including seleno-D,L-methionine, in mallards (Anas platyrhynchos). This study compares the effects of Se (seleno-D,L-methionine) and Hg (methylmercury chloride) separately and in combination. Mallard drakes received one of the following diets: untreated feed (controls), or feed containing 10 ppm Se, 10 ppm Hg, or 10 ppm Se in combination with 10 ppm Hg. After 10 weeks, blood, liver, and brain samples were collected for biochemical assays. The following clinical and biochemical alterations occurred in response to mercury exposure: hematocrit and hemoglobin concentrations decreased; activities of the enzymes glutathione (GSH) peroxidase (plasma and liver), glutathione-S-transferase (liver), and glucose-6-phosphate dehydrogenase (G-6-PDH) (liver and brain) decreased; hepatic oxidized glutathione (GSSG) concentration increased relative to reduced glutathione (GSH); and lipid peroxidation in the brain was evident as detected by increased thiobarbituric reactive substances (TBARS). Effects of Se alone included increased hepatic GSSG reductase activity and brain TBARS concentration. Se in combination with Hg partially or totally alleviated effects of Hg on GSH peroxidase, G-6-PDH, and GSSG. These findings are compared in relation to field observations for diving ducks and other aquatic birds. It is concluded that since both Hg and excess Se can affect thiol status, measurement of associated enzymes in conjunction with thiol status may be a useful bioindicator to discriminate between Hg and Se effects. The ability of Se to restore the activities of G-6-PDH, GSH peroxidase, and glutathione status involved in antioxidative defense mechanisms may be crucial to biological protection from the toxic effects of methyl mercury.

  5. Glutathione and its related enzymes in the gonad of Nile Tilapia (Oreochromis niloticus).

    PubMed

    Hamed, R R; Saleh, N S M; Shokeer, A; Guneidy, R A; Abdel-Ghany, S S

    2016-02-01

    Glutathione (GSH) concentration, the activity of its metabolizing enzymes, glutathione transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), and the antioxidant enzyme catalase (CAT) in O. niloticus ovary and testis were examined. GSH concentration of O. niloticus testis exhibited high concentration (129 ± 21 nmol/g tissue) compared with GSH concentration (49.2 ± 8.3 nmol/g tissue) in the ovary. GST, GPx, GR, and CAT activities of O. niloticus testis exhibited high values compared with their corresponding values in ovary homogenates. However, protein concentration in ovary homogenates exhibited higher values (175 ± 40.6 mg) compared with testis homogenates (27.1 ± 3.7 mg). O. niloticus ovary was less effective in excretion of xenobiotices compared with the testis, where its function is mainly in increasing the protein content of the eggs; however, in O. niloticus testis, the glutathione cycle operated in accelerated way in the direction of reduced GSH production in order to protect the maturation stages in a save way. A simple reproducible procedure for the purification of GST from O. niloticus ovary was established. The enzymes proved to be homogenous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and its molecular weight was calculated to be 25.1 kDa. GST of O. niloticus ovary exhibited maximum activity at pH 7.5. The Michaelis-Menten constant (K(m)) of the purified ovary GST for GSH and CDNB was 0.076 mM and 1.0 mM, respectively. Cibacron blue was the most potent inhibitor of ovary GST activity (IC50 value, concentration of inhibitor that will give 50% inhibition, equal 0.002 μM). The specific activity of GST toward different electrophilic substrates was determined. GST activity toward benzyl isothiocyanate was the highest compared with phenethyl isothiocyanate and allyl isothiocyanate.

  6. Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation1234

    PubMed Central

    Patel, Sanjeet G; Guthikonda, Anuradha P; Reid, Marvin; Balasubramanyam, Ashok; Taffet, George E; Jahoor, Farook

    2011-01-01

    Background: Aging is associated with oxidative stress, but underlying mechanisms remain poorly understood. Objective: We tested whether glutathione deficiency occurs because of diminished synthesis and contributes to oxidative stress in aging and whether stimulating glutathione synthesis with its precursors cysteine and glycine could alleviate oxidative stress. Design: Eight elderly and 8 younger subjects received stable-isotope infusions of [2H2]glycine, after which red blood cell (RBC) glutathione synthesis and concentrations, plasma oxidative stress, and markers of oxidant damage (eg, F2-isoprostanes) were measured. Elderly subjects were restudied after 2 wk of glutathione precursor supplementation. Results: Compared with younger control subjects, elderly subjects had markedly lower RBC concentrations of glycine (486.7 ± 28.3 compared with 218.0 ± 23.7 μmol/L; P < 0.01), cysteine (26.2 ± 1.4 compared with 19.8 ± 1.3 μmol/L; P < 0.05), and glutathione (2.08 ± 0.12 compared with 1.12 ± 0.18 mmol/L RBCs; P < 0.05); lower glutathione fractional (83.14 ± 6.43% compared with 45.80 ± 5.69%/d; P < 0.01) and absolute (1.73 ± 0.16 compared with 0.55 ± 0.12 mmol/L RBCs per day; P < 0.01) synthesis rates; and higher plasma oxidative stress (304 ± 16 compared with 346 ± 20 Carratelli units; P < 0.05) and plasma F2-isoprostanes (97.7 ± 8.3 compared with 136.3 ± 11.3 pg/mL; P < 0.05). Precursor supplementation in elderly subjects led to a 94.6% higher glutathione concentration, a 78.8% higher fractional synthesis rate, a 230.9% higher absolute synthesis rate, and significantly lower plasma oxidative stress and F2-isoprostanes. No differences in these measures were observed between younger subjects and supplemented elderly subjects. Conclusions: Glutathione deficiency in elderly humans occurs because of a marked reduction in synthesis. Dietary supplementation with the glutathione precursors cysteine and glycine fully restores glutathione synthesis and

  7. [Study of Lavoisier morphine chlorhydrate stability in different active perfusion systems after reconstitution in different solvents].

    PubMed

    Truelle-Hugon, B; Tourrette, G; Couineaux, B; Gache-Charrette, C

    1997-01-01

    The stability of morphine chlorhydrate injectable solutions with no preservative used for drug delivery system (PCA) was investigated. Many concentrations of morphine chlorhydrate were prepared using different solvents and in several containers: PCA cartridges and plastic syringes stored at 37 degrees C. Assays of drug substance and of degradation products were determined at different time within 14 days. In such conditions, morphine chlorhydrate solutions were stable: degradation products were quantitated less than the usual normal i.e. 2% of the theoric concentration of the drug.

  8. A Geo-Distributed System Architecture for Different Domains

    NASA Astrophysics Data System (ADS)

    Moßgraber, Jürgen; Middleton, Stuart; Tao, Ran

    2013-04-01

    The presentation will describe work on the system-of-systems (SoS) architecture that is being developed in the EU FP7 project TRIDEC on "Collaborative, Complex and Critical Decision-Support in Evolving Crises". In this project we deal with two use-cases: Natural Crisis Management (e.g. Tsunami Early Warning) and Industrial Subsurface Development (e.g. drilling for oil). These use-cases seem to be quite different at first sight but share a lot of similarities, like managing and looking up available sensors, extracting data from them and annotate it semantically, intelligently manage the data (big data problem), run mathematical analysis algorithms on the data and finally provide decision support on this basis. The main challenge was to create a generic architecture which fits both use-cases. The requirements to the architecture are manifold and the whole spectrum of a modern, geo-distributed and collaborative system comes into play. Obviously, one cannot expect to tackle these challenges adequately with a monolithic system or with a single technology. Therefore, a system architecture providing the blueprints to implement the system-of-systems approach has to combine multiple technologies and architectural styles. The most important architectural challenges we needed to address are 1. Build a scalable communication layer for a System-of-sytems 2. Build a resilient communication layer for a System-of-sytems 3. Efficiently publish large volumes of semantically rich sensor data 4. Scalable and high performance storage of large distributed datasets 5. Handling federated multi-domain heterogeneous data 6. Discovery of resources in a geo-distributed SoS 7. Coordination of work between geo-distributed systems The design decisions made for each of them will be presented. These developed concepts are also applicable to the requirements of the Future Internet (FI) and Internet of Things (IoT) which will provide services like smart grids, smart metering, logistics and

  9. Assessing System Thinking Through Different Concept-Mapping Practices

    NASA Astrophysics Data System (ADS)

    Brandstädter, Kristina; Harms, Ute; Großschedl, Jörg

    2012-09-01

    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 features of CM practices affect the valid assessment of students' system thinking. The particular features analysed were the medium (computer versus paper-pencil) and the directedness (highly directed versus nondirected) of CM practices. These features were evaluated with respect to their influence on (a) students' performance in CM and (b) the validity of different CM practices for system thinking. One hundred fifty-four German fourth graders (mean age: 9.95 years) and 93 eighth graders (mean age: 14.07 years) participated in the study following an experimental pre-test-post-test design. Three variations of CM practices were applied: (a) highly directed computer mapping, (b) highly directed paper-pencil mapping, and (c) nondirected paper-pencil mapping. In addition to the CM task, a paper-pencil questionnaire was employed to investigate the validity of the CM practices. Results showed that the computer positively influenced student performance in CM when compared with paper-pencil. By contrast, there was no difference between highly directed and nondirected mapping. Whereas the medium rarely influenced the validity of CM for system thinking, high directedness showed a positive influence. Considering the limitations and benefits of particular CM practices, we suggest highly directed and computer-based CM as an appropriate assessment tool-in particular, with regard to large-scale assessments of system thinking.

  10. Effect of glutathione during bottle storage of sparkling wine.

    PubMed

    Webber, Vanessa; Dutra, Sandra Valduga; Spinelli, Fernanda Rodrigues; Carnieli, Gilberto João; Cardozo, Alejandro; Vanderlinde, Regina

    2017-02-01

    Reduced glutathione (GSH) is an efficient antioxidant on limiting browning, losing varietal aromas and off-flavor formation. Therefore, this study aims to evaluate the effect of GSH addition (10, 20 and 30mgL(-1)) after the disgorging of the sparkling wine during storage. The sparkling wines were analyzed at 1, 6, 12 and 18months of storage according to the color index, concentration of the free SO2, phenolic compounds, catechin, epicatechin, caffeic acid, coumaric acid, acetaldehyde, total and reduced glutathione. The results show that GSH concentration decreased to the level of the control sparkling wine during the first 6months, and the total glutathione gradually declined up to 12months. The GSH reduces browning and acetaldehyde formation for up to 12months. However, the presence of glutathione had low or no influence on the concentration of free SO2, total phenolics, catechin, epicatechin, caffeic and coumaric acids. PMID:27596417

  11. Elemental composition at different points of the rainwater harvesting system.

    PubMed

    Morrow, A C; Dunstan, R H; Coombes, P J

    2010-09-15

    Entry of contaminants, such as metals and non-metals, into rainwater harvesting systems can occur directly from rainfall with contributions from collection surfaces, accumulated debris and leachate from storage systems, pipes and taps. Ten rainwater harvesting systems on the east coast of Australia were selected for sampling of roof runoff, storage systems and tap outlets to investigate the variations in rainwater composition as it moved throughout the system, and to identify potential points of contribution to elemental loads. A total of 26 elements were screened at each site. Iron was the only element which was present in significantly higher concentrations in roof runoff samples compared with tank tap samples (P<0.05). At one case study site, results suggested that piping and tap material can contribute to contaminant loads of harvested rainwater. Increased loads of copper were observed in hot tap samples supplied by the rainwater harvesting system via copper piping and a storage hot water system (P<0.05). Similarly, zinc, lead, arsenic, strontium and molybdenum were significantly elevated in samples collected from a polyvinyl chloride pipe sampling point that does not supply household uses, compared with corresponding roof runoff samples (P<0.05). Elemental composition was also found to vary significantly between the tank tap and an internal cold tap at one of the sites investigated, with several elements fluctuating significantly between the two outlets of interest at this site, including potassium, zinc, manganese, barium, copper, vanadium, chromium and arsenic. These results highlighted the variability in the elemental composition of collected rainwater between different study sites and between different sampling points. Atmospheric deposition was not a major contributor to the rainwater contaminant load at the sites tested. Piping materials, however, were shown to contribute significantly to the total elemental load at some locations.

  12. Evolutionary divergence of Ure2pA glutathione transferases in wood degrading fungi.

    PubMed

    Roret, Thomas; Thuillier, Anne; Favier, Frédérique; Gelhaye, Eric; Didierjean, Claude; Morel-Rouhier, Mélanie

    2015-10-01

    The intracellular systems of detoxification are crucial for the survival of wood degrading fungi. Within these systems, glutathione transferases could play a major role since this family of enzymes is specifically extended in lignolytic fungi. In particular the Ure2p class represents one third of the total GST number in Phanerochaete chrysosporium. These proteins have been phylogenetically split into two subclasses called Ure2pA and Ure2pB. Ure2pB can be classified as Nu GSTs because of shared structural and functional features with previously characterized bacterial isoforms. Ure2pA can rather be qualified as Nu-like GSTs since they exhibit a number of differences. Ure2pA possess a classical transferase activity, a more divergent catalytic site and a higher structural flexibility for some of them, compared to Nu GSTs. The characterization of four members of this Ure2pA subclass (PcUre2pA4, PcUre2pA5, PcUre2pA6 and PcUre2pA8) revealed specific functional and structural features, suggesting that these enzymes have rapidly evolved and differentiated, probably to adapt to the complex chemical environment associated with wood decomposition.

  13. Nanofiltration concentration of extracellular glutathione produced by engineered Saccharomyces cerevisiae.

    PubMed

    Sasaki, Kengo; Hara, Kiyotaka Y; Kawaguchi, Hideo; Sazuka, Takashi; Ogino, Chiaki; Kondo, Akihiko

    2016-01-01

    This study aimed to optimize extracellular glutathione production by a Saccharomyces cerevisiae engineered strain and to concentrate the extracellular glutathione by membrane separation processes, including ultrafiltration (UF) and nanofiltration (NF). Synthetic defined (SD) medium containing 20 g L(-1) glucose was fermented for 48 h; the fermentation liquid was passed through an UF membrane to remove macromolecules. Glutathione in this permeate was concentrated for 48 h to 545.1 ± 33.6 mg L(-1) using the NF membrane; this was a significantly higher concentration than that obtained with yeast extract peptone dextrose (YPD) medium following 96 h NF concentration (217.9 ± 57.4 mg L(-1)). This higher glutathione concentration results from lower cellular growth in SD medium (final OD600 = 6.9 ± 0.1) than in YPD medium (final OD600 = 11.0 ± 0.6) and thus higher production of extracellular glutathione (16.0 ± 1.3 compared to 9.2 ± 2.1 mg L(-1) in YPD medium, respectively). Similar fermentation and membrane processing of sweet sorghum juice containing 20 g L(-1) total sugars provided 240.3 ± 60.6 mg L(-1) glutathione. Increased extracellular production of glutathione by this engineered strain in SD medium and subsequent UF permeation and NF concentration in shortend time may help realize industrial recovery of extracellular glutathione.

  14. Allyl isothiocyanate depletes glutathione and upregulates expression of glutathione S-transferases in Arabidopsis thaliana

    PubMed Central

    Øverby, Anders; Stokland, Ragni A.; Åsberg, Signe E.; Sporsheim, Bjørnar; Bones, Atle M.

    2015-01-01

    Allyl isothiocyanate (AITC) is a phytochemical associated with plant defense in plants from the Brassicaceae family. AITC has long been recognized as a countermeasure against external threats, but recent reports suggest that AITC is also involved in the onset of defense-related mechanisms such as the regulation of stomatal aperture. However, the underlying cellular modes of action in plants remain scarcely investigated. Here we report evidence of an AITC-induced depletion of glutathione (GSH) and the effect on gene expression of the detoxification enzyme family glutathione S-transferases (GSTs) in Arabidopsis thaliana. Treatment of A. thaliana wild-type with AITC resulted in a time- and dose-dependent depletion of cellular GSH. AITC-exposure of mutant lines vtc1 and pad2-1 with elevated and reduced GSH-levels, displayed enhanced and decreased AITC-tolerance, respectively. AITC-exposure also led to increased ROS-levels in the roots and loss of chlorophyll which are symptoms of oxidative stress. Following exposure to AITC, we found that GSH rapidly recovered to the same level as in the control plant, suggesting an effective route for replenishment of GSH or a rapid detoxification of AITC. Transcriptional analysis of genes encoding GSTs showed an upregulation in response to AITC. These findings demonstrate cellular effects by AITC involving a reversible depletion of the GSH-pool, induced oxidative stress, and elevated expression of GST-encoding genes. PMID:25954298

  15. Functional mimicry of the active site of glutathione peroxidase by glutathione imprinted selenium-containing protein.

    PubMed

    Liu, Lei; Mao, Shi-zhong; Liu, Xiao-man; Huang, Xin; Xu, Jia-yun; Liu, Jun-qiu; Luo, Gui-min; Shen, Jia-cong

    2008-01-01

    For imitating the active site of antioxidant selenoenzyme glutathione peroxidase (GPx), an artificial enzyme selenosubtilisin was employed as a scaffold for reconstructing substrate glutathione (GSH) specific binding sites by a bioimprinting strategy. GSH was first covalently linked to selenosubtilisin to form a covalent complex GSH-selenosubtilisin through a Se-S bond, then the GSH molecule was used as a template to cast a complementary binding site for substrate GSH recognition. The bioimprinting procedure consists of unfolding the conformation of selenosubtilisin and fixing the new conformation of the complex GSH-selenosubtilisin. Thus a new specificity for naturally occurring GPx substrate GSH was obtained. This bioimprinting procedure facilitates the catalytic selenium moiety of the imprinted selenosubtilisin to match the reactive thiol group of GSH in the GSH binding site, which contributes to acceleration of the intramolecular catalysis. These imprinted selenium-containing proteins exhibited remarkable rate enhancement for the reduction of H2O2 by GSH. The average GPx activity was found to be 462 U/micromol, and it was approximately 100 times that for unimprinted selenosubtilisin. Compared with ebselen, a well-known GPx mimic, an activity enhancement of 500-fold was observed. Detailed steady-state kinetic studies demonstrated that the novel selenoenzyme followed a ping-pong mechanism similar to the naturally occurring GPx. PMID:18163571

  16. Glutathione and glutathione peroxidase activities in blood of patients in early stages following kidney transplantation.

    PubMed

    Zachara, Bronislaw A; Wlodarczyk, Zbigniew; Andruszkiewicz, Jacek; Gromadzinska, Jolanta; Wasowicz, Wojciech

    2005-01-01

    This study focuses on glutathione (GSH) level in red blood cells, as well as on glutathione peroxidases (GSH-Px) activities in red blood cells and in plasma of chronic renal failure (CRF) patients following renal transplantation. We want to focus our main attention on plasma GSH-Px, the selenoenzyme that is synthesized primarily in the kidney. In CRF patients, activity of this enzyme is significantly reduced, and the reduction decreases with the progress of the disease, reaching in the end-stage 20% to 30% of the activity of healthy patients. We have shown that following renal transplantation the activity of plasma GSH-Px is restored very rapidly, and 2 weeks after surgery it reached the value of the control group. Red blood cell GSH level is significantly higher in CRF patients, and following transplantation, no significant changes were observed. Red blood cell GSH-Px activity before transplantation was the same as in healthy patients and did not change significantly after surgery. PMID:16350829

  17. Microbiological quality of goat's milk obtained under different production systems.

    PubMed

    Kyozaire, J K; Veary, C M; Petzer, I M; Donkin, E F

    2005-06-01

    In order to determine the safety of milk produced by smallholder dairy goat farms, a farm-based research study was conducted on commercial dairy goat farms to compare the microbiological quality of milk produced using 3 different types of dairy goat production systems (intensive, semi-intensive and extensive). A survey of dairy goat farms in and around Pretoria carried out by means of a questionnaire revealed that most of the smallholder dairy goat farms surveyed used an extensive type of production system. The method of milking varied with the type of production system, i.e. machine milking; bucket system machine milking and hand-milking, respectively. Udder half milk samples (n=270) were analysed, of which 31.1% were infected with bacteria. The lowest intra-mammary infection was found amongst goats in the herd under the extensive system (13.3%), compared with 43.3% and 36.7% infection rates under the intensive and semi-intensive production systems, respectively. Staphylococcus intermedius (coagulase positive), Staphylococcus epidermidis and Staphylococcus simulans (both coagulase negative), were the most common cause of intramammary infection with a prevalence of 85.7% of the infected udder halves. The remaining 14.3% of the infection was due to Staphylococcus aureus. Bacteriology of bulk milk samples on the other hand, showed that raw milk obtained by the bucket system milking machine had the lowest total bacterial count (16,450 colony forming units (CFU)/ml) compared to that by pipeline milking machine (36,300 CFU/ml) or hand-milking (48,000 CFU/ml). No significant relationship was found between the somatic cell counts (SCC) and presence of bacterial infection in goat milk In comparison with the herds under the other 2 production systems, it was shown that dairy goat farming under the extensive production system, where hand-milking was used, can be adequate for the production of safe raw goat milk.

  18. Sensory characteristics and consumer acceptability of beef soup with added glutathione and/or MSG.

    PubMed

    Jung, D W; Hong, J H; Kim, K O

    2010-01-01

    The sensory characteristics and consumer acceptability of beef soup with added glutathione (GSH) and/or monosodium glutamate (MSG) were investigated to examine the feasibility of GSH as a flavor enhancer. The sensory characteristics of beef soup samples, containing only GSH or MSG at different levels or a mixture of these, were examined by descriptive analysis. Principle component analysis was conducted to summarize the relationships between the beef soup samples and the attributes. In consumer testing, separate groups of consumers evaluated overall liking as well as the flavor intensities of beef, seasoning, and MSG. Partial least square regression was conducted to observe the relationships between the descriptive data and consumer data. The samples containing GSH had stronger "beef flavor,"garlic flavor," and "green onion flavor" while the samples containing MSG had stronger "salty taste,"sweet taste,"MSG taste," and "potato flavor." The consumers preferred samples containing both GSH and MSG, which had higher perceived flavor intensities of beef, seasonings, MSG. This study indicates that GSH has potential as a flavor enhancer, but more tests in different food systems with additions of GSH at varying levels are required to elucidate its effectiveness as a flavor enhancer more clearly. PMID:20492200

  19. Mitochondrial structural and antioxidant system responses to aging in oat (Avena sativa L.) seeds with different moisture contents.

    PubMed

    Xia, Fangshan; Wang, Xianguo; Li, Manli; Mao, Peisheng

    2015-09-01

    We observed the relationship between lifespan and mitochondria, including antioxidant systems, ultrastructure, and the hydrogen peroxide and malondialdehyde contents in 4 h imbibed oat (Avena sativa L.) seeds that were aged with different moisture contents (4%, 10% and 16%) for 0 (the control), 8, 16, 24, 32 and 40 d at 45 °C. The results showed that the decline in the oat seed vigor and in the integrity of the mitochondrial ultrastructure occurred during the aging process, and that these changes were enhanced by higher moisture contents. Mitochondrial antioxidants in imbibed oat seeds aged with a 4% moisture content were maintained at higher levels than imbibed oat seeds aged with a 10% and 16% moisture content. These results indicated that the levels of mitochondrial antioxidants and malondialdehyde after imbibition were related to the integrity of the mitochondrial membrane in aged oat seeds. The scavenging role of mitochondrial superoxide dismutase was inhibited in imbibed oat seeds aged at the early stage. Monodehydroascorbate reductase and dehydroascorbate reductase played more important roles than glutathione reductase in ascorbate regeneration in aged oat seeds during imbibition.

  20. Physiological evaluation of men wearing three different toxicological protective systems

    SciTech Connect

    Levine, L.; Cadarette, B.S.; Sawka, M.N.; Pandolf, K.B.

    1989-08-01

    This study examined the physiological responses of seven volunteers exercising in the heat while wearing three different toxicological protective systems. The Toxicological Agent Protective (TAP) suit has been available for use for more than 30 years while the other two protective systems are developmental efforts. The Self-Contained Toxicological Environmental Protection Outfit (STEPO) includes either a backpack-rebreather (with CO{sub 2} scrubber) and ice-cooling vest (STEPO-R), or a tether system which supplies breathing/cooling air inside the suit (STEPO-T). After the volunteers were heat acclimated, the three toxicological protection systems were evaluated utilizing a counter-balanced experimental design initially in a hot and then in a cool environment while subjects walked at 1.12 m/s, 0% grade for an attempted two hours. There was no statistical advantage of any one system in terms of exercise time in the cool environment. While evaporated sweating rate was greater for the STEPO-T in the cool environment compared to both STEPO-R and TAP. Development efforts to improve the STEPO system designs continue, and physiological evaluation of new developmental models is underway.

  1. Bilateral Control of Master-Slave Systems with Different Scaling

    NASA Astrophysics Data System (ADS)

    Susa, Shigeru; Natori, Kenji; Ohnishi, Kouhei

    Bilateral control is one of control methods used to achieve haptic teleoperation between remote places. If the bilateral system is utilized for small or large environments such as those in brain surgery and space development, it is necessary that the system takes into account scaling factors between the master and slave. In this paper, we propose the bilateral control of master-slave system with different scaling on the basis of reproducibility and operationality which are one of the evaluation indices of bilateral control system. The proposed control system contains two kinds of scaling factors. One of them is scaling factors of position and force responses that are used to determine the scaling ratio between the master and the slave. The other one is used to adjust the control gains at the master and the slave, respectively. In this paper, some scaling types depending on the nominal masses of the systems are proposed. In order to compare the scaling methods, the analysis results of the proposed method on reproducibility and operationality are shown. Moreover, experimental results confirm the validity of the proposed method.

  2. Modeling pulse driven antenna systems with finite differences

    SciTech Connect

    Barth, M.; Pennock, S.; Ziolkowski, R.; McLeod, R.

    1990-03-01

    We have developed a capability of modeling the performance of general, pulse driven, antenna systems. Our approach is to use TSAR, a three dimensional finite difference time domain (FDTD) code, to model the antenna structure and the surrounding near field environment. We then use a far field projection algorithm to obtain its far field response. Specifically, this algorithm utilizes the tangential electric and magnetic fields at a specified surface of the TSAR FDTD computational volume and calculates the resulting fields far from the equivalent magnetic and electric sources. This approach will be illustrated by considering the TEB antenna system. The system is modeled with the code and the results are compared with anechoic chamber data. 10 figs., 2 tabs.

  3. Light intensity matching between different intravascular optical coherence tomography systems

    NASA Astrophysics Data System (ADS)

    Liu, Shengnan; Eggermont, Jeroen; Nakatani, Shimpei; Lelieveldt, Boudewijn P. F.; Dijkstra, Jouke

    2016-02-01

    Currently two commercial intravascular optical coherence tomography (IVOCT) systems are available: Illumien Optis from St. Jude Medical (SJM) and Lunawave from Terumo. Both systems store the light intensity data in a raw vendor specific polar format. However, whereas SJM uses 16-bits per pixel Terumo uses 8-bits meaning the intensity values are in different ranges. This complicates quantitative light intensity based analysis when comparing results based on data from both systems. Therefore, this work aims to find an intensity transformation function from Terumo's 8-bit OFDI data to SJM's 16-bit range. The data consists of 8 pullbacks, 4 acquired with each system in the same arteries of 2 different patents pre- and post-stenting implantation. A total of 133 matching sections without stent struts from the two sets of pullbacks were identified based on landmarks such as side-branches and calcified regions. Since the main region of interest in the image is the tissue region only the pixels within 2mm behind the lumen border are used. In order to match the SJM data range, the Terumo data was rescaled and cumulative distribution functions (CDF) were calculated based on the histogram distributions. Comparing these CDFs, the transformation function can be determined. Application of this transformation function not only improves the visual similarity of matching slices it can also be used for further quantitative analysis.

  4. Comparing the health and environmental hazards of different energy systems

    SciTech Connect

    Hamilton, L.D.

    1982-01-01

    Energy and environment can pose difficult challenges for policy makers and scientists. Assessing health impacts of different energy sources requires synthesis of research results from many different disciplines into a rational framework. Information is often scanty; qualitatively different risks, or energy systems with quite different end uses, must be put on a common footing. Risk-assessment methods reviewed include examples drawn from work of the Biomedical and Environmental Assessment Division at Brookhaven National Laboratory and elsewhere. Coal and nuclear fuel cycles are compared in respect to morbidity and mortality. Other cycles (oil, gas and renewables) are also examined. In broadening comparisons to include new technologies, one must include the impact of manufacturing the energy-producing devices as part of an expanded fuel cycle, via input-output methods. Input-output analysis allows comparisons of direct and system-wide impacts. Throughout the analysis, uncertainties must be explicitly recognized in the results, including uncertainty in validity of data and uncertainty in choice of appropriate models. No single method of comparative risk assessment is fully satisfactory; each has its limitations. By use of several methods progress has been made in understanding the relative impact of energy technologies.

  5. Factors controlling air quality in different European subway systems.

    PubMed

    Martins, Vânia; Moreno, Teresa; Mendes, Luís; Eleftheriadis, Konstantinos; Diapouli, Evangelia; Alves, Célia A; Duarte, Márcio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier; Minguillón, María Cruz

    2016-04-01

    Sampling campaigns using the same equipment and methodology were conducted to assess and compare the air quality at three South European subway systems (Barcelona, Athens and Oporto), focusing on concentrations and chemical composition of PM2.5 on subway platforms, as well as PM2.5 concentrations inside trains. Experimental results showed that the mean PM2.5 concentrations widely varied among the European subway systems, and even among different platforms within the same underground system, which might be associated to distinct station and tunnel designs and ventilation systems. In all cases PM2.5 concentrations on the platforms were higher than those in the urban ambient air, evidencing that there is generation of PM2.5 associated with the subway systems operation. Subway PM2.5 consisted of elemental iron, total carbon, crustal matter, secondary inorganic compounds, insoluble sulphate, halite and trace elements. Of all metals, Fe was the most abundant, accounting for 29-43% of the total PM2.5 mass (41-61% if Fe2O3 is considered), indicating the existence of an Fe source in the subway system, which could have its origin in mechanical friction and wear processes between rails, wheels and brakes. The trace elements with the highest enrichment in the subway PM2.5 were Ba, Cu, Mn, Zn, Cr, Sb, Sr, Ni, Sn, Co, Zr and Mo. Similar PM2.5 diurnal trends were observed on platforms from different subway systems, with higher concentrations during subway operating hours than during the transport service interruption, and lower levels on weekends than on weekdays. PM2.5 concentrations depended largely on the operation and frequency of the trains and the ventilation system, and were lower inside the trains, when air conditioning system was operating properly, than on the platforms. However, the PM2.5 concentrations increased considerably when the train windows were open. The PM2.5 levels inside the trains decreased with the trains passage in aboveground sections.

  6. Factors controlling air quality in different European subway systems.

    PubMed

    Martins, Vânia; Moreno, Teresa; Mendes, Luís; Eleftheriadis, Konstantinos; Diapouli, Evangelia; Alves, Célia A; Duarte, Márcio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier; Minguillón, María Cruz

    2016-04-01

    Sampling campaigns using the same equipment and methodology were conducted to assess and compare the air quality at three South European subway systems (Barcelona, Athens and Oporto), focusing on concentrations and chemical composition of PM2.5 on subway platforms, as well as PM2.5 concentrations inside trains. Experimental results showed that the mean PM2.5 concentrations widely varied among the European subway systems, and even among different platforms within the same underground system, which might be associated to distinct station and tunnel designs and ventilation systems. In all cases PM2.5 concentrations on the platforms were higher than those in the urban ambient air, evidencing that there is generation of PM2.5 associated with the subway systems operation. Subway PM2.5 consisted of elemental iron, total carbon, crustal matter, secondary inorganic compounds, insoluble sulphate, halite and trace elements. Of all metals, Fe was the most abundant, accounting for 29-43% of the total PM2.5 mass (41-61% if Fe2O3 is considered), indicating the existence of an Fe source in the subway system, which could have its origin in mechanical friction and wear processes between rails, wheels and brakes. The trace elements with the highest enrichment in the subway PM2.5 were Ba, Cu, Mn, Zn, Cr, Sb, Sr, Ni, Sn, Co, Zr and Mo. Similar PM2.5 diurnal trends were observed on platforms from different subway systems, with higher concentrations during subway operating hours than during the transport service interruption, and lower levels on weekends than on weekdays. PM2.5 concentrations depended largely on the operation and frequency of the trains and the ventilation system, and were lower inside the trains, when air conditioning system was operating properly, than on the platforms. However, the PM2.5 concentrations increased considerably when the train windows were open. The PM2.5 levels inside the trains decreased with the trains passage in aboveground sections. PMID:26717078

  7. Spatio-temporal changes in glutathione and thioredoxin redox couples during ionizing radiation-induced oxidative stress regulate tumor radio-resistance.

    PubMed

    Patwardhan, R S; Sharma, D; Checker, R; Thoh, M; Sandur, S K

    2015-10-01

    Ionizing radiation (IR)-induced oxidative stress in tumor cells is effectively managed by constitutive and inducible antioxidant defense systems. This study was initiated to understand the relative contribution of different redox regulatory systems in determining the tumor radio-resistance. In this study, human T-cell lymphoma (Jurkat) cells were exposed to IR (4 Gy) and monitored for the spatio-temporal changes in cellular redox regulatory parameters. We monitored the changes in the levels of reactive oxygen species (ROS) (total, mitochondrial, primary, and secondary), thiols (total, surface, and intracellular), GSH/GSSG ratio, antioxidant enzyme activity viz. thioredoxin (Trx), Trx reductase (TrxR), glutathione peroxidase, and glutathione reductase with respect to time. We have also measured protein glutathionylation. We observed that tumor cells mount a biphasic response after IR exposure which can be divided into early (0-6 h) and late (16-48 h) responses in terms of changes in cellular redox parameters. During early response, constitutively active GSH and Trx systems respond to restore cellular redox balance to pre-exposure levels and help in activation of redox-sensitive transcription factor Nrf-2. During late response, increase in the levels of antioxidants GSH and Trx rescue cells against IR-mediated damage. We observed that disruption of either glutathione or thioredoxin metabolism led to partial impairment of ability of cells to survive against IR-induced damage. But simultaneous disruption of both the pathways significantly increased radio sensitivity of Jurkat cells. This highlighted the importance of these two antioxidant pathways in regulating redox homeostasis under conditions of IR-induced oxidative stress. PMID:26021764

  8. Spatio-temporal changes in glutathione and thioredoxin redox couples during ionizing radiation-induced oxidative stress regulate tumor radio-resistance.

    PubMed

    Patwardhan, R S; Sharma, D; Checker, R; Thoh, M; Sandur, S K

    2015-10-01

    Ionizing radiation (IR)-induced oxidative stress in tumor cells is effectively managed by constitutive and inducible antioxidant defense systems. This study was initiated to understand the relative contribution of different redox regulatory systems in determining the tumor radio-resistance. In this study, human T-cell lymphoma (Jurkat) cells were exposed to IR (4 Gy) and monitored for the spatio-temporal changes in cellular redox regulatory parameters. We monitored the changes in the levels of reactive oxygen species (ROS) (total, mitochondrial, primary, and secondary), thiols (total, surface, and intracellular), GSH/GSSG ratio, antioxidant enzyme activity viz. thioredoxin (Trx), Trx reductase (TrxR), glutathione peroxidase, and glutathione reductase with respect to time. We have also measured protein glutathionylation. We observed that tumor cells mount a biphasic response after IR exposure which can be divided into early (0-6 h) and late (16-48 h) responses in terms of changes in cellular redox parameters. During early response, constitutively active GSH and Trx systems respond to restore cellular redox balance to pre-exposure levels and help in activation of redox-sensitive transcription factor Nrf-2. During late response, increase in the levels of antioxidants GSH and Trx rescue cells against IR-mediated damage. We observed that disruption of either glutathione or thioredoxin metabolism led to partial impairment of ability of cells to survive against IR-induced damage. But simultaneous disruption of both the pathways significantly increased radio sensitivity of Jurkat cells. This highlighted the importance of these two antioxidant pathways in regulating redox homeostasis under conditions of IR-induced oxidative stress.

  9. Melatonin and nitric oxide modulate glutathione content and glutathione reductase activity in sunflower seedling cotyledons accompanying salt stress.

    PubMed

    Kaur, Harmeet; Bhatla, Satish C

    2016-09-30

    The present findings demonstrate significant modulation of total glutathione content, reduced glutathione (GSH) content, oxidized glutathione (GSSG) content, GSH/GSSG ratio and glutathione reductase (GR; EC 1.6.4.2) activity in dark-grown seedling cotyledons in response to salt-stress (120 mM NaCl) in sunflower (Helianthus annuus L.) seedlings. A differential spatial distribution of GR activity (monitored by confocal laser scanning microscopic (CLSM) imaging) is also evident. Melatonin and nitric oxide (NO) differentially ameliorate salt stress effect by modulating GR activity and GSH content in seedling cotyledons. Total glutathione content (GSH + GSSG) exhibit a seedling age-dependent increase in the cotyledons, more so in salt-stressed conditions and when subjected to melatonin treatment. Seedlings raised in presence of 15 μM of melatonin exhibit significant increase in GR activity in cotyledon homogenates (10,000 g supernatant) coinciding with significant increase in GSH content. GSSG content and GSH/GSSG ratio also increased due to melatonin treatment. A correlation is thus evident in NaCl-sensitized modulation of GSH content and GR activity by melatonin. GSH content is down regulated by NO provided as 250 μM of sodium nitroprusside (SNP) although total glutathione content remained in similar range. A reversal of response (enhanced total glutathione accumulation) by NO scavenger (cPTIO) highlights the critical role of NO in modulating glutathione homeostasis. SNP lowers the activity of hydroxyindole-O-methyltransferase (HIOMT) - a regulatory enzyme in melatonin biosynthesis in control seedlings whereas its activity is upregulated in salt-stressed seedling cotyledons. Melatonin content of seedling cotyledons is also modulated by NO. NO and melatonin thus seem to modulate GR activity and GSH content during seedling growth under salt stress. PMID:27432590

  10. Central Asian Post-Soviet health systems in transition: has different aid engagement produced different outcomes?

    PubMed Central

    Ulikpan, Anar; Mirzoev, Tolib; Jimenez, Eliana; Malik, Asmat; Hill, Peter S.

    2014-01-01

    Background The collapse of the Soviet Union in 1991 resulted in a transition from centrally planned socialist systems to largely free-market systems for post-Soviet states. The health systems of Central Asian Post-Soviet (CAPS) countries (Kyrgyzstan, Mongolia, Tajikistan, Turkmenistan, and Uzbekistan) have undergone a profound revolution. External development partners have been crucial to this reorientation through financial and technical support, though both relationships and outcomes have varied. This research provides a comparative review of the development assistance provided in the health systems of CAPS countries and proposes future policy options to improve the effectiveness of development. Design Extensive documentary review was conducted using Pubmed, Medline/Ovid, Scopus, and Google scholar search engines, local websites, donor reports, and grey literature. The review was supplemented by key informant interviews and participant observation. Findings The collapse of the Soviet dominance of the region brought many health system challenges. Donors have played an essential role in the reform of health systems. However, as new aid beneficiaries, neither CAPS countries’ governments nor the donors had the experience of development collaboration in this context. The scale of development assistance for health in CAPS countries has been limited compared to other countries with similar income, partly due to their limited history with the donor community, lack of experience in managing donors, and a limited history of transparency in international dealings. Despite commonalities at the start, two distinctive trajectories formed in CAPS countries, due to their differing politics and governance context. Conclusions The influence of donors, both financially and technically, remains crucial to health sector reform, despite their relatively small contribution to overall health budgets. Kyrgyzstan, Mongolia, and Tajikistan have demonstrated more effective development

  11. The mitochondrial dicarboxylate and 2-oxoglutarate carriers do not transport glutathione.

    PubMed

    Booty, Lee M; King, Martin S; Thangaratnarajah, Chancievan; Majd, Homa; James, Andrew M; Kunji, Edmund R S; Murphy, Michael P

    2015-02-27

    Glutathione carries out vital protective roles within mitochondria, but is synthesised in the cytosol. Previous studies have suggested that the mitochondrial dicarboxylate and 2-oxoglutarate carriers were responsible for glutathione uptake. We set out to characterise the putative glutathione transport by using fused membrane vesicles of Lactococcus lactis overexpressing the dicarboxylate and 2-oxoglutarate carriers. Although transport of the canonical substrates could be measured readily, an excess of glutathione did not compete for substrate uptake nor could transport of glutathione be measured directly. Thus these mitochondrial carriers do not transport glutathione and the identity of the mitochondrial glutathione transporter remains unknown.

  12. Protein–Polymer Conjugation via Ligand Affinity and Photoactivation of Glutathione S-Transferase

    PubMed Central

    2014-01-01

    A photoactivated, site-selective conjugation of poly(ethylene glycol) (PEG) to the glutathione (GSH) binding pocket of glutathione S-transferase (GST) is described. To achieve this, a GSH analogue (GSH-BP) was designed and chemically synthesized with three functionalities: (1) the binding affinity of GSH to GST, (2) a free thiol for polymer functionalization, and (3) a photoreactive benzophenone (BP) component. Different molecular weights (2 kDa, 5 kDa, and 20 kDa) of GSH-BP modified PEGs (GSBP-PEGs) were synthesized and showed conjugation efficiencies between 52% and 76% to GST. Diazirine (DA) PEG were also prepared but gave conjugation yields lower than for GSBP-PEGs. PEGs with different end-groups were also synthesized to validate the importance of each component in the end-group design. End-groups included glutathione (GS-PEG) and benzophenone (BP-PEG). Results showed that both GSH and BP were crucial for successful conjugation to GST. In addition, conjugations of 5 kDa GSBP-PEG to different proteins were investigated, including bovine serum albumin (BSA), lysozyme (Lyz), ubiquitin (Ubq), and GST-fused ubiquitin (GST-Ubq) to ensure specific binding to GST. By combining noncovalent and covalent interactions, we have developed a new phototriggered protein–polymer conjugation method that is generally applicable to GST-fusion proteins. PMID:25315970

  13. System for objective assessment of image differences in digital cinema

    NASA Astrophysics Data System (ADS)

    Fliegel, Karel; Krasula, Lukáš; Páta, Petr; Myslík, Jiří; Pecák, Josef; Jícha, Marek

    2014-09-01

    There is high demand for quick digitization and subsequent image restoration of archived film records. Digitization is very urgent in many cases because various invaluable pieces of cultural heritage are stored on aging media. Only selected records can be reconstructed perfectly using painstaking manual or semi-automatic procedures. This paper aims to answer the question what are the quality requirements on the restoration process in order to obtain acceptably close visual perception of the digitally restored film in comparison to the original analog film copy. This knowledge is very important to preserve the original artistic intention of the movie producers. Subjective experiment with artificially distorted images has been conducted in order to answer the question what is the visual impact of common image distortions in digital cinema. Typical color and contrast distortions were introduced and test images were presented to viewers using digital projector. Based on the outcome of this subjective evaluation a system for objective assessment of image distortions has been developed and its performance tested. The system utilizes calibrated digital single-lens reflex camera and subsequent analysis of suitable features of images captured from the projection screen. The evaluation of captured image data has been optimized in order to obtain predicted differences between the reference and distorted images while achieving high correlation with the results of subjective assessment. The system can be used to objectively determine the difference between analog film and digital cinema images on the projection screen.

  14. Improvement of different vaccine delivery systems for cancer therapy

    PubMed Central

    2011-01-01

    Cancer vaccines are the promising tools in the hands of the clinical oncologist. Many tumor-associated antigens are excellent targets for immune therapy and vaccine design. Optimally designed cancer vaccines should combine the best tumor antigens with the most effective immunotherapy agents and/or delivery strategies to achieve positive clinical results. Various vaccine delivery systems such as different routes of immunization and physical/chemical delivery methods have been used in cancer therapy with the goal to induce immunity against tumor-associated antigens. Two basic delivery approaches including physical delivery to achieve higher levels of antigen production and formulation with microparticles to target antigen-presenting cells (APCs) have demonstrated to be effective in animal models. New developments in vaccine delivery systems will improve the efficiency of clinical trials in the near future. Among them, nanoparticles (NPs) such as dendrimers, polymeric NPs, metallic NPs, magnetic NPs and quantum dots have emerged as effective vaccine adjuvants for infectious diseases and cancer therapy. Furthermore, cell-penetrating peptides (CPP) have been known as attractive carrier having applications in drug delivery, gene transfer and DNA vaccination. This review will focus on the utilization of different vaccine delivery systems for prevention or treatment of cancer. We will discuss their clinical applications and the future prospects for cancer vaccine development. PMID:21211062

  15. Glutathione-Induced Calcium Shifts in Chick Retinal Glial Cells.

    PubMed

    Freitas, Hercules R; Ferraz, Gabriel; Ferreira, Gustavo C; Ribeiro-Resende, Victor T; Chiarini, Luciana B; do Nascimento, José Luiz M; Matos Oliveira, Karen Renata H; Pereira, Tiago de Lima; Ferreira, Leonardo G B; Kubrusly, Regina C; Faria, Robson X; Herculano, Anderson Manoel; Reis, Ricardo A de Melo

    2016-01-01

    Neuroglia interactions are essential for the nervous system and in the retina Müller cells interact with most of the neurons in a symbiotic manner. Glutathione (GSH) is a low-molecular weight compound that undertakes major antioxidant roles in neurons and glia, however, whether this compound could act as a signaling molecule in neurons and/or glia is currently unknown. Here we used embryonic avian retina to obtain mixed retinal cells or purified Müller glia cells in culture to evaluate calcium shifts induced by GSH. A dose response curve (0.1-10 mM) showed that 5-10 mM GSH, induced calcium shifts exclusively in glial cells (later labeled and identified as 2M6 positive cells), while neurons responded to 50 mM KCl (labeled as βIII tubulin positive cells). BBG 100 nM, a P2X7 blocker, inhibited the effects of GSH on Müller glia. However, addition of DNQX 70 μM and MK-801 20 μM, non-NMDA and NMDA blockers, had no effect on GSH calcium induced shift. Oxidized glutathione (GSSG) at 5 mM failed to induce calcium mobilization in glia cells, indicating that the antioxidant and/or structural features of GSH are essential to promote elevations in cytoplasmic calcium levels. Indeed, a short GSH pulse (60s) protects Müller glia from oxidative damage after 30 min of incubation with 0.1% H2O2. Finally, GSH induced GABA release from chick embryonic retina, mixed neuron-glia or from Müller cell cultures, which were inhibited by BBG or in the absence of sodium. GSH also induced propidium iodide uptake in Müller cells in culture in a P2X7 receptor dependent manner. Our data suggest that GSH, in addition to antioxidant effects, could act signaling calcium shifts at the millimolar range particularly in Müller glia, and could regulate the release of GABA, with additional protective effects on retinal neuron-glial circuit. PMID:27078878

  16. Glutathione-Induced Calcium Shifts in Chick Retinal Glial Cells

    PubMed Central

    Freitas, Hercules R.; Ferraz, Gabriel; Ferreira, Gustavo C.; Ribeiro-Resende, Victor T.; Chiarini, Luciana B.; do Nascimento, José Luiz M.; Matos Oliveira, Karen Renata H.; Pereira, Tiago de Lima; Ferreira, Leonardo G. B.; Kubrusly, Regina C.; Faria, Robson X.

    2016-01-01

    Neuroglia interactions are essential for the nervous system and in the retina Müller cells interact with most of the neurons in a symbiotic manner. Glutathione (GSH) is a low-molecular weight compound that undertakes major antioxidant roles in neurons and glia, however, whether this compound could act as a signaling molecule in neurons and/or glia is currently unknown. Here we used embryonic avian retina to obtain mixed retinal cells or purified Müller glia cells in culture to evaluate calcium shifts induced by GSH. A dose response curve (0.1–10mM) showed that 5–10mM GSH, induced calcium shifts exclusively in glial cells (later labeled and identified as 2M6 positive cells), while neurons responded to 50mM KCl (labeled as βIII tubulin positive cells). BBG 100nM, a P2X7 blocker, inhibited the effects of GSH on Müller glia. However, addition of DNQX 70μM and MK-801 20μM, non-NMDA and NMDA blockers, had no effect on GSH calcium induced shift. Oxidized glutathione (GSSG) at 5mM failed to induce calcium mobilization in glia cells, indicating that the antioxidant and/or structural features of GSH are essential to promote elevations in cytoplasmic calcium levels. Indeed, a short GSH pulse (60s) protects Müller glia from oxidative damage after 30 min of incubation with 0.1% H2O2. Finally, GSH induced GABA release from chick embryonic retina, mixed neuron-glia or from Müller cell cultures, which were inhibited by BBG or in the absence of sodium. GSH also induced propidium iodide uptake in Müller cells in culture in a P2X7 receptor dependent manner. Our data suggest that GSH, in addition to antioxidant effects, could act signaling calcium shifts at the millimolar range particularly in Müller glia, and could regulate the release of GABA, with additional protective effects on retinal neuron-glial circuit. PMID:27078878

  17. Protective role of glutathione reductase in paraquat induced neurotoxicity.

    PubMed

    Djukic, Mirjana M; Jovanovic, Marina D; Ninkovic, Milica; Stevanovic, Ivana; Ilic, Katarina; Curcic, Marijana; Vekic, Jelena

    2012-08-30

    Paraquat (PQ), a widely used herbicide is a well-known free radical producing agent. The mechanistic pathways of PQ neurotoxicity were examined by assessing oxidative/nitrosative stress markers. Focus was on the role of glutathione (GSH) cycle and to examine whether the pre-treatment with enzyme glutathione reductase (GR) could protect the vulnerable brain regions (VBRs) against harmful oxidative effect of PQ. The study was conducted on Wistar rats, randomly divided in five groups: intact-control group, (n = 8) and four experimental groups (n = 24). All tested compounds were administered intrastriatally (i.s.) in one single dose. The following parameters of oxidative status were measured in the striatum, hippocampus and cortex, at 30 min, 24 h and 7 days post treatment: superoxide anion radical (O₂·⁻), nitrate (NO₃⁻), malondialdehyde (MDA), superoxide dismutase (SOD), total GSH (tGSH) and its oxidized, disulfide form (GSSG) and glutathione peroxidase (GPx). Results obtained from the intact and the sham operated groups were not statistically different, confirming that invasive i.s. route of administration would not influence the reliability of results. Also, similar pattern of changes were observed between ipsi- and contra- lateral side of examined VBRs, indicating rapid spatial spreading of oxidative stress. Mortality of the animals (10%), within 24h, along with symptoms of Parkinsonism, after awakening from anesthesia for 2-3 h, were observed in the PQ group, only. Increased levels of O₂·⁻, NO₃⁻ and MDA, increased ratio of GSSG/GSH and considerably high activity of GPx were measured at 30 min after the treatment. Cytotoxic effect of PQ was documented by drastic drop of all measured parameters and extremely high peak of the ratio GSSG/GSH at 24th hrs after the PQ i.s. injection. In the GR+PQ group, markedly low activity of GPx and low content of NO₃⁻ (in striatum and cortex) were measured during whole experiment, while increase value was

  18. 1,4-Naphthoquinones and Others NADPH-Dependent Glutathione Reductase-Catalyzed Redox Cyclers as Antimalarial Agents

    PubMed Central

    Belorgey, Didier; Lanfranchi, Don Antoine; Davioud-Charvet, Elisabeth

    2013-01-01

    The homodimeric flavoenzyme glutathione reductase catalyzes NADPH-dependent glutathione disulfide reduction. This reaction is important for keeping the redox homeostasis in human cells and in the human pathogen Plasmodium falciparum. Different types of NADPH-dependent disulfide reductase inhibitors were designed in various chemical series to evaluate the impact of each inhibition mode on the propagation of the parasites. Against malaria parasites in cultures the most potent and specific effects were observed for redox-active agents acting as subversive substrates for both glutathione reductases of the Plasmodium-infected red blood cells. In their oxidized form, these redox-active compounds are reduced by NADPH-dependent flavoenzyme-catalyzed reactions in the cytosol of infected erythrocytes. In their reduced forms, these compounds can reduce molecular oxygen to reactive oxygen species, or reduce oxidants like methemoglobin, the major nutrient of the parasite, to indigestible hemoglobin. Furthermore, studies on a fluorinated suicide-substrate of the human glutathione reductase indicate that the glutathione reductase-catalyzed bioactivation of 3-benzylnaphthoquinones to the corresponding reduced 3-benzoyl metabolites is essential for the observed antimalarial activity. In conclusion, the antimalarial lead naphthoquinones are suggested to perturb the major redox equilibria of the targeted cells. These effects result in development arrest of the parasite and contribute to the removal of the parasitized erythrocytes by macrophages. PMID:23116403

  19. An Investigation of Glutathione-Platinum(II) Interactions by Means of the Flow Injection Analysis Using Glassy Carbon Electrode

    PubMed Central

    Zitka, Ondrej; Huska, Dalibor; Krizkova, Sona; Adam, Vojtech; Chavis, Grace J.; Trnkova, Libuse; Horna, Ales; Hubalek, Jaromir; Kizek, Rene

    2007-01-01

    Despite very intensive research in the synthesising of new cytostatics, cisplatin is still one of the most commonly used anticancer drugs. Therefore, an investigation of interactions of cisplatin with different biologically important amino acids, peptides and proteins is very topical. In the present paper, we utilized flow injection analysis coupled with electrochemical detection to study and characterize the behaviour of various forms of glutathione (reduced glutathione – GSH, oxidized glutathione – GSSG and S-nitroso glutathione – GSNO). The optimized conditions were as follows: mobile phase consisted of acetate buffer (pH 3) with a flow rate of 1 mL min-1. Based on results obtained we chose 850 mV as the optimal potential for detection of GSH and 1,100 mV as the optimal potential for detection of GSSG and GSNO. The detection limits of GSH, GSSG and GSNO were 100 pg mL-1, 50 ng mL-1 and 300 pg mL-1, respectively. Further, the optimized technique was used for investigation of interactions between cisplatin and GSH. We were able to observe the interaction between GSH and cisplatin via decrease in the signal corresponding to glutathione. Moreover, we evaluated the formation of the complex by spectrometry. The spectrometric results obtained were in good agreement with electrochemical ones.

  20. Hepatic glutathione and glutathione S-transferase in selenium deficiency and toxicity in the chick

    SciTech Connect

    Kim, Y. S.

    1989-01-01

    First, the hepatic activity of GSH-T{sub CDNB} was increased only under conditions of severe oxidative stress produced by combined Se- and vitamin E (VE)-deficiency, indicating that VE also affects GSH metabolism. Second, the incorporation of {sup 35}S-methionine into GSH and protein was about 4- and 2-fold higher, respectively, in Se- and VE-deficient chick hepatocytes as compared to controls. Third, chicks injected with the glutathione peroxidase (SeGSHpx) inhibitor, aurothioglucose (AuTG), showed increase hepatic GSH-T{sub CDNB} activity and plasma GSH concentration regardless of their Se status. Fourth, the effect of ascorbic acid (AA), on GSH metabolism was studied. Chicks fed 1000 ppm AA showed decreased hepatic GSH concentration compared to chicks fed no AA in a Se- and VE-deficient diet. Fifth, chicks fed excess Se showed increase hepatic activity of GSH-T{sub CDNB} and GSH concentration regardless of VE status.

  1. Measuring glutathione-induced feeding response in hydra.

    PubMed

    Kulkarni, Ram; Galande, Sanjeev

    2014-01-01

    Hydra is among the most primitive organisms possessing a nervous system and chemosensation for detecting reduced glutathione (GSH) for capturing the prey. The movement of prey organisms causes mechanosensory discharge of the stinging cells called nematocysts from hydra, which are inserted into the prey. The feeding response in hydra, which includes curling of the tentacles to bring the prey towards the mouth, opening of the mouth and consequent engulfing of the prey, is triggered by GSH present in the fluid released from the injured prey. To be able to identify the molecular mechanism of the feeding response in hydra which is unknown to date, it is necessary to establish an assay to measure the feeding response. Here, we describe a simple method for the quantitation of the feeding response in which the distance between the apical end of the tentacle and mouth of hydra is measured and the ratio of such distance before and after the addition of GSH is determined. The ratio, called the relative tentacle spread, was found to give a measure of the feeding response. This assay was validated using a starvation model in which starved hydra show an enhanced feeding response in comparison with daily fed hydra. PMID:25490534

  2. The evolution of glutathione metabolism in phototrophic microorganisms

    NASA Technical Reports Server (NTRS)

    Fahey, Robert C.; Buschbacher, Ralph M.; Newton, Gerald L.

    1988-01-01

    The low molecular weight thiol composition of a variety of phototropic microorganisms is examined in order to ascertain how evolution of glutathione (GSH) production is related to the evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols (RSH) to fluorescent derivatives (RSmB) which were analyzed by high performance liquid chromatography (HPLC). Significant levels of GSH were not found in green sulfur bacteria. Substantial levels were present in purple bacteria, cyanobacteria, and eukaryotic algae. Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide. Many of the organisms also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability which was quenched by treatment with 2-pyridyl disulfide or 5,5 prime-bisdithio - (2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of reactive disulfides. The distribution of GSH in phototropic eubacteria indicates that GSH synthesis evolved at or around the time that oxygenic photosynthesis evolved.

  3. MITOCHONDRIAL GLUTATHIONE: FEATURES, REGULATION AND ROLE IN DISEASE

    PubMed Central

    Marí, Montserrat; Morales, Albert; Colell, Anna; García-Ruiz, Carmen; Kaplowitz, Neil; Fernández-Checa, José C

    2012-01-01

    BACKGROUND Mitochondria are the powerhouse of mammalian cells and the main source of reactive oxygen species (ROS) associated with oxygen consumption. In addition, they also play a strategic role in controlling the fate of cells through regulation of death pathways. Mitochondrial ROS production fulfills a signaling role through regulation of redox pathways, but also contributes to mitochondrial damage in a number of pathological states. SCOPE OF REVIEW Mitochondria are exposed to the constant generation of oxidant species, and yet the organelle remains functional due to the existence of an armamentarium of antioxidant defense systems aimed to repair oxidative damage, of which mitochondrial glutathione (mGSH) is of particular relevance. Thus, the aim of the review is to cover the regulation of mGSH and its role in disease. MAJOR CONCLUSIONS Cumulating evidence over recent years has demonstrated the essential role for mGSH in mitochondrial physiology and disease. Despite its high concentration in the mitochondrial matrix, mitochondria lack the enzymes to synthesize GSH de novo, so that mGSH originates from cytosolic GSH via transport through specific mitochondrial carriers, which exhibit sensitivity to membrane dynamics. Depletion of mGSH sensitizes cells to stimuli leading to oxidative stress such as TNF, hypoxia or amyloid β-peptide, thereby contributing to disease pathogenesis. GENERAL SIGNIFICANCE Understanding the regulation of mGSH may provide novel insights to disease pathogenesis and toxicity and the opportunity to design therapeutic targets of intervention in cell death susceptibility and disease. PMID:23123815

  4. Sensory evolution of hearing in tettigoniids with differing communication systems.

    PubMed

    Strauß, J; Lehmann, A W; Lehmann, G U C

    2014-01-01

    In Tettigoniidae (Orthoptera: Ensifera), hearing organs are essential in mate detection. Male tettigoniids usually produce calling songs by tegminal stridulation, whereas females approach the males phonotactically. This unidirectional communication system is the most common one among tettigoniids. In several tettigoniid lineages, females have evolved acoustic replies to the male calling song which constitutes a bidirectional communication system. The genus Poecilimon (Tettigoniidae: Phaneropterinae) is of special interest because the ancestral state of bidirectional communication, with calling males and responding females, has been reversed repeatedly to unidirectional communication. Acoustic communication is mediated by hearing organs that are adapted to the conspecific signals. Therefore, we analyse the auditory system in the Tettigoniidae genus Poecilimon for functional adaptations in three characteristics: (i) dimension of sound-receiving structures (tympanum and acoustic spiracle), (ii) number of auditory sensilla and (iii) hearing sensitivity. Profound differences in the auditory system correlate with uni- or bidirectional communication. Among the sound-receiving structures, the tympana scale with body size, whereas the acoustic spiracle, the major sound input structure, was drastically reduced in unidirectional communicating species. In the unidirectional P. ampliatus group, auditory sensilla are severely reduced in numbers, but not in the unidirectional P. propinquus group. Within the P. ampliatus group, the number of auditory sensilla is further reduced in P. intermedius which lost acoustic signalling due to parthenogenesis. The auditory sensitivity correlated with the size of the acoustic spiracle, as hearing sensitivity was better with larger spiracles, especially in the ultrasonic range. Our results show a significant reduction in auditory structures, shaped by the differing sex roles during mate detection.

  5. Tissue glutathione levels in mice treated with delta-9-tetrahydrocannabinol.

    PubMed

    Husain, S; Ahmed, K M

    1991-11-01

    Glutathione (GSH) is widely distributed among living cells and is involved in many biological functions. It provides the sulfhydryl groups for conjugation of toxic metabolites of several xenobiotica. Acetaminophen (Tylenol) toxicity is a classical example of this property. For this purpose, we studied the effects of delta-9-tetrahydrocannabinol (THC) on tissue levels of GSH in the mice. Groups of male Swiss Webster mice weighing 25 +/- 5 g were treated with 50 mg/kg, PO THC at 1300 h. Control mice were given equal volume of sesame oil (5 ml/kg, PO) which was the vehicle for THC. Ninety minutes following THC administration, mice were sacrificed, their plasma, brain, heart, liver, kidney and testis were collected. All tissues were homogenized in 5% TCA/EDTA solution and supernatant solutions of these homogenates were diluted. In these diluted samples, levels of GSH were determined by a modified spectrophotometric procedure and the GSH levels were expressed as micromoles of GSH/g tissue. In this study, THC caused no effects on GSH levels in brain, heart, testis and plasma. However, GSH levels in liver and kidney were decreased by 14% and 7% respectively. Although the decrease in kidney GSH levels were insignificant, these changes in liver and kidney could be indicative of a possible metabolic and/or dispositional interaction between THC and different commonly available drugs such as acetaminophen. PMID:1666916

  6. Beta-amyloidolysis and glutathione in Alzheimer’s disease

    PubMed Central

    Lasierra-Cirujeda, J; Coronel, P; Aza, MJ; Gimeno, M

    2013-01-01

    In this review, we hypothesized the importance of the interaction between the brain glutathione (GSH) system, the proteolytic tissue plasminogen activator (t-PA)/plasminogen/ plasmin system, regulated by plasminogen activator inhibitor (PAI-1), and neuroserpin in the pathogenesis of Alzheimer’s disease. The histopathological characteristic hallmark that gives personality to the diagnosis of Alzheimer’s disease is the accumulation of neurofibroid tangles located intracellularly in the brain, such as the protein tau and extracellular senile plaques made primarily of amyloidal substance. These formations of complex etiology are intimately related to GSH, brain protective antioxidants, and the proteolytic system, in which t-PA plays a key role. There is scientific evidence that suggests a relationship between aging, a number of neurodegenerative disorders, and the excessive production of reactive oxygen species and accompanying decreased brain proteolysis. The plasminogen system in the brain is an essential proteolytic mechanism that effectively degrades amyloid peptides (“beta-amyloidolysis”) through action of the plasmin, and this physiologic process may be considered to be a means of prevention of neurodegenerative disorders. In parallel to the decrease in GSH levels seen in aging, there is also a decrease in plasmin brain activity and a progressive decrease of t-PA activity, caused by a decrease in the expression of the t-PA together with an increase of the PAI-1 levels, which rise to an increment in the production of amyloid peptides and a lesser clearance of them. Better knowledge of the GSH mechanism and cerebral proteolysis will allow us to hypothesize about therapeutic practices. PMID:23650462

  7. Diversification of Fungal Specific Class A Glutathione Transferases in Saprotrophic Fungi

    PubMed Central

    Favier, Frédérique; Harvengt, Luc; Didierjean, Claude; Jacquot, Jean-Pierre; Morel-Rouhier, Mélanie; Gelhaye, Eric

    2013-01-01

    Glutathione transferases (GSTs) form a superfamily of multifunctional proteins with essential roles in cellular detoxification processes and endogenous metabolism. The distribution of fungal-specific class A GSTs was investigated in saprotrophic fungi revealing a recent diversification within this class. Biochemical characterization of eight GSTFuA isoforms from Phanerochaete chrysosporium and Coprinus cinereus demonstrated functional diversity in saprotrophic fungi. The three-dimensional structures of three P. chrysosporium isoforms feature structural differences explaining the functional diversity of these enzymes. Competition experiments between fluorescent probes, and various molecules, showed that these GSTs function as ligandins with various small aromatic compounds, derived from lignin degradation or not, at a L-site overlapping the glutathione binding pocket. By combining genomic data with structural and biochemical determinations, we propose that this class of GST has evolved in response to environmental constraints induced by wood chemistry. PMID:24278272

  8. Glutathione peroxidase inhibitory assay for electrophilic pollutants in diesel exhaust and tobacco smoke.

    PubMed

    Staimer, Norbert; Nguyen, Tran B; Nizkorodov, Sergey A; Delfino, Ralph J

    2012-04-01

    We developed a rapid kinetic bioassay demonstrating the inhibition of glutathione peroxidase 1 (GPx-1) by organic electrophilic pollutants, such as acrolein, crotonaldehyde, and p-benzoquinone, that are frequently found as components of tobacco smoke, diesel exhaust, and other combustion sources. In a complementary approach, we applied a high-resolution proton-transfer reaction time-of-flight mass spectrometer to monitor in real-time the generation of electrophilic volatile carbonyls in cigarette smoke. The new bioassay uses the important antioxidant selenoenzyme GPx-1, immobilized to 96-well microtiter plates, as a probe. The selenocysteine bearing subunits of the enzyme's catalytic site are viewed as cysteine analogues and are vulnerable to electrophilic attack by compounds with conjugated carbonyl systems. The immobilization of GPx-1 to microtiter plate wells enabled facile removal of excess reactive inhibitory compounds after incubation with electrophilic chemicals or aqueous extracts of air samples derived from different sources. The inhibitory response of cigarette smoke and diesel exhaust particle extracts were compared with chemical standards of a group of electrophilic carbonyls and the arylating p-benzoquinone. GPx-1 activity was directly inactivated by millimolar concentrations of highly reactive electrophilic chemicals (including acrolein, glyoxal, methylglyoxal, and p-benzoquinone) and extracts of diesel and cigarette smoke. We conclude that the potential of air pollutant components to generate oxidative stress may be, in part, a result of electrophile-derived covalent modifications of enzymes involved in the cytosolic antioxidant defense.

  9. Reduced Glutathione Mediates Resistance to H2S Toxicity in Oral Streptococci

    PubMed Central

    Ooi, Xi Jia

    2016-01-01

    Periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while Gram-negative anaerobes predominate in disease. A key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (H2S) abundantly as a by-product of anaerobic metabolism. So far, H2S has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. Although oral anaerobes produce large amounts of H2S, the potential effects of H2S on oral streptococci are currently unknown. The aim of this study was to determine the effects of H2S on the survival and biofilm formation of oral streptococci. The growth and biofilm formation of Streptococcus mitis and Streptococcus oralis were inhibited by H2S. However, H2S did not significantly affect the growth of Streptococcus gordonii or Streptococcus sanguinis. The differential susceptibility of oral streptococci to H2S was attributed to differences in the intracellular concentrations of reduced glutathione (GSH). In the absence of GSH, H2S elicited its toxicity through an iron-dependent mechanism. Collectively, our results showed that H2S exerts antimicrobial effects on certain oral streptococci, potentially contributing to the decrease in health-associated plaque microflora. PMID:26801579

  10. Selenium levels and Glutathione peroxidase activity in the plasma of patients with type II diabetes mellitus.

    PubMed

    González de Vega, Raquel; Fernández-Sánchez, María Luisa; Fernández, Juan Carlos; Álvarez Menéndez, Francisco Vicente; Sanz-Medel, Alfredo

    2016-09-01

    Selenium, an essential trace element, is involved in the complex system of defense against oxidative stress through selenium-dependent glutathione peroxidases (GPx) and other selenoproteins. Because of its antioxidant properties, selenium or its selenospecies at appropriate levels could hinder oxidative stress and so development of diabetes. In this vein, quantitative speciation of selenium in human plasma samples from healthy and diabetic patients (controlled and non-controlled) was carried out by affinity chromatography (AF) coupled on-line to inductively coupled plasma mass spectrometry (ICP-MS) and isotope dilution analysis (IDA). Similarly, it is well known that patients with diabetes who exhibit poor control of blood glucose show a decreased total antioxidant activity. Thus, we evaluated the enzymatic activity of GPx in diabetic and healthy individuals, using the Paglia and Valentine enzymatic method, observing a significant difference (p<0.05) between the three groups of assayed patients (healthy (n=24): 0.61±0.11U/ml, controlled diabetic (n=38): 0.40±0.12U/ml and non-controlled diabetic patients (n=40): 0.32±0.09U/ml). Our results show that hyperglycemia induces oxidative stress in diabetic patients compared with healthy controls. What is more, glycation of GPx experiments demonstrated that it is the degree of glycation of the selenoenzyme (another species of the Se protein) what actually modulates its eventual activity against ROS in type II diabetes mellitus patients. PMID:27473831

  11. Ferrocene labelings as inhibitors and dual electrochemical sensors of human glutathione S-transferase P1-1.

    PubMed

    Martos-Maldonado, Manuel C; Quesada-Soriano, Indalecio; García-Maroto, Federico; Vargas-Berenguel, Antonio; García-Fuentes, Luís

    2012-12-01

    The inhibitory and sensor properties of two ferrocene conjugates, in which the ferrocene and glutathione are linked through a spacer arm of different length and chemical structure, on human Pi glutathione S-transferase, were examined by activity assays, ITC, fluorescence spectroscopy and voltammetry. Such ferrocene conjugates are strong competitive inhibitors of this enzyme with an enhanced binding affinity, the one bearing the longest spacer arm being the most potent inhibitor. Voltammetric measurements showed a strong decrease of the peak current intensity and an increase of the oxidation potential upon binding of ferrocene-glutathione conjugates to GST P1-1 showing that both conjugates can be used as dual electrochemical sensors for GST P1-1.

  12. Activities of gamma-glutamyl transpeptidase and erythrocyte glutathione dependent enzymes in nasopharyngeal carcinoma patients and normal controls.

    PubMed

    Ngah, W Z; Shamaan, N A; Said, M H; Azhar, M T

    1993-01-01

    Plasma gamma-glutamyltranspeptidase (gamma-GT), glutathione peroxidase (GPx) and glutathione reductase (GR) activities were determined in normal and nasopharyngeal carcinoma (NPC) patients. No difference in enzyme activities was observed in the three major races of the Malaysian population, i.e. Malay, Chinese and Indian patients. However, plasma gamma-GT, erythrocyte glutathione S-transferase (GST) and GPx activities were significantly increased in all NPC patients, while GR activity remained unchanged. Patients with elevated plasma gamma-GT activities also had increased GST and GPx activities. Plasma gamma-GT and GPx activities were then found to be affected by treatment. Patients with plasma gamma-GT activity greater than 70 IU/l had very poor prognoses but patients with decreased gamma-GT activities were found to be in remission.

  13. Purification, crystallization and preliminary X-ray analysis of glutathione peroxidase Gpx3 from Saccharomyces cerevisiae

    SciTech Connect

    Yang, Zhu; Zhou, Cong-Zhao

    2006-06-01

    The glutathione peroxidase Gpx3 from the yeast S. cerevisiae has been overexpressed, purified, crystallized and diffracted to 2.6 Å resolution. Gpx3 is a monomer in solution which is different from its counterparts in mammals. The glutathione peroxidase Gpx3 from the yeast Saccharomyces cerevisiae has been overexpressed, purified and crystallized. Both gel-filtration and dynamic light-scattering (DLS) results indicate that Gpx3 is a monomer in solution at a concentration of about 2 mg ml{sup −1}, whereas glutathione peroxidases are normally tetrameric or dimeric. X-ray diffraction data from a single crystal of Gpx3 have been collected to 2.6 Å resolution. The crystals are triclinic and belong to space group P1, with unit-cell parameters a = 38.187, b = 43.372, c = 56.870 Å, α = 71.405, β = 73.376, γ = 89.633°. There are two Gpx3 monomers in a crystallographic asymmetric unit. Preliminary analyses show that the yeast Gpx3 is quite different from those of mammals.

  14. Glutathione S-transferase in the midgut tissue of gypsy moth (Lymantria dispar) caterpillars exposed to dietary cadmium.

    PubMed

    Vlahović, Milena; Ilijin, Larisa; Mrdaković, Marija; Todorović, Dajana; Matić, Dragana; Lazarević, Jelica; Mataruga, Vesna Perić

    2016-06-01

    Activity of glutathione S-transferase (GST) in midgut of gypsy moth caterpillars exposed to 10 and 30μg Cd/g dry food was examined. Based on the enzyme reaction through conjugation with glutathione, overall activity remained unaltered after acute and chronic treatment. No-observed-effect-concentration (10μg Cd/g dry food) significantly increased activity only after 3-day recovery following cadmium administration. Almost all comparisons of the indices of phenotypic plasticity revealed statistically significant differences. Despite the facts that GST has important role in xenobiotic biotransformation, our results indicate that this enzyme in insect midgut does not represent the key factor in cadmium detoxification.

  15. A redox-dependent dimerization switch regulates activity and tolerance for reactive oxygen species of barley seed glutathione peroxidase.

    PubMed

    Navrot, Nicolas; Skjoldager, Nicklas; Bunkenborg, Jakob; Svensson, Birte; Hägglund, Per

    2015-05-01

    Monomeric and dimeric forms of recombinant barley (Hordeum vulgare subsp. vulgare) glutathione peroxidase 2 (HvGpx2) are demonstrated to display distinctly different functional properties in vitro. Monomeric HvGpx2 thus has five fold higher catalytic efficiency than the dimer towards tert-butyl hydroperoxide, but is more sensitive to inactivation by hydrogen peroxide. Treatment of the monomer with hydrogen peroxide results in dimer formation. This observed new behavior of a plant glutathione peroxidase suggests a mechanism involving a switch from a highly catalytically competent monomer to a less active, but more oxidation-resistant dimer. PMID:25796076

  16. Glutathione is required for efficient production of infectious picornavirus virions

    SciTech Connect

    Smith, Allen D. . E-mail: smitha@ba.ars.usda.gov; Dawson, Harry . E-mail: dawsonh@ba.ars.usda.gov

    2006-09-30

    Glutathione is an intracellular reducing agent that helps maintain the redox potential of the cell and is important for immune function. The drug L-buthionine sulfoximine (BSO) selectively inhibits glutathione synthesis. Glutathione has been reported to block replication of HIV, HSV-1, and influenza virus, whereas cells treated with BSO exhibit increased replication of Sendai virus. Pre-treatment of HeLa cell monolayers with BSO inhibited replication of CVB3, CVB4, and HRV14 with viral titers reduced by approximately 6, 5, and 3 log{sub 1}, respectively. The addition of glutathione ethyl ester, but not dithiothreitol or 2-mercaptoethanol, to the culture medium reversed the inhibitory effect of BSO. Viral RNA and protein synthesis were not inhibited by BSO treatment. Fractionation of lysates from CVB3-infected BSO-treated cells on cesium chloride and sucrose gradients revealed that empty capsids but not mature virions were being produced. The levels of the 5S and 14S assembly intermediates, however, were not affected by BSO treatment. These results demonstrate that glutathione is important for production of mature infectious picornavirus virions.

  17. Genetic study of glutathione accumulation during cold hardening in wheat.

    PubMed

    Kocsy, G; Szalai, G; Vágújfalvi, A; Stéhli, L; Orosz, G; Galiba, G

    2000-01-01

    The effect of cold hardening on the accumulation of glutathione (GSH) and its precursors was studied in the shoots and roots of wheat (Triticum aestivum L.) cv. Cheyenne (Ch, frost-tolerant) and cv. Chinese Spring (CS, moderately frost-sensitive), in a T. spelta L. accession (Tsp, frost-sensitive) and in chromosome substitution lines CS (Ch 5A) and CS (Tsp 5A). The fast induction of total glutathione accumulation was detected during the first 3 d of hardening in the shoots, especially in the frost-tolerant Ch and CS (Ch 5A). This observation was corroborated by the study of de novo GSH synthesis using [(35)S]sulfate. In Ch and CS (Ch 5A) the total cysteine, gamma-glutamylcysteine (precursors of GSH), hydroxymethylglutathione and GSH contents were greater during the 51-d treatment than in the sensitive genotypes. After 35 d hardening, when the maximum frost tolerance was observed, greater ratios of reduced to oxidised hydroxymethylglutathione and glutathione were detected in Ch and CS (Ch 5A) compared to the sensitive genotypes. A correspondingly greater glutathione reductase (EC 1.6.4.2) activity was also found in Ch and CS (Ch 5A). It can be assumed that chromosome 5A of wheat has an influence on GSH accumulation and on the ratio of reduced to oxidised glutathione as part of a complex regulatory function during hardening. Consequently, GSH may contribute to the enhancement of frost tolerance in wheat. PMID:10664136

  18. Glutamate and glutathione interplay in a motor neuronal model of amyotrophic lateral sclerosis reveals altered energy metabolism.

    PubMed

    D'Alessandro, Giuseppina; Calcagno, Eleonora; Tartari, Silvia; Rizzardini, Milena; Invernizzi, Roberto William; Cantoni, Lavinia

    2011-08-01

    Impairment of mitochondrial function might contribute to oxidative stress associated with neurodegeneration in amyotrophic lateral sclerosis (ALS). Glutamate levels in tissues of ALS patients are sometimes altered. In neurons, mitochondrial metabolism of exogenous glutamine is mainly responsible for the net synthesis of glutamate, which is a neurotransmitter, but it is also necessary for the synthesis of glutathione, the main endogenous antioxidant. We investigated glutathione synthesis and glutamine/glutamate metabolism in a motor neuronal model of familial ALS. In standard culture conditions (with glutamine) or restricting glutamine or cystine, the level of glutathione was always lower in the cell line expressing the mutant (G93A) human Cu, Zn superoxide dismutase (G93ASOD1) than in the line expressing wild-type SOD1. With glutamine the difference in glutathione was associated with a lower glutamate and impairment of the glutamine/glutamate metabolism as evidenced by lower glutaminase and cytosolic malate dehydrogenase activity. d-β-hydroxybutyrate, as an alternative to glutamine as energy substrate in addition to glucose, reversed the decreases of cytosolic malate dehydrogenase activity and glutamate and glutathione. However, in the G93ASOD1 cell line, in all culture conditions the expression of pyruvate dehydrogenase kinase l protein, which down-regulates pyruvate dehydrogenase activity, was induced, together with an increase in lactate release in the medium. These findings suggest that the glutathione decrease associated with mutant SOD1 expression is due to mitochondrial dysfunction caused by the reduction of the flow of glucose-derived pyruvate through the TCA cycle; it implies altered glutamate metabolism and depends on the different mitochondrial energy substrates. PMID:21530659

  19. A novel glutathione-S transferase immunosensor based on horseradish peroxidase and double-layer gold nanoparticles.

    PubMed

    Lu, Dingqiang; Lu, Fuping; Pang, Guangchang

    2016-06-01

    GSTs, a biotransformation enzyme group, can perform metabolism, drug transfer and detoxification functions. Rapid detection of the GSTs with more sensitive approaches is of great importance. In the current study, a novel double-layer gold nanoparticles-electrochemical immunosensor electrode (DGN-EIE) immobilized with Glutathione S-Transferase (GST) antibody derived from Balb/c mice was developed. To increase the fixed quantity of antibodies and electrochemical signal, an electrochemical biosensing signal amplification system was utilized with gold nanoparticles-thionine-chitosan absorbing horseradish peroxidase (HRP). In addition, transmission electron microscope (TEM) was used to characterize the nanogold solution. To evaluate the quality of DGN-EIE, the amperometric I-t curve method was applied to determine the GST in PBS. The results showed that the response current had a good linear correlation with the GST concentration ranged from 0.1-10(4) pg/mL. The lowest detection limit was found at 0.03 pg/mL(S/N = 3). The linear equation was deduced as △I/% = 7.386lgC + 22.36 (R(2) = 0.998). Moreover, it was validated with high sensitivity and reproducibility. Apparently, DGN-EIE may be a very useful tool for monitoring the GST. PMID:27220630

  20. Efficacy of free glutathione and niosomal glutathione in the treatment of acetaminophen-induced hepatotoxicity in cats.

    PubMed

    Vulcano, L A Denzoin; Confalonieri, O; Franci, R; Tapia, M O; Soraci, A L

    2013-01-01

    Acetaminophen (APAP) administration results in hepatotoxicity and hematotoxicity in cats. The response to three different treatments against APAP poisoning was evaluated. Free glutathione (GSH) (200mg/kg), niosomal GSH (14 mg/kg) and free amino acids (180 mg/kg of N-acetylcysteine and 280 mg/kg of methionine) were administered to cats that were intoxicated with APAP (a single dose of 150 mg/kg, p.o.). Serum concentration of alanine aminotransferase (ALT) along with serum, liver and erythrocyte concentration of GSH and methemoglobin percentage were measured before and 4, 24 and 72 hours after APAP administration. Free GSH (200 mg/kg) and niosomal GSH (14 mg/kg) were effective in reducing hepatotoxicity and hematotoxicity in cats intoxicated with a dose of 150 mg/kg APAP. We conclude that both types of treatments can protect the liver and haemoglobin against oxidative stress in APAP intoxicated cats. Furthermore, our results showed that treatment with niosomal GSH represents an effective therapeutic approach for APAP poisoning. PMID:26623313

  1. Efficacy of free glutathione and niosomal glutathione in the treatment of acetaminophen-induced hepatotoxicity in cats

    PubMed Central

    Vulcano, L.A. Denzoin; Confalonieri, O.; Franci, R.; Tapia, M.O.; Soraci, A.L.

    2013-01-01

    Acetaminophen (APAP) administration results in hepatotoxicity and hematotoxicity in cats. The response to three different treatments against APAP poisoning was evaluated. Free glutathione (GSH) (200mg/kg), niosomal GSH (14 mg/kg) and free amino acids (180 mg/kg of N-acetylcysteine and 280 mg/kg of methionine) were administered to cats that were intoxicated with APAP (a single dose of 150 mg/kg, p.o.). Serum concentration of alanine aminotransferase (ALT) along with serum, liver and erythrocyte concentration of GSH and methemoglobin percentage were measured before and 4, 24 and 72 hours after APAP administration. Free GSH (200 mg/kg) and niosomal GSH (14 mg/kg) were effective in reducing hepatotoxicity and hematotoxicity in cats intoxicated with a dose of 150 mg/kg APAP. We conclude that both types of treatments can protect the liver and haemoglobin against oxidative stress in APAP intoxicated cats. Furthermore, our results showed that treatment with niosomal GSH represents an effective therapeutic approach for APAP poisoning. PMID:26623313

  2. Differences in the force system delivered by different beta-titanium wires in elaborate designs

    PubMed Central

    Martins, Renato Parsekian; Caldas, Sergei Godeiro Fernandes Rabelo; Ribeiro, Alexandre Antonio; Vaz, Luís Geraldo; Shimizu, Roberto Hideo; Martins, Lídia Parsekian

    2015-01-01

    Abstract Objective: Evaluation of the force system produced by four brands of b-Ti wires bent into an elaborate design. Methods: A total of 40 T-loop springs (TLS) hand-bent from 0.017 x 0.025-in b-Ti were randomly divided into four groups according to wire brand: TMATM(G1), BETA FLEXYTM (G2), BETA III WIRETM (G3) and BETA CNATM (G4). Forces and moments were recorded by a moment transducer, coupled to a digital extensometer indicator adapted to a testing machine, every 0.5 mm of deactivation from 5 mm of the initial activation. The moment-to-force (MF) ratio, the overlapping of the vertical extensions of the TLSs and the load-deflection (LD) ratio were also calculated. To complement the results, the Young's module (YM) of each wire was determined by the slope of the load-deflection graph of a tensile test. The surface chemical composition was also evaluated by an energy dispersive X-ray fluorescence spectrometer. Results: All groups, except for G2, produced similar force levels initially. G3 produced the highest LD rates and G1 and G4 had similar amounts of overlap of the vertical extensions of the TLSs in "neutral position". G1 and G3 delivered the highest levels of moments, and G2 and G3 produced the highest MF ratios. b-Ti wires from G3 produced the highest YM and all groups showed similar composition, except for G2. Conclusion: The four beta-titanium wires analyzed produced different force systems when used in a more elaborate design due to the fact that each wire responds differently to bends. PMID:26691975

  3. Skin delivery of ferulic acid from different vesicular systems.

    PubMed

    Chen, Ming; Liu, Xiangli; Fahr, Alfred

    2010-10-01

    The aim of the present research is to evaluate the skin delivery capabilities of different vesicular systems, including conventional liposomes (CL), Tween 80-based deformable liposomes (DL), invasomes (INS) and ethosomes bearing ferulic acid (FA) being an antioxidant exhibiting a wide range of therapeutic effects against various diseases. All of the test formulations were characterized for particle size distribution, zeta-potential, vesicular shape and surface morphology, in vitro human skin permeation and skin deposition. Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM) defined that all of liposomal vesicles were almost spherical, displaying unilamellar structures with low polydispersity (PDI < 0.2) and nanometric size range (z-average no more than 150 nm). In addition, all the vesicular systems except conventional liposomes were negatively charged to a certain extent. In vitro skin permeation and skin deposition experiments demonstrated that the permeation profile of ferulic acid through human stratum corneum epidermis membrane (SCE) and the drug deposition in skin were both improved significantly using these vesicular liposomal systems. Permeation and skin deposition enhancing effect was highlighted by the ethosomal system containing 18.0 mg/ml of ferulic acid with an significantly (P < 0.01) enhanced skin flux (267.8 +/- 16.77 microg/cm2/h) and skin drug deposition (51.67 +/- 1.94 microg/cm2), which was 75 times and 7.3 times higher than those of ferulic acid from saturated PBS (pH 7.4) solution, respectively. This study demonstrated that ethosomes are promising vesicular carriers for delivering ferulic acid into or across the skin. PMID:21329050

  4. Nouns and verbs are retrieved with differently distributed neural systems.

    PubMed Central

    Damasio, A R; Tranel, D

    1993-01-01

    In a task designed to elicit the production of verbs, the patients known as AN-1033 and Boswell consistently produced the correct target words, performing no differently from normal controls. However, in a similar task designed to elicit the production of nouns, both patients performed quite defectively, and their scores were many SDs below those of controls. Language processing was otherwise normal--i.e., there were no impairments in grammar, morphology, phonetic implementation, or prosody; reading and writing were normal. In a third patient (KJ-1360), we obtained the reverse outcome--i.e., retrieval of common and proper nouns was preserved, but verb retrieval was defective. Together, the findings in the three patients constitute a double dissociation between noun and verb retrieval. In AN-1033 and Boswell, the lesions are located outside the so-called language areas (left frontoparietal operculum, posterior temporal region, inferior parietal lobule), where damage is associated with aphasia. The region of damage shared by the two patients is in left anterior and middle temporal lobe. This sector of left hemisphere contains systems for the retrieval of nouns that denote concrete entities. We propose that those systems are not essential for the retrieval of verbs and not involved in the vocal implementation of word forms. Those systems perform a two-way lexical-mediation role for concrete nouns and promote the reconstruction of a word form after the processing of sensory-motor characteristics of the entity denoted by that word. The findings in patient KJ-1360, whose lesion is in left premotor cortex, suggest that equivalent mediation systems for verbs are located in the left frontal region. Images Fig. 1 PMID:8506341

  5. Glutathione Homeostasis and Functions: Potential Targets for Medical Interventions

    PubMed Central

    Lushchak, Volodymyr I.

    2012-01-01

    Glutathione (GSH) is a tripeptide, which has many biological roles including protection against reactive oxygen and nitrogen species. The primary goal of this paper is to characterize the principal mechanisms of the protective role of GSH against reactive species and electrophiles. The ancillary goals are to provide up-to-date knowledge of GSH biosynthesis, hydrolysis, and utilization; intracellular compartmentalization and interorgan transfer; elimination of endogenously produced toxicants; involvement in metal homeostasis; glutathione-related enzymes and their regulation; glutathionylation of sulfhydryls. Individual sections are devoted to the relationships between GSH homeostasis and pathologies as well as to developed research tools and pharmacological approaches to manipulating GSH levels. Special attention is paid to compounds mainly of a natural origin (phytochemicals) which affect GSH-related processes. The paper provides starting points for development of novel tools and provides a hypothesis for investigation of the physiology and biochemistry of glutathione with a focus on human and animal health. PMID:22500213

  6. Thioltransferase activity of bovine lens glutathione S-transferase.

    PubMed Central

    Dal Monte, M; Cecconi, I; Buono, F; Vilardo, P G; Del Corso, A; Mura, U

    1998-01-01

    A Mu-class glutathione S-transferase purified to electrophoretic homogeneity from bovine lens displayed thioltransferase activity, catalysing the transthiolation reaction between GSH and hydroxyethyldisulphide. The thiol-transfer reaction is composed of two steps, the formation of GSSG occurring through the generation of an intermediate mixed disulphide between GSH and the target disulphide. Unlike glutaredoxin, which is only able to catalyse the second step of the transthiolation process, glutathioneS-transferase catalyses both steps of the reaction. Data are presented showing that bovine lens glutathione S-transferase and rat liver glutaredoxin, which was used as a thioltransferase enzyme model, can operate in synergy to catalyse the GSH-dependent reduction of hydroxyethyldisulphide. PMID:9693102

  7. Cadmium-glutathione complex formation in human t-cell and b-cell lymphocytes after their incubation with organo-cadmium diacetate.

    PubMed

    Ullah, Hashmat; Khan, Muhammad Farid; Jan, Syed Umer; Hashmat, Farwa

    2015-11-01

    Cadmium intake is associated with oxidative stress that causes depletion of intracellular as well as extra cellular reduced glutathione. There is strong evidence indicating that reactive oxygen species and reactive nitrogen species generated in the presence of cadmium could be responsible for its toxic effects in many cells and tissues. Depletion of reduced glutathione in various cells, especially in T and B-lymphocytes, causes extreme damage to the antioxidant defense system of body. The aim of this research work was to investigate the metabolic changes that occur in T and B lymphocytes after their incubation with organ cadmium diacetate by using Ellman's spectrophotometric method of thiol quantification. The results of the present study indicate that cadmium depleted T and B lymphocytes GSH to a harmful extent. It is proposed that this depletion is due to the bivalent cadmium glutathione complex formation, oxidation of reduced glutathione (GSH) to its oxidized form, or both.

  8. Optical biosensor consisting of glutathione-S-transferase for detection of captan.

    PubMed

    Choi, Jeong-Woo; Kim, Young-Kee; Song, Sun-Young; Lee, In-ho; Lee, Won-Hong

    2003-10-15

    The optical biosensor consisting of a glutathione-S-transferase (GST)-immobilized gel film was developed to detect captan in contaminated water. The sensing scheme was based on the decrease of yellow product, s-(2,4-dinitrobenzene) glutathione, produced from substrates, 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione (GSH), due to the inhibition of GST reaction by captan. Absorbance of the product as the output of enzyme reaction was detected and the light was guided through the optical fibers. The enzyme reactor of the sensor system was fabricated by the gel entrapment technique for the immobilized GST film. The immobilized GST had the maximum activity at pH 6.5. The optimal concentrations of substrates were determined with 1 mM for both of CDNB and GSH. The optimum concentration of enzyme was also determined with 100 microg/ml. The activity of immobilized enzyme was fairly sustained during 30 days. The proposed biosensor could successfully detect the captan up to 2 ppm and the response time to steady signal was about 15 min.

  9. Application of glutathione to roots selectively inhibits cadmium transport from roots to shoots in oilseed rape

    PubMed Central

    Nakamura, Shin-ichi

    2013-01-01

    Glutathione is a tripeptide involved in various aspects of plant metabolism. This study investigated the effects of the reduced form of glutathione (GSH) applied to specific organs (source leaves, sink leaves, and roots) on cadmium (Cd) distribution and behaviour in the roots of oilseed rape plants (Brassica napus) cultured hydroponically. The translocation ratio of Cd from roots to shoots was significantly lower in plants that had root treatment of GSH than in control plants. GSH applied to roots reduced the Cd concentration in the symplast sap of root cells and inhibited root-to-shoot Cd translocation via xylem vessels significantly. GSH applied to roots also activated Cd efflux from root cells to the hydroponic solution. Inhibition of root-to-shoot translocation of Cd was visualized, and the activation of Cd efflux from root cells was also shown by using a positron-emitting tracer imaging system (PETIS). This study investigated a similar inhibitory effect on root-to-shoot translocation of Cd by the oxidized form of glutathione, GSSG. Inhibition of Cd accumulation by GSH was abolished by a low-temperature treatment. Root cells of plants exposed to GSH in the root zone had less Cd available for xylem loading by actively excluding Cd from the roots. Consequently, root-to-shoot translocation of Cd was suppressed and Cd accumulation in the shoot decreased. PMID:23364937

  10. Modulation of Brain Glutathione Reductase and Peroxiredoxin 2 by α-Tocopheryl Phosphate.

    PubMed

    Uchoa, Mariana Figueiroa; de Souza, Luiz Felipe; Dos Santos, Danubia Bonfanti; Peres, Tanara Vieira; Mello, Danielle Ferraz; Leal, Rodrigo Bainy; Farina, Marcelo; Dafre, Alcir Luiz

    2016-08-01

    α-Tocopheryl phosphate (αTP) is a phosphorylated form of α-tocopherol. Since it is phosphorylated in the hydroxyl group that is essential for the antioxidant property of α-tocopherol, we hypothesized that αTP would modulate the antioxidant system, rather than being an antioxidant agent per se. α-TP demonstrated antioxidant activity in vitro against iron-induced oxidative stress in a mitochondria-enriched fraction preparation treated with 30 or 100 µM α-TP. However, this effect was not observed ex vivo with mitochondrial-enriched fraction from mice treated with an intracerebroventricular injection of 0.1 or 1 nmol/site of αTP. Two days after treatment (1 nmol/site αTP), peroxiredoxin 2 (Prx2) and glutathione reductase (GR) expression and GR activity were decreased in cerebral cortex and hippocampus. Glutathione content, glutathione peroxidase, and thioredoxin reductase activities were not affected by αTP. In conclusion, the persistent decrease in GR and Prx2 protein content is the first report of an in vivo effect of αTP on protein expression in the mouse brain, potentially associated to a novel and biologically relevant function of this naturally occurring compound. PMID:26749581

  11. Multiple System Searching: A Searcher's Guide to Making Use of Real Differences between Systems.

    ERIC Educational Resources Information Center

    Conger, Lucinda D.

    1980-01-01

    Examines the relative benefits and searching philosophies of five major search systems (DIALOG, ORBIT, BRS, NLM, and DOE/RECON) as a selection aid. Differences in command language, full text searching capability, use and expression of Boolean operators, and searching mechanisms are discussed, and comparison charts and system/database comparisons…

  12. Proteomic analysis of Ketogulonicigenium vulgare under glutathione reveals high demand for thiamin transport and antioxidant protection.

    PubMed

    Ma, Qian; Zhang, Weiwen; Zhang, Lu; Qiao, Bin; Pan, Chensong; Yi, Hong; Wang, Lili; Yuan, Ying-jin

    2012-01-01

    Ketogulonicigenium vulgare, though grows poorly when mono-cultured, has been widely used in the industrial production of the precursor of vitamin C with the coculture of Bacillus megaterium. Various efforts have been made to clarify the synergic pattern of this artificial microbial community and to improve the growth and production ability of K. vulgare, but there is still no sound explanation. In previous research, we found that the addition of reduced glutathione into K. vulgare monoculture could significantly improve its growth and productivity. By performing SEM and TEM, we observed that after adding GSH into K. vulgare monoculture, cells became about 4-6 folds elongated, and formed intracytoplasmic membranes (ICM). To explore the molecular mechanism and provide insights into the investigation of the synergic pattern of the co-culture system, we conducted a comparative iTRAQ-2-D-LC-MS/MS-based proteomic analysis of K. vulgare grown under reduced glutathione. Principal component analysis of proteomic data showed that after the addition of glutathione, proteins for thiamin/thiamin pyrophosphate (TPP) transport, glutathione transport and the maintenance of membrane integrity, together with several membrane-bound dehydrogenases had significant up-regulation. Besides, several proteins participating in the pentose phosphate pathway and tricarboxylic acid cycle were also up-regulated. Additionally, proteins combating intracellular reactive oxygen species were also up-regulated, which similarly occurred in K. vulgare when the co-cultured B. megaterium cells lysed from our former research results. This study reveals the demand for transmembrane transport of substrates, especially thiamin, and the demand for antioxidant protection of K. vulgare.

  13. Stereochemical Features of Glutathione-dependent Enzymes in the Sphingobium sp. Strain SYK-6 β-Aryl Etherase Pathway*

    PubMed Central

    Gall, Daniel L.; Kim, Hoon; Lu, Fachuang; Donohue, Timothy J.; Noguera, Daniel R.; Ralph, John

    2014-01-01

    Glutathione-dependent enzymes play important protective, repair, or metabolic roles in cells. In particular, enzymes in the glutathione S-transferase (GST) superfamily function in stress responses, defense systems, or xenobiotic detoxification. Here, we identify novel features of bacterial GSTs that cleave β-aryl ether bonds typically found in plant lignin. Our data reveal several original features of the reaction cycle of these GSTs, including stereospecific substrate recognition and stereoselective formation of β-S-thioether linkages. Products of recombinant GSTs (LigE, LigP, and LigF) are β-S-glutathionyl-α-keto-thioethers that are degraded by a β-S-thioetherase (LigG). All three Lig GSTs produced the ketone product (β-S-glutathionyl-α-veratrylethanone) from an achiral side chain-truncated model substrate (β-guaiacyl-α-veratrylethanone). However, when β-etherase assays were conducted with a racemic model substrate, β-guaiacyl-α-veratrylglycerone, LigE- or LigP-catalyzed reactions yielded only one of two potential product (β-S-glutathionyl-α-veratrylglycerone) epimers, whereas the other diastereomer (differing in configuration at the β-position (i.e. its β-epimer)) was produced only in the LigF-catalyzed reaction. Thus, β-etherase catalysis causes stereochemical inversion of the chiral center, converting a β(R)-substrate to a β(S)-product (LigE and LigP), and a β(S)-substrate to a β(R)-product (LigF). Further, LigG catalyzed glutathione-dependent β-S-thioether cleavage with β-S-glutathionyl-α-veratrylethanone and with β(R)-configured β-S-glutathionyl-α-veratrylglycerone but exhibited no or significantly reduced β-S-thioether-cleaving activity with the β(S)-epimer, demonstrating that LigG is a stereospecific β-thioetherase. We therefore propose that multiple Lig enzymes are needed in this β-aryl etherase pathway in order to cleave the racemic β-ether linkages that are present in the backbone of the lignin polymer. PMID:24509858

  14. Recurrent Isolated Neonatal Hemolytic Anemia: Think About Glutathione Synthetase Deficiency.

    PubMed

    Signolet, Isabelle; Chenouard, Rachel; Oca, Florine; Barth, Magalie; Reynier, Pascal; Denis, Marie-Christine; Simard, Gilles

    2016-09-01

    Hemolytic anemia (HA) of the newborn should be considered in cases of rapidly developing, severe, or persistent hyperbilirubinemia. Several causes of corpuscular hemolysis have been described, among which red blood cell enzyme defects are of particular concern. We report a rare case of red blood cell enzyme defect in a male infant, who presented during his first months of life with recurrent and isolated neonatal hemolysis. All main causes were ruled out. At 6.5 months of age, the patient presented with gastroenteritis requiring hospitalization; fortuitously, urine organic acid chromatography revealed a large peak of 5-oxoproline. Before the association between HA and 5-oxoprolinuria was noted, glutathione synthetase deficiency was suspected and confirmed by a low glutathione synthetase concentration and a collapse of glutathione synthetase activity in erythrocytes. Moreover, molecular diagnosis revealed 2 mutations in the glutathione synthetase gene: a previously reported missense mutation (c.[656A>G]; p.[Asp219Gly]) and a mutation not yet described in the binding site of the enzyme (c.[902T>C]; p.[Leu301Pro]). However, 15 days later, a control sample revealed no signs of 5-oxoprolinuria and the clinical history discovered administration of acetaminophen in the 48 hours before hospitalization. Thus, in this patient, acetaminophen exposure allowed the diagnosis of a mild form of glutathione synthetase deficiency, characterized by isolated HA. Early diagnosis is important because treatment with bicarbonate, vitamins C and E, and elimination of trigger factors are recommended to improve long-term outcomes. Glutathione synthetase deficiency should be screened for in cases of unexplained newborn HA. PMID:27581854

  15. The effects of acute ethanol exposure and ageing on rat brain glutathione metabolism.

    PubMed

    Sommavilla, Michela; Sánchez-Villarejo, M Victoria; Almansa, Inmaculada; Sánchez-Vallejo, Violeta; Barcia, Jorge M; Romero, Francisco Javier; Miranda, María

    2012-09-01

    Binge alcohol consumption in adolescents is increasing, and it has been proposed that immature brain deals poorly with oxidative stress. The aim of our work was to study the effect of an acute dose of ethanol on glutathione (GSH) metabolism in frontal cortex, hippocampus and striatum of juvenile and adult rats. We have observed no change in levels of glutathione produced by acute alcohol in the three brain areas studied of juvenile and adult rats. Only in the frontal cortex the ratio of GSH/GSSG was increased in the ethanol-treated adult rats. GSH levels in the hippocampus and striatum were significantly higher in adult animals compared to young ones. Higher glutathione peroxidase (GPx) activity in adult rats was observed in frontal cortex and in striatum. Our data show an increased GSH concentration and GPx activity in different cerebral regions of the adult rat, compared to the young ones, suggesting that age-related variations of total antioxidant defences in brain may predispose young brain structures to ethanol-induced, oxidative stress-mediated tissue damage.

  16. Long-term tocotrienol supplementation and glutathione-dependent enzymes during hepatocarcinogenesis in the rat.

    PubMed

    Rahmat, A; Wan Ngah, W Z; Gapor, A; Khalid, B A

    1993-09-01

    The effects of long-term administration of tocotrienol on hepatocarcinogenesis in rats induced by diethyl nitrosamine (DEN) and 2-acetylaminofluorene (AAF) were investigated by the determination of plasma and liver gamma-glutamyl transpeptidase (GGT), cytosolic glutathione reductase (GSSG-Rx), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST). Twenty-eight male Rattus norwegicus rats (120-160g) were divided according to treatments into four groups: control group, tocotrienol - supplemented diet group (30mg/kg food), DEN/AAF-treated group and DEN/AAF treated plus tocotrienol-supplemented-diet group (30mg/kg food). The rats were sacrificed after nine months. The results obtained indicated no difference in the morphology and histology of the livers of control and tocotrienol-treated rats. Greyish-white neoplastic nodules (two per liver) were found in all the DEN/ AAF treated rats (n-10) whereas only one nodule was found in one of the carcinogen treated rats receiving tocotrienol supplementation (n-6). Histological examination showed obvious cellular damage for both the DEN/AAF-treated rats and the tocotrienol-supplemented rats but were less severe in the latter. Treatment with DEN/AAF caused increases in GGT, GSH-Px, GST and GSSG-Rx activities when compared to controls. These increases were also observed when tocotrienol was supplemented with DEN/AAF but the increases were less when compared to the rats receiving DEN/AAF only.

  17. Glutathione and transpiration as key factors conditioning oxidative stress in Arabidopsis thaliana exposed to uranium.

    PubMed

    Aranjuelo, Iker; Doustaly, Fany; Cela, Jana; Porcel, Rosa; Müller, Maren; Aroca, Ricardo; Munné-Bosch, Sergi; Bourguignon, Jacques

    2014-04-01

    Although oxidative stress has been previously described in plants exposed to uranium (U), some uncertainty remains about the role of glutathione and tocopherol availability in the different responsiveness of plants to photo-oxidative damage. Moreover, in most cases, little consideration is given to the role of water transport in shoot heavy metal accumulation. Here, we investigated the effect of uranyl nitrate exposure (50 μM) on PSII and parameters involved in water transport (leaf transpiration and aquaporin gene expression) of Arabidopsis wild type (WT) and mutant plants that are deficient in tocopherol (vte1: null α/γ-tocopherol and vte4: null α-tocopherol) and glutathione biosynthesis (high content: cad1.3 and low content: cad2.1). We show how U exposure induced photosynthetic inhibition that entailed an electron sink/source imbalance that caused PSII photoinhibition in the mutants. The WT was the only line where U did not damage PSII. The increase in energy thermal dissipation observed in all the plants exposed to U did not avoid photo-oxidative damage of mutants. The maintenance of control of glutathione and malondialdehyde contents probed to be target points for the overcoming of photoinhibition in the WT. The relationship between leaf U content and leaf transpiration confirmed the relevance of water transport in heavy metals partitioning and accumulation in leaves, with the consequent implication of susceptibility to oxidative stress.

  18. Antenna-specific glutathione S-transferase in male silkmoth Bombyx mori.

    PubMed

    Tan, Xiang; Hu, Xiao-Ming; Zhong, Xiao-Wu; Chen, Quan-Mei; Xia, Qing-You; Zhao, Ping

    2014-04-29

    Glutathione S-transferases (GSTs) are multifunctional enzymes that are widely distributed in different species. GSTs detoxify exogenous and endogenous substances by conjugation to reduced glutathione. We characterized BmGSTD4, an antenna-specific GST, in male silkmoths. The full-length mRNA of Bmgstd4 was cloned by RACE-PCR and contained an open reading frame of 738 bp encoding a 245 amino acid protein. The antenna specificity of BmGSTD4 was validated at the mRNA and protein levels and BmGSTD4 was shown to localize in the sensillum of male silkmoth antennae. Homology modeling and multi-sequence alignment suggested that BmGSTD4 was a typical GST belonging to the δ class and had a canonical GST fold with a conserved N-terminus, including a glutathione-binding site and a C-terminal domain harboring a hydrophobic substrate-binding site. Restricted expression of BmGSTD4 in silkmoth antennae combined with GST activity suggested that BmGSTD4 was involved in the detoxification of harmful chemicals.

  19. Serum Malondialdehyde Concentration and Glutathione Peroxidase Activity in a Longitudinal Study of Gestational Diabetes

    PubMed Central

    Miranda, María; Muriach, María; Romero, Francisco J.; Villar, Vincent M.

    2016-01-01

    Aims The main goal of this study was to evaluate the presence of oxidative damage and to quantify its level in gestational diabetes. Methods Thirty-six healthy women and thirty-six women with gestational diabetes were studied in the three trimesters of pregnancy regarding their levels of oxidative stress markers. These women were diagnosed with diabetes in the second trimester of pregnancy. Blood glucose levels after 100g glucose tolerance test were higher than 190, 165 or 145 mg/dl, 1, 2 or 3 hours after glucose intake. Results The group of women with gestational diabetes had higher serum malondialdehyde levels, with significant differences between groups in the first and second trimester. The mean values of serum glutathione peroxidase activity in the diabetic women were significantly lower in the first trimester. In the group of women with gestational diabetes there was a negative linear correlation between serum malondialdehyde concentration and glutathione peroxidase activity in the second and third trimester. Conclusions In this observational and longitudinal study in pregnant women, the alterations attributable to oxidative stress were present before the biochemical detection of the HbA1c increase. Usual recommendations once GD is detected (adequate metabolic control, as well as any other normally proposed to these patients) lowered the concentration of malondialdehyde at the end of pregnancy to the same levels of the healthy controls. Serum glutathione peroxidase activity in women with gestational diabetes increased during the gestational period. PMID:27228087

  20. Transcriptional activation of glutathione pathways and role of glucose homeostasis during copper imbalance.

    PubMed

    Quiroz, Natalia; Rivas, Nicole; del Pozo, Talía; Burkhead, Jason; Suazo, Miriam; González, Mauricio; Latorre, Mauricio

    2015-04-01

    Copper is an essential micronutrient for organism health. Dietary changes or pathologies linked to this metal induce changes in intracellular glutathione concentrations. Here, we studied the transcriptional activation of glutathione pathways in Jurkat cell lines, analyzing the effect of change in glucose homeostasis during a physiological and supra-physiological copper exposure. An immortalized line of human T lymphocyte cell line (Jurkat) was exposed to different copper and glucose conditions to mimic concentrations present in human blood. We applied treatments for 6 (acute) and 24 h (sustained) to 2 µM (physiological) or 20 µM (supra-physiological, Wilson disease scenario) of CuSO4 in combination with 25 mg/dL (hypoglycemia), 100 mg/dL (normal) and 200 mg/dL (hyperglycemia, diabetes scenario) of glucose. The results indicate that a physiological concentration of copper exposure does not induce transcriptional changes in the glutathione synthesis pathway after 6 or 24 h. The G6PDH gene (regeneration pathway), however, is induced during a supra-physiological copper condition. This data was correlated with the viability assays, where fluctuation in both glucose conditions (hypo and hyperglycemia scenario) affected Jurkat proliferation when 20 µM of CuSO4 was added to the culture media. Under a copper overload condition, the transcription of a component of glutathione regeneration pathway (G6PDH gene) is activated in cells chronically exposed to a hyperglycemia scenario, indicating that fluctuations in glucose concentration impact the resistance against the metal. Our findings illustrate the importance of glucose homeostasis during copper excess.

  1. Emergy Analysis of Biogas Systems Based on Different Raw Materials

    PubMed Central

    Wang, Yang; Lin, Cong; Li, Jing; Duan, Na; Li, Xue; Fu, Yanyan

    2013-01-01

    Environmental pollution and energy crisis restrict the development of China, and the utilization of renewable technology is an effective strategy to alleviate the damage. Biogas engineering has rapidly developed attributes to solve environmental problems and create a renewable energy product biogas. In this paper, two different biogas plants' materials were analyzed by emergy method. One of them is a biogas project whose degraded material is feces (BPF system), and the other is the one whose degraded material is corn straw (BPC system). As a result, the ecological-economic values of BPF and BPC are $28,300/yr and $8,100/yr, respectively. Considering currency, environment, and human inputs, both of the biogas projects have the ability of disposing waste and potential for development. The proportion of biogas output is much more than fertilizer output; so, fertilizer utilization should be emphasized in the future. In comparison, BPF is better than BPC in the aspects of ecological-economic benefits, environmental benefits, and sustainability. The reason is the difficulty of corn straw seasonal collection and degradation. Thus it is proposed that BPC should be combined with the other raw materials. PMID:23476134

  2. Emergy analysis of biogas systems based on different raw materials.

    PubMed

    Wang, Yang; Lin, Cong; Li, Jing; Duan, Na; Li, Xue; Fu, Yanyan

    2013-01-01

    Environmental pollution and energy crisis restrict the development of China, and the utilization of renewable technology is an effective strategy to alleviate the damage. Biogas engineering has rapidly developed attributes to solve environmental problems and create a renewable energy product biogas. In this paper, two different biogas plants' materials were analyzed by emergy method. One of them is a biogas project whose degraded material is feces (BPF system), and the other is the one whose degraded material is corn straw (BPC system). As a result, the ecological-economic values of BPF and BPC are $28,300/yr and $8,100/yr, respectively. Considering currency, environment, and human inputs, both of the biogas projects have the ability of disposing waste and potential for development. The proportion of biogas output is much more than fertilizer output; so, fertilizer utilization should be emphasized in the future. In comparison, BPF is better than BPC in the aspects of ecological-economic benefits, environmental benefits, and sustainability. The reason is the difficulty of corn straw seasonal collection and degradation. Thus it is proposed that BPC should be combined with the other raw materials.

  3. Emergy analysis of biogas systems based on different raw materials.

    PubMed

    Wang, Yang; Lin, Cong; Li, Jing; Duan, Na; Li, Xue; Fu, Yanyan

    2013-01-01

    Environmental pollution and energy crisis restrict the development of China, and the utilization of renewable technology is an effective strategy to alleviate the damage. Biogas engineering has rapidly developed attributes to solve environmental problems and create a renewable energy product biogas. In this paper, two different biogas plants' materials were analyzed by emergy method. One of them is a biogas project whose degraded material is feces (BPF system), and the other is the one whose degraded material is corn straw (BPC system). As a result, the ecological-economic values of BPF and BPC are $28,300/yr and $8,100/yr, respectively. Considering currency, environment, and human inputs, both of the biogas projects have the ability of disposing waste and potential for development. The proportion of biogas output is much more than fertilizer output; so, fertilizer utilization should be emphasized in the future. In comparison, BPF is better than BPC in the aspects of ecological-economic benefits, environmental benefits, and sustainability. The reason is the difficulty of corn straw seasonal collection and degradation. Thus it is proposed that BPC should be combined with the other raw materials. PMID:23476134

  4. Implication of two different regeneration systems in limb regeneration

    PubMed Central

    Makanae, Aki; Mitogawa, Kazumasa

    2014-01-01

    Abstract Limb regeneration is a representative phenomenon of organ regeneration in urodele amphibians, such as an axolotl. An amputated limb starts regenerating from a remaining stump (proximal) to lost finger tips (distal). In the present case, proximal−distal (PD) reorganization takes place in a regenerating tissue, called a blastema. It has been a mystery how an induced blastema recognizes its position and restores an exact replica of missing parts. Recently, a new experimental system called the accessory limb model (ALM) has been established. The gained ALM phenotypes are demanding to reconsider the reorganization PD positional values. Based on the ALM phenotype, it is reasonable to hypothesize that reorganization of positional values has a certain discontinuity and that two different regeneration systems cooperatively reorganize the PD axis to restore an original structure. In this review, PD axis reestablishments are focused on limb regeneration. Knowledge from ALM studies in axolotls and Xenopus is providing a novel concept of PD axis reorganization in limb regeneration. PMID:27499860

  5. Individual Differences in Premotor Brain Systems Underlie Behavioral Apathy

    PubMed Central

    Bonnelle, Valerie; Manohar, Sanjay; Behrens, Tim; Husain, Masud

    2016-01-01

    Lack of physical engagement, productivity, and initiative—so-called “behavioral apathy”—is a common problem with significant impact, both personal and economic. Here, we investigate whether there might be a biological basis to such lack of motivation using a new effort and reward-based decision-making paradigm, combined with functional and diffusion-weighted imaging. We hypothesized that behavioral apathy in otherwise healthy people might be associated with differences in brain systems underlying either motivation to act (specifically in effort and reward-based decision-making) or in action processing (transformation of an intention into action). The results demonstrate that behavioral apathy is associated with increased effort sensitivity as well as greater recruitment of neural systems involved in action anticipation: supplementary motor area (SMA) and cingulate motor zones. In addition, decreased structural and functional connectivity between anterior cingulate cortex (ACC) and SMA were associated with increased behavioral apathy. These findings reveal that effort sensitivity and translation of intentions into actions might make a critical contribution to behavioral apathy. We propose a mechanism whereby inefficient communication between ACC and SMA might lead to increased physiological cost—and greater effort sensitivity—for action initiation in more apathetic people. PMID:26564255

  6. Pharmacokinetics of tetraplatin administered intraperitoneally with reduced glutathione in mice.

    PubMed

    Kido, Y; Khokhar, A R; Yoshida, M; Thai, G W; Siddik, Z H

    1994-01-01

    Tetraplatin (Ormaplatin) has been developed as a second generation platinum complex because of its good antitumor activity against some cisplatin-resistant tumor cell lines. It is currently in clinical trials. Its reduction to diaminocyclohexane (DACH)-dichloroplatinum(II) [DACH-Pt(II)Cl2] or closely similar species is essential for binding to DNA to produce the desired antitumor effects. We have studied the pharmacokinetics of tetraplatin in mice after intraperitoneal administration with the reducing agent glutathione (GSH). The systemic absorption of tetraplatin (5 mg/kg) with GSH (31 mg/kg) was faster than of tetraplatin alone. Peak plasma platinum (Pt) levels of 0.89 and 1.44 micrograms Pt/ml were observed at 15 min and 2 hr after administration of tetraplatin with and without GSH, respectively, and the Pt then decayed biphasically when administered with GSH and monophasically when administered alone. The plasma Pt level was 4-fold lower (0.17 vs. 0.71 micrograms Pt/ml) by 24 hr when tetraplatin was administered with GSH compared with its administration alone. DACH-Pt(II)Cl2 (4.21 mg/kg, ip) gave similar plasma Pt kinetics to that seen with the combination of tetraplatin and GSH. Pt levels in kidney 24 hr after administration of tetraplatin+GSH or of DACH-Pt(II)Cl2 were lower (1.6-fold) than after tetraplatin alone. Plasma and ascitic fluid from tumor-bearing mice demonstrated equivalent abilities to reduce tetraplatin rapidly. However, tetraplatin treatment of intraperitoneal-inoculated L1210/0 (parent) or L1210/DDP (cisplatin-resistant) tumor cells was unaffected by GSH. As GSH lowered systemic tetraplatin exposure in vivo without compromising antitumor activity against peritoneal tumor models, the combination of thiol and tetraplatin may be clinically useful in the treatment of intraperitoneal disseminated cancers. PMID:8013287

  7. Role of glutathione in cancer progression and chemoresistance.

    PubMed

    Traverso, Nicola; Ricciarelli, Roberta; Nitti, Mariapaola; Marengo, Barbara; Furfaro, Anna Lisa; Pronzato, Maria Adelaide; Marinari, Umberto Maria; Domenicotti, Cinzia

    2013-01-01

    Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and disturbances in GSH homeostasis are involved in the etiology and progression of many human diseases including cancer. While GSH deficiency, or a decrease in the GSH/glutathione disulphide (GSSG) ratio, leads to an increased susceptibility to oxidative stress implicated in the progression of cancer, elevated GSH levels increase the antioxidant capacity and the resistance to oxidative stress as observed in many cancer cells. The present review highlights the role of GSH and related cytoprotective effects in the susceptibility to carcinogenesis and in the sensitivity of tumors to the cytotoxic effects of anticancer agents.

  8. Influence of Zn-contaminated soils in the antioxidative defence system of wheat (Triticum aestivum) and maize (Zea mays) at different exposure times: potential use as biomarkers.

    PubMed

    Alonso-Blázquez, Nieves; García-Gómez, Concepción; Fernández, María Dolores

    2015-03-01

    In this study, we evaluated the antioxidant responses of wheat and maize growing in Zn-treated soils (200, 450 and 900 mg kg(-1)) at different exposure times (7, 14, 21 and 35 days). The Zn concentration in the plants increased with an increase in the Zn concentration in the soil, thereby causing an increase in the accumulation of Mg and Mn. The emergence of wheat and the growth of maize were inhibited by Zn. The chlorophyll levels increased in wheat, whereas the opposite effect was observed in maize. Regarding enzymatic activities, Zn only provoked pronounced increases in the ascorbate peroxidase activity in maize at the early exposure times and occasionally in the superoxide dismutase (14 days) and catalase (7 and 35 days) activities in wheat. The most notable effect of the exposure of plants to Zn was an inhibition of antioxidative activities after 35 days in both plant species. The reduced glutathione levels increased in wheat and maize after 35 days and the protein levels in wheat after 7 and 35 days. The only significant alteration of lipid peroxidation was a decrease in the malondialdehyde level in wheat after 35 days. Results of this work suggest that Zn may generate oxidative stress by interfering with the plant antioxidant defence system (peroxidases, catalases and superoxide dismutase) responsible for free radical detoxification. The enzymatic activities, particularly ascorbate peroxidase, and the content of reduced glutathione could be considered good biomarkers of serious stress by Zn in soils.

  9. Evaluation of Glutathione Peroxidase 4 role in Preeclampsia.

    PubMed

    Peng, Xinguo; Lin, Yan; Li, Jinling; Liu, Mengchun; Wang, Jingli; Li, Xueying; Liu, Jingjing; Jia, Xuewen; Jing, Zhongcui; Huang, Zuzhou; Chu, Kaiqiu; Liu, Shiguo

    2016-01-01

    Preeclampsia (PE) is a pregnancy-specific syndrome that may be lifethreatening to pregnancies and fetus. Glutathione Peroxidase 4 (GPx4) is a powerful antioxidant enzyme that can provide protection from oxidative stress damage which plays a pivotal role in the pathology of PE. Therefore, this study aims to investigate the association between Gpx4 polymorphisms and the susceptibility to PE in Chinese Han women. TaqMan allelic discrimination real-time PCR was used to perform the genotyping of rs713041 and rs4807542 in 1008 PE patients and 1386 normotensive pregnancies. Obviously statistical difference of genotypic and allelic frequencies were found of rs713041 in GPx4 between PE patients and controls and the C allele has the higher risk for pathogenesis of PE (χ(2) = 12.292, P = 0.002 by genotype; χ(2) = 11.035, P = 0.001, OR = 1.216, 95% CI 1.084-1.365 by allele). Additionally, when subdividing these samples into CC + CT and TT groups, we found a significant difference between the two groups (χ(2) = 11.241, P = 0.001, OR = 1.417, 95% CI 1.155-1.738). Furthermore, the genotype of rs713041 was found to be associated with the mild, severe and early-onset PE. Our results suggest that rs713041 in GPx4 may play a key role in the pathogenesis of PE. PMID:27641822

  10. Function of glutathione peroxidases in legume root nodules

    PubMed Central

    Matamoros, Manuel A.; Saiz, Ana; Peñuelas, Maria; Bustos-Sanmamed, Pilar; Mulet, Jose M.; Barja, Maria V.; Rouhier, Nicolas; Moore, Marten; James, Euan K.; Dietz, Karl-Josef; Becana, Manuel

    2015-01-01

    Glutathione peroxidases (Gpxs) are antioxidant enzymes not studied so far in legume nodules, despite the fact that reactive oxygen species are produced at different steps of the symbiosis. The function of two Gpxs that are highly expressed in nodules of the model legume Lotus japonicus was examined. Gene expression analysis, enzymatic and nitrosylation assays, yeast cell complementation, in situ mRNA hybridization, immunoelectron microscopy, and LjGpx-green fluorescent protein (GFP) fusions were used to characterize the enzymes and to localize each transcript and isoform in nodules. The LjGpx1 and LjGpx3 genes encode thioredoxin-dependent phospholipid hydroperoxidases and are differentially regulated in response to nitric oxide (NO) and hormones. LjGpx1 and LjGpx3 are nitrosylated in vitro or in plants treated with S-nitrosoglutathione (GSNO). Consistent with the modification of the peroxidatic cysteine of LjGpx3, in vitro assays demonstrated that this modification results in enzyme inhibition. The enzymes are highly expressed in the infected zone, but the LjGpx3 mRNA is also detected in the cortex and vascular bundles. LjGpx1 is localized to the plastids and nuclei, and LjGpx3 to the cytosol and endoplasmic reticulum. Based on yeast complementation experiments, both enzymes protect against oxidative stress, salt stress, and membrane damage. It is concluded that both LjGpxs perform major antioxidative functions in nodules, preventing lipid peroxidation and other oxidative processes at different subcellular sites of vascular and infected cells. The enzymes are probably involved in hormone and NO signalling, and may be regulated through nitrosylation of the peroxidatic cysteine essential for catalytic function. PMID:25740929

  11. Evaluation of Glutathione Peroxidase 4 role in Preeclampsia

    PubMed Central

    Peng, Xinguo; Lin, Yan; Li, Jinling; Liu, Mengchun; Wang, Jingli; Li, Xueying; Liu, Jingjing; Jia, Xuewen; Jing, Zhongcui; Huang, Zuzhou; Chu, Kaiqiu; Liu, Shiguo

    2016-01-01

    Preeclampsia (PE) is a pregnancy-specific syndrome that may be lifethreatening to pregnancies and fetus. Glutathione Peroxidase 4 (GPx4) is a powerful antioxidant enzyme that can provide protection from oxidative stress damage which plays a pivotal role in the pathology of PE. Therefore, this study aims to investigate the association between Gpx4 polymorphisms and the susceptibility to PE in Chinese Han women. TaqMan allelic discrimination real-time PCR was used to perform the genotyping of rs713041 and rs4807542 in 1008 PE patients and 1386 normotensive pregnancies. Obviously statistical difference of genotypic and allelic frequencies were found of rs713041 in GPx4 between PE patients and controls and the C allele has the higher risk for pathogenesis of PE (χ2 = 12.292, P = 0.002 by genotype; χ2 = 11.035, P = 0.001, OR = 1.216, 95% CI 1.084–1.365 by allele). Additionally, when subdividing these samples into CC + CT and TT groups, we found a significant difference between the two groups (χ2 = 11.241, P = 0.001, OR = 1.417, 95% CI 1.155–1.738). Furthermore, the genotype of rs713041 was found to be associated with the mild, severe and early-onset PE. Our results suggest that rs713041 in GPx4 may play a key role in the pathogenesis of PE. PMID:27641822

  12. Mercury(II) Complex Formation With Glutathione in Alkaline Aqueous Solution

    SciTech Connect

    Mah, V.; Jalilehvand, F.

    2009-05-19

    speciation, as shown by the similarity of the EXAFS spectra obtained at room temperature for two parallel series of Hg(II)-glutathione solutions with C{sub Hg{sup 2+}} {approx} 7 mmol dm{sup -3}, with and without 33% glycerol. Also, the {sup 199}Hg NMR chemical shifts of a series of {approx} 18 mmol dm{sup -3} mercury(II) glutathione solutions with 33% glycerol were not significantly different from those of the corresponding series in aqueous solution.

  13. Drought and salt stress tolerance of an Arabidopsis glutathione S-transferase U17 knockout mutant are attributed to the combined effect of glutathione and abscisic acid.

    PubMed

    Chen, Jui-Hung; Jiang, Han-Wei; Hsieh, En-Jung; Chen, Hsing-Yu; Chien, Ching-Te; Hsieh, Hsu-Liang; Lin, Tsan-Piao

    2012-01-01

    Although glutathione S-transferases (GSTs) are thought to play major roles in oxidative stress metabolism, little is known about the regulatory functions of GSTs. We have reported that Arabidopsis (Arabidopsis thaliana) GLUTATHIONE S-TRANSFERASE U17 (AtGSTU17; At1g10370) participates in light signaling and might modulate various aspects of development by affecting glutathione (GSH) pools via a coordinated regulation with phytochrome A. Here, we provide further evidence to support a negative role of AtGSTU17 in drought and salt stress tolerance. When AtGSTU17 was mutated, plants were more tolerant to drought and salt stresses compared with wild-type plants. In addition, atgstu17 accumulated higher levels of GSH and abscisic acid (ABA) and exhibited hyposensitivity to ABA during seed germination, smaller stomatal apertures, a lower transpiration rate, better development of primary and lateral root systems, and longer vegetative growth. To explore how atgstu17 accumulated higher ABA content, we grew wild-type plants in the solution containing GSH and found that they accumulated ABA to a higher extent than plants grown in the absence of GSH, and they also exhibited the atgstu17 phenotypes. Wild-type plants treated with GSH also demonstrated more tolerance to drought and salt stresses. Furthermore, the effect of GSH on root patterning and drought tolerance was confirmed by growing the atgstu17 in solution containing l-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH biosynthesis. In conclusion, the atgstu17 phenotype can be explained by the combined effect of GSH and ABA. We propose a role of AtGSTU17 in adaptive responses to drought and salt stresses by functioning as a negative component of stress-mediated signal transduction pathways.

  14. Evaluation of surface roughness of three different composite resins with three different polishing systems

    PubMed Central

    Abzal, Mohammed S; Rathakrishnan, Mensudar; Prakash, Venkatachalam; Vivekanandhan, Paramasivam; Subbiya, Arunajatesan; Sukumaran, Vridhachalam Ganapathy

    2016-01-01

    Aim: The aim of this study was to evaluate the surface roughness of three composites with three different polishing systems. Materials and Methods: Composite specimens were made from the Teflon mold with a standardized cavity size (6 mm diameter and 3 mm height). Group I — Filtek Z350XT (Nano clusters), group II — T-Econom plus (Microhybrid), group III — G-aenial Flo (True Nano). The samples were cured for 30 s from both sides with the matrices in place. The 60 samples were divided into 3 groups (N = 20), which accounted for 40 surfaces, (n = 20 × 2 = 40) in each groups. Each group were subdivided into four subgroups based on the type polishing material, subgroup A — Control, subgroup B — Astrobrush, subgroup C — Astropol, and subgroup D — Soflex spiral wheel. The samples of all groups except group A (control) were finished and polished according to the manufacture's instruction. Results: After polishing, the roughness (Ra) of the resin composite of all the specimens were measured using a profilometer. Soflex spiral wheel (group D) significantly had the least roughness (Ra) value as compared to the other groups. Conclusion: Among the three resin composites tested, G-aenial Flo exhibited least Ra value due to its reduced filler size and its uniform distribution. PMID:27099426

  15. Understanding the degradation of ascorbic acid and glutathione in relation to the levels of oxidative stress biomarkers in broccoli (Brassica oleracea L. italica cv. Bellstar) during storage and mechanical processing.

    PubMed

    Raseetha, Siva; Leong, Sze Ying; Burritt, David John; Oey, Indrawati

    2013-06-01

    The purpose of this research was to understand the degradation of ascorbic acid and glutathione content in broccoli florets (Brassica oleracea L. italica cv. Bellstar) during prolonged storage and subsequent mechanical processing. The initial content of total ascorbic acid and glutathione in broccoli florets averaged at 5.18 ± 0.23 and 0.70 ± 0.03 μmol/g fresh weight, respectively. Results showed that the content of ascorbic acid and glutathione in broccoli degraded during storage at 23°C, for at least 4.5-fold after 6 days of storage. On each day of storage, broccoli florets were mechanically processed, but the content of total ascorbic acid and glutathione was not significantly affected. When the mechanically processed broccoli florets were further incubated for up to 6h, the amount of ascorbic acid was greatly reduced as compared to glutathione. To obtain an in-depth understanding on the degradation of ascorbic acid and glutathione, the activity of enzymes involved in plant antioxidative system via ascorbate-glutathione cycle, as a response towards oxidative stress that took place during storage was determined in this study. The content of total ascorbic acid and glutathione in broccoli florets before and after mechanical processing were found to decrease concurrently with the activity of ascorbic acid peroxidase and glutathione reductase over the experimental storage duration. Meanwhile, the effect of oxidative stress on the content of ascorbic acid and glutathione was apparent during the 6h of incubation after mechanical processing. This phenomenon was demonstrated by the level of oxidative stress biomarkers examined, in which the formation of lipid peroxides, protein carbonyls and DNA oxidised products was positively associated with the degradation of total ascorbic acid and glutathione.

  16. The evolution of glutathione metabolism in phototrophic microorganisms

    NASA Technical Reports Server (NTRS)

    Fahey, R. C.; Buschbacher, R. M.; Newton, G. L.

    1987-01-01

    Of the many roles ascribed to glutathione (GSH) the one most clearly established is its role in the protection of higher eucaryotes against oxygen toxicity through destruction of thiol-reactive oxygen byproducts. If this is the primary function of GSH then GSH metabolism should have evolved during or after the evolution of oxygenic photosynthesis. That many bacteria do not produce GSH is consistent with this view. In the present study we have examined the low-molecular-weight thiol composition of a variety of phototrophic microorganisms to ascertain how evolution of GSH production is related to evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols to fluorescent derivatives, which were analyzed by high-pressure liquid chromatography. Significant levels of GSH were not found in the green bacteria (Chlorobium thiosulfatophilum and Chloroflexus aurantiacus). Substantial levels of GSH were present in the purple bacteria (Chromatium vinosum, Rhodospirillum rubrum, Rhodobacter sphaeroides, and Rhodocyclus gelatinosa), the cyanobacteria [Anacystis nidulans, Microcoleus chthonoplastes S.G., Nostoc muscorum, Oscillatoria amphigranulata, Oscillatoria limnetica, Oscillatoria sp. (Stinky Spring, Utah), Oscillatoria terebriformis, Plectonema boryanum, and Synechococcus lividus], and eucaryotic algae (Chlorella pyrenoidsa, Chlorella vulgaris, Euglena gracilis, Scenedesmus obliquus, and Chlamydomonas reinhardtii). Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide; several unidentified thiols were also detected. Many of the organisms examined also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability that was quenched by treatment with 2-pyridyl disulfide or 5,5'-bisdithio-(2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of

  17. The evolution of glutathione metabolism in phototrophic microorganisms.

    PubMed

    Fahey, R C; Buschbacher, R M; Newton, G L

    1987-01-01

    Of the many roles ascribed to glutathione (GSH) the one most clearly established is its role in the protection of higher eucaryotes against oxygen toxicity through destruction of thiol-reactive oxygen byproducts. If this is the primary function of GSH then GSH metabolism should have evolved during or after the evolution of oxygenic photosynthesis. That many bacteria do not produce GSH is consistent with this view. In the present study we have examined the low-molecular-weight thiol composition of a variety of phototrophic microorganisms to ascertain how evolution of GSH production is related to evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols to fluorescent derivatives, which were analyzed by high-pressure liquid chromatography. Significant levels of GSH were not found in the green bacteria (Chlorobium thiosulfatophilum and Chloroflexus aurantiacus). Substantial levels of GSH were present in the purple bacteria (Chromatium vinosum, Rhodospirillum rubrum, Rhodobacter sphaeroides, and Rhodocyclus gelatinosa), the cyanobacteria [Anacystis nidulans, Microcoleus chthonoplastes S.G., Nostoc muscorum, Oscillatoria amphigranulata, Oscillatoria limnetica, Oscillatoria sp. (Stinky Spring, Utah), Oscillatoria terebriformis, Plectonema boryanum, and Synechococcus lividus], and eucaryotic algae (Chlorella pyrenoidsa, Chlorella vulgaris, Euglena gracilis, Scenedesmus obliquus, and Chlamydomonas reinhardtii). Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide; several unidentified thiols were also detected. Many of the organisms examined also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability that was quenched by treatment with 2-pyridyl disulfide or 5,5'-bisdithio-(2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of

  18. Behavioral pattern of Rohilkhandi kids under different feeding systems

    PubMed Central

    Kumari, Anjali; Patel, B. H. M.; Maurya, Vipin; Godara, Asu Singh; Verma, Med Ram; Singh, Mukesh

    2016-01-01

    Aim: The present study designed to evaluate the effect of different feeding systems on the behavior of local Rohilkhandi kids. Materials and Methods: A total of 21 growing goats (local goat of Rohilkhand region), weighing around 7-11 kg and aging 4-5 months, were used. These animals were kept in three groups. Group I was fed un-chopped green fodder in circular feeder (newly designed). Group II was fed un-chopped green fodder in linear feeder that was similar to the existing farm practice. Group III was fed chopped green fodder in linear feeder (modified version). Amount of concentrate and dry fodder fed was kept constant for all the three groups subject to equal increment in accordance with their increasing age. Adlibitum green fodder was made available to the animals. The experiment was conducted for 3 months. On-going behavior was recorded each day 4 h (2 h in the morning from 9:00 am to 11:00 am, after offering the feed, and same was repeated for 2 h in the afternoon, i.e., from 2:00 pm to 4:00 pm) was made between 9 am and 5 pm. The individual behaviors, viz., feeding, drinking, lying down, ruminating, idling, butting, pressing, pushing, frontal clashing, and physical displacement at feed barrier (active and passive: Without physical contact) of the goat were recorded using time-sampling method. Further, incidental activities such as defecation and urination were also recorded. Results: Among all the groups, butting, head to head, and pushing were the common agonistic behavior found but values did not differ significantly. The pushing while feeding was relatively less in Group II (0.22±0.04 min) which differed significantly (p<0.05) from the other two groups. The idling time was found significantly (p<0.05) lower in Group II (1.68±0.21) as compared to Group I (4.67±0.52) and Group III (4.27±0.56). Time spent in rumination near the feeding trough as well as away from the feeding trough was also significantly higher in Group I (p<0.05) than the other two

  19. Investigation of different emulsion systems for dermal delivery of nicotinamide.

    PubMed

    Tuncay, Sakine; Özer, Özgen

    2013-01-01

    Nicotinamide (NA) has been shown to have beneficial effects on several skin diseases such as tumor, acne vulgaris, photodamage, cellulite and atopic dermatitis. The purpose of this study was to develop a multiple emulsion and a microemulsion formulation as delivery systems for NA. A two-step process was used to prepare the W/O/W multiple emulsion. Optimum microemulsion formulation was selected by using construction of pseudo-ternary phase diagram. The physicochemical properties such as droplet size and viscosity measurements, stability studies were also evaluated. Ex-vivo permeation studies were performed with Franz-type diffusion cells and the samples were analysed by high performance liquid chromatography (HPLC). The permeation data showed that there was no significant difference between multiple emulsion and microemulsion (p > 0.05). Transepidermal water loss (TEWL) was also measured. As a result of TEWL studies, a slight increase of TEWL values was observed for microemulsion formulation on rat skin when compared with multiple emulsion and commercial formulation. The results suggested that microemulsion and multiple emulsion formulations could be new and alternative dosage forms for topical application of NA.

  20. Selection of antisense oligodeoxynucleotides against glutathione S-transferase Mu.

    PubMed Central

    't Hoen, Peter A C; Out, Ruud; Commandeur, Jan N M; Vermeulen, Nico P E; van Batenburg, F H D; Manoharan, Muthiah; van Berkel, Theo J C; Biessen, Erik A L; Bijsterbosch, Martin K

    2002-01-01

    The aim of the present study was to identify functional antisense oligodeoxynucleotides (ODNs) against the rat glutathione S-transferase Mu (GSTM) isoforms, GSTM1 and GSTM2. These antisense ODNs would enable the study of the physiological consequences of GSTM deficiency. Because it has been suggested that the effectiveness of antisense ODNs is dependent on the secondary mRNA structures of their target sites, we made mRNA secondary structure predictions with two software packages, Mfold and STAR. The two programs produced only marginally similar structures, which can probably be attributed to differences in the algorithms used. The effectiveness of a set of 18 antisense ODNs was evaluated with a cell-free transcription/translation assay, and their activity was correlated with the predicted secondary RNA structures. Four phosphodiester ODNs specific for GSTM1, two ODNs specific for GSTM2, and four ODNs targeted at both GSTM isoforms were found to be potent, sequence-specific, and RNase H-dependent inhibitors of protein expression. The IC50 value of the most potent ODN was approximately 100 nM. Antisense ODNs targeted against regions that were predicted by STAR to be predominantly single stranded were more potent than antisense ODNs against double-stranded regions. Such a correlation was not found for the Mfold prediction. Our data suggest that simulation of the local folding of RNA facilitates the discovery of potent antisense sequences. In conclusion, we selected several promising antisense sequences, which, when synthesized as biologically stable oligonucleotides, can be applied for study of the physiological impact of reduced GSTM expression. PMID:12515389

  1. Glutathione and cellular redox control in epigenetic regulation.

    PubMed

    García-Giménez, José Luis; Ibañez-Cabellos, José Santiago; Seco-Cervera, Marta; Pallardó, Federico V

    2014-10-01

    Epigenetics is defined as the mitotically/meiotically heritable changes in gene expression that are not due to changes in the primary DNA sequence. Over recent years, growing evidence has suggested a link between redox metabolism and the control of epigenetic mechanisms. The effect of the redox control, oxidative stress, and glutathione (GSH) on the epigenetic mechanisms occur at different levels affecting DNA methylation, miRNAs expression, and histone post-translational modifications (PTMs). Furthermore, a number of redox PTMs are being described, so enriching the histone code. Pioneer works showed how oxidized GSH inhibits the activity of S-adenosyl methionine synthetase, MAT1A, a key enzyme involved in the synthesis of S-adenosyl methionine (SAM), which is used by DNA methyltransferases (DNMTs) and histone methyltransferases (HMTs). Alteration in NAD /NADH ratio affects the activity of class III histone deacetylases (HDACs) and poly-ADP ribosyltransferases (PARPs). Furthermore, the iron redox state of the catalytic center of key enzymes influences the activity of HDACs and the activity of Tet methylcytosine dioxygenases (DNA demetylases) and JmjC histone demethylases. In this communication, we will show the intricate mechanisms that participate in the redox control of the epigenetic mechanisms. We specially focus our work in the characterization of new PTMs in histones, such as histone carbonylation and glutathionylation. Demonstrating how GSH influences the epigenetic mechanisms beyond a mere regulation of SAM levels. The mechanisms described in this communication place GSH and redox control in the landscape of the epigenetic regulation. The results shown underscore the relevant role that oxidative stress and GSH play as key factors in epigenetics, opening a new window for understating the underlying mechanisms that control cell differentiation, proliferation, development, and disease. PMID:26461333

  2. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  3. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  4. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  5. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  6. 21 CFR 864.7375 - Glutathione reductase assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Glutathione reductase assay. 864.7375 Section 864.7375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7375...

  7. Rational design of an organometallic glutathione transferase inhibitor

    SciTech Connect

    Ang, W.H.; Parker, L.J.; De Luca, A.; Juillerat-Jeanneret, L.; Morton, C.J.; LoBello, M.; Parker, M.W.; Dyson, P.J.

    2010-08-17

    A hybrid organic-inorganic (organometallic) inhibitor was designed to target glutathione transferases. The metal center is used to direct protein binding, while the organic moiety acts as the active-site inhibitor. The mechanism of inhibition was studied using a range of biophysical and biochemical methods.

  8. REACTION OF BENZENE OXIDE WITH THIOLS INCLUDING GLUTATHIONE

    EPA Science Inventory

    This study accounts for the observations that the metabolism of benzene is dominated by the formation of phenol. As demonstrated here, the pathway leading to S-phenylmercapturic acid is necessarily minor on account of the low efficiency of benzene oxide capture by glutathione at ...

  9. Electrochemical evaluation of glutathione S-transferase kinetic parameters.

    PubMed

    Enache, Teodor Adrian; Oliveira-Brett, Ana Maria

    2015-02-01

    Glutathione S-transferases (GSTs), are a family of enzymes belonging to the phase II metabolism that catalyse the formation of thioether conjugates between the endogenous tripeptide glutathione and xenobiotic compounds. The voltammetric behaviour of glutathione (GSH), 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione S-transferase (GST), as well as the catalytic conjugation reaction of GSH to CDNB by GST was investigated at room temperature, T=298.15K (25°C), at pH6.5, for low concentration of substrates and enzyme, using differential pulse (DP) voltammetry at a glassy carbon electrode. Only GSH can be oxidized; a sensitivity of 0.14nA/μM and a LOD of 6.4μM were obtained. The GST kinetic parameter electrochemical evaluation, in relation to its substrates, GSH and CDNB, using reciprocal Michaelis-Menten and Lineweaver-Burk double reciprocal plots, was determined. A value of KM~100μM was obtained for either GSH or CDNB, and Vmax varied between 40 and 60μmol/min per mg of GST.

  10. Glutathione plays an essential role in nitric oxide-mediated iron-deficiency signaling and iron-deficiency tolerance in Arabidopsis.

    PubMed

    Shanmugam, Varanavasiappan; Wang, Yi-Wen; Tsednee, Munkhtsetseg; Karunakaran, Krithika; Yeh, Kuo-Chen

    2015-11-01

    Iron (Fe) deficiency is a common agricultural problem that affects both the productivity and nutritional quality of plants. Thus, identifying the key factors involved in the tolerance of Fe deficiency is important. In the present study, the zir1 mutant, which is glutathione deficient, was found to be more sensitive to Fe deficiency than the wild type, and grew poorly in alkaline soil. Other glutathione-deficient mutants also showed various degrees of sensitivity to Fe-limited conditions. Interestingly, we found that the glutathione level was increased under Fe deficiency in the wild type. By contrast, blocking glutathione biosynthesis led to increased physiological sensitivity to Fe deficiency. On the other hand, overexpressing glutathione enhanced the tolerance to Fe deficiency. Under Fe-limited conditions, glutathione-deficient mutants, zir1, pad2 and cad2 accumulated lower levels of Fe than the wild type. The key genes involved in Fe uptake, including IRT1, FRO2 and FIT, are expressed at low levels in zir1; however, a split-root experiment suggested that the systemic signals that govern the expression of Fe uptake-related genes are still active in zir1. Furthermore, we found that zir1 had a lower accumulation of nitric oxide (NO) and NO reservoir S-nitrosoglutathione (GSNO). Although NO is a signaling molecule involved in the induction of Fe uptake-related genes during Fe deficiency, the NO-mediated induction of Fe-uptake genes is dependent on glutathione supply in the zir1 mutant. These results provide direct evidence that glutathione plays an essential role in Fe-deficiency tolerance and NO-mediated Fe-deficiency signaling in Arabidopsis.

  11. Poly(vinylpyrrolidone) supported copper nanoclusters: glutathione enhanced blue photoluminescence for application in phosphor converted light emitting devices

    NASA Astrophysics Data System (ADS)

    Wang, Zhenguang; Susha, Andrei S.; Chen, Bingkun; Reckmeier, Claas; Tomanec, Ondrej; Zboril, Radek; Zhong, Haizheng; Rogach, Andrey L.

    2016-03-01

    Poly(vinylpyrrolidone) supported Cu nanoclusters were synthesized by reduction of Cu(ii) ions with ascorbic acid in water, and initially showed blue photoluminescence with a quantum yield of 8%. An enhancement of the emission quantum yield has been achieved by treatment of Cu clusters with different electron-rich ligands, with the most pronounced effect (photoluminescence quantum yield of 27%) achieved with glutathione. The bright blue emission of glutathione treated Cu NCs is fully preserved in the solid state powder, which has been combined with commercial green and red phosphors to fabricate down-conversion white light emitting diodes with a high colour rendering index of 92.Poly(vinylpyrrolidone) supported Cu nanoclusters were synthesized by reduction of Cu(ii) ions with ascorbic acid in water, and initially showed blue photoluminescence with a quantum yield of 8%. An enhancement of the emission quantum yield has been achieved by treatment of Cu clusters with different electron-rich ligands, with the most pronounced effect (photoluminescence quantum yield of 27%) achieved with glutathione. The bright blue emission of glutathione treated Cu NCs is fully preserved in the solid state powder, which has been combined with commercial green and red phosphors to fabricate down-conversion white light emitting diodes with a high colour rendering index of 92. Electronic supplementary information (ESI) available: The optical spectra of control experiments for Cu NC synthesis, optimization of the reaction conditions, and spectra for LEDs chips and blue LEDs. See DOI: 10.1039/c6nr00806b

  12. Hepatic ischemia-reperfusion syndrome after partial liver resection (LR): hepatic venous oxygen saturation, enzyme pattern, reduced and oxidized glutathione, procalcitonin and interleukin-6.

    PubMed

    Kretzschmar, Michael; Krüger, Antie; Schirrmeister, Wulf

    2003-06-01

    The hepatic ischemia-reperfusion syndrome was investigated in 28 patients undergoing elective partial liver resection with intraoperative occlusion of hepatic inflow (Pringle maneuver) using the technique of liver vein catheterization. Hepatic venous oxygen saturation (ShvO2) was monitored continuously up to 24 hours after surgery. Aspartate aminotransferase, glutamate dehydrogenase, gamma-glutamyl transpeptidase, pseudocholinesterase, alpha-glutathione S-transferase, reduced and oxidized glutathione, procalcitonine, and interleukin-6 were serially measured both before and after Pringle maneuver during the resection and postoperatively in arterial and/or hepatic venous blood. ShvO2 measurement demonstrated that peri- and postoperative management was suitable to maintain an optimal hepatic oxygen supply. As expected, we were able to demonstrate a typical enzyme pattern of postischemic liver injury. There was a distinct decrease of reduced glutathione levels both in arterial and hepatic venous plasma after LR accompanied by a strong increase in oxidized glutathione concentration during the phase of reperfusion. We observed increases in procalcitonin and interleukin-6 levels both in arterial and hepatic venous blood after declamping. Our data support the view that liver resection in man under conditions of inflow occlusion resulted in ischemic lesion of the liver (loss of glutathione synthesizing capacity with disturbance of protection against oxidative stress) and an additional impairment during reperfusion (liberation of reactive oxygen species, local and systemic inflammation reaction with cytokine production). Additionally, we found some evidence for the assumption that the liver has an export function for reduced glutathione into plasma in man. PMID:12877355

  13. Association of mercury and selenium with altered glutathione metabolism and oxidative stress in diving ducks from the San Francisco Bay region, USA

    SciTech Connect

    Hoffman, D.J.; Pendleton, G.W.; Ohlendorf, H.M.; Marn, C.M.

    1998-02-01

    Adult male greater scaup (Aythya marila), surf scoters (Melanitta perspicillata), and ruddy ducks (Oxyura jamaicensis) were collected from Suisun Bay and coastal Tomales Bay in the greater San Francisco Bay area to assess exposure to inorganic contaminants. Hepatic Se concentrations were highest in greater scaup and surf scoters in Suisun Bay, whereas hepatic Hg was highest in greater scaup and surf scoters from Tomales Bay. Hepatic Se and Hg were lower in ruddy ducks and did not differ between locations. Hepatic supernatants were assayed for enzymes related to glutathione metabolism and antioxidant activity, including glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase (GSH peroxidase), glutathione reductase (GSSG reductase), and glutathione-S-transferase (GSH transferase). Glutathione peroxidase activity was higher in surf scoters and ruddy ducks, and G-6-PDH was higher in greater scaup and surf scoters from Suisun Bay than Tomales Bay. Glutathione reductase (GSSG) was higher in SS from Suisun Bay. The ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH) was greater in all species from Tomales Bay. The following significant relationships were found in one or more species with increasing hepatic Hg concentration; lower body, liver, and heart weights; decreased hepatic GSH concentration and G-6-PDH and GSH peroxidase activities; increased ratio of GSSG to GSH; and increased GSSG reductase activity. With increasing hepatic Se concentration, GSH peroxidase increased, but GSH decreased. It is concluded that measurement of associated enzymes in conjunction with thiol status may be a useful bioindicator to discriminate between Hg and Se effects. Concentrations of Hg and Se and the above variables affected have been associated with adverse effects on reproduction and neurological function in experimental studies with mallards.

  14. Effect of High-Dose Cysteine Supplementation on Erythrocyte Glutathione: a Double-Blinded, Randomized Placebo Controlled Pilot Study in Critically Ill Neonates

    PubMed Central

    Calkins, Kara L.; Sanchez, Lauren A.; Tseng, Chi-Hong; Faull, Kym F.; Yoon, Alexander J.; Ryan, Christopher M.; Le, Thuc; Shew, Stephen B.

    2015-01-01

    Background This study’s objective was to determine if parenteral cysteine when compared to isonitrogenous non-cysteine supplementation increases erythrocyte reduced glutathione (GSH) in neonates at high risk for inflammatory injury. Material and Methods Neonates with a score for neonatal acute physiology (SNAP) > 10 requiring mechanical ventilation and parenteral nutrition (PN) were randomized in a double-blinded, placebo controlled study to receive parenteral cysteine-HCl (CYS group) or additional PN amino acids (ISO group) at 121 mg/kg/day for ≥ seven days. A six-hour [13C2] glycine IV infusion was administered at study week one to determine fractional synthetic rate of glutathione (FSR-GSH). Results Baseline characteristics were similar between the CYS (n=17) and ISO groups (n=21). Erythrocyte GSH and total glutathione concentrations, GSH:oxidized glutathione (GSSG), and FSR-GSH after treatment were not different between groups. However, the CYS group had a larger individual positive change in GSH and total glutathione (infusion day – baseline) compared to the ISO group (p=0.02 for each). After adjusting for treatment, a lower enrollment weight and red blood cell (RBC) transfusion were associated with a decreased change in total glutathione and GSH (p< 0.05 for each). Conclusion When compared to isonitrogenous non-cysteine supplementation, high dose cysteine supplementation for at least one week in critically ill neonates resulted in a larger and more positive individual change in glutathione. Smaller infants and those who received transfused blood demonstrated less effective change in glutathione with cysteine supplementation. The benefit of cysteine remains promising and deserves further investigation. PMID:25139979

  15. A Systems Biology Approach Utilizing a Mouse Diversity Panel Identifies Genetic Differences Influencing Isoniazid-Induced Microvesicular Steatosis

    PubMed Central

    Sumner, Susan J.; Pathmasiri, Wimal; Kurtz, Catherine L.; Pletcher, Mathew T.; Eaddy, John S.; Pandher, Karamjeet; Singer, Monica; Batheja, Ameesha; Watkins, Paul B.; Harrill, Alison H.

    2014-01-01

    Isoniazid (INH), the mainstay therapeutic for tuberculosis infection, has been associated with rare but serious hepatotoxicity in the clinic. However, the mechanisms underlying inter-individual variability in the response to this drug have remained elusive. A genetically diverse mouse population model in combination with a systems biology approach was utilized to identify transcriptional changes, INH-responsive metabolites, and gene variants that contribute to the liver response in genetically sensitive individuals. Sensitive mouse strains developed severe microvesicular steatosis compared with corresponding vehicle control mice following 3 days of oral treatment with INH. Genes involved in mitochondrial dysfunction were enriched among liver transcripts altered with INH treatment. Those associated with INH treatment and susceptibility to INH-induced steatosis in the liver included apolipoprotein A-IV, lysosomal-associated membrane protein 1, and choline phosphotransferase 1. These alterations were accompanied by metabolomic changes including reduced levels of glutathione and the choline metabolites betaine and phosphocholine, suggesting that oxidative stress and reduced lipid export may additionally contribute to INH-induced steatosis. Finally, genome-wide association mapping revealed that polymorphisms in perilipin 2 were linked to increased triglyceride levels following INH treatment, implicating a role for inter-individual differences in lipid packaging in the susceptibility to INH-induced steatosis. Taken together, our data suggest that INH-induced steatosis is caused by not one, but multiple events involving lipid retention in the livers of genetically sensitive individuals. This work also highlights the value of using a mouse diversity panel to investigate drug-induced responses across a diverse population. PMID:24848797

  16. A systems biology approach utilizing a mouse diversity panel identifies genetic differences influencing isoniazid-induced microvesicular steatosis.

    PubMed

    Church, Rachel J; Wu, Hong; Mosedale, Merrie; Sumner, Susan J; Pathmasiri, Wimal; Kurtz, Catherine L; Pletcher, Mathew T; Eaddy, John S; Pandher, Karamjeet; Singer, Monica; Batheja, Ameesha; Watkins, Paul B; Adkins, Karissa; Harrill, Alison H

    2014-08-01

    Isoniazid (INH), the mainstay therapeutic for tuberculosis infection, has been associated with rare but serious hepatotoxicity in the clinic. However, the mechanisms underlying inter-individual variability in the response to this drug have remained elusive. A genetically diverse mouse population model in combination with a systems biology approach was utilized to identify transcriptional changes, INH-responsive metabolites, and gene variants that contribute to the liver response in genetically sensitive individuals. Sensitive mouse strains developed severe microvesicular steatosis compared with corresponding vehicle control mice following 3 days of oral treatment with INH. Genes involved in mitochondrial dysfunction were enriched among liver transcripts altered with INH treatment. Those associated with INH treatment and susceptibility to INH-induced steatosis in the liver included apolipoprotein A-IV, lysosomal-associated membrane protein 1, and choline phosphotransferase 1. These alterations were accompanied by metabolomic changes including reduced levels of glutathione and the choline metabolites betaine and phosphocholine, suggesting that oxidative stress and reduced lipid export may additionally contribute to INH-induced steatosis. Finally, genome-wide association mapping revealed that polymorphisms in perilipin 2 were linked to increased triglyceride levels following INH treatment, implicating a role for inter-individual differences in lipid packaging in the susceptibility to INH-induced steatosis. Taken together, our data suggest that INH-induced steatosis is caused by not one, but multiple events involving lipid retention in the livers of genetically sensitive individuals. This work also highlights the value of using a mouse diversity panel to investigate drug-induced responses across a diverse population.

  17. Purification and kinetic analysis of cytosolic and mitochondrial thioredoxin glutathione reductase extracted from Taenia solium cysticerci.

    PubMed

    Plancarte, Agustin; Nava, Gabriela

    2015-02-01

    Thioredoxin glutathione reductases (TGRs) (EC 1.8.1.9) were purified to homogeneity from the cytosolic (cTsTGR) and mitochondrial (mTsTGR) fractions of Taenia solium, the agent responsible for neurocysticercosis, one of the major central nervous system parasitic diseases in humans. TsTGRs had a relative molecular weight of 132,000, while the corresponding value per subunit obtained under denaturing conditions, was of 62,000. Specific activities for thioredoxin reductase and glutathione reductase substrates for both TGRs explored were in the range or lower than values obtained for other platyhelminths and mammalian TGRs. cTsTGR and mTsTGR also showed hydroperoxide reductase activity using hydroperoxide as substrate. Km(DTNB) and Kcat(DTNB) values for cTsTGR and mTsTGR (88 µM and 1.9 s(-1); 45 µM and 12.6 s(-1), respectively) and Km(GSSG) and Kcat(GSSG) values for cTsTGR and mTsTGR (6.3 µM and 0.96 s(-1); 4 µM and 1.62 s(-1), respectively) were similar to or lower than those reported for mammalian TGRs. Mass spectrometry analysis showed that 12 peptides from cTsTGR and seven from mTsTGR were a match for gi|29825896 thioredoxin glutathione reductase [Echinococcus granulosus], confirming that both enzymes are TGRs. Both T. solium TGRs were inhibited by the gold compound auranofin, a selective inhibitor of thiol-dependent flavoreductases (I₅₀ = 3.25, 2.29 nM for DTNB and GSSG substrates, respectively for cTsTGR; I₅₀ = 5.6, 25.4 nM for mTsTGR toward the same substrates in the described order). Glutathione reductase activity of cTsTGR and mTsTGR exhibited hysteretic behavior with moderate to high concentrations of GSSG; this result was not observed either with thioredoxin, DTNB or NADPH. However, the observed hysteretic kinetics was suppressed with increasing amounts of both parasitic TGRs. These data suggest the existence of an effective substitute which may account for the lack of the detoxification enzymes glutathione reductase

  18. The role of mitochondrial phospholipid hydroperoxide glutathione peroxidase in cancer therapy

    NASA Astrophysics Data System (ADS)

    Wang, Hong

    Phospholipid hydroperoxide glutathione peroxidase (PhGPx) is a unique selenoenzyme that directly detoxifies lipid hydroperoxides in situ . It therefore plays an important role in the protection of cellular membranes. PhGPx is expressed in most mammalian tissues. It is present as a mitochondrial form (L-PhGPx) and a cytosolic form (S-PhGPx). Overexpression of PhGPx has been shown to significantly protect cells from oxidative damage. The hypothesis of this thesis is that mitochondrial PhGPx (L-PhGPx) may play an important role in the resistance of cells to certain oxidative stress- mediated cancer therapies. A human breast carcinoma MCF-7 cell line was used as a cell model system in this research. It was stably transfected with human L-PhGPx sense cDNA. Four clones (P-1, P-2, P-3, and P-4) with 3- to 7-fold increases in PhGPx activity were selected for study. Overexpression of L-PhGPx did not significantly influence other cellular antioxidants, including superoxide dismutases, cytosolic glutathione peroxidase, catalase, glutathione reductase, and glutathione. However, L-PhGPx did decrease the rate of cell growth. Cell plating efficiency was inversely correlated with effective PhGPx activity, which is defined as the product of cellular PhGPx activity and total glutathione. The biological functions of L-PhGPx have been investigated in cancer treatment, including photodynamic therapy (PDT) and hyperthermia (HT). Both PDT and HT can induce oxidative stress. Overexpression of L-PhGPx in MCF-7 cells significantly increased the resistance of cells to PDT- and HT-mediated cytotoxicity. The effective PhGPx activity had a remarkable inverse linear correlation (r = -0.80) to the rate of removal of lipid hydroperoxides in living cells, and correlated positively with cell survival after photooxidation (r = 0.91). L-PhGPx protected mitochondrial function by preserving the mitochondrial membrane potential. These data demonstrate that L-PhGPx provides significant protection against

  19. The Use of Screen-Printed Electrodes in a Proof of Concept Electrochemical Estimation of Homocysteine and Glutathione in the Presence of Cysteine Using Catechol

    PubMed Central

    Lee, Patricia T.; Lowinsohn, Denise; Compton, Richard G.

    2014-01-01

    Screen printed electrodes were employed in a proof of concept determination of homocysteine and glutathione using electrochemically oxidized catechol via a 1,4-Michael addition reaction in the absence and presence of cysteine, and each other. Using cyclic voltammetry, the Michael reaction introduces a new adduct peak which is analytically useful in detecting thiols. The proposed procedure relies on the different rates of reaction of glutathione and homocysteine with oxidized catechol so that at fast voltage scan rates only homocysteine is detected in cyclic voltammetry. At slower scan rates, both glutathione and homocysteine are detected. The combination of the two sets of data provides quantification for homocysteine and glutathione. The presence of cysteine is shown not to interfere provided sufficient high concentrations of catechol are used. Calibration curves were determined for each homocysteine and glutathione detection; where the sensitivities are 0.019 μA·μM−1 and 0.0019 μA·μM−1 and limit of detections are ca. 1.2 μM and 0.11 μM for homocysteine and glutathione, respectively, within the linear range. This work presents results with potential and beneficial use in re-useable and/or disposable point-of-use sensors for biological and medical applications. PMID:24926695

  20. Functional consequences of structural differences in stingray sensory systems. Part II: electrosensory system.

    PubMed

    Jordan, Laura K; Kajiura, Stephen M; Gordon, Malcolm S

    2009-10-01

    Elasmobranch fishes (sharks, skates and rays) possess highly sensitive electrosensory systems, which enable them to detect weak electric fields such as those produced by potential prey organisms. Different species have unique electrosensory pore numbers, densities and distributions. Functional differences in detection capabilities resulting from these structural differences are largely unknown. Stingrays and other batoid fishes have eyes positioned on the opposite side of the body from the mouth. Furthermore, they often feed on buried prey, which can be located non-visually using the electrosensory system. In the present study we test functional predictions based on structural differences in three stingray species (Urobatis halleri, Pteroplatytrygon violacea and Myliobatis californica) with differing electrosensory system morphology. We compare detection capabilities based upon behavioral responses to dipole electric signals (5.3-9.6 microA). Species with greater ventral pore numbers and densities were predicted to demonstrate enhanced electrosensory capabilities. Electric field intensities at orientation were similar among these species, although they differed in response type and orientation pathway. Minimum voltage gradients eliciting feeding responses were well below 1 nVcm(-1) for all species regardless of pore number and density. PMID:19749096

  1. Cerebral mechanisms for different second language writing systems.

    PubMed

    Koyama, Maki S; Stein, John F; Stoodley, Catherine J; Hansen, Peter C

    2013-09-01

    In this fMRI study, we examined the cerebral processing associated with second language (L2) reading in different writing systems in late L2 learners. To examine the impacts of cross-linguistic differences between the first language (L1) and L2 on learning to read in L2, we employed a bidirectional approach and compared brain activation during single word processing in two groups of late L2 readers: (1) L2 readers of English whose L1 was Japanese (Japanese-L1/English-L2) and (2) L2 readers of Japanese (of syllabic Kana only) whose L1 was English (English-L1/Japanese-L2). During English reading, the L2 readers of English (Japanese-L1/English-L2) exhibited stronger activation in the left superior parietal lobule/supramarginal gyrus, relative to the L1 readers of English (English-L1/Japanese-L2). This is a region considered to be involved in phonological processing. The increased activation in the Japanese-L1/English-L2 group likely reflects the increased cognitive load associated with L2 English reading, possibly because L1 readers of Kana, which has an extremely regular orthography, may need to adjust to the greater phonological demands of the irregular L2 English orthography. In contrast, during Kana reading, the L2 readers of Japanese Kana (English-L1/Japanese-L2) exhibited stronger activation in the lingual gyrus in both the left and right hemispheres compared to the L1 readers of Kana (Japaese-L1/English-L2). This additional activation is likely to reflect the lower level of visual familiarity to the L2 symbols in the English-L1/Japanese-L2 group; Kana symbols are uniquely used only in Japan, whereas Roman alphabetic symbols are seen nearly everywhere. These findings, bolstered by significant relationships between the activation of the identified regions and cognitive competence, suggest that the cerebral mechanisms for L2 reading in late learners depends both on which language is their L1 and which language is to be learnt as their L2. Educational implications

  2. Effect of human glutathione S-transferases on glutathione-dependent inactivation of cytochrome P450-dependent reactive intermediates of diclofenac.

    PubMed

    Dragovic, Sanja; Boerma, Jan Simon; Vermeulen, Nico P E; Commandeur, Jan N M

    2013-11-18

    Idiosyncratic adverse drug reactions due to the anti-inflammatory drug diclofenac have been proposed to be caused by the generation of reactive acyl glucuronides and oxidative metabolites. For the oxidative metabolism of diclofenac by cytochromes P450 at least five different reactive intermediates have been proposed previously based on structural identification of their corresponding GSH-conjugates. In the present study, the ability of four human glutathione S-transferases (hGSTs) to catalyze the GSH-conjugation of the different reactive intermediates formed by P450s was investigated. Addition of pooled human liver cytosol and recombinant hGSTA1-1, hGSTM1-1, and hGSTP1-1 to incubations of diclofenac with human liver microsomes or purified CYP102A1M11 L437N as a model system significantly increased total GSH-conjugation. The strongest increase of total GSH-conjugation was observed by adding hGSTP1-1, whereas hGSTM1-1 and hGSTA1-1 showed lower activity. Addition of hGSTT1-1 only showed a minor effect. When considering the effects of hGSTs on GSH-conjugation of the different quinoneimines of diclofenac, it was found that hGSTP1-1 showed the highest activity in GSH-conjugation of the quinoneimine derived from 5-hydroxydiclofenac (5-OH-DF). hGSTM1-1 showed the highest activity in inactivation of the quinoneimine derived from 4'-hydroxydiclofenac (4'-OH-DF). Separate incubations with 5-OH-DF and 4'-OH-DF as substrates confirmed these results. hGSTs also catalyzed GSH-conjugation of the o-iminemethide formed by oxidative decarboxylation of diclofenac as well as the substitution of one of the chlorine atoms of DF by GSH. hGSTP1-1 showed the highest activity for the formation of these minor GSH-conjugates. These results suggest that hGSTs may play an important role in the inactivation of DF quinoneimines and its minor reactive intermediates especially in stress conditions when tissue levels of GSH are decreased.

  3. Evaluation of atrazine degradation applied to different energy systems.

    PubMed

    Moreira, Ailton J; Pinheiro, Bianca S; Araújo, André F; Freschi, Gian P G

    2016-09-01

    Atrazine is an herbicide widely used in crops and has drawn attention due to potential pollution present in soil, sediment, water, and food. Since conventional methods are not potentially efficient to persistent degradation of organic compounds, new technology has been developed to remove them, especially practices utilizing advanced oxidation processes (AOPs). This work aims to evaluate the use of different energies (ultraviolet (UV), microwaves (MW), and radiations (MW-UV)) to the herbicide atrazine through the process of photo-oxidation. These systems found degradation rates of around 12 % (UV), 28 % (MW), and 83 % (MW-UV), respectively, with time intervals of 120 s. After the photolytic processes, the samples were analyzed at a wavelength scanning the range of 190 to 300 nm, where the spectral analysis of the signal was used to evaluate the degradation of atrazine and the appearance of some other peaks (degradation products). The spectrum evaluation resulting from photolytic processes gave rise to a new signal which was confirmed by chromatography. This spectrum indicated the possible pathway of atrazine degradation by the process of photolytic MW-UV, generating atrazine-2-hydroxy, atrazine-desethyl-2-hidroxy, and atrazine-desisopropyl-2-hydroxy. The process indicated that in all situations, chloride was present in the analytic structure and was substituted by a hydroxyl group, which lowered the toxicity of the compound through the photolytic process MW-UV. Chromatographic analysis ascertained these preliminary assessments using spectrophotometry. It was also significantly observed that the process can be optimized by adjusting the pH of the solution, which was evident by an improvement of 10 % in the rate of degradation when subjected to a pH solution equal to 8.37. PMID:27289373

  4. Photoelastic analysis of stress distribution with different implant systems.

    PubMed

    Pellizzer, Eduardo Piza; Carli, Rafael Imai; Falcón-Antenucci, Rosse Mary; Verri, Fellippo Ramos; Goiato, Marcelo Coelho; Villa, Luiz Marcelo Ribeiro

    2014-04-01

    The aim of this study was to evaluate stress distribution with different implant systems through photoelasticity. Five models were fabricated with photoelastic resin PL-2. Each model was composed of a block of photoelastic resin (10 × 40 × 45 mm) with an implant and a healing abutment: model 1, internal hexagon implant (4.0 × 10 mm; Conect AR, Conexão, São Paulo, Brazil); model 2, Morse taper/internal octagon implant (4.1 × 10 mm; Standard, Straumann ITI, Andover, Mass); model 3, Morse taper implant (4.0 × 10 mm; AR Morse, Conexão); model 4, locking taper implant (4.0 × 11 mm; Bicon, Boston, Mass); model 5, external hexagon implant (4.0 × 10 mm; Master Screw, Conexão). Axial and oblique load (45°) of 150 N were applied by a universal testing machine (EMIC-DL 3000), and a circular polariscope was used to visualize the stress. The results were photographed and analyzed qualitatively using Adobe Photoshop software. For the axial load, the greatest stress concentration was exhibited in the cervical and apical thirds. However, the highest number of isochromatic fringes was observed in the implant apex and in the cervical adjacent to the load direction in all models for the oblique load. Model 2 (Morse taper, internal octagon, Straumann ITI) presented the lowest stress concentration, while model 5 (external hexagon, Master Screw, Conexão) exhibited the greatest stress. It was concluded that Morse taper implants presented a more favorable stress distribution among the test groups. The external hexagon implant showed the highest stress concentration. Oblique load generated the highest stress in all models analyzed.

  5. Chronomodulated delivery system: a tailored cap to fit different heads.

    PubMed

    Agarwal, Vaibhav; Bansal, Mayank

    2012-08-01

    "Blind race ends in a pit". A similar scenario is observed with the use of conventional dosage forms for different pathological conditions. Of late various disease states had regularly been reported to bear direct concurrence to the body's secretions that bear a constant rotationary cycle. Moreover the pharmacokinetic as well as pharmacodynamic responsiveness of various drugs had been reported to bear constant swings with the changing hours of the day. Thus, usage of the conventional zero order dosage form for every disease state or every active moiety developed, will only leave the researchers as well as the consumers in doldrums. Chronomodulated dosage forms are a silver lining in these overshadowed clouds. They are the dosage forms that spearhead the innovative researches because of their pre-programmed and pre-regulated pulsed release of the drug, at desired sites. Drug release pattern from these dosage forms considerably mimics the circadian timing of the body's secretion which are held responsible for the symptoms of the pathological irregularities arising in one's body. Thus, in a way these dosage forms are a shield against the inducers of the disease symptoms. Current review enlists the pathological states for which the chronomodulated delivery systems can prove to be a miraculous cure. This review emphasizes to summarize the patents granted as well as the novel researches undertaken by various researchers to upgrade the previously existing dosage form scenario. Moreover, this work is an attempt to summarize the various proprietary techniques and marketed formulations, thus trying to help the researchers to fabricate a better and novel dosage form from previously existing ones.

  6. Performance evaluation of radiant cooling system integrated with air system under different operational strategies

    SciTech Connect

    Khan, Yasin; Khare, Vaibhav Rai; Mathur, Jyotirmay; Bhandari, Mahabir

    2015-03-26

    The paper describes a parametric study developed to estimate the energy savings potential of a radiant cooling system installed in a commercial building in India. The study is based on numerical modeling of a radiant cooling system installed in an Information Technology (IT) office building sited in the composite climate of Hyderabad. To evaluate thermal performance and energy consumption, simulations were carried out using the ANSYS FLUENT and EnergyPlus softwares, respectively. The building model was calibrated using the measured data for the installed radiant system. Then this calibrated model was used to simulate the energy consumption of a building using a conventional all-air system to determine the proportional energy savings. For proper handling of the latent load, a dedicated outside air system (DOAS) was used as an alternative to Fan Coil Unit (FCU). A comparison of energy consumption calculated that the radiant system was 17.5 % more efficient than a conventional all-air system and that a 30% savings was achieved by using a DOAS system compared with a conventional system. Computational Fluid Dynamics (CFD) simulation was performed to evaluate indoor air quality and thermal comfort. It was found that a radiant system offers more uniform temperatures, as well as a better mean air temperature range, than a conventional system. To further enhance the energy savings in the radiant system, different operational strategies were analyzed based on thermal analysis using EnergyPlus. Lastly, the energy savings achieved in this parametric run were more than 10% compared with a conventional all-air system.

  7. Performance evaluation of radiant cooling system integrated with air system under different operational strategies

    DOE PAGESBeta

    Khan, Yasin; Khare, Vaibhav Rai; Mathur, Jyotirmay; Bhandari, Mahabir

    2015-03-26

    The paper describes a parametric study developed to estimate the energy savings potential of a radiant cooling system installed in a commercial building in India. The study is based on numerical modeling of a radiant cooling system installed in an Information Technology (IT) office building sited in the composite climate of Hyderabad. To evaluate thermal performance and energy consumption, simulations were carried out using the ANSYS FLUENT and EnergyPlus softwares, respectively. The building model was calibrated using the measured data for the installed radiant system. Then this calibrated model was used to simulate the energy consumption of a building usingmore » a conventional all-air system to determine the proportional energy savings. For proper handling of the latent load, a dedicated outside air system (DOAS) was used as an alternative to Fan Coil Unit (FCU). A comparison of energy consumption calculated that the radiant system was 17.5 % more efficient than a conventional all-air system and that a 30% savings was achieved by using a DOAS system compared with a conventional system. Computational Fluid Dynamics (CFD) simulation was performed to evaluate indoor air quality and thermal comfort. It was found that a radiant system offers more uniform temperatures, as well as a better mean air temperature range, than a conventional system. To further enhance the energy savings in the radiant system, different operational strategies were analyzed based on thermal analysis using EnergyPlus. Lastly, the energy savings achieved in this parametric run were more than 10% compared with a conventional all-air system.« less

  8. [Optimization of a spectrophotometry assay of total and oxidized blood glutathione: comparison with a fluorimetric method].

    PubMed

    Coutelle, C; Iron, A; Higueret, D; Cassaigne, A

    1992-01-01

    We developed a method for the enzymatic assay of glutathione which is easy to practice, rapid, specific, based on the reaction of the thiol group of glutathione with dithiobis-nitrobenzoic acid after the action of glutathione reductase in the presence of NADPH. This spectrophotometric technique allowed, on the one hand, the determination of total glutathione and on the other hand, that of oxidized glutathione (disulfide), after the blockage of reduced glutathione by 2-vinyl-pyridine. The improvements of the assay of blood glutathione concerned the sample preparation, the reaction sensitivity, thanks to a better definition of the optimal pH and a reduction ot the blockage time by 2-vinyl-pyridine in well defined operating conditions. We compared the performances of our technique with a fluorimetric method. We used our method for the determination of total and oxidized blood glutathione in a control population.

  9. CHARACTERIZATION OF DANSYLATED CYSTEINE, CYSTINE, GLUTATHIONE, AND GLUTATHIONE DISULFIDE BY NARROW BORE LIQUID CHROMATOGRAPHY - ELECTROSPRAY IONIZATION MASS SPECTROMETRY

    EPA Science Inventory

    A method using reversed phase high performance liquid chromtography/electrospray ionization-mass spectrometry (RP-LC/ESI-MS) has been developed to confirm the dientity of dansylated derivatives of cysteine (C) and glutathione (GSH), and their respective dimers, cystine (CSSC) and...

  10. Activities of Antioxidant Scavenger Enzymes (Superoxide Dismutase and Glutathione Peroxidase) in Erythrocytes in Adult Women With and Without Type II Diabetes

    PubMed Central

    Coleman, Raymond; Berner, Yitshal N.

    2004-01-01

    It is widely believed that oxidative stress plays an important role in the pathogenesis of type II diabetes. The present study was undertaken to examine the functioning of two antioxidant scavenger enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), in erythrocytes in a population of healthy aging adult women compared with a similar population with type II diabetes. Blood samples were examined from 42 female adult healthy subjects at different ages and from 59 female patients with type II diabetes. A significant increase in SOD activities was correlated with aging in erythrocytes of the healthy control subjects (r = .550, P = .001); however, this correlation was not found in subjects with type II diabetes (r = .250, P < .07). A trend showing a reduction in glutathione peroxidase activities was demonstrated with aging (r = −.331, P = .228); however, this trend was not found in diabetic subjects (r = .031, P < .820). The results indicate a possible imbalance in the antioxidant system in erythrocytes of aging adult women, which is even more pronounced in cases of type II diabetes. This study may indicate possible therapeutic treatment or preventive measures to limit oxidative damage and reduce complications of diabetes. PMID:15203888

  11. Evaluation of aflatoxin B/sub 1/ mutagenesis: addition of glutathione and glutathione-S-transferase to the Salmonella mutagenicity assay

    SciTech Connect

    Jorgensen, K.V.; Clayton, J.W.; Price, R.L.

    1987-01-01

    The effects of glutathione (GSH) and the combination of GSH and glutathione-S-transferase (GST) on aflatoxin B/sub 1/ (AFB/sub 1/) mutagenesis in the Salmonella mutagenicity assay using Salmonella typhimurium strains TA98 and TA100 were tested. Ten concentrations of AFB/sub 1/ (0-1.0 ..mu..g/plate) were added to a liver microsomal homogenate (S9 mix) or to S9 mix containing GSH or S9 mix containing the combination of GSH + GST. One third of the samples were plated directly. Two-thirds were incubated for 30 min at 37/sup 0/C prior to plating, and of those, half included bacteria. The results show that the addition of GSH and GSH + GST affected AFB/sub 1/ mutagenesis by forming the AFB/sub 1/-GSH conjugate and decreasing the availability of AFB/sub 1/-8,9-epoxide. The effect of GST on GSH activity varied with the strain because of the different amounts of S9 mix used. The formation of the AFB/sub 1/-GSH conjugate was verified by using reverse-phase high-performance liquid chromatography for quantitation of AFB/sub 1/ and detection of AFB/sub 1/-GSH.

  12. Glutathione- and pH-responsive nonporous silica prodrug nanoparticles for controlled release and cancer therapy

    NASA Astrophysics Data System (ADS)

    Xu, Zhigang; Liu, Shiying; Kang, Yuejun; Wang, Mingfeng

    2015-03-01

    A myriad of drug delivery systems such as liposomes, micelles, polymers and inorganic nanoparticles (NPs) have been developed for cancer therapy. Very few of them, however, have the ability to integrate multiple functionalities such as specific delivery, high circulation stability, controllable release and good biocompatibility and biodegradability in a single system to improve the therapeutic efficacy. Herein, we report two types of stimuli-responsive nonporous silica prodrug NPs towards this goal for controlled release of anticancer drugs and efficient combinatorial cancer therapy. As a proof of concept, anticancer drugs camptothecin (CPT) and doxorubicin (DOX) were covalently encapsulated into silica matrices through glutathione (GSH)-responsive disulfide and pH-responsive hydrazone bonds, respectively, resulting in NPs with sizes tunable in the range of 50-200 nm. Both silica prodrug NPs showed stimuli-responsive controlled release upon exposure to a GSH-rich or acidic environment, resulting in improved anticancer efficacy. Notably, two prodrug NPs simultaneously taken up by HeLa cells showed a remarkable combinatorial efficacy compared to free drug pairs. These results suggest that the stimuli-responsive silica prodrug NPs are promising anticancer drug carriers for efficient cancer therapy.A myriad of drug delivery systems such as liposomes, micelles, polymers and inorganic nanoparticles (NPs) have been developed for cancer therapy. Very few of them, however, have the ability to integrate multiple functionalities such as specific delivery, high circulation stability, controllable release and good biocompatibility and biodegradability in a single system to improve the therapeutic efficacy. Herein, we report two types of stimuli-responsive nonporous silica prodrug NPs towards this goal for controlled release of anticancer drugs and efficient combinatorial cancer therapy. As a proof of concept, anticancer drugs camptothecin (CPT) and doxorubicin (DOX) were

  13. Algorithmic requirements for swarm intelligence in differently coupled collective systems.

    PubMed

    Stradner, Jürgen; Thenius, Ronald; Zahadat, Payam; Hamann, Heiko; Crailsheim, Karl; Schmickl, Thomas

    2013-05-01

    Swarm systems are based on intermediate connectivity between individuals and dynamic neighborhoods. In natural swarms self-organizing principles bring their agents to that favorable level of connectivity. They serve as interesting sources of inspiration for control algorithms in swarm robotics on the one hand, and in modular robotics on the other hand. In this paper we demonstrate and compare a set of bio-inspired algorithms that are used to control the collective behavior of swarms and modular systems: BEECLUST, AHHS (hormone controllers), FGRN (fractal genetic regulatory networks), and VE (virtual embryogenesis). We demonstrate how such bio-inspired control paradigms bring their host systems to a level of intermediate connectivity, what delivers sufficient robustness to these systems for collective decentralized control. In parallel, these algorithms allow sufficient volatility of shared information within these systems to help preventing local optima and deadlock situations, this way keeping those systems flexible and adaptive in dynamic non-deterministic environments. PMID:23805030

  14. Comparative study between two different active flutter suppression systems

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1978-01-01

    An activated leading-edge (LE)-tailing-edge (TE) control system is applied to a drone aircraft with the objective of enabling the drone to fly subsonically at dynamic pressures which are 44% above the open-loop flutter dynamic pressure. The control synthesis approach is based on the aerodynamic energy concept and it incorporates recent developments in this area. A comparison is made between the performance of the activated LE-TE control system and the performance of a TE control system, analyzed in a previous work. The results obtained indicate that although all the control systems achieve the flutter suppression objectives, the TE control system appears to be somewhat superior to the LE-TE control system, in this specific application. This superiority is manifested through reduced values of control surface activity over a wide range of flight conditions.

  15. Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings

    PubMed Central

    Sytykiewicz, Hubert

    2016-01-01

    Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans’ attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants. PMID:26907270

  16. Jamming and chaotic dynamics in different granular systems

    NASA Astrophysics Data System (ADS)

    Maghsoodi, Homayoon; Luijten, Erik

    Although common in nature and industry, the jamming transition has long eluded a concrete, mechanistic explanation. Recently, Banigan et al. (Nat. Phys. 9, 288-292, 2013) proposed a method for characterizing this transition in a granular system in terms of the system's chaotic properties, as quantified by the largest Lyapunov exponent. They demonstrated that in a two-dimensional shear cell the jamming transition coincides with the bulk density at which the system's largest Lyapunov exponent changes sign, indicating a transition between chaotic and non-chaotic regimes. To examine the applicability of this observation to realistic granular systems, we study a model that includes frictional forces within an expanded phase space. Furthermore, we test the generality of the relation between chaos and jamming by investigating the relationship between jamming and the chaotic properties of several other granular systems, notably sheared systems (Howell, D., Behringer R. P., Veje C., Phys. Rev. Lett. 82, 5241-5244, 1999) and systems with a free boundary. Finally, we quantify correlations between the largest Lyapunov vector and collective rearrangements of the system to demonstrate the predictive capabilities enabled by adopting this perspective of jamming.

  17. The Stress Response Systems: Universality and Adaptive Individual Differences

    ERIC Educational Resources Information Center

    Ellis, Bruce J.; Jackson, Jenee James; Boyce, W. Thomas

    2006-01-01

    Biological reactivity to psychological stressors comprises a complex, integrated system of central neural and peripheral neuroendocrine responses designed to prepare the organism for challenge or threat. Developmental experience plays a role, along with heritable variation, in calibrating the response dynamics of this system. This calibration…

  18. Erythrocyte glutathione peroxidase in subjects of Mediterranean origin. A family study.

    PubMed

    Gerli, G C; Mongiat, R; Gualandri, V; Orsini, G B; Porta, E

    1984-01-01

    Erythrocyte glutathione peroxidase (GSH-Px) was assayed in subjects of Mediterranean origin and the distribution of the data obtained seems to confirm the existence of two alleles coding for low and high enzyme activity. In order to define the limits of expected genotypes less arbitrarily we studied families where parents' genotypes could allow us to define that of the children. Gene frequencies were calculated from genotype frequencies of an unrelated population and from crossings distribution by the Hardy-Weinberg equation. We observed a good agreement between gene frequencies obtained by these two different methods. PMID:6469259

  19. Apd1(+), a Gene Required for Red Pigment Formation in Ade6 Mutants of Schizosaccharomyces Pombe, Encodes an Enzyme Required for Glutathione Biosynthesis: A Role for Glutathione and a Glutathione-Conjugate Pump

    PubMed Central

    Chaudhuri, B.; Ingavale, S.; Bachhawat, A. K.

    1997-01-01

    Mutants in the adenine biosynthetic pathway of yeasts (ade1 and ade2 of Saccharomyces cerevisiae, ade6 and ade7 of Schizosaccharomyces pombe) accumulate an intense red pigment in their vacuoles when grown under adenine-limiting conditions. The precise events that determine the formation of the pigment are however, still unknown. We have begun a genetic investigation into the nature and cause of pigmentation of ade6 mutants of S. pombe and have discovered that one of these pigmentation defective mutants, apd1 (adenine pigmentation defective), is a strict glutathione auxotroph. The gene apd1(+) was found to encode the first enzyme in glutathione biosynthesis, γ-glutamylcysteine synthetase, gcs1(+). This gene when expressed in the mutant could confer both glutathione prototrophy and the characteristic red pigmentation, and disruption of the gene led to a loss in both phenotypes. Supplementation of glutathione in the medium, however, could only restore growth but not the pigmentation because the cells were unable to achieve sufficient intracellular levels of glutathione. Disruption of the second enzyme in glutathione biosynthesis, glutathione synthetase, gsh2(+), also led to glutathione auxotrophy, but only a partial defect in pigment formation. A reevaluation of the major amino acids previously reported to be present in the pigment indicated that the pigment is probably a glutathione conjugate. The ability of vanadate to inhibit pigment formation indicated that the conjugate was transported into the vacuole through a glutathione-conjugate pump. This was further confirmed using strains of S. cerevisiae bearing disruptions in the recently identified glutathione-conjugate pump, YCF1, where a significant reduction in pigment formation was observed. The pump of S. pombe is distinct from the previously identified vacuolar pump, hmt1p, for transporting cadystin peptides into vacuoles of S. pombe. PMID:9017391

  20. Regulative roles of glutathione reductase and four glutaredoxins in glutathione redox, antioxidant activity, and iron homeostasis of Beauveria bassiana.

    PubMed

    Zhang, Long-Bin; Tang, Li; Ying, Sheng-Hua; Feng, Ming-Guang

    2016-07-01

    Multiple glutaredoxins (Grx) and glutathione reductase (Glr) are vital for the thiol-disulfide redox system in budding yeast but generally unexplored in filamentous fungi. Here we characterized the Beauveria bassiana redox system comprising dithiol Grx1, monothiol Grx2-4, Grx-like Grx5, and Glr orthologue. Each grx or glr deletion was compensated by increased transcripts of some other grx genes in normal cultures. Particularly, grx3 compensated the absence of grx1, grx2, grx5, or glr under oxidative stress while its absence was compensated only by undeletable grx4 under normal conditions but by most of other undeleted grx and glr genes in response to menadione. Consequently, the redox state was disturbed in Δglr more than in Δgrx3 but not in Δgrx1/2/5. Superoxide dismutases were more active in normal Δgrx1-3 cultures but less in Δgrx5 or Δglr response to menadione. Total catalase activity increased differentially in all the mutant cultures stressed with or without H2O2 while total peroxidase activity decreased more in the normal or H2O2-stressed culture of Δglr than of Δgrx3. Among the mutants, Δgrx3 showed slightly increased sensitivity to menadione or H2O2; Δglr exhibited greater sensitivity to thiol-oxidizing diamide than thiol-reducing 1-chloro-2,4-dinitrobenzene as well as increased sensitivity to the two oxidants. Intriguingly, all the mutants grew slower in a Fe(3+)-inclusive medium perhaps due to elevated transcripts of two Fe(3+) transporter genes. More or fewer phenotypes linked with biocontrol potential were altered in four deletion mutants excluding Δgrx5. All the changes were restored by targeted gene complementation. Overall, Grx3 played more critical role than other Grx homologues in the Glr-dependent redox system of the fungal entomopathogen. PMID:26969041

  1. A biophysically based mathematical model for the catalytic mechanism of glutathione reductase.

    PubMed

    Pannala, Venkat R; Bazil, Jason N; Camara, Amadou K S; Dash, Ranjan K

    2013-12-01

    Glutathione reductase (GR) catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) using NADPH as the reducing cofactor, and thereby maintains a constant GSH level in the system. GSH scavenges superoxide (O2(*-)) and hydroxyl radicals (OH) nonenzymatically or by serving as an electron donor to several enzymes involved in reactive oxygen species (ROS) detoxification. In either case, GSH oxidizes to GSSG and is subsequently regenerated by the catalytic action of GR. Although the GR kinetic mechanism has been extensively studied under various experimental conditions with variable substrates and products, the catalytic mechanism has not been studied in terms of a mechanistic model that accounts for the effects of the substrates and products on the reaction kinetics. The aim of this study is therefore to develop a comprehensive mathematical model for the catalytic mechanism of GR. We use available experimental data on GR kinetics from various species/sources to develop the mathematical model and estimate the associated model parameters. The model simulations are consistent with the experimental observation that GR operates via both ping-pong and sequential branching mechanisms based on relevant concentrations of its reaction substrate GSSG. Furthermore, we show the observed pH-dependent substrate inhibition of GR activity by GSSG and bimodal behavior of GR activity with pH. The model presents a unique opportunity to understand the effects of products on the kinetics of GR. The model simulations show that under physiological conditions, where both substrates and products are present, the flux distribution depends on the concentrations of both GSSG and NADP(+), with ping-pong flux operating at low levels and sequential flux dominating at higher levels. The kinetic model of GR may serve as a key module for the development of integrated models for ROS-scavenging systems to understand protection of cells under normal and oxidative stress

  2. The gut microbiota modulates host amino acid and glutathione metabolism in mice.

    PubMed

    Mardinoglu, Adil; Shoaie, Saeed; Bergentall, Mattias; Ghaffari, Pouyan; Zhang, Cheng; Larsson, Erik; Bäckhed, Fredrik; Nielsen, Jens

    2015-10-16

    The gut microbiota has been proposed as an environmental factor that promotes the progression of metabolic diseases. Here, we investigated how the gut microbiota modulates the global metabolic differences in duodenum, jejunum, ileum, colon, liver, and two white adipose tissue depots obtained from conventionally raised (CONV-R) and germ-free (GF) mice using gene expression data and tissue-specific genome-scale metabolic models (GEMs). We created a generic mouse metabolic reaction (MMR) GEM, reconstructed 28 tissue-specific GEMs based on proteomics data, and manually curated GEMs for small intestine, colon, liver, and adipose tissues. We used these functional models to determine the global metabolic differences between CONV-R and GF mice. Based on gene expression data, we found that the gut microbiota affects the host amino acid (AA) metabolism, which leads to modifications in glutathione metabolism. To validate our predictions, we measured the level of AAs and N-acetylated AAs in the hepatic portal vein of CONV-R and GF mice. Finally, we simulated the metabolic differences between the small intestine of the CONV-R and GF mice accounting for the content of the diet and relative gene expression differences. Our analyses revealed that the gut microbiota influences host amino acid and glutathione metabolism in mice.

  3. The gut microbiota modulates host amino acid and glutathione metabolism in mice

    PubMed Central

    Mardinoglu, Adil; Shoaie, Saeed; Bergentall, Mattias; Ghaffari, Pouyan; Zhang, Cheng; Larsson, Erik; Bäckhed, Fredrik; Nielsen, Jens

    2015-01-01

    The gut microbiota has been proposed as an environmental factor that promotes the progression of metabolic diseases. Here, we investigated how the gut microbiota modulates the global metabolic differences in duodenum, jejunum, ileum, colon, liver, and two white adipose tissue depots obtained from conventionally raised (CONV-R) and germ-free (GF) mice using gene expression data and tissue-specific genome-scale metabolic models (GEMs). We created a generic mouse metabolic reaction (MMR) GEM, reconstructed 28 tissue-specific GEMs based on proteomics data, and manually curated GEMs for small intestine, colon, liver, and adipose tissues. We used these functional models to determine the global metabolic differences between CONV-R and GF mice. Based on gene expression data, we found that the gut microbiota affects the host amino acid (AA) metabolism, which leads to modifications in glutathione metabolism. To validate our predictions, we measured the level of AAs and N-acetylated AAs in the hepatic portal vein of CONV-R and GF mice. Finally, we simulated the metabolic differences between the small intestine of the CONV-R and GF mice accounting for the content of the diet and relative gene expression differences. Our analyses revealed that the gut microbiota influences host amino acid and glutathione metabolism in mice. PMID:26475342

  4. Brain-specific delivery of naproxen using different carrier systems.

    PubMed

    Mahmoud, Sheha; Mohammad, Alhawi

    2010-11-01

    Naproxen is one of the most potent NSAIDs and plays an important role in the treatment of neurodegenerative diseases. Poor brain delivery of naproxen at therapeutic doses, in addition to its serious gastrointestinal side effects, has prompted research into the development of a specific carrier system that is capable of delivering naproxen to the brain at smaller doses. The purpose of this study was to evaluate two brain-specific carrier systems of naproxen. The first was the dihydropyridine/pyridinium redox system that utilized a lipophilic chemical delivery system coupled to the carboxylic acid group of naproxen through an ethanolamine linker. Secondly, an ascorbic acid system, which has reducing properties and acts as a biological carrier through sodium-dependent vitamin-C transporter, was used for brain-specific delivery of naproxen. The prepared prodrugs were stable in aqueous buffers (pH 1.2 and 7.4) and rapidly hydrolyzed in biological fluids. Bioavailability studies revealed that both prodrugs 10 and 17 were rapidly cleared from blood with half lives of about 1 h, which will likely decrease systemic adverse effects. The rapid clearance from the blood was accompanied by an increase in the prodrug concentration in the brain, which occurred as a result of the prodrug being more locked in compared to the parent drug naproxen.

  5. Pleiotropic Functions of Glutathione S-Transferase P

    PubMed Central

    Zhang, Jie; Grek, Christina; Ye, Zhi-Wei; Manevich, Yefim; Tew, Kenneth D.; Townsend, Danyelle M.

    2016-01-01

    Glutathione S-transferase P (GSTP) is one member of the GST superfamily that is prevalently expressed in mammals. Known to possess catalytic activity through deprotonating glutathione allowing formation of thioether bonds with electrophilic substrates, more recent discoveries have broadened our understanding of the biological roles of this protein. In addition to catalytic detoxification, other properties so far ascribed to GSTP include chaperone functions, regulation of nitric oxide pathways, regulation of a variety of kinase signaling pathways, and participation in the forward reaction of protein S-glutathionylation. The expression of GSTP has been linked with cancer and other human pathologies and more recently even with drug addiction. With respect to human health, polymorphic variants of GSTP may determine individual susceptibility to oxidative stress and/or be critical in the design and development of drugs that have used redox pathways as a discovery platform. PMID:24974181

  6. Role of Glutathione in Cancer Progression and Chemoresistance

    PubMed Central

    Traverso, Nicola; Ricciarelli, Roberta; Nitti, Mariapaola; Marengo, Barbara; Furfaro, Anna Lisa; Pronzato, Maria Adelaide; Marinari, Umberto Maria; Domenicotti, Cinzia

    2013-01-01

    Glutathione (GSH) plays an important role in a multitude of cellular processes, including cell differentiation, proliferation, and apoptosis, and disturbances in GSH homeostasis are involved in the etiology and progression of many human diseases including cancer. While GSH deficiency, or a decrease in the GSH/glutathione disulphide (GSSG) ratio, leads to an increased susceptibility to oxidative stress implicated in the progression of cancer, elevated GSH levels increase the antioxidant capacity and the resistance to oxidative stress as observed in many cancer cells. The present review highlights the role of GSH and related cytoprotective effects in the susceptibility to carcinogenesis and in the sensitivity of tumors to the cytotoxic effects of anticancer agents. PMID:23766865

  7. Pleiotropic functions of glutathione S-transferase P.

    PubMed

    Zhang, Jie; Grek, Christina; Ye, Zhi-Wei; Manevich, Yefim; Tew, Kenneth D; Townsend, Danyelle M

    2014-01-01

    Glutathione S-transferase P (GSTP) is one member of the GST superfamily that is prevalently expressed in mammals. Known to possess catalytic activity through deprotonating glutathione allowing formation of thioether bonds with electrophilic substrates, more recent discoveries have broadened our understanding of the biological roles of this protein. In addition to catalytic detoxification, other properties so far ascribed to GSTP include chaperone functions, regulation of nitric oxide pathways, regulation of a variety of kinase signaling pathways, and participation in the forward reaction of protein S-glutathionylation. The expression of GSTP has been linked with cancer and other human pathologies and more recently even with drug addiction. With respect to human health, polymorphic variants of GSTP may determine individual susceptibility to oxidative stress and/or be critical in the design and development of drugs that have used redox pathways as a discovery platform.

  8. The mechanism of biliary secretion of reduced glutathione. Analysis of transport process in isolated rat-liver canalicular membrane vesicles.

    PubMed

    Inoue, M; Kinne, R; Tran, T; Arias, I M

    1983-08-15

    Transport of reduced glutathione (GSH) was studied in isolated rat liver canalicular membrane vesicles by a rapid filtration technique. The membrane vesicles exhibit uptake of [2-3H]glycine--labeled GSH into an osmotically reactive intravesicular space. Although the canalicular membrane vesicles possess gamma-glutamyltransferase and aminopeptidase M, enzymes that hydrolyze glutathione into component amino acids, inactivation of the vesicle-associated transferase by affinity labeling with L-(alpha S,5S)-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (AT-125) had no effect on the initial rate of GSH transport. Chemical analysis revealed that intact GSH accounted for most of vesicle-associated radioactivity. The initial rate of transport followed saturation kinetics with respect to GSH concentration; an apparent Km of 0.33 mM and V of 1.47 nmol/mg protein in 20 s were calculated. These results indicate that transport of GSH across the canalicular membranes is a carrier-mediated process. Replacement of NaCl in the transport medium by KCl, LiCl or choline chloride had no effect on the transport activity of the vesicles. The rate of GSH uptake by the vesicles was enhanced by valinomycin-induced K+-diffusion potential (vesicle inside-positive) and was inhibited by probenecid, indicating that GSH transport across the canalicular membranes is electrogenic and involves the transfer of negative charge. The transport of GSH was inhibited by oxidized glutathione or S-benzyl-glutathione. This transport system in canalicular plasma membranes may function in biliary secretion of GSH and its derivatives which are synthesized in hepatocytes by oxidative processes or glutathione S-transferase.

  9. Reversal of an aluminium induced alteration in redox status in different regions of rat brain by administration of centrophenoxine.

    PubMed

    Nehru, Bimla; Bhalla, Punita

    2006-10-01

    Aluminium is one of the most studied neurotoxin, and its effects on nervous system are both structural and functional, involving various regions of brain. Aluminium toxicity is known to have multiple mechanisms of action in the central nervous system. Affinity of aluminium for thiol substrates is considered a possible molecular mechanism involved in aluminium neurotoxicity. The reduced glutathione (GSH) is especially important for cellular defence against aluminium toxicity. This study pertains to the modulatory action of centrophenoxine on GSH status in aluminium exposed different brain regions of the female rats. Aluminium was administered orally at a dose of 40 mg/Kg x b x wt x /day for a period of eight weeks whereas, centrophenoxine was administered intraperitoneally at a dose of 100 mg/Kg x b x wt x /day for a period of six weeks. The study was carried out in different regions of brain namely cerebrum, cerebellum, medulla oblongata and hypothalamus. Animals exposed to aluminum, registered a significant decrease in the levels of reduced glutathione, and oxidized glutathione as well as in the activity of glutathione reductase in all the different regions studied when compared to normal control animals. Post-treatment with centrophenoxine, showed a significant improvement in the thiol levels in different regions. Centrophenoxine when administered alone also had a profound effect on the levels of reduced glutathione as well as on the activity of glutathione reductase. From the present results, it can be stated that centrophenoxine administration, as a thiol-antioxidant, arrests the aluminium induced cellular damage by improving the thiol status in brain regions.

  10. Glutathione and plant response to the biotic environment.

    PubMed

    Frendo, Pierre; Baldacci-Cresp, Fabien; Benyamina, Sofiane M; Puppo, Alain

    2013-12-01

    Glutathione (GSH) is a major antioxidant molecule in plants. It is involved in regulating plant development and responses to the abiotic and biotic environment. In recent years, numerous reports have clarified the molecular processes involving GSH in plant-microbe interactions. In this review, we summarize recent studies, highlighting the roles of GSH in interactions between plants and microbes, whether pathogenic or beneficial to plants.

  11. Proton mobilities in crambin and glutathione S-transferase

    NASA Astrophysics Data System (ADS)

    Wanderlingh, U. N.; Corsaro, C.; Hayward, R. L.; Bée, M.; Middendorf, H. D.

    2003-08-01

    Using a neutron backscattering spectrometer, the temperature dependence of mean-square atomic displacements derived from window-integrated quasielastic spectra was measured for two D 2O-hydrated proteins: crambin and glutathione S-transferase. Analyses show that the anharmonic dynamics observed around and above 200 K is consistent with a description in terms of proton/deuteron jumps within asymmetric double-minimum potentials. Also determined were activation energies along with estimates of effective masses and average oscillator energies.

  12. Negative effect of combined cysteine and glutathione in soy lecithin-based extender on post-thawed ram spermatozoa.

    PubMed

    Zhandi, Mahdi; Sharafi, Mohsen

    2015-09-01

    This study was conducted to evaluate the effect of combined cysteine and glutathione in soy lecithin-based semen extender on post-thawed ram sperm quality. A total of 28 ejaculates were collected twice a week (from four rams) during breeding season. In each replicate, semen samples (n = 4, one ejaculate for each ram) were pooled and divided into three equal parts, and each part was diluted with one of following extender: (1) soy lecithin-based extender containing no cysteine and no glutathione (C0-G0), (2) soy lecithin-based extender containing cysteine (5 mM) and glutathione (5 mM) (C5-G5), and (3) soy lecithin-based extender containing cysteine (10 mM) and glutathione (10 mM) (C10-G10). After freeze-thawing process, motility and velocity parameters, plasma membrane integrity and functionality, mitochondrial activity, and apoptosis features of spermatozoa were evaluated. The obtained results showed that total and progressive motility, plasma membrane integrity and functionality, and live post-thawed spermatozoa was lower in C10-G10 extender compared to C0-G0 and C5-G5 extenders (P < 0.05). Also, the percentage of dead spermatozoa was higher in C10-G10 extender compared to C0-G0 extender (P < 0.05). Apoptotic spermatozoa was lower in C10-G10 extender compared to C0-G0 and C5-G5 extenders (P < 0.05). All velocity parameters, exception of BCF, did not different between extenders (P > 0.05). In conclusion, it seems that high concentration of combined cysteine and glutathione in soy lecithin-based semen extender has a detrimental effect of post-thawed ram sperm quality.

  13. Do glutathione and related enzymes play a role in drug resistance in small cell lung cancer cell lines?

    PubMed Central

    Campling, B. G.; Baer, K.; Baker, H. M.; Lam, Y. M.; Cole, S. P.

    1993-01-01

    Small cell lung cancer (SCLC) is treated primarily with combination chemotherapy. Despite high initial response rates, most patients eventually die with drug resistant disease. In some tumours, resistance to multiple chemotherapeutic agents is attributed to overexpression of P-glycoprotein (P-gp). However, this does not appear to be a frequent occurrence in drug resistant SCLC. Increased levels of glutathione (GSH) and related enzymes may play a role in resistance to alkylating agents as well as natural product drugs. We measured levels of GSH, glutathione S-transferase (GST), glutathione reductase (GSH Red), glutathione peroxidase (GSH Px), and gamma-glutamyl transpeptidase (gamma-GT) in a panel of 20 SCLC cell lines. Most of these lines were established from patients treated at this centre. Each cell line had a characteristic and reproducible profile of GSH and related enzyme levels. Immunoblot analysis indicated that the predominant GST in the cell lines was the anionic pi isoenzyme. The relative sensitivity of each of these cell lines to 16 different chemotherapeutic agents was measured using a modified MTT assay. Spearman rank correlation analysis was used to determine the relationships between the relative chemosensitivity of these cell lines and the levels of GSH and related enzymes. The number of positive correlations was no greater than expected by chance alone. Furthermore, there was no correlation with the treatment history of the patients from whom the cell lines were derived. These data suggest that alterations in glutathione metabolism do not play a major role in resistance to chemotherapeutic agents in these human SCLC cell lines. Images Figure 1 PMID:8102244

  14. Glutathione peroxidase activity, selenium, and lipid peroxide concentrations in blood from a healthy Polish population : I. Maternal and cord blood.

    PubMed

    Zachara, B A; Wąsowicz, W; Gromadzińska, J; Skłodowska, M; Krasomski, G

    1986-09-01

    Selenium (Se) concentrations in whole blood and plasma of 19 nonpregnant women. 14 mothers at delivery, 14 neonates, and 13 infants, aged 2-12 mo, were evaluated. The activity of glutathione peroxidase (GSH-Px) in erythrocytes and plasma and the level of lipid peroxides in plasma were also analyzed. Selenium concentrations in whole blood and plasma in mothers at delivery were significantly lower compared to nonpregnant women. Selenium concentrations in cord blood components were lower compared to mothers, but the differences were not significant. The concentration of the element decreased in the first few months of life. Glutathione peroxidase activity in erythrocytes differed only slightly in the examined groups. In plasma, however, the enzyme activity was significantly lower in pregnant compared to nonpregnant women and in neonates compared to their mothers. Lipid peroxide concentrations in plasma differed only slightly in the examined groups. The results obtained are discussed in terms of the observations of other investigators. PMID:24254392

  15. Newly identified protein Imi1 affects mitochondrial integrity and glutathione homeostasis in Saccharomyces cerevisiae.

    PubMed

    Kowalec, Piotr; Grynberg, Marcin; Pająk, Beata; Socha, Anna; Winiarska, Katarzyna; Fronk, Jan; Kurlandzka, Anna

    2015-09-01

    Glutathione homeostasis is crucial for cell functioning. We describe a novel Imi1 protein of Saccharomyces cerevisiae affecting mitochondrial integrity and involved in controlling glutathione level. Imi1 is cytoplasmic and, except for its N-terminal Flo11 domain, has a distinct solenoid structure. A lack of Imi1 leads to mitochondrial lesions comprising aberrant morphology of cristae and multifarious mtDNA rearrangements and impaired respiration. The mitochondrial malfunctioning is coupled to significantly decrease the level of intracellular reduced glutathione without affecting oxidized glutathione, which decreases the reduced/oxidized glutathione ratio. These defects are accompanied by decreased cadmium sensitivity and increased phytochelatin-2 level. PMID:26091838

  16. Newly identified protein Imi1 affects mitochondrial integrity and glutathione homeostasis in Saccharomyces cerevisiae.

    PubMed

    Kowalec, Piotr; Grynberg, Marcin; Pająk, Beata; Socha, Anna; Winiarska, Katarzyna; Fronk, Jan; Kurlandzka, Anna

    2015-09-01

    Glutathione homeostasis is crucial for cell functioning. We describe a novel Imi1 protein of Saccharomyces cerevisiae affecting mitochondrial integrity and involved in controlling glutathione level. Imi1 is cytoplasmic and, except for its N-terminal Flo11 domain, has a distinct solenoid structure. A lack of Imi1 leads to mitochondrial lesions comprising aberrant morphology of cristae and multifarious mtDNA rearrangements and impaired respiration. The mitochondrial malfunctioning is coupled to significantly decrease the level of intracellular reduced glutathione without affecting oxidized glutathione, which decreases the reduced/oxidized glutathione ratio. These defects are accompanied by decreased cadmium sensitivity and increased phytochelatin-2 level.

  17. Glutathione depletion exacerbates impairment by oxidative stress of phosphoinositide hydrolysis, AP-1, and NF-kappaB activation by cholinergic stimulation.

    PubMed

    Li, X; Song, L; Jope, R S

    1998-01-01

    Oxidative stress appears to contribute to neuronal dysfunction associated with Alzheimer's disease and other CNS neurodegenerative disorders. This investigation examined if oxidative stress might contribute to impairments in cholinergic receptor-linked signaling systems and if intracellular glutathione levels modulated responses to oxidative stress. To do this the activation of the AP-1 and NF-kappaB transcription factors and of the phosphoinositide second-messenger system was measured in human neuroblastoma SH-SY5Y cells after exposure to the oxidants H2O2 or diamide, with or without prior depletion of cellular glutathione. H2O2 concentration-dependently inhibited carbachol-stimulated AP-1 activation and this inhibition was potentiated in glutathione-depleted cells. Carbachol-stimulated NF-kappaB activation was unaffected by H2O2 unless glutathione was depleted, in which case there was a H2O2 concentration-dependent inhibition. Glutathione depletion also potentiated the inhibition by H2O2 of carbachol- or G-protein (NaF)-stimulated phosphoinositide hydrolysis, whereas phospholipase C activated by the calcium ionophore ionomycin was not inhibited. The thiol-oxidizing agent diamide also inhibited phosphoinositide hydrolysis stimulated by carbachol or NaF, and glutathione depletion potentiated the diamide concentration-dependent inhibition. Unlike H2O2, diamide also inhibited ionomycin-stimulated phosphoinositide hydrolysis. Activation of both AP-1 and NF-kappaB stimulated by carbachol was inhibited by diamide, and glutathione depletion potentiated the inhibitory effects of diamide. Thus, diamide inhibited a wider range of signaling processes than did H2O2, but glutathione depletion increased the susceptibility of phosphoinositide hydrolysis and of transcription factor activation to inhibition by both H2O2 and diamide. These results demonstrate that the vulnerability of signaling systems to oxidative stress is influenced by intracellular glutathione levels

  18. Glutamine: a precursor of glutathione and its effect on liver

    PubMed Central

    Yu, Jian-Chun; Jiang, Zhu-Ming; Li, De-Min

    1999-01-01

    AIM To investigate the relationship between alanyl-glutamine (ALA-GLN) and glutathione (GSH) biosynthesis in hepatic protection. METHODS Twenty male Wistar rats were randomly divided into two groups: one receiving standard parenteral nutrition (STD) and the other supplemented with or without ALA-GLN for 7 days. The blood and liver tissue samples were examined after 5-fluorouracil (5-FU) was injected peritoneally. RESULTS The concentration measurements were significantly highe r in ALA-GLN group than in STD group in serum GLN (687 μmol/ L ± 50 μmol/L vs 505 μmol/L ± 39 μmol/L,P < 0.05), serum GSH (14 μmol/L ± 5 μmol/L vs 7 μmol/L ± 3 μmol/L, P < 0.01) and in liver GSH content (6.9 μmol/g ± 2.5 μmol/g vs 4.4 μmol/ g ± 1.6 μmol/g liver tissue, P < 0.05). Rats in ALA-GLN group had lesser elevations in hepatic enzymes after 5-FU administration. CONCLUSION The supplemented nutrition ALA-GLN can protect the liver function through increasing the glutathione biosynthesis and pre-serving the glutathione stores in hepatic tissue. PMID:11819414

  19. Benzene oxide is a substrate for glutathione S-transferases.

    PubMed

    Zarth, Adam T; Murphy, Sharon E; Hecht, Stephen S

    2015-12-01

    Benzene is a known human carcinogen which must be activated to benzene oxide (BO) to exert its carcinogenic potential. BO can be detoxified in vivo by reaction with glutathione and excretion in the urine as S-phenylmercapturic acid. This process may be catalyzed by glutathione S-transferases (GSTs), but kinetic data for this reaction have not been published. Therefore, we incubated GSTA1, GSTT1, GSTM1, and GSTP1 with glutathione and BO and quantified the formation of S-phenylglutathione. Kinetic parameters were determined for GSTT1 and GSTP1. At 37 °C, the putative Km and Vmax values for GSTT1 were 420 μM and 450 fmol/s, respectively, while those for GSTP1 were 3600 μM and 3100 fmol/s. GSTA1 and GSTM1 did not exhibit sufficient activity for determination of kinetic parameters. We conclude that GSTT1 is a critical enzyme in the detoxification of BO and that GSTP1 may also play an important role, while GSTA1 and GSTM1 seem to be less important.

  20. Systematic analysis of reactivities and fragmentation of glutathione and its isomer GluCysGly.

    PubMed

    Feng, Shan; Zheng, Xiaoyan; Wang, Dong; Gong, Yiyi; Wang, Qingtao; Deng, Haiteng

    2014-09-18

    Glutathione (GSH) is the most abundant tripeptide in human cells and plays an important role in protecting cells' integrity against oxidative stress. GSH has an unusual amide linkage formed between the γ-carboxylic group of the glutamic acid in its side-chain and the amine group of cysteine residue. In the present study, we have compared reactivities of GSH to its isomer GluCysGly (ECG), which has a regular amide bond formed between the α-carboxylic group of glutamic acid and the amine group of cysteine residue. The fragmentation pattern of GSH ions in the gas phase is different from that of ECG ions, showing that the loss of H2O is the major dissociation pathway in ECG fragmentation. This is consistent with the dissociation pathway predicted by density functional calculation. Formation of GSSG from oxidation of GSH is faster than that of ECG disulfide, and the gas phase fragmentation pattern of GSSG is different from that of ECG disulfide. GSH and ECG display similar rates in nucleophilic aromatic substitution when reacting with 1-chloro-2,4-dinitrobenzene (CDNB). However, in the presence of glutathione S-transferases (GST), substitution of CDNB by GSH is 10 times faster than that by ECG. GSH and ECG also show differences in clustering patterns in the gas phase. Taken together, our results shed light on understanding effects of unique boding structure in GSH on its stability and reactivities.

  1. Geographic Information Systems: Empowering Kinds to Make a Difference.

    ERIC Educational Resources Information Center

    Michelsen, Michael W., Jr.

    1996-01-01

    Describes ArcView, a Geographic Information System (GIS) that enables K-12 classrooms to access electronic maps and information databases for specific communities. Presents actual applications of ArcView at an elementary school and a high school. Finds that students are using GIS technology to collect, analyze, and apply local data to real…

  2. Describing Polygonum aviculare emergence in different tillage systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of four tillage systems (direct drill, subsoiler, chisel plough and mouldboard plough) on the dynamics of Polygonum aviculare populations were studied over three growing seasons. Densities before and after herbicide application and cumulative emergence on a weekly basis were determined in ea...

  3. Beyond different levels: embodiment and the developmental system

    PubMed Central

    Marshall, Peter J.

    2014-01-01

    The value of studying a phenomenon at multiple levels of analysis is often emphasized in psychology, but a lack of clarity about the nature of levels and the relations among them remains an impediment to progress. The suggestion here is that an approach combining the tenets of embodiment with the construct of the developmental system provides a way forward. Embodiment opposes the splitting off and elevation of a level of mechanisms that has characterized much of cognitive science. In contrast, a constructivist embodied approach places a level of mechanisms in the context of a formal or systems level of analysis, with developmental process framing the interpenetrating relations between levels. Such an approach stems from a relational worldview that opposes conceptual splits and posits that levels of structure and process comprise an indissociable complementarity. The combination of embodiment and developmental systems within a relational worldview is discussed and elaborated through outlining the integrative approach of relational developmental systems, which has been proposed as a scientific paradigm within which formulations of the interrelations among brain, body, and mind can be advanced. PMID:25191302

  4. Validating the Airspace Concept Evaluation System for Different Weather Days

    NASA Technical Reports Server (NTRS)

    Zelinski, Shannon; Meyn, Larry

    2006-01-01

    This paper extends the process for validating the Airspace Concept Evaluation System using real-world historical flight operational data. System inputs such as flight plans and airport en-route capacities, are generated and processed to create a realistic reproduction of a single day's operations within the National Airspace System. System outputs such as airport throughput, delays, and en-route sector loads are then compared to real world operational metrics and delay statistics for the reproduced day. The process is repeated for 4 historical days with high and low traffic volume and delay attributed to weather. These 4 days are simulated using default en-route capacities and variable en-route capacities used to emulate weather. The validation results show that default enroute capacity simulations are closer to real-world data for low weather days than high weather days. The use of reduced variable enroute capacities adds a large delay bias to ACES but delay trends between weather days are better represented.

  5. Changes in Antioxidant Defense System Using Different Lipid Emulsions in Parenteral Nutrition in Children after Hematopoietic Stem Cell Transplantation

    PubMed Central

    Baena-Gómez, María Auxiliadora; De La Torre Aguilar, María José; Mesa, María Dolores; Pérez Navero, Juan Luis; Gil-Campos, Mercedes

    2015-01-01

    Background: Traditionally, lipids used in parenteral nutrition (PN) are based on ω-6 fatty acid-rich vegetable oils, such as soybean oil, with potential adverse effects involving oxidative stress. Methods: We evaluated the antioxidant defense system in children, after hematopoietic stem cell transplantation (HSCT), who were randomized to use a lipid emulsion with fish oil or soybean oil. Blood samples at baseline, at 10 days, and at the end of the PN were taken to analyze plasma retinol, α-tocopherol, β-carotene, coenzyme Q9 and coenzyme Q10 levels, and catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPOX), and superoxide dismutase (SOD) levels in lysed erythrocytes. Results: An increase in plasma α-tocopherol levels in the group of patients receiving the fish oil-containing emulsion (FO) compared with the group receiving the soybean emulsion was observed at day 10 of PN. Concurrently, plasma α-tocopherol increased in the FO group and β-carotene decreased in both groups at day 10 compared with baseline levels, being more significant in the group receiving the FO emulsion. Conclusion: FO-containing emulsions in PN could improve the antioxidant profile by increasing levels of α-tocopherol in children after HSCT who are at higher risk of suffering oxidative stress and metabolic disorders. PMID:26343717

  6. Effect of glutathione on phytochelatin synthesis in tomato cells. [Lycopersicon esculentum

    SciTech Connect

    Mendum, M.L.; Gupta, S.C.; Goldsbrough, P.B. )

    1990-06-01

    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 ({gamma}-Glu-Cys){sub 2}-Gly. In the presence of buthionine sulfoximine and glutathione, phytochelatins that are produced upon exposure to cadmium incorporate little ({sup 35}S)cysteine, indicating that these peptides are probably not synthesized by sequential addition of cysteine and glutamate to glutathione.

  7. Comparative Analysis of Different LIDAR System Calibration Techniques

    NASA Astrophysics Data System (ADS)

    Miller, M.; Habib, A.

    2016-06-01

    With light detection and ranging (LiDAR) now being a crucial tool for engineering products and on the fly spatial analysis, it is necessary for the user community to have standardized calibration methods. The three methods in this study were developed and proven by the Digital Photogrammetry Research Group (DPRG) for airborne LiDAR systems and are as follows; Simplified, Quasi-Rigorous, and Rigorous. In lieu of using expensive control surfaces for calibration, these methods compare overlapping LiDAR strips to estimate the systematic errors. These systematic errors are quantified by these methods and include the lever arm biases, boresight biases, range bias and scan angle scale bias. These three methods comprehensively represent all of the possible flight configurations and data availability and this paper will test the limits of the method with the most assumptions, the simplified calibration, by using data that violates the assumptions it's math model is based on and compares the results to the quasi-rigorous and rigorous techniques. The overarching goal is to provide a LiDAR system calibration that does not require raw measurements which can be carried out with minimal control and flight lines to reduce costs. This testing is unique because the terrain used for calibration does not contain gable roofs, all other LiDAR system calibration testing and development has been done with terrain containing features with high geometric integrity such as gable roofs.

  8. Different portions of the maize root system host Burkholderia cepacia populations with different degrees of genetic polymorphism.

    PubMed

    Chiarini, L; Giovannelli, V; Bevivino, A; Dalmastri, C; Tabacchioni, S

    2000-02-01

    In order to acquire a better understanding of the spatial and temporal variations of genetic diversity of Burkholderia cepacia populations in the rhizosphere of Zea mays, 161 strains were isolated from three portions of the maize root system at different soil depths and at three distinct plant growth stages. The genetic diversity among B. cepacia isolates was analysed by means of the random amplified polymorphic DNA (RAPD) technique. A number of diversity indices (richness, Shannon diversity, evenness and mean genetic distance) were calculated for each bacterial population isolated from the different root system portions. Moreover, the analysis of molecular variance (AMOVA) method was applied to estimate the genetic differences among the various bacterial populations. Our results showed that, in young plants, B. cepacia colonized preferentially the upper part of the root system, whereas in mature plants, B. cepacia was mostly recovered from the terminal part of the root system. This uneven distribution of B. cepacia cells among different root system portions partially reflected marked genetic differences among the B. cepacia populations isolated along maize roots on three distinct sampling occasions. In fact, all the diversity indices calculated indicated that genetic diversity increased during plant development and that the highest diversity values were found in mature maize plants, in particular in the middle and terminal portions of the root system. Moreover, the analysis of RAPD patterns by means of the AMOVA method revealed highly significant divergences in the degree of genetic polymorphism among the various B. cepacia populations. PMID:11243257

  9. Acetaminophen-induced depletion of glutathione and cysteine in the aging mouse kidney.

    PubMed

    Richie, J P; Lang, C A; Chen, T S

    1992-07-01

    Glutathione (GSH) plays an essential role in the detoxification of acetaminophen (APAP) and the prevention of APAP-induced toxicity in the kidney. Our previous results demonstrated that a GSH deficiency is a general property of aging tissues, including the kidney, suggesting a hypothesis that senescent organisms are at greater risk to APAP-induced renal damage. To test this, C57BL/6NIA mice of different ages through the life span were injected with various doses of APAP, and the extent of GSH and cysteine (Cys) depletion and recovery were determined. At time intervals up to 24 hr, kidney cortex samples were obtained, processed and analyzed for glutathione status, namely GSH, glutathione disulfide (GSSG), Cys and cystine, using an HPLC method with dual electrochemical detection. In the uninjected controls, GSH and Cys concentrations decreased about 30% in the aging mouse, but the GSSG and cystine levels were unchanged during the life span. APAP administration depleted the kidney GSH and Cys contents in a dose- and time-dependent manner. Four hours after APAP administration, GSH levels of the young, growing (3- to 6-month) and the mature (12-month) mice decreased 34 and 58%, respectively, and recovered to near control values by 24 hr (95 and 98%). In contrast, the extent of depletion in old (31-month) mice was greater (64%) and the 24-hr recovery was less, returning only to 56%. Likewise, Cys levels of the young and mature mice decreased 49 and 65%, respectively, 4 hr following APAP, and increased to 99 and 85% by 24 hr. In contrast, in old mice, there was a 78% depletion after 4 hr followed by a recovery of only 65% by 24 hr. These results demonstrated clearly that in the aging mouse kidney, a GSH and Cys deficiency occurs that is accompanied by an impaired APAP detoxification capacity. PMID:1632827

  10. Abnormal glutathione and sulfate levels after interleukin 6 treatment and in tumor-induced cachexia.

    PubMed

    Hack, V; Gross, A; Kinscherf, R; Bockstette, M; Fiers, W; Berke, G; Dröge, W

    1996-08-01

    Excessive urea excretion associated with a negative nitrogen balance and massive loss of skeletal muscle mass (cachexia) is a frequent life threatening complication in malignancies and HIV infection. As these patients have often elevated interleukin-6 (IL-6) and abnormally low cystine levels, we have now determined the intracellular levels of glutathione and other cysteine derivatives in the liver and muscle tissue of IL-6-treated or tumor-bearing C57BL/6 mice. IL-6 treatment or inoculation of the MCA-105 fibrosarcoma caused a significant increase in hepatic gamma-glutamyl-cysteine synthetase activity and a decrease in the sulfate level, glutamine/urea ratio, and glutamine/glutamate ratio, suggesting that a decrease of the proton generating cysteine catabolism in the liver may increase carbamoyl-phosphate synthesis and urea formation at the expense of net glutamine synthesis. Treatment with cysteine, conversely, caused an increase in sulfate, glutamine/urea ratios, and glutamine/glutamate ratios and may thus be a useful therapeutic tool in clinical medicine. In contrast to the liver, muscle tissue of tumor-bearing mice showed decreased glutathione and increased sulfate levels, suggesting that the cysteine pool may be drained by an increased cysteine catabolism in this tissue. The findings indicate that tumor cachexia is triggered initially by IL-6 and is later sustained by processes driven by an abnormal cysteine metabolism in different organs.-Hack, V., Gross, A., Kinscherf, R., Bockstette, M., Fiers, W., Berke, G., and Dröge, W. Abnormal glutathione and sulfate levels after interleukin 6 treatment and in tumor-induced cachexia.

  11. Effect of glutathione S-transferase M1 polymorphisms on biomarkers of exposure and effects.

    PubMed Central

    Srám, R J

    1998-01-01

    Genotypes responsible for interindividual differences in ability to activate or detoxify genotoxic agents are recognized as biomarkers of susceptibility. Among the most studied genotypes are human glutathione transferases. The relationship of genetic susceptibility to biomarkers of exposure and effects was studied especially in relation to the genetic polymorphism of glutathione S-transferase M1 (GSTM1). For this review papers reporting the effect of GSTM1 genotype on DNA adducts, protein adducts, urine mutagenicity, Comet assay parameters, chromosomal aberrations, sister chromatid exchanges (SCE), micronuclei, and hypoxanthine-guanine phosphoribosyl transferase mutations were assessed. Subjects in groups occupationally exposed to polycyclic aromatic hydrocarbons, benzidine, pesticides, and 1,3-butadiene were included. As environmentally exposed populations, autopsy donors, coal tar-treated patients, smokers, nonsmokers, mothers, postal workers, and firefighters were followed. From all biomarkers the effect of GSTM1 and N-acetyl transferase 2 was seen in coke oven workers on mutagenicity of urine and of glutathione S-transferase T1 on the chromosomal aberrations in subjects from 1,3-butadiene monomer production units. Effects of genotypes on DNA adducts were found from lung tissue of autopsy donors and from placentas of mothers living in an air-polluted region. The GSTM1 genotype affected mutagenicity of urine in smokers and subjects from polluted regions, protein adducts in smokers, SCE in smokers and nonsmokers, and Comet assay parameters in postal workers. A review of all studies on GSTM1 polymorphisms suggests that research probably has not reached the stage where results can be interpreted to formulate preventive measures. The relationship between genotypes and biomarkers of exposure and effects may provide an important guide to the risk assessment of human exposure to mutagens and carcinogens. PMID:9539016

  12. Effect of ovariectomy and sex hormone replacement on glutathione and glutathione-related enzymes in rat hepatocarcinogenesis.

    PubMed

    Hambali, Z; Ngah, W Z; Wahid, S A; Kadir, K A

    1995-01-01

    The effects of ovariectomy and hormone replacement in control and carcinogen treated female rats were investigated by measuring whole blood and liver glutathione (WGSH, HGSH), glutathione S-transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GRx) and histological evaluation. Hepatocarcinogenesis was induced by diethylnitrosamine and 2-acetylaminofluorene. In control rats not receiving carcinogen, ovariectomy significantly increased the GST and GRx activities. Replacement with either estrogen or progesterone reduced the GST activities to below intact female values whereas replacement of both hormones together brought the GST activities to that of intact females. GRx activities were brought to intact female values by replacement with estrogen or progesterone, either singly or in combination. Neither ovariectomy nor sex hormone/s replacement influenced the levels of WGSH, HGSH and GPx activities. Carcinogen administration to intact rats increased all the parameters measured. Ovariectomized rats treated with carcinogen showed lower GPx and GRx activities at 2 mths. However, replacement with either progesterone or combined estrogen and progesterone increased GPx and GRx activities to original values. On the other hand GST and GPx activities in ovariectomized rats which had carcinogen treatment were lower than intact rats after 5 mths. Replacement with hormones either singly or both brought GST and GPx activities up to intact rat levels receiving carcinogen. The levels of WGSH, HGSH and GRx activities (5 mths) in carcinogen treated rats were not influenced by ovariectomy and/or hormone/s replacement. The results from this study suggested that ovariectomy reduced the severity of hepatocarcinogenesis which was restored by sex hormone/s replacement.

  13. Retrograde amnesia induced by drugs acting on different molecular systems.

    PubMed

    Rossato, Janine I; Bonini, Juliana S; Coitinho, Adriana S; Vianna, Monica R M; Medina, Jorge H; Cammarota, Martín; Izquierdo, Iván

    2004-06-01

    The gamma aminobutyric acid-A (GABA-sub(A)) agonist, muscimol, the glutamate N-methyl-D-aspartate (NMDA) receptor antagonist, D-2-amino-5-phosphonopentanoic acid (AP5), and the inhibitor of the extracellularly regulated kinases (ERKs), UO 126, cause retrograde amnesia when administered to the hippocampus. In the present study, the authors found that they all cause retrograde amnesia for 1-trial inhibitory avoidance, not only when infused into the dorsal CA1 region of the hippocampus, but also when infused into the basolateral amygdala or the entorhinal, parietal, and posterior cingulate cortices. The posttraining time course of the effect of each drug was, however, quite different across brain structures. Thus, in all of them, NMDA receptors and the ERK pathway are indispensable for memory consolidation, and GABA-sub(A) receptor activation inhibits memory consolidation: but in each case, their influence is interwoven differently.

  14. Antioxidant defense mechanisms of endothelial cells and renal tubular epithelial cells in vitro: role of the glutathione redox cycle and catalase.

    PubMed

    Andreoli, S P; Mallett, C; McAteer, J A; Williams, L V

    1992-09-01

    We recently demonstrated that endothelial cells are more susceptible than renal tubular epithelial cells to oxidant injury and that renal tubular epithelial cells with proximal tubular characteristics including porcine proximal tubular epithelial cells, opossum kidney proximal tubular epithelial cells, and normal human kidney cortical epithelial cells are more susceptible to oxidant injury than the distal nephron-derived Madin Darby canine kidney cell line. To determine the basis of this differential response, we evaluated several antioxidant defenses in the five cell lines. Glutathione levels were not significantly different among the five cell lines, but catalase and glutathione reductase levels were significantly (p less than 0.01) lower in endothelial cells compared to all renal tubular epithelial cells. Among renal tubular epithelial cells, Madin Darby canine kidney cells had significantly (p less than 0.05) higher glutathione peroxidase activity. To further evaluate the role of antioxidant defenses in limiting oxidant injury, we determined two responses to oxidant injury (ATP depletion and 51Cr release) when glutathione was depleted with buthionine sulfoxamine and when catalase was inhibited with aminotriazole. Oxidant-induced ATP depletion was accentuated when catalase was inhibited as well as when glutathione was depleted with buthionine sulfoxamine. In contrast, inhibition of catalase had little or no effect on 51Cr release, whereas glutathione depletion resulted in accentuated 51Cr release. We conclude that the increased susceptibility of endothelial cells to oxidant injury as compared with epithelial cells is associated with lower antioxidant defenses. Disruption of the glutathione redox cycle results in accentuated ATP depletion and lytic injury, whereas inhibition of catalase results in accentuated ATP depletion with little effect on lytic injury.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. A temporal analysis of the relationships between social stress, humoral immune response and glutathione-related antioxidant defenses.

    PubMed

    Gonçalves, Luciane; Dafre, Alcir Luiz; Carobrez, Sonia Gonçalves; Gasparotto, Odival Cezar

    2008-10-10

    The exposure to different kinds of stress impacts on the reactive oxygen species production with potential risk to the integrity of the tissues. Psychological or biological stress is responsible for a significant increase in the oxidative stress markers and also for activation of the antioxidant defense system. In this study, we analyzed the relationships between social stress, humoral immune response and glutathione-related antioxidant defenses. Groups of male Swiss mice were subjected to different lengths of social stress exposure (social confrontation) which varied from 1 up to 13 days. As a biological stressor, 10(9) sheep red blood cells (SRBC)/mL were injected by intraperitoneal route. As controls, animals not subjected to social stress and/or injected with vehicle solution were used. The serum samples and the cerebral cortex were collected at 4 h, 3, 5, 7, 9, 11, and 13 days after the end of social confrontation. The results indicated that the antioxidant enzymes activities were affected by psychological as well as by biological stressor. These alterations were dependent on the timing of stress exposure which resulted in a positive or in a negative correlation between the antibody titres to SRBC and antioxidant enzymes. We also discuss the possible role of SRBC injection in the modulation of the effects of psychosocial stress on antioxidant metabolism.

  16. Thermal power transfer system using applied potential difference to sustain operating pressure difference

    NASA Technical Reports Server (NTRS)

    Bhandari, Pradeep (Inventor); Fujita, Toshio (Inventor)

    1991-01-01

    A thermal power transfer system using a phase change liquid gas fluid in a closed loop configuration has a heat exchanger member connected to a gas conduit for inputting thermal energy into the fluid. The pressure in the gas conduit is higher than a liquid conduit that is connected to a heat exchanger member for outputting thermal energy. A solid electrolyte member acts as a barrier between the gas conduit and the liquid conduit adjacent to a solid electrolyte member. The solid electrolyte member has the capacity of transmitting ions of a fluid through the electrolyte member. The ions can be recombined with electrons with the assistance of a porous electrode. An electrical field is applied across the solid electrolyte member to force the ions of the fluid from a lower pressure liquid conduit to the higher pressure gas conduit.

  17. Photosynthesis and antioxidant defense system of Gynura Bicolor DC grown at different elevated CO2 levels

    NASA Astrophysics Data System (ADS)

    Wang, Minjuan; Liu, Hong; Fu, Yuming

    Atmospheric carbon dioxide concentration [CO _{2}] will increase in the future and will affect global climate and ecosystem productivity. However, this is not clearly an area that requires further study on the most appropriate [CO _{2}] selection for plant growth and quality in a closed, controlled environment. The aim of this study was to determine the variation of photosynthetic characteristics and antioxidant status under five CO _{2} concentration (400, 800, 1200, 2000 and 3000 umol mol (-1) ) on the leaf of Gynura bicolor DC. Here the results show that net photosynthetic rate(Pn), Chl content, edible biomass(EB), leaf blade width(LBW), root weight(RW), fructose(Fru) and sucrose(Suc) of Gynura bicolor DC increased under elevated [CO _{2}] of 800 umol mol (-1) , 1200 umol mol (-1) and 2000 umol mol (-1) . On the contrary, photosynthesis and biomass production declined significantly at 3000 umol mol (-1) CO _{2}, While Lipid peroxidation (LPO), malondialdehyde (MDA) and hydrogen peroxide (H _{2}O _{2}) achieved the highest levels. Furthermore, the contents of glutathione (GSH), vitamin C (VC), and vitamin E (VE), and total antioxidant capacity (T-AOC), the activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) reached the highest level at 2000 umol mol ({-1) }CO _{2}. Results imply that a significant increase in growth and antioxidant defense system of Gynura bicolor DC occurred under 800-2000 umol mol (-1) of CO _{2} concentration provided a theoretical basis for the application for plants selection in Bioregeneration Life Support System (BLSS) and a closed controlled environment.

  18. Hydraulic transmission control system having different state corresponding to different octane fuels

    SciTech Connect

    Yamamori, T.; Takagi, Y.; Furukawa, J.

    1987-07-07

    A vehicle is described having a road wheel and an engine for operating on a fuel having an octane number, wherein the tendency of the engine to knock differs depending on the octane number of the fuel: a transmission having an input member drivingly connected to the engine to receive the output produced by the engine and an output member drivingly connected to the road wheel; the transmission constructed to produce a shift in ratio between the rotational speed of the input member and the rotational speed of the output member; means for hydraulically controlling the transmission; means for generating a fuel octane number indicative signal when a change in octane number of the fuel on which the engine is operating occurs; and means for modifying operation of the hydraulically controlling means in response to the fuel octane number indicative signal.

  19. Toxicity of nickel and silver to Nostoc muscorum: interaction with ascorbic acid, glutathione, and sulfur-containing amino acids

    SciTech Connect

    Rai, L.C.; Raizada, M.

    1987-08-01

    Exposure of Nostoc muscorum to different concentrations of Ni and Ag brought about reduction in growth, carbon fixation, heterocyst production, and nitrogenase activity and increase in the loss of ions (K+, Na+). In an attempt to ameliorate the toxicity of test metals by ascorbic acid, glutathione, and sulfur-containing amino acids (L-cysteine and L-methionine), it was found that the level of protection by ascorbic acid and glutathione was more for Ag than Ni. However, metal-induced inhibition of growth and carbon fixation was equally ameliorated by methionine. But the level of protection by cysteine was quite different, i.e., 27% for Ni and 22% for Ag. Protection of metal toxicity in N. muscorum by amino acids lends further support to self-detoxifying ability of cyanobacteria because they are known to synthesize all essential amino acids.

  20. pH-dependent immobilization of urease on glutathione-capped gold nanoparticles.

    PubMed

    Garg, Seema; De, Arnab; Mozumdar, Subho

    2015-05-01

    Urease is a nickel-dependent metalloenzyme that catalyzes the hydrolysis of urea to form ammonia and carbon dioxide. Although the enzyme serves a significant role in several detoxification and analytical processes, its usability is restricted due to high cost, availability in small amounts, instability, and a limited possibility of economic recovery from a reaction mixture. Hence, there is a need to develop an efficient, simple, and reliable immobilization strategy for the enzyme. In this study, the carboxyl terminated surface of glutathione-capped gold nanoparticles have been utilized as a solid support for the covalent attachment of urease. The immobilization has been carried out at different pH conditions so as to elucidate its effect on the immobilization efficiency and enzyme bioactivity. The binding of the enzyme has been quantitatively and qualitatively analyzed through techniques like ultraviolet-visible spectroscopy, intrinsic steady state fluorescence, and circular dichorism. The bioactivity of the immobilized enzyme was investigated with respect to the native enzyme under different thermal conditions. Recyclability and shelf life studies of the immobilized enzyme have also been carried out. Results reveal that the immobilization is most effective at pH of 7.4 followed by that in an acidic medium and is least in alkaline environment. The immobilized enzyme also exhibits enhance activity in comparison to the native form at physiological temperature. The immobilized urease (on gold glutathione nanoconjugates surface) can be effectively employed for biosensor fabrication, immunoassays and as an in vivo diagnostic tool in the future.

  1. Identification of Glutathione S-Transferase Pi as a Protein Involved in Parkinson Disease Progression

    PubMed Central

    Shi, Min; Bradner, Joshua; Bammler, Theo K.; Eaton, David L.; Zhang, JianPeng; Ye, ZuCheng; Wilson, Angela M.; Montine, Thomas J.; Pan, Catherine; Zhang, Jing

    2009-01-01

    Parkinson disease (PD) typically affects the cortical regions during the later stages of disease, with neuronal loss, gliosis, and formation of diffuse cortical Lewy bodies in a significant portion of patients with dementia. To identify novel proteins involved in PD progression, we prepared synaptosomal fractions from the frontal cortices of pathologically verified PD patients at different stages along with age-matched controls. Protein expression profiles were compared using a robust quantitative proteomic technique. Approximately 100 proteins displayed significant differences in their relative abundances between PD patients at various stages and controls; three of these proteins were validated using independent techniques. One of the confirmed proteins, glutathione S-transferase Pi, was further investigated in cellular models of PD, demonstrating that its level was intimately associated with several critical cellular processes that are directly related to neurodegeneration in PD. These results have, for the first time, suggested that the levels of glutathione S-transferase Pi may play an important role in modulating the progression of PD. PMID:19498008

  2. Predicted binding of certain antifilarial compounds with glutathione-S-transferase of human Filariids

    PubMed Central

    Saeed, Mohd; Baig, Mohd Hassan; Bajpai, Preeti; Srivastava, Ashwini Kumar; Ahmad, Khurshid; Mustafa, Huma

    2013-01-01

    Glutathione-S-transferase is a major phase-II detoxification enzyme in parasitic helminthes. Previous research highlights the importance of GSTs in the establishment of chronic infections in cytotoxic microenvironments. Filarial nematodes depend on these detoxification enzymes for their survival in the host. GST plays an important role in filariasis and other diseases. GST from W.bancrofti and B.malayi are very much different from human GST. This structural difference makes GST potential chemotherapeutic targets for antifilarial treatment. In this study we have checked the efficacy of some well known antifilarial compounds against GST from B.malayi and W.bancrofti. The structure of BmGST was modeled using modeller9v10 and was submitted to PMDB. Molecular docking study reveals arbindazole to be the most potent compounds against GST from both the filarial parasites. Role of some residues playing important role in the binding of compounds within the active site of GST has also been revealed in the present study. The BmGST and WbGST structural information and docking studies could aid in screening new antifilarials or selective inhibitors for chemotherapy against filariasis. Abbreviations GST - Glutathione-S-transferase, Bm - Brugia malayi, Wb - Wuchereria bancrofti. PMID:23516334

  3. Cryogenic Testing of Different Seam Concepts for Multilayer Insulation Systems

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley L.; Fesmire, J. E.

    2009-01-01

    Recent testing in a cylindrical, comparative cryostat at the Cryogenics Test Laboratory has focused on various seam concepts for multilayer insulation systems. Three main types of seams were investigated: straight overlap, fold-over, and roll wrapped. Each blanket was comprised of 40 layer pairs of reflector and spacer materials. The total thickness was approximately 12.5-mm, giving an average layer density of 32 layers per centimeter. The blankets were tested at high vacuum, soft vacuum, and no vacuum using liquid nitrogen to maintain the cold boundary temperature at 77 K. Test results show that all three seam concepts are all close in thermal performance; however the fold-over method provides the lowest heat flux. For the first series of tests, seams were located 120 degrees around the circumference of the cryostat from the previous seam. This technique appears to have lessened the degradation of the blanket due to the seams. In a follow-on test, a 20 layer blanket was tested in a roll wrapped configuration and then cut down the side of the cylinder, taped together, and re-tested. This test result shows the thermal performance impact of having the seams all in one location versus having the seams clocked around the vessel. This experimental investigation indicates that the method of joining the seams in multilayer insulation systems is not as critical as the quality of the installation process.

  4. Structure-activity relationships for chemical and glutathione S-transferase-catalysed glutathione conjugation reactions of a series of 2-substituted 1-chloro-4-nitrobenzenes.

    PubMed Central

    Van der Aar, E M; Bouwman, T; Commandeur, J N; Vermeulen, N P

    1996-01-01

    Glutathione S-transferases (GSTs) constitute an important class of phase II (de)toxifying enzymes, catalysing the conjugation of glutathione (GSH) with electrophilic compounds. In the present study, Km, kcat and kcat/Km values for the rat GST 1-1-, 3-3-, 4-4- and 7-7-catalysed conjugation reactions between GSH and a series of 10 different 2-substituted 1-chloro-4-nitrobenzenes, and the second-order rate constants (ks) of the corresponding base-catalysed reactions, were correlated with nine classical physicochemical parameters (electronic, steric and lipophilic) of the substituents and with 16 computer-calculated molecular parameters of the substrates and of the corresponding Meisenheimer complexes with MeS- as a model nucleophile for GS- (charge distributions and several energy values), giving structure-activity relationships. On the basis of an identical dependence of the base-catalysed as well as the GST 1-1- and GST 7-7-catalysed reactions on electronic parameters (among others, Hammett substituent constant sigma p and charge on p-nitro substituents), and the finding that the corresponding reactions catalysed by GSTs 3-3 and 4-4 depend to a significantly lesser extent on these parameters, it was concluded that the Mu-class GST isoenzymes have a rate-determining transition state in the conjugation reaction between 2-substituted 1-chloro-4-nitrobenzenes and GSH which is different from that of the other two GSTs. Several alternative rate-limiting transition states for GST 3-3 and 4-4 are discussed. Furthermore, based on the obtained structure-activity relationships, it was possible to predict the kcat/Km values of the four GST isoenzymes and the ks of the base-catalysed GSH conjugation of 1-chloro-4-nitrobenzene. PMID:8973562

  5. Plastid-Localized Glutathione Reductase2–Regulated Glutathione Redox Status Is Essential for Arabidopsis Root Apical Meristem Maintenance[C][W

    PubMed Central

    Yu, Xin; Pasternak, Taras; Eiblmeier, Monika; Ditengou, Franck; Kochersperger, Philip; Sun, Jiaqiang; Wang, Hui; Rennenberg, Heinz; Teale, William; Paponov, Ivan; Zhou, Wenkun; Li, Chuanyou; Li, Xugang; Palme, Klaus

    2013-01-01

    Glutathione is involved in thiol redox signaling and acts as a major redox buffer against reactive oxygen species, helping to maintain a reducing environment in vivo. Glutathione reductase (GR) catalyzes the reduction of glutathione disulfide (GSSG) into reduced glutathione (GSH). The Arabidopsis thaliana genome encodes two GRs: GR1 and GR2. Whereas the cytosolic/peroxisomal GR1 is not crucial for plant development, we show here that the plastid-localized GR2 is essential for root growth and root apical meristem (RAM) maintenance. We identify a GR2 mutant, miao, that displays strong inhibition of root growth and severe defects in the RAM, with GR activity being reduced to ∼50%. miao accumulates high levels of GSSG and exhibits increased glutathione oxidation. The exogenous application of GSH or the thiol-reducing agent DTT can rescue the root phenotype of miao, demonstrating that the RAM defects in miao are triggered by glutathione oxidation. Our in silico analysis of public microarray data shows that auxin and glutathione redox signaling generally act independently at the transcriptional level. We propose that glutathione redox status is essential for RAM maintenance through both auxin/PLETHORA (PLT)-dependent and auxin/PLT-independent redox signaling pathways. PMID:24249834

  6. Different Mechanisms for Establishing Liquid Walls in Advanced Reactor Systems

    NASA Astrophysics Data System (ADS)

    Hançerlioğullari, Aybaba; Cini, Mesut

    2013-04-01

    The APEX study is investigating the use of free flowing liquid surfaces to form the inner surface of the chamber around a fusion plasma. In this study the modeling of APEX hybrid reactor produced by using ARIES-RS hybrid reactor technology, was performed by using the Monte Carlo code and ENF/B-V-VI nuclear data. The most important feature of APEX hybrid reactor is that the first wall surrounding the plasma is liquid. The advantages of utilizing a liquid wall are high power density capacity, good power transformation productivity the magnitude of the reactor's operational duration, low failure percentage, short maintenance time and the inclusion of the system's simple technology and material. Around the fusion chamber, molten salt Li2BeF4 and natural lithium were used as cooling materials. The result of the study indicated that fissile material production UF4 and ThF4 heavy metal salt increased nearly at the same percentage.

  7. Chemical Reactivity Window Determines Prodrug Efficiency toward Glutathione Transferase Overexpressing Cancer Cells.

    PubMed

    van Gisbergen, Marike W; Cebula, Marcus; Zhang, Jie; Ottosson-Wadlund, Astrid; Dubois, Ludwig; Lambin, Philippe; Tew, Kenneth D; Townsend, Danyelle M; Haenen, Guido R M M; Drittij-Reijnders, Marie-José; Saneyoshi, Hisao; Araki, Mika; Shishido, Yuko; Ito, Yoshihiro; Arnér, Elias S J; Abe, Hiroshi; Morgenstern, Ralf; Johansson, Katarina

    2016-06-01

    Glutathione transferases (GSTs) are often overexpressed in tumors and frequently correlated to bad prognosis and resistance against a number of different anticancer drugs. To selectively target these cells and to overcome this resistance we previously have developed prodrugs that are derivatives of existing anticancer drugs (e.g., doxorubicin) incorporating a sulfonamide moiety. When cleaved by GSTs, the prodrug releases the cytostatic moiety predominantly in GST overexpressing cells, thus sparing normal cells with moderate enzyme levels. By modifying the sulfonamide it is possible to control the rate of drug release and specifically target different GSTs. Here we show that the newly synthesized compounds, 4-acetyl-2-nitro-benzenesulfonyl etoposide (ANS-etoposide) and 4-acetyl-2-nitro-benzenesulfonyl doxorubicin (ANS-DOX), function as prodrugs for GSTA1 and MGST1 overexpressing cell lines. ANS-DOX, in particular, showed a desirable cytotoxic profile by inducing toxicity and DNA damage in a GST-dependent manner compared to control cells. Its moderate conversion of 500 nmol/min/mg, as catalyzed by GSTA1, seems hereby essential since the more reactive 2,4-dinitrobenzenesulfonyl doxorubicin (DNS-DOX) (14000 nmol/min/mg) did not display a preference for GSTA1 overexpressing cells. DNS-DOX, however, effectively killed GSTP1 (20 nmol/min/mg) and MGST1 (450 nmol/min/mg) overexpressing cells as did the less reactive 4-mononitrobenzenesulfonyl doxorubicin (MNS-DOX) in a MGST1-dependent manner (1.5 nmol/min/mg) as shown previously. Furthermore, we show that the mechanism of these prodrugs involves a reduction in GSH levels as well as inhibition of the redox regulatory enzyme thioredoxin reductase 1 (TrxR1) by virtue of their electrophilic sulfonamide moiety. TrxR1 is upregulated in many tumors and associated with resistance to chemotherapy and poor patient prognosis. Additionally, the prodrugs potentially acted as a general shuttle system for DOX, by overcoming resistance

  8. Drop-Out: Problems of Comparing Drop-Out in Different Distance Education Systems.

    ERIC Educational Resources Information Center

    Bartels, Jorn; Willen, Brigitta

    It is argued that because the term "dropout" has different meanings in different systems of distance education, it is difficult to compare dropout rates of two or more distance education universities. Two very different European distance education systems, the FernUniversitat in West Germany and the Swedish system, are examined. Background…

  9. S-adenosyl-L-methionine modifies antioxidant-enzymes, glutathione-biosynthesis and methionine adenosyltransferases-1/2 in hepatitis C virus-expressing cells

    PubMed Central

    Lozano-Sepulveda, Sonia Amelia; Bautista-Osorio, Eduardo; Merino-Mascorro, Jose Angel; Varela-Rey, Marta; Muñoz-Espinosa, Linda Elsa; Cordero-Perez, Paula; Martinez-Chantar, María Luz; Rivas-Estilla, Ana Maria

    2016-01-01

    AIM: To elucidate the mechanism(s) by which S-adenosyl-L-methionine (SAM) decreases hepatitis C virus (HCV) expression. METHODS: We examined the effects of SAM on viral expression using an HCV subgenomic replicon cell culture system. Huh7 HCV-replicon cells were treated with 1 mmol/L SAM for different times (24-72 h), then total RNA and proteins were isolated. cDNA was synthesized and real time-PCR was achieved to quantify HCV-RNA, superoxide dismutase 1 and 2 (SOD-1, SOD-2) catalase, thioredoxin 1, methionine adenosyltransferase 1A and 2A (MAT1A, MAT2A) expression, and GAPDH and RPS18 as endogenous genes. Expression of cellular and viral protein was evaluated by western-blot analysis using antibodies vs HCV-NS5A, SOD-1, SOD-2, catalase, thioredoxin-1, MAT1A, MAT2A, GAPDH and actin. Total glutathione levels were measured at different times by Ellman’s recycling method (0-24 h). Reactive oxidative species (ROS) levels were quantified by the dichlorofluorescein assay (0-48 h); Pyrrolidin dithiocarbamate (PDTC) was tested as an antioxidant control and H2O2 as a positive oxidant agent. RESULTS: SAM exposition decreased HCV-RNA levels 50%-70% compared to non-treated controls (24-72 h). SAM induced a synergic antiviral effect with standard IFN treatment but it was independent of IFN signaling. In addition, 1 mmol/L SAM exposition did not modify viral RNA stability, but it needs cellular translation machinery in order to decrease HCV expression. Total glutathione levels increased upon SAM treatment in HCV-replicon cells. Transcriptional antioxidant enzyme expression (SOD-1, SOD-2 and thioredoxin-1) was increased at different times but interestingly, there was no significant change in ROS levels upon SAM treatment, contrary to what was detected with PDTC treatment, where an average 40% reduction was observed in exposed cells. There was a turnover from MAT1A/MAT2A, since MAT1A expression was increased (2.5 fold-times at 48 h) and MAT2A was diminished (from 24 h) upon SAM

  10. Research Collaboration across Higher Education Systems: Maturity, Language Use, and Regional Differences

    ERIC Educational Resources Information Center

    Shin, Jung Cheol; Lee, Soo Jeung; Kim, Yangson

    2013-01-01

    This study analyzed whether research collaboration patterns differ across higher education systems based on maturity of the systems, their language, and their geographical region. This study found that collaboration patterns differ across higher education systems: academics in developed systems are more collaborative than their colleagues in…

  11. Hydrogen Flame Imaging System Soars to New, Different Heights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    When Judy and Dave Duncan of Auburn, Calif.-based Duncan Technologies Inc. (DTI) developed their color hydrogen flame imaging system in the early 1990's, their market prospects were limited. 'We talked about commercializing the technology in the hydrogen community, but we also looked at commercialization on a much broader aspect. While there were some hydrogen applications, the market was not large enough to suppport an entire company; also, safety issues were a concern,' said Judy Duncan, owner and CEO of Duncan Technologies. Using the basic technology developed under the Small Business Innovation Research Program (SBIR); DTI conducted market research, identified other applications, formulated a plan for next generation development, and implemented a far-reaching marketing strategy. 'We took that technology; reinvested our own funds and energy into a second-generation design on the overall camera electronics and deployed that basic technology intially in a series of what we call multi-spectral cameras; cameras that could image in both the visible range and the infrared,' explains Duncan. 'The SBIR program allowed us to develop the technology to do a 3CCD camera, which very few compaines in the world do, particularly not small companies. The fact that we designed our own prism and specked the coding as we had for the hydrogen application, we were able to create a custom spectral configuration which could support varying types of research and applications.' As a result, Duncan Technologies Inc. of Auburn, Ca., has achieved a milestone $ 1 million in sales.

  12. Morphological differences in the mirror neuron system in Williams Syndrome

    PubMed Central

    Ng, Rowena; Brown, Timothy T.; Erhart, Matthew; Järvinen, Anna M.; Korenberg, Julie R.; Bellugi, Ursula; Halgren, Eric

    2015-01-01

    Williams syndrome (WS) is a genetic condition characterized by an overly gregarious personality, including high empathetic concern for others. Although seemingly disparate from the profile of autism spectrum disorder (ASD), both are associated with deficits in social communication/cognition. Notably, the mirror neuron system (MNS) has been implicated in social dysfunction for ASD; yet, the integrity of this network and its association with social functioning in WS remains unknown. Magnetic resonance imaging methods were used to examine the structural integrity of the MNS of adults with WS versus typically developing (TD) individuals. The Social Responsiveness Scale (SRS), a tool typically used to screen for social features of ASD, was also employed to assess the relationships between social functioning with the MNS morphology in WS participants. WS individuals showed reduced cortical surface area of MNS substrates yet relatively preserved cortical thickness as compared to TD adults. Increased cortical thickness of the inferior parietal lobule was associated with increased deficits in social communication, social awareness, social cognition, and autistic mannerisms. However, social motivation was not related to anatomical features of the MNS. Our findings indicate that social deficits typical to both ASD and WS may be attributed to an aberrant MNS, whereas the unusual social drive marked in WS is subserved by substrates distinct from this network. PMID:26230578

  13. Integrated biodiesel production: a comparison of different homogeneous catalysts systems.

    PubMed

    Vicente, Gemma; Martínez, Mercedes; Aracil, José

    2004-05-01

    The most common catalysts for biodiesel production are homogeneous basic catalysts. In the present paper, a comparison is made of different basic catalysts (sodium methoxide, potassium methoxide, sodium hydroxide and potassium hydroxide) for methanolysis of sunflower oil. All the reactions were carried out under the same experimental conditions in a batch stirred reactor and the subsequent separation and purification stages in a decanter. The analytical methods included gas chromatography and the determination of fat and oil conventional parameters. The biodiesel purity was near 100 wt.% for all catalysts. However, near 100 wt.% biodiesel yields were only obtained with the methoxide catalysts. According to the material balance of the process, yield losses were due to triglyceride saponification and methyl ester dissolution in glycerol. Obtained biodiesel met the measured specifications, except for the iodine value, according to the German and EU draft standards. Although all the transesterification reactions were quite rapid and the biodiesel layers achieved nearly 100% methyl ester concentrations, the reactions using sodium hydroxide turned out the fastest.

  14. Soil surface roughness and porosity under different tillage systems

    NASA Astrophysics Data System (ADS)

    Rodriguez-Gonzalez, J.; Saa-Requejo, A.; Gómez, J. A.; Valencia, J. L.; Zarco, P.; Tarquis, A. M.

    2012-04-01

    Both soil porosity and surface elevation can be altered by tillage operation. Even though the surface porosity is an important parameter of a tilled field, however, no practical technique for rapid and non-contact measurement of surface porosity has been developed yet. On the contrary, the surface elevation of tilled soil can be quickly determined with a laser profiler. Working under the assumption that the surface elevation of a tilled field is a complicated superposition of the soil terrain profile at a larger-scale and the roughness at a fine-scale, this study included three aspects: (i) to establish an index (Roughness Index, RI) at a fine-scale to associate the surface roughness with porosity; (ii) to examine the correlation between surface porosity and the proposed RI by three types of tillage treatment in the field; and (iii) to check the scaling/multiscaling behavior among different grid sizes of calculating RI on predicting surface porosity. Consequently, the statistical results from each tilled plot show a strong correlation between the surface porosity and the defined RI in an early stage (ca. 2 days) after tillage. Acknowledgements Funding provided by CEIGRAM (Research Centre for the Management of Agricultural and Environmental Risks)and Spanish Ministerio de Ciencia e Innovación (MICINN) through project AGL2010-21501/AGR is greatly appreciated.

  15. A cyanobacterial protein with similarity to phytochelatin synthases catalyzes the conversion of glutathione to gamma-glutamylcysteine and lacks phytochelatin synthase activity.

    PubMed

    Harada, Emiko; von Roepenack-Lahaye, Edda; Clemens, Stephan

    2004-12-01

    Phytochelatins are glutathione-derived, non-translationally synthesized peptides essential for cadmium and arsenic detoxification in plant, fungal and nematode model systems. Recent sequencing programs have revealed the existence of phytochelatin synthase-related genes in a wide range of organisms that have not been reported yet to produce phytochelatins. Among those are several cyanobacteria. We have studied one of the encoded proteins (alr0975 from Nostoc sp. strain PCC 7120) and demonstrate here that it does not possess phytochelatin synthase activity. Instead, this protein catalyzes the conversion of glutathione to gamma-glutamylcysteine. The thiol spectrum of yeast cells expressing alr0975 shows the disappearance of glutathione and the formation of a compound that by LC-MSMS analysis was unequivocally identified as gamma-glutamylcysteine. Purified recombinant protein catalyzes the respective reaction. Unlike phytochelatin synthesis, the conversion of glutathione to gamma-glutamylcysteine is not dependent on activation by metal cations. No evidence was found for the accumulation of phytochelatins in cyanobacteria even after prolonged exposure to toxic Cd2+ concentrations. Expression of alr0975 was detected in Nostoc sp. cells with an antiserum raised against the protein. No indication for a responsiveness of expression to toxic metal exposure was found. Taken together, these data provide further evidence for possible additional functions of phytochelatin synthase-related proteins in glutathione metabolism and provide a lead as to the evolutionary history of phytochelatin synthesis.

  16. Molecular and structural basis of glutathione import in Gram-positive bacteria via GshT and the cystine ABC importer TcyBC of Streptococcus mutans.

    PubMed

    Vergauwen, Bjorn; Verstraete, Kenneth; Senadheera, Dilani B; Dansercoer, Ann; Cvitkovitch, Dennis G; Guédon, Eric; Savvides, Savvas N

    2013-07-01

    Glutathione (GSH) protects cells against oxidative injury and maintains a range of vital functions across all branches of life. Despite recent advances in our understanding of the transport mechanisms responsible for maintaining the spatiotemporal homeostasis of GSH and its conjugates in eukaryotes and Gram-negative bacteria, the molecular and structural basis of GSH import into Gram-positive bacteria has remained largely uncharacterized. Here, we employ genetic, biochemical and structural studies to investigate a possible glutathione import axis in Streptococcus mutans, an organism that has hitherto served as a model system. We show that GshT, a type 3 solute binding protein, displays physiologically relevant affinity for GSH and glutathione disulfide (GSSG). The crystal structure of GshT in complex with GSSG reveals a collapsed structure whereby the GS-I-leg of GSSG is accommodated tightly via extensive interactions contributed by the N- and C-terminal lobes of GshT, while the GS-II leg extends to the solvent. This can explain the ligand promiscuity of GshT in terms of binding glutathione analogues with substitutions at the cysteine-sulfur or the glycine-carboxylate. Finally, we show that GshT primes glutathione import via the L-cystine ABC transporter TcyBC, a membrane permease, which had previously exclusively been associated with the transport of L-cystine.

  17. Targeting Aberrant Glutathione Metabolism to Eradicate Human Acute Myelogenous Leukemia Cells*

    PubMed Central

    Pei, Shanshan; Minhajuddin, Mohammad; Callahan, Kevin P.; Balys, Marlene; Ashton, John M.; Neering, Sarah J.; Lagadinou, Eleni D.; Corbett, Cheryl; Ye, Haobin; Liesveld, Jane L.; O'Dwyer, Kristen M.; Li, Zheng; Shi, Lei; Greninger, Patricia; Settleman, Jeffrey; Benes, Cyril; Hagen, Fred K.; Munger, Joshua; Crooks, Peter A.; Becker, Michael W.; Jordan, Craig T.

    2013-01-01

    The development of strategies to eradicate primary human acute myelogenous leukemia (AML) cells is a major challenge to the leukemia research field. In particular, primitive leukemia cells, often termed leukemia stem cells, are typically refractory to many forms of therapy. To investigate improved strategies for targeting of human AML cells we compared the molecular mechanisms regulating oxidative state in primitive (CD34+) leukemic versus normal specimens. Our data indicate that CD34+ AML cells have elevated expression of multiple glutathione pathway regulatory proteins, presumably as a mechanism to compensate for increased oxidative stress in leukemic cells. Consistent with this observation, CD34+ AML cells have lower levels of reduced glutathione and increased levels of oxidized glutathione compared with normal CD34+ cells. These findings led us to hypothesize that AML cells will be hypersensitive to inhibition of glutathione metabolism. To test this premise, we identified compounds such as parthenolide (PTL) or piperlongumine that induce almost complete glutathione depletion and severe cell death in CD34+ AML cells. Importantly, these compounds only induce limited and transient glutathione depletion as well as significantly less toxicity in normal CD34+ cells. We further determined that PTL perturbs glutathione homeostasis by a multifactorial mechanism, which includes inhibiting key glutathione metabolic enzymes (GCLC and GPX1), as well as direct depletion of glutathione. These findings demonstrate that primitive leukemia cells are uniquely sensitive to agents that target aberrant glutathione metabolism, an intrinsic property of primary human AML cells. PMID:24089526

  18. Exposure to cadmium changes the content of glutathione in maize seedlings

    SciTech Connect

    Rauser, W.E.

    1987-04-01

    Glutathione may be involved in the biosynthesis of Cd-binding peptides known as phytochelatins. Five-day old maize seedlings in hydroponic culture were exposed to 3 ..mu..M CdSO/sub 4/ for 2, 6 and 12 hours and 1, 2 and 3 days. Total glutathione (glutathione + glutathione disulfide) in roots and shoots was measured enzymatically. Exposure to Cd for 12 hours or longer reduced root elongation growth. Shoots contained more glutathione than did roots. Within 2 hours of exposure to Cd the glutathione content declined by 47% of control and stayed low for a day. Shoot glutathione decreased gradually and less markedly (by 34% in 24 hours). Following the decline in the first day the glutathione per seedling increased with time in the presence of Cd. Cadmium-binding peptide in roots increased during the recovery phase. If glutathione is a substrate for Cd-binding peptide synthesis, such a use accounts for only part of the decline in root glutathione observed during the first day.