1
|
Bilinsky LM. A Computational Model of Endogenous Hydrogen Peroxide Metabolism in Hepatocytes, Featuring a Critical Role for GSH. COMPUTATIONAL TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 29:100299. [PMID: 38682127 PMCID: PMC11044893 DOI: 10.1016/j.comtox.2024.100299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
This paper presents an ordinary differential equation (ODE) model of endogenous H2O2 production and elimination in hepatocytes that is unique, at the time of writing, in its ability to accurately compute intracellular H2O2 concentration during incidents of oxidative stress and in its usefulness for constructing PBPK/PD models for ROS-generating xenobiotics. Versions of the model are presented for rat hepatocytes in vitro and mouse liver in vivo. A generic method is given for using the model to create PBPK/PD models which predict intracellular H2O2 concentration and oxidative-stress-induced hepatocyte death; these are identifiable from in vitro data sets reporting cell mortality following xenobiotic exposure at various levels. The procedure is demonstrated for the trivalent arsenical dimethylarsinous acid (DMAIII), which is produced in liver as part of the arsenic elimination pathway. This is the first model of H2O2 metabolism in hepatocytes to feature values for the endogenous rates of H2O2 production by mitochondria and other organelles which are inferred from the physiology literature, and to feature a detailed, realistic treatment of GSH metabolism; the latter is achieved by incorporating a minimal version of Reed and coworkers' pioneering model of GSH metabolism in liver. Model simulations indicate that critical GSH depletion is the immediate trigger for intracellular H2O2 rising to concentrations associated with apoptosis (> 1 μM), that this may only occur hours after the xenobiotic concentration peaks ("delay effect"), that when critical GSH depletion does occur, H2O2 concentration rises rapidly in a sequence of two boundary layers, characterized by the kinetics of glutathione peroxidase (first boundary layer) and catalase (second boundary layer), and that intracellular H2O2 concentration > 1 μM implies critical GSH depletion. There has been speculation that ROS levels in the range associated with apoptosis simply indicate, rather than cause, an apoptotic milieu. Model simulations are consistent with this view. In a result of interest to the wider physiology community, the delay effect is shown to provide a GSH-based mechanism by which cells can distinguish transient elevations in H2O2 concentration, of use in intracellular signaling, from persistent ones indicative of either pathology or the presence of toxins, the second state of affairs eventually triggering apoptosis.
Collapse
Affiliation(s)
- L M Bilinsky
- Division of Biochemical Toxicology, National Center for Toxicological Research (U.S. FDA), 3900 NCTR Rd., Jefferson, AR 72079, USA
| |
Collapse
|
2
|
Ma J, Zhang C, He Y, Chen X, Lin G. Fasting augments pyrrolizidine alkaloid-induced hepatotoxicity. Arch Toxicol 2021; 96:639-651. [PMID: 34792613 DOI: 10.1007/s00204-021-03193-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/04/2021] [Indexed: 12/16/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are phytotoxins widely present in various natural products and foodstuffs. The present study aims to investigate the effects of fasting on PA-induced hepatotoxicity and the underlying biochemical mechanisms. The results of hepatotoxic study showed that 15-h overnight fasting significantly exacerbated the hepatotoxicity of retrorsine (RTS, a representative toxic PA) in fasted rats compared to fed rats, as indicated by remarkably elevated plasma ALT and bilirubin levels and obvious liver histological changes. Further toxicokinetic studies revealed that fasting significantly enhanced cytochromes P450 enzymes (CYPs)-mediated metabolic activation of RTS leading to increased formation of pyrrole-protein adducts and thus decreased the in vivo exposure and excretion of both parent RTS and its N-oxide metabolite. Metabolic studies demonstrated that fasting induced enzyme activities of CYP1A2, CYP2B6 and CYP2E1 that participated in catalyzing RTS to its reactive pyrrolic metabolites. Moreover, fasting also dramatically decreased hepatic glutathione (GSH) content, which restricted the detoxification of GSH by neutralizing the reactive pyrrolic metabolite of RTS, further contributing to the enhanced hepatotoxicity. The present findings may have an impact on future PA toxicity tests with different dietary styles and/or risk assessment of metabolite-mediated toxins by considering the profound effects of fasting.
Collapse
Affiliation(s)
- Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chunyuan Zhang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yisheng He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xinmeng Chen
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
| |
Collapse
|
3
|
Abstract
Glutathione (GSH) is the most abundant non-protein thiol, and plays crucial roles in the antioxidant defense system and the maintenance of redox homeostasis in neurons. GSH depletion in the brain is a common finding in patients with neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease, and can cause neurodegeneration prior to disease onset. Excitatory amino acid carrier 1 (EAAC1), a sodium-dependent glutamate/cysteine transporter that is selectively present in neurons, plays a central role in the regulation of neuronal GSH production. The expression of EAAC1 is posttranslationally controlled by the glutamate transporter-associated protein 3–18 (GTRAP3-18) or miR-96-5p in neurons. The regulatory mechanism of neuronal GSH production mediated by EAAC1 may be a new target in therapeutic strategies for these neurodegenerative diseases. This review describes the regulatory mechanism of neuronal GSH production and its potential therapeutic application in the treatment of neurodegenerative diseases.
Collapse
|
4
|
The effect of short-term methionine restriction on glutathione synthetic capacity and antioxidant responses at the whole tissue and mitochondrial level in the rat liver. Exp Gerontol 2019; 127:110712. [PMID: 31472257 DOI: 10.1016/j.exger.2019.110712] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/19/2019] [Accepted: 08/26/2019] [Indexed: 12/13/2022]
Abstract
Dietary methionine restriction (MR) where methionine is the sole source of sulfur amino acid increases lifespan in diverse species. Methionine restricted rodents experience a decrease in glutathione (GSH), a major antioxidant, in several tissues, which is paradoxical to longevity interventions because tissues with low GSH might experience more oxidative damage. Liver plays a key role in GSH synthesis and here we examined how MR influences GSH metabolism in the liver. We also hypothesised that low GSH might be subsidized by compensatory pathway(s) in the liver. To investigate GSH synthesis and antioxidant responses, Fischer-344 rats were given either a MR diet or a control diet for 8 weeks. Based on γ-glutamylcysteine synthetase activity, GSH synthetic capacity did not respond to low dietary methionine availability. Tissue level protein and lipid oxidation markers do not support elevated oxidative damage, despite low GSH availability. Whole tissue and mitochondrial level responses to MR differed. Specifically, the activity of glutathione reductase and thioredoxin reductase increase in whole liver tissue which might offset the effects of declined GSH availability whereas mitochondrial GSH levels were unperturbed by MR. Moreover, enhanced proton leak in liver mitochondria by MR (4 week) presumably diminishes ROS production. Taken together, we suggest that the effect of low GSH in liver tissue is subsidized, at least in part, by increased antioxidant activity and possibly by enhanced mitochondrial proton leak.
Collapse
|
5
|
Pannala VR, Vinnakota KC, Rawls KD, Estes SK, O'Brien TP, Printz RL, Papin JA, Reifman J, Shiota M, Young JD, Wallqvist A. Mechanistic identification of biofluid metabolite changes as markers of acetaminophen-induced liver toxicity in rats. Toxicol Appl Pharmacol 2019; 372:19-32. [PMID: 30974156 DOI: 10.1016/j.taap.2019.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/22/2019] [Accepted: 04/05/2019] [Indexed: 12/12/2022]
Abstract
Acetaminophen (APAP) is the most commonly used analgesic and antipyretic drug in the world. Yet, it poses a major risk of liver injury when taken in excess of the therapeutic dose. Current clinical markers do not detect the early onset of liver injury associated with excess APAP-information that is vital to reverse injury progression through available therapeutic interventions. Hence, several studies have used transcriptomics, proteomics, and metabolomics technologies, both independently and in combination, in an attempt to discover potential early markers of liver injury. However, the casual relationship between these observations and their relation to the APAP mechanism of liver toxicity are not clearly understood. Here, we used Sprague-Dawley rats orally gavaged with a single dose of 2 g/kg of APAP to collect tissue samples from the liver and kidney for transcriptomic analysis and plasma and urine samples for metabolomic analysis. We developed and used a multi-tissue, metabolism-based modeling approach to integrate these data, characterize the effect of excess APAP levels on liver metabolism, and identify a panel of plasma and urine metabolites that are associated with APAP-induced liver toxicity. Our analyses, which indicated that pathways involved in nucleotide-, lipid-, and amino acid-related metabolism in the liver were most strongly affected within 10 h following APAP treatment, identified a list of potential metabolites in these pathways that could serve as plausible markers of APAP-induced liver injury. Our approach identifies toxicant-induced changes in endogenous metabolism, is applicable to other toxicants based on transcriptomic data, and provides a mechanistic framework for interpreting metabolite alterations.
Collapse
Affiliation(s)
- Venkat R Pannala
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, USA; Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA.
| | - Kalyan C Vinnakota
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, USA; Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA
| | - Kristopher D Rawls
- Department of Biomedical Engineering, University of Virginia, Box 800759, Health System, Charlottesville, Virginia 22908, USA
| | - Shanea K Estes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Tracy P O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Richard L Printz
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jason A Papin
- Department of Biomedical Engineering, University of Virginia, Box 800759, Health System, Charlottesville, Virginia 22908, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA
| | - Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jamey D Young
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Department of Chemical and Biomolecular Engineering, Vanderbilt University School of Engineering, Nashville, TN 37232, USA.
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA.
| |
Collapse
|
6
|
Ignowski E, Winter AN, Duval N, Fleming H, Wallace T, Manning E, Koza L, Huber K, Serkova NJ, Linseman DA. The cysteine-rich whey protein supplement, Immunocal®, preserves brain glutathione and improves cognitive, motor, and histopathological indices of traumatic brain injury in a mouse model of controlled cortical impact. Free Radic Biol Med 2018; 124:328-341. [PMID: 29940352 PMCID: PMC6211803 DOI: 10.1016/j.freeradbiomed.2018.06.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 06/08/2018] [Accepted: 06/22/2018] [Indexed: 01/09/2023]
Abstract
Traumatic brain injury (TBI) is a major public health problem estimated to affect nearly 1.7 million people in the United States annually. Due to the often debilitating effects of TBI, novel preventative agents are highly desirable for at risk populations. Here, we tested a whey protein supplement, Immunocal®, for its potential to enhance resilience to TBI. Immunocal® is a non-denatured whey protein preparation which has been shown to act as a cysteine delivery system to increase levels of the essential antioxidant glutathione (GSH). Twice daily oral supplementation of CD1 mice with Immunocal® for 28 days prior to receiving a moderate TBI prevented an ~ 25% reduction in brain GSH/GSSG observed in untreated TBI mice. Immunocal® had no significant effect on the primary mechanical injury induced by TBI, as assessed by MRI, changes in Tau phosphorylation, and righting reflex time or apnea. However, pre-injury supplementation with Immunocal® resulted in statistically significant improvements in motor function (beam walk and rotarod) and cognitive function (Barnes maze). We also observed a significant preservation of corpus callosum width (axonal myelination), a significant decrease in degenerating neurons, a reduction in Iba1 (microglial marker), decreased lipid peroxidation, and preservation of brain-derived neurotrophic factor (BDNF) in the brains of Immunocal®-pretreated mice compared to untreated TBI mice. Taken together, these data indicate that pre-injury supplementation with Immunocal® significantly enhances the resilience to TBI induced by a moderate closed head injury in mice. We conclude that Immunocal® may hold significant promise as a preventative agent for TBI, particularly in certain high risk populations such as athletes and military personnel.
Collapse
Affiliation(s)
- Elizabeth Ignowski
- University of Denver, Department of Biological Sciences, Denver, CO 80208, United States.
| | - Aimee N Winter
- University of Denver, Department of Biological Sciences, Denver, CO 80208, United States.
| | - Nathan Duval
- University of Denver, Knoebel Institute for Healthy Aging, Denver, CO 80208, United States.
| | - Holly Fleming
- University of Denver, Knoebel Institute for Healthy Aging, Denver, CO 80208, United States.
| | - Tyler Wallace
- University of Denver, Department of Biological Sciences, Denver, CO 80208, United States.
| | - Evan Manning
- University of Denver, Department of Biological Sciences, Denver, CO 80208, United States.
| | - Lilia Koza
- University of Denver, Department of Biological Sciences, Denver, CO 80208, United States.
| | - Kendra Huber
- University of Colorado Cancer Center, Aurora, CO 80045, United States.
| | - Natalie J Serkova
- University of Colorado Cancer Center, Aurora, CO 80045, United States.
| | - Daniel A Linseman
- University of Denver, Department of Biological Sciences and Knoebel Institute for Healthy Aging, 2155 E. Wesley Ave., Denver, CO 80208, United States.
| |
Collapse
|
7
|
Kobayashi S, Hamashima S, Homma T, Sato M, Kusumi R, Bannai S, Fujii J, Sato H. Cystine/glutamate transporter, system x c − , is involved in nitric oxide production in mouse peritoneal macrophages. Nitric Oxide 2018; 78:32-40. [DOI: 10.1016/j.niox.2018.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/14/2018] [Accepted: 05/18/2018] [Indexed: 02/07/2023]
|
8
|
Maclean KN, Jiang H, Aivazidis S, Kim E, Shearn CT, Harris PS, Petersen DR, Allen RH, Stabler SP, Roede JR. Taurine treatment prevents derangement of the hepatic γ-glutamyl cycle and methylglyoxal metabolism in a mouse model of classical homocystinuria: regulatory crosstalk between thiol and sulfinic acid metabolism. FASEB J 2018; 32:1265-1280. [PMID: 29101223 DOI: 10.1096/fj.201700586r] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cystathionine β-synthase-deficient homocystinuria (HCU) is a poorly understood, life-threatening inborn error of sulfur metabolism. Analysis of hepatic glutathione (GSH) metabolism in a mouse model of HCU demonstrated significant depletion of cysteine, GSH, and GSH disulfide independent of the block in trans-sulfuration compared with wild-type controls. HCU induced the expression of the catalytic and regulatory subunits of γ-glutamyl ligase, GSH synthase (GS), γ-glutamyl transpeptidase 1, 5-oxoprolinase (OPLAH), and the GSH-dependent methylglyoxal detoxification enzyme, glyoxalase-1. Multiple components of the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated antioxidant-response regulatory axis were induced without any detectable activation of Nrf2. Metabolomic analysis revealed the accumulation of multiple γ-glutamyl amino acids and that plasma ophthalmate levels could serve as a noninvasive marker for hepatic redox stress. Neither cysteine, nor betaine treatment was able to reverse the observed enzyme inductions. Taurine treatment normalized the expression levels of γ-glutamyl ligase C/M, GS, OPLAH, and glyoxalase-1, and reversed HCU-induced deficits in protein glutathionylation by acting to double GSH levels relative to controls. Collectively, our data indicate that the perturbation of the γ-glutamyl cycle could contribute to multiple sequelae in HCU and that taurine has significant therapeutic potential for both HCU and other diseases for which GSH depletion is a critical pathogenic factor.-Maclean, K. N., Jiang, H., Aivazidis, S., Kim, E., Shearn, C. T., Harris, P. S., Petersen, D. R., Allen, R. H., Stabler, S. P., Roede, J. R. Taurine treatment prevents derangement of the hepatic γ-glutamyl cycle and methylglyoxal metabolism in a mouse model of classical homocystinuria: regulatory crosstalk between thiol and sulfinic acid metabolism.
Collapse
Affiliation(s)
- Kenneth N Maclean
- Department of Pediatrics, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Hua Jiang
- Department of Pediatrics, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Stefanos Aivazidis
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Eugene Kim
- Department of Pediatrics, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Colin T Shearn
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Peter S Harris
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Dennis R Petersen
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Robert H Allen
- Department of Medicine, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - Sally P Stabler
- Department of Medicine, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| | - James R Roede
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Aurora, Colorado, USA
| |
Collapse
|
9
|
Silva NCD, Härter CJ, Figueiredo FOM, Leite RF, Neto JMS, Negrão JA, Teixeira IAMA, Resende KT. Growing goats of different sexes have distinct metabolic responses to continuous feed restriction. ANIMAL PRODUCTION SCIENCE 2018. [DOI: 10.1071/an16419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The objective of the present study was to investigate the effect of sex on the hormonal and metabolic changes in growing goats subjected to levels of feed restriction. We used 72 Saanen kids, including 24 intact males, 24 castrated males and 24 females with initial bodyweight of 15.76 ± 0.174 kg and initial age of 108.4 ± 18.86 days respectively. A split-plot design was employed (3 sexes = intact males, castrated males, and females; 3 levels of feed restriction = 0% (ad libitum), 25% and 50%). Groups of three goat kids were formed by sex (each goat eating one level of feed restriction); goats of each group were slaughtered when animals fed ad libitum reached 30 kg bodyweight. Fat and protein deposition were calculated by the difference between the determinations performed on samples of homogenates of control animals slaughtered at the start of the experiment and the experimental animals. Blood samples were collected every 10 days to evaluate glucose, total protein, albumin, urea, creatinine, cholesterol, non-esterified fatty acid, β-hydroxybutyrate, aspartate aminotransferase, gamma glutamyltransferase, creatine kinase, triiodothyronine (T3), thyroxine and insulin-like growth factor. Females presented greater fat deposition than did castrated and intact males, regardless of feed restriction (P < 0.0001). Protein body retention (kg) was affected only by feed restriction (P < 0.0001). In females, aspartate aminotransferase activity was greater in those subjected to 50% feed restriction (83.83 ± 4.96 U/L). Regardless of sex, the greatest serum β-hydroxybutyrate concentration was observed when animals were subjected to 50% feed restriction (P < 0.0149). Plasma concentration of insulin-like growth factor 1 was similar in castrated and females, being lower than in intact males. Intact males showed lower plasma T3 concentration than did females (P < 0.05). Females changed their glycolytic metabolism to retain fat deposition even under feed restriction, whereas males mainly changed their protein metabolism to retain protein synthesis, and were less affected by feed restriction.
Collapse
|
10
|
Finamor I, Pérez S, Bressan CA, Brenner CE, Rius-Pérez S, Brittes PC, Cheiran G, Rocha MI, da Veiga M, Sastre J, Pavanato MA. Chronic aspartame intake causes changes in the trans-sulphuration pathway, glutathione depletion and liver damage in mice. Redox Biol 2017; 11:701-707. [PMID: 28187322 PMCID: PMC5300302 DOI: 10.1016/j.redox.2017.01.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 01/20/2017] [Accepted: 01/29/2017] [Indexed: 01/23/2023] Open
Abstract
No-caloric sweeteners, such as aspartame, are widely used in various food and beverages to prevent the increasing rates of obesity and diabetes mellitus, acting as tools in helping control caloric intake. Aspartame is metabolized to phenylalanine, aspartic acid, and methanol. Our aim was to study the effect of chronic administration of aspartame on glutathione redox status and on the trans-sulphuration pathway in mouse liver. Mice were divided into three groups: control; treated daily with aspartame for 90 days; and treated with aspartame plus N-acetylcysteine (NAC). Chronic administration of aspartame increased plasma alanine aminotransferase (ALT) and aspartate aminotransferase activities and caused liver injury as well as marked decreased hepatic levels of reduced glutathione (GSH), oxidized glutathione (GSSG), γ-glutamylcysteine (γ-GC), and most metabolites of the trans-sulphuration pathway, such as cysteine, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH). Aspartame also triggered a decrease in mRNA and protein levels of the catalytic subunit of glutamate cysteine ligase (GCLc) and cystathionine γ-lyase, and in protein levels of methionine adenosyltransferase 1A and 2A. N-acetylcysteine prevented the aspartame-induced liver injury and the increase in plasma ALT activity as well as the decrease in GSH, γ-GC, cysteine, SAM and SAH levels and GCLc protein levels. In conclusion, chronic administration of aspartame caused marked hepatic GSH depletion, which should be ascribed to GCLc down-regulation and decreased cysteine levels. Aspartame triggered blockade of the trans-sulphuration pathway at two steps, cystathionine γ-lyase and methionine adenosyltransferases. NAC restored glutathione levels as well as the impairment of the trans-sulphuration pathway. Aspartame down-regulates glutamate cysteine ligase and decreased cysteine levels. Aspartame blockades the trans-sulphuration pathways.
Collapse
Affiliation(s)
- Isabela Finamor
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Av. Vicente Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
| | - Salvador Pérez
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Av. Vicente Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
| | - Caroline A Bressan
- Department of Physiology and Pharmacology, Federal University of Santa Maria, Av. Roraima, 1000, 97105900 Santa Maria, Rio Grande do Sul, Brazil
| | - Carlos E Brenner
- Department of Physiology and Pharmacology, Federal University of Santa Maria, Av. Roraima, 1000, 97105900 Santa Maria, Rio Grande do Sul, Brazil
| | - Sergio Rius-Pérez
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Av. Vicente Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
| | - Patricia C Brittes
- University Hospital of Santa Maria, Federal University of Santa Maria,, Av. Roraima, 1000, 97105900 Santa Maria, Rio Grande do Sul, Brazil
| | - Gabriele Cheiran
- Department of Morphology, Federal University of Santa Maria, Av. Roraima, 1000, 97105900 Santa Maria, Rio Grande do Sul, Brazil
| | - Maria I Rocha
- Department of Morphology, Federal University of Santa Maria, Av. Roraima, 1000, 97105900 Santa Maria, Rio Grande do Sul, Brazil
| | - Marcelo da Veiga
- Department of Morphology, Federal University of Santa Maria, Av. Roraima, 1000, 97105900 Santa Maria, Rio Grande do Sul, Brazil
| | - Juan Sastre
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Av. Vicente Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain
| | - Maria A Pavanato
- Department of Physiology and Pharmacology, Federal University of Santa Maria, Av. Roraima, 1000, 97105900 Santa Maria, Rio Grande do Sul, Brazil
| |
Collapse
|
11
|
Kumar SM, Haridoss M, Swaminathan K, Gopal RK, Clemens D, Dey A. The effects of changes in glutathione levels through exogenous agents on intracellular cysteine content and protein adduct formation in chronic alcohol-treated VL17A cells. Toxicol Mech Methods 2016; 27:128-135. [DOI: 10.1080/15376516.2016.1268229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- S. Mathan Kumar
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | - Madhumitha Haridoss
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | - Kavitha Swaminathan
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | - Ramesh Kumar Gopal
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | - Dahn Clemens
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
- Nebraska and Western Iowa Veterans Administration Medical Center, University of Nebraska Medical Center, Omaha, NE, USA
- Fred and Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - Aparajita Dey
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| |
Collapse
|
12
|
Kurahashi T, Lee J, Nabeshima A, Homma T, Kang ES, Saito Y, Yamada S, Nakayama T, Yamada KI, Miyata S, Fujii J. Ascorbic acid prevents acetaminophen-induced hepatotoxicity in mice by ameliorating glutathione recovery and autophagy. Arch Biochem Biophys 2016; 604:36-46. [PMID: 27288086 DOI: 10.1016/j.abb.2016.06.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 05/18/2016] [Accepted: 06/06/2016] [Indexed: 12/19/2022]
Abstract
Aldehyde reductase (AKR1A) plays a role in the biosynthesis of ascorbic acid (AsA), and AKR1A-deficient mice produce about 10-15% of the AsA that is produced by wild-type mice. We found that acetaminophen (AAP) hepatotoxicity was aggravated in AKR1A-deficient mice. The pre-administration of AsA in the drinking water markedly ameliorated the AAP hepatotoxicity in the AKR1A-deficient mice. Treatment of the mice with AAP decreased both glutathione and AsA levels in the liver in the early phase after AAP administration, and an AsA deficiency delayed the recovery of the glutathione content in the healing phase. While in cysteine supply systems; a neutral amino acid transporter ASCT1, a cystine transporter xCT, enzymes for the transsulfuration pathway, and autophagy markers, were all elevated in the liver as the result of the AAP treatment, the AsA deficiency suppressed their induction. Thus, AsA appeared to exert a protective effect against AAP hepatotoxicity by ameliorating the supply of cysteine that is available for glutathione synthesis as a whole. Because some drugs produce reactive oxygen species, resulting in the consumption of glutathione during the metabolic process, the intake of sufficient amounts of AsA would be beneficial for protecting against the hepatic damage caused by such drugs.
Collapse
Affiliation(s)
- Toshihiro Kurahashi
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Jaeyong Lee
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Atsunori Nabeshima
- Department of Pathology and Cell Biology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka 807-8555, Japan
| | - Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Eun Sil Kang
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Yuka Saito
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan
| | - Sohsuke Yamada
- Department of Pathology and Cell Biology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka 807-8555, Japan
| | - Toshiyuki Nakayama
- Department of Pathology and Cell Biology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka 807-8555, Japan
| | - Ken-Ichi Yamada
- Department of Bio-functional Science, Faculty of Pharmacological Science, Kyushu University, Fukuoka 812-8582, Japan; JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Satoshi Miyata
- Department of Internal Medicine, Osaka Hospital, Japan Community Healthcare Organization, Osaka 553-0003, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan.
| |
Collapse
|
13
|
Mori K, Kumano A, Kodama T, Takiguchi S, Takano N, Kumada K, Hatao K, Kimura T. Evaluation of hepatic damage by reactive metabolites--with consideration of circadian variation of murine hepatic glutathione levels. J Toxicol Sci 2015; 39:537-44. [PMID: 25056778 DOI: 10.2131/jts.39.537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Generally, reactive metabolites are detoxified by conjugation with glutathione (GSH). A GSH-depleted model was prepared by administering L-buthionine-(S,R)-sulfoximine (BSO), which can be used to detect hepatic damage by reactive metabolites. However, BSO may cause adverse effects on other organs, such as renal damage by reactive metabolites because it depletes GSH in the whole body. The present study was designed to examine whether it was possible to specifically detect hepatic damage by reactive metabolites without reducing renal GSH levels by administering BSO in a time course when hepatic GSH levels are naturally reduced. Male BALB/c mice were administered reverse osmosis (RO) water or 20 mmol/l BSO in drinking water for 4 days. Subsequently, animals in the RO water group were orally administered 500 mg/kg acetaminophen (APAP) at 9:00 or 15:00 and in the BSO group at 9:00 for 4 days. As a result, severe hepatic damage and necrosis of the renal proximal tubules were observed in the BSO/APAP administration at 9:00 group, and all animals died on 1 or 2 days after APAP administration. Hepatic damage was clearly increased in the RO water/APAP administration at 15:00 group compared with the RO water/APAP administration at 9:00 group. However, renal damage and deaths were not observed. This BSO administration model may detect renal damage induced by reactive metabolites. Using an administration time course, whereby hepatic GSH levels were naturally reduced, hepatic damage by reactive metabolites can be detected without secondary renal effects.
Collapse
Affiliation(s)
- Koji Mori
- Fukushima Research Laboratories, R&D Department, TOA EIYO LTD
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Patarrão RS, Lautt WW, Macedo MP. Acute glucagon induces postprandial peripheral insulin resistance. PLoS One 2015; 10:e0127221. [PMID: 25961284 PMCID: PMC4427479 DOI: 10.1371/journal.pone.0127221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 04/13/2015] [Indexed: 11/18/2022] Open
Abstract
Glucagon levels are often moderately elevated in diabetes. It is known that glucagon leads to a decrease in hepatic glutathione (GSH) synthesis that in turn is associated with decreased postprandial insulin sensitivity. Given that cAMP pathway controls GSH levels we tested whether insulin sensitivity decreases after intraportal (ipv) administration of a cAMP analog (DBcAMP), and investigated whether glucagon promotes insulin resistance through decreasing hepatic GSH levels.Insulin sensitivity was determined in fed male Sprague-Dawley rats using a modified euglycemic hyperinsulinemic clamp in the postprandial state upon ipv administration of DBcAMP as well as glucagon infusion. Glucagon effects on insulin sensitivity was assessed in the presence or absence of postprandial insulin sensitivity inhibition by administration of L-NMMA. Hepatic GSH and NO content and plasma levels of NO were measured after acute ipv glucagon infusion. Insulin sensitivity was assessed in the fed state and after ipv glucagon infusion in the presence of GSH-E. We founf that DBcAMP and glucagon produce a decrease of insulin sensitivity, in a dose-dependent manner. Glucagon-induced decrease of postprandial insulin sensitivity correlated with decreased hepatic GSH content and was restored by administration of GSH-E. Furthermore, inhibition of postprandial decrease of insulin sensitivity L-NMMA was not overcome by glucagon, but glucagon did not affect hepatic and plasma levels of NO. These results show that glucagon decreases postprandial insulin sensitivity through reducing hepatic GSH levels, an effect that is mimicked by increasing cAMP hepatic levels and requires physiological NO levels. These observations support the hypothesis that glucagon acts via adenylate cyclase to decrease hepatic GSH levels and induce insulin resistance. We suggest that the glucagon-cAMP-GSH axis is a potential therapeutic target to address insulin resistance in pathological conditions.
Collapse
Affiliation(s)
- Rita S. Patarrão
- Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal
| | - W. Wayne Lautt
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - M. Paula Macedo
- Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal
- APDP-ERC Portuguese Diabetes AssociationEducationand Research Center, Rua do Salitre, Lisboa, Portugal
- * E-mail:
| |
Collapse
|
15
|
Bilinsky LM, Reed MC, Nijhout HF. The role of skeletal muscle in liver glutathione metabolism during acetaminophen overdose. J Theor Biol 2015; 376:118-33. [PMID: 25890031 DOI: 10.1016/j.jtbi.2015.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/29/2015] [Accepted: 04/06/2015] [Indexed: 01/03/2023]
Abstract
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.
Collapse
Affiliation(s)
- L M Bilinsky
- Department of Mathematics, Duke University, United States.
| | - M C Reed
- Department of Mathematics, Duke University, United States
| | - H F Nijhout
- Department of Biology, Duke University, United States
| |
Collapse
|
16
|
Kumar SM, Swaminathan K, Clemens DL, Dey A. Modulation of GSH with exogenous agents leads to changes in glyoxalase 1 enzyme activity in VL-17A cells exposed to chronic alcohol plus high glucose. Food Funct 2014; 5:345-58. [PMID: 24352527 DOI: 10.1039/c3fo60354g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Gluthathione (GSH) is a major cellular antioxidant. The present study utilizing VL-17A cells exposed to chronic alcohol plus high glucose investigated the changes in oxidative stress, toxicity, and glyoxalase 1 activity as a detoxification pathway due to changes in GSH level through GSH supplementation with N-acetyl cysteine (NAC) or ursodeoxycholic acid (UDCA) and its depletion through buthionine sulfoximine (BSO) or diethyl maleate (DEM). Glyoxalase 1 plays an important role in detoxification of methylglyoxal which is formed as a precursor of advanced glycated end products formed due to high glucose mediated oxidative stress. Significant changes in glyoxalase 1 activity utilizing methylglyoxal or glyoxal as substrates occurred with NAC or UDCA or BSO or DEM supplementation in chronic alcohol plus high glucose treated VL-17A cells. NAC or UDCA administration in chronic alcohol plus high glucose treated VL-17A cells increased viability and decreased ROS levels, lipid peroxidation and 3-nitrotyrosine adduct formation. Similarly, GSH depletion with BSO or DEM had an opposite effect on the parameters in chronic alcohol plus high glucose treated VL-17A cells. In conclusion, modulation of GSH with NAC or UDCA or BSO or DEM leads to significant changes in oxidative stress, glyoxalase 1 enzyme activity and toxicity in chronic alcohol plus high glucose treated VL-17A cells.
Collapse
Affiliation(s)
- S Mathan Kumar
- Life Science Division, AU-KBC Research Centre, MIT Campus of Anna University, Chromepet, Chennai-600044, India.
| | | | | | | |
Collapse
|
17
|
Kabil O, Motl N, Banerjee R. H2S and its role in redox signaling. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1844:1355-66. [PMID: 24418393 PMCID: PMC4048824 DOI: 10.1016/j.bbapap.2014.01.002] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/19/2013] [Accepted: 01/02/2014] [Indexed: 02/08/2023]
Abstract
Hydrogen sulfide (H2S) has emerged as an important gaseous signaling molecule that is produced endogenously by enzymes in the sulfur metabolic network. H2S exerts its effects on multiple physiological processes important under both normal and pathological conditions. These functions include neuromodulation, regulation of blood pressure and cardiac function, inflammation, cellular energetics and apoptosis. Despite the recognition of its biological importance and its beneficial effects, the mechanism of H2S action and the regulation of its tissue levels remain unclear in part owing to its chemical and physical properties that render handling and analysis challenging. Furthermore, the multitude of potential H2S effects has made it difficult to dissect its signaling mechanism and to identify specific targets. In this review, we focus on H2S metabolism and provide an overview of the recent literature that sheds some light on its mechanism of action in cellular redox signaling in health and disease. This article is part of a Special Issue entitled: Thiol-Based Redox Processes.
Collapse
Affiliation(s)
- Omer Kabil
- University of Michigan Medical School, Ann Arbor, MI 48109-0600, USA
| | - Nicole Motl
- University of Michigan Medical School, Ann Arbor, MI 48109-0600, USA
| | - Ruma Banerjee
- University of Michigan Medical School, Ann Arbor, MI 48109-0600, USA.
| |
Collapse
|
18
|
Melideo SL, Jackson MR, Jorns MS. Biosynthesis of a central intermediate in hydrogen sulfide metabolism by a novel human sulfurtransferase and its yeast ortholog. Biochemistry 2014; 53:4739-53. [PMID: 24981631 PMCID: PMC4108183 DOI: 10.1021/bi500650h] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Human sulfide:quinone oxidoreductase (SQOR) catalyzes the conversion of H2S to thiosulfate, the first step in mammalian H2S metabolism. SQOR's inability to produce the glutathione persulfide (GSS(-)) substrate for sulfur dioxygenase (SDO) suggested that a thiosulfate:glutathione sulfurtransferase (TST) was required to provide the missing link between the SQOR and SDO reactions. Although TST could be purified from yeast, attempts to isolate the mammalian enzyme were not successful. We used bioinformatic approaches to identify genes likely to encode human TST (TSTD1) and its yeast ortholog (RDL1). Recombinant TSTD1 and RDL1 catalyze a predicted thiosulfate-dependent conversion of glutathione to GSS(-). Both enzymes contain a rhodanese homology domain and a single catalytically essential cysteine, which is converted to cysteine persulfide upon reaction with thiosulfate. GSS(-) is a potent inhibitor of TSTD1 and RDL1, as judged by initial rate accelerations and ≥25-fold lower Km values for glutathione observed in the presence of SDO. The combined action of GSS(-) and SDO is likely to regulate the biosynthesis of the reactive metabolite. SDO drives to completion p-toluenethiosulfonate:glutathione sulfurtransferase reactions catalyzed by TSTD1 and RDL1. The thermodynamic coupling of the irreversible SDO and reversible TST reactions provides a model for the physiologically relevant reaction with thiosulfate as the sulfane donor. The discovery of bacterial Rosetta Stone proteins that comprise fusions of SDO and TSTD1 provides phylogenetic evidence of the association of these enzymes. The presence of adjacent bacterial genes encoding SDO-TSTD1 fusion proteins and human-like SQORs suggests these prokaryotes and mammals exhibit strikingly similar pathways for H2S metabolism.
Collapse
Affiliation(s)
- Scott L Melideo
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine , Philadelphia, Pennsylvania 19102, United States
| | | | | |
Collapse
|
19
|
Anilakumar KR, Khanum F, Bawa AS. Effect of coriander seed powder (CSP) on 1, 2-dimethyl hydrazine-induced changes in antioxidant enzyme system and lipid peroxide formation in rats. J Diet Suppl 2013; 7:9-20. [PMID: 22435570 DOI: 10.3109/19390210903534970] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The effect of coriander seed powder (CSP), a culinary spice, on dimethyl hydrazine (DMH)-induced oxidative stress and toxicity in rats was investigated. Six groups of 6 male rats each were maintained for 12 weeks as (a) Control; (b) DMH (60 mg/kg body weight) injected; (c) 5% CSP incorporated diet; (d) 5% CSP incorporated diet + DMH; (e) 10% CSP incorporated diet; and (f) 10% CSP incorporated diet + DMH. The rats were sacrificed after 12 weeks. The results revealed that DMH administration lead to an increase in hepatic lipid peroxidation associated with reduction in levels of glutathione (GSH), activity of superoxide dismutase (SOD), and catalase and glucose-6-phosphate dehydrogenase. The coadministration of CSP and DMH diminished the hepatic malondialdehyde (MDA) significantly as compared to DMH-alone administered rats. The intake of coriander seeds at 10% level also enhanced the hepatic GSH-redox system by elevating GSH-Px, GSSGR, and GST activities. The DMH-induced decline in SOD and catalase activities was brought to normal by 10% CSP. The coadministration of CSP and the DMH produced a significant reduction in MDA and enhancement in catalase activity as compared to control. Coriander powder at 5% and 10% levels produced a significant rise in colonic catalase and GSH-Px. The coriander seeds produced significant beneficial effects by reducing the DMH-induced oxidative stress and enhancing the tissue levels of antioxidant/detoxification agent in tissues.
Collapse
Affiliation(s)
- K R Anilakumar
- Biochemistry and Nutrition Discipline, Defence Food Research Laboratory, Mysore, Karnataka, India.
| | | | | |
Collapse
|
20
|
Borburema J, Cezar M, Marques D, Cunha M, Pereira Filho J, Sousa W, Furtado D, Costa R. Efeito do regime alimentar sobre o perfil metabólico de ovinos Santa Inês em confinamento. ARQ BRAS MED VET ZOO 2012. [DOI: 10.1590/s0102-09352012000400027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Avaliou-se o perfil metabólico de 40 ovinos Santa Inês, inteiros, com peso vivo médio inicial de 17±1,7kg,, submetidos à restrição alimentar seguida de realimentação em confinamento, distribuídos em quatro tratamentos: 0, 20, 40 e 60% de restrição alimentar. Dois ensaios foram desenvolvidos, um referente à restrição e outro à realimentação. Para tanto, foi utilizado delineamento experimental inteiramente ao acaso, com quatro tratamentos e 10 repetições, e distribuído em fatorial cruzado 4x3. Observou-se na fase de restrição que os níveis de fósforo foram mais altos nos animais sob restrição alimentar; o mesmo ocorrendo na fase final para as concentrações de proteínas totais (PT), albumina (Alb) e colesterol total. A gama-glutamiltransferase (GGT) decresceu de forma linear com o aumento da restrição. No segundo ensaio, verificou-se que as concentrações de PT, Alb, globulina, colesterol total, lipoproteína de alta densidade, GGT e magnésio (Mg) apresentaram diferença (P<0,05) entre os períodos de coleta. Já na restrição prévia, observou-se comportamento linear decrescente para GGT e interação tratamento versus período de coleta para a concentração de cálcio. Os níveis de restrição alimentar afetaram o metabolismo proteico e não interferiram no metabolismo energético, e a realimentação resultou em alteração no metabolismo proteico, energético e mineral.
Collapse
|
21
|
Modulation of Liver l-γ-Glutamyl-l-cysteinylglycine Homeostasis By N-Acetyl-Glucosamine-thiazolidine-4(R)-carboxylic Acid in Mice. Am J Med Sci 2012; 343:310-5. [DOI: 10.1097/maj.0b013e31822b02f4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
22
|
Yang L, Shen J, He S, Hu G, Shen J, Wang F, Xu L, Dai W, Xiong J, Ni J, Guo C, Wan R, Wang X. L-cysteine administration attenuates pancreatic fibrosis induced by TNBS in rats by inhibiting the activation of pancreatic stellate cell. PLoS One 2012; 7:e31807. [PMID: 22359633 PMCID: PMC3281011 DOI: 10.1371/journal.pone.0031807] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 01/16/2012] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND AIMS Recent studies have shown that activated pancreatic stellate cells (PSCs) play a major role in pancreatic fibrogenesis. We aimed to study the effect of L-cysteine administration on fibrosis in chronic pancreatitis (CP) induced by trinitrobenzene sulfonic acid (TNBS) in rats and on the function of cultured PSCs. METHODS CP was induced by TNBS infusion into rat pancreatic ducts. L-cysteine was administrated for the duration of the experiment. Histological analysis and the contents of hydroxyproline were used to evaluate pancreatic damage and fibrosis. Immunohistochemical analysis of α-SMA in the pancreas was performed to detect the activation of PSCs in vivo. The collagen deposition related proteins and cytokines were determined by western blot analysis. DNA synthesis of cultured PSCs was evaluated by BrdU incorporation. We also evaluated the effect of L-cysteine on the cell cycle and cell activation by flow cytometry and immunocytochemistry. The expression of PDGFRβ, TGFβRII, collagen 1α1 and α-SMA of PSCs treated with different concentrations of L-cysteine was determined by western blot. Parameters of oxidant stress were evaluated in vitro and in vivo. Nrf2, NQO1, HO-1, IL-1β expression were evaluated in pancreas tissues by qRT-PCR. RESULTS The inhibition of pancreatic fibrosis by L-cysteine was confirmed by histological observation and hydroxyproline assay. α-SMA, TIMP1, IL-1β and TGF-β1 production decreased compared with the untreated group along with an increase in MMP2 production. L-cysteine suppressed the proliferation and extracellular matrix production of PSCs through down-regulating of PDGFRβ and TGFβRII. Concentrations of MDA+4-HNE were decreased by L-cysteine administration along with an increase in GSH levels both in tissues and cells. In addition, L-cysteine increased the mRNA expression of Nrf2, NQO1 and HO-1 and reduced the expression of IL-1β in L-cysteine treated group when compared with control group. CONCLUSION L-cysteine treatment attenuated pancreatic fibrosis in chronic pancreatitis in rats.
Collapse
Affiliation(s)
- LiJuan Yang
- Department of Gastroenterology, The First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - JiaQing Shen
- Department of Gastroenterology, The First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - ShanShan He
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - GuoYong Hu
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - Jie Shen
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - Feng Wang
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - Ling Xu
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - WeiQi Dai
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - Jie Xiong
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - JianBo Ni
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - ChuanYong Guo
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - Rong Wan
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| | - XingPeng Wang
- Department of Gastroenterology, The First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
- Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, People's Republic of China
| |
Collapse
|
23
|
Lautt WW, Ming Z, Legare DJ. Attenuation of age- and sucrose-induced insulin resistance and syndrome X by a synergistic antioxidant cocktail: the AMIS syndrome and HISS hypothesis. Can J Physiol Pharmacol 2011; 88:313-23. [PMID: 20393596 DOI: 10.1139/y09-130] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Absence of meal-induced insulin sensitization (AMIS) results in a predictable progression of dysfunctions, including postprandial hyperglycemia, compensatory hyperinsulinemia, resultant hyperlipidemia, increased oxidative stress, and obesity, progressing to syndrome X and diabetes. To one year of age, rats show a slow development of AMIS, but this can be potentiated by addition of a low-dose sucrose supplement to the diet. Provision of a synergistic antioxidant cocktail consisting of S-adenosylmethionine, vitamin E, and vitamin C (Samec) attenuates the rate and extent of development of AMIS in both normal aging animals and in aging animals on the sucrose diet. Adiposity, assessed from weighed regional fat masses and from bioelectrical impedance to estimate whole-body adiposity, correlated strongly with AMIS (r2 = 0.7-0.8). Rats given the sucrose supplement had accelerated AMIS and developed fasting hyperinsulinemia and postprandial hyperglycemia, hyperlipidemia, hyperinsulinemia, and adiposity. Samec completely compensated for the negative impact of this sucrose supplement and attenuated development of the associated dysfunctions. AMIS is explained by the HISS (hepatic insulin-sensitizing substance) hypothesis, which is outlined in the paper.
Collapse
Affiliation(s)
- W Wayne Lautt
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, 753 McDermot Avenue, Winnipeg, MB R3E 0T6, Canada.
| | | | | |
Collapse
|
24
|
Biterova EI, Barycki JJ. Structural basis for feedback and pharmacological inhibition of Saccharomyces cerevisiae glutamate cysteine ligase. J Biol Chem 2010; 285:14459-66. [PMID: 20220146 DOI: 10.1074/jbc.m110.104802] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Structural characterization of glutamate cysteine ligase (GCL), the enzyme that catalyzes the initial, rate-limiting step in glutathione biosynthesis, has revealed many of the molecular details of substrate recognition. To further delineate the mechanistic details of this critical enzyme, we have determined the structures of two inhibited forms of Saccharomyces cerevisiae GCL (ScGCL), which shares significant sequence identity with the human enzyme. In vivo, GCL activity is feedback regulated by glutathione. Examination of the structure of ScGCL-glutathione complex (2.5 A; R = 19.9%, R(free) = 25.1%) indicates that the inhibitor occupies both the glutamate- and the presumed cysteine-binding site and disrupts the previously observed Mg(2+) coordination in the ATP-binding site. l-Buthionine-S-sulfoximine (BSO) is a mechanism-based inhibitor of GCL and has been used extensively to deplete glutathione in cell culture and in vivo model systems. Inspection of the ScGCL-BSO structure (2.2 A; R = 18.1%, R(free) = 23.9%) confirms that BSO is phosphorylated on the sulfoximine nitrogen to generate the inhibitory species and reveals contacts that likely contribute to transition state stabilization. Overall, these structures advance our understanding of the molecular regulation of this critical enzyme and provide additional details of the catalytic mechanism of the enzyme.
Collapse
Affiliation(s)
- Ekaterina I Biterova
- Department of Biochemistry and the Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588, USA
| | | |
Collapse
|
25
|
Biterova EI, Barycki JJ. Mechanistic details of glutathione biosynthesis revealed by crystal structures of Saccharomyces cerevisiae glutamate cysteine ligase. J Biol Chem 2009; 284:32700-8. [PMID: 19726687 DOI: 10.1074/jbc.m109.025114] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glutathione is a thiol-disulfide exchange peptide critical for buffering oxidative or chemical stress, and an essential cofactor in several biosynthesis and detoxification pathways. The rate-limiting step in its de novo biosynthesis is catalyzed by glutamate cysteine ligase, a broadly expressed enzyme for which limited structural information is available in higher eukaryotic species. Structural data are critical to the understanding of clinical glutathione deficiency, as well as rational design of enzyme modulators that could impact human disease progression. Here, we have determined the structures of Saccharomyces cerevisiae glutamate cysteine ligase (ScGCL) in the presence of glutamate and MgCl(2) (2.1 A; R = 18.2%, R(free) = 21.9%), and in complex with glutamate, MgCl(2), and ADP (2.7 A; R = 19.0%, R(free) = 24.2%). Inspection of these structures reveals an unusual binding pocket for the alpha-carboxylate of the glutamate substrate and an ATP-independent Mg(2+) coordination site, clarifying the Mg(2+) dependence of the enzymatic reaction. The ScGCL structures were further used to generate a credible homology model of the catalytic subunit of human glutamate cysteine ligase (hGCLC). Examination of the hGCLC model suggests that post-translational modifications of cysteine residues may be involved in the regulation of enzymatic activity, and elucidates the molecular basis of glutathione deficiency associated with patient hGCLC mutations.
Collapse
Affiliation(s)
- Ekaterina I Biterova
- Department of Biochemistry and the Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664, USA
| | | |
Collapse
|
26
|
Jun J, Savransky V, Nanayakkara A, Bevans S, Li J, Smith PL, Polotsky VY. Intermittent hypoxia has organ-specific effects on oxidative stress. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1274-81. [PMID: 18703411 DOI: 10.1152/ajpregu.90346.2008] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Obstructive sleep apnea is characterized by upper airway collapse, leading to intermittent hypoxia (IH). It has been postulated that IH-induced oxidative stress may contribute to several chronic diseases associated with obstructive sleep apnea. We hypothesize that IH induces systemic oxidative stress by upregulating NADPH oxidase, a superoxide-generating enzyme. NADPH oxidase is regulated by a cytosolic p47(phox) subunit, which becomes phosphorylated during enzyme activation. Male C57BL/6J mice were exposed to IH with an inspired O(2) fraction nadir of 5% 60 times/h during the 12-h light phase (9 AM-9 PM) for 1 or 4 wk. In the aorta and heart, IH did not affect lipid peroxidation [malondialdehyde (MDA) level], nitrotyrosine level, or p47(phox) expression and phosphorylation. In contrast, in the liver, exposure to IH for 1 wk resulted in a trend to an increase in MDA levels, whereas IH for 4 wk resulted in a 38% increase in MDA levels accompanied by upregulation of p47(phox) expression and phosphorylation. Administration of an NADPH oxidase inhibitor, apocynin, during IH exposure attenuated IH-induced increases in hepatic MDA. In p47(phox)-deficient mice, MDA levels were higher at baseline and, unexpectedly, decreased during IH. In conclusion, oxidative stress levels and pathways under IH conditions are organ and duration specific.
Collapse
Affiliation(s)
- Jonathan Jun
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
| | | | | | | | | | | | | |
Collapse
|
27
|
Reed MC, Thomas RL, Pavisic J, James SJ, Ulrich CM, Nijhout HF. A mathematical model of glutathione metabolism. Theor Biol Med Model 2008; 5:8. [PMID: 18442411 PMCID: PMC2391141 DOI: 10.1186/1742-4682-5-8] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Accepted: 04/28/2008] [Indexed: 12/04/2022] Open
Abstract
Background Glutathione (GSH) plays an important role in anti-oxidant defense and detoxification reactions. It is primarily synthesized in the liver by the transsulfuration pathway and exported to provide precursors for in situ GSH synthesis by other tissues. Deficits in glutathione have been implicated in aging and a host of diseases including Alzheimer's disease, Parkinson's disease, cardiovascular disease, cancer, Down syndrome and autism. Approach We explore the properties of glutathione metabolism in the liver by experimenting with a mathematical model of one-carbon metabolism, the transsulfuration pathway, and glutathione synthesis, transport, and breakdown. The model is based on known properties of the enzymes and the regulation of those enzymes by oxidative stress. We explore the half-life of glutathione, the regulation of glutathione synthesis, and its sensitivity to fluctuations in amino acid input. We use the model to simulate the metabolic profiles previously observed in Down syndrome and autism and compare the model results to clinical data. Conclusion We show that the glutathione pools in hepatic cells and in the blood are quite insensitive to fluctuations in amino acid input and offer an explanation based on model predictions. In contrast, we show that hepatic glutathione pools are highly sensitive to the level of oxidative stress. The model shows that overexpression of genes on chromosome 21 and an increase in oxidative stress can explain the metabolic profile of Down syndrome. The model also correctly simulates the metabolic profile of autism when oxidative stress is substantially increased and the adenosine concentration is raised. Finally, we discuss how individual variation arises and its consequences for one-carbon and glutathione metabolism.
Collapse
Affiliation(s)
- Michael C Reed
- Department of Mathematics, Duke University, Durham, NC 27708, USA.
| | | | | | | | | | | |
Collapse
|
28
|
Oh C, Dong Y, Harman C, Mighty HE, Kopelman J, Thompson LP. Chronic hypoxia differentially increases glutathione content and gamma-glutamyl cysteine synthetase expression in fetal guinea pig organs. Early Hum Dev 2008; 84:121-7. [PMID: 17512683 PMCID: PMC6314291 DOI: 10.1016/j.earlhumdev.2007.03.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Revised: 03/02/2007] [Accepted: 03/28/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Glutathione is a natural antioxidant in the fetus and adult. We sought to determine whether maternal hypoxia alters glutathione levels in fetal organs as an adaptive response to the reduced oxygenation. STUDY DESIGN Timed pregnant guinea pigs were housed in either a Plexiglas chamber containing 10.5% O(2) from 46 to 60 days gestation (HPX, n=6) or in room air, as the normoxic control (NMX, n=5). Pregnant guinea pigs were anesthetized at near term ( approximately 60 days, term=65 days) and liver, lungand kidney were excised from anesthetized fetuses and stored frozen (-80 degrees C) prior to sample processing. Using the hypoxia marker, pimonidazole, we measured a hypoxia-induced increase in stained cells of fetal liver compared to no change in either the lung or kidney. To measure the effect of hypoxia among different organs, total glutathione (GSH) content and protein levels of gamma-glutamyl cysteine synthetase (gamma-GCS) were measured from the same organs. RESULTS Maternal hypoxia increased (P<0.05) total glutathione levels by 121% in the fetal liver but had no effect in either fetal lung or kidney. Chronic hypoxia increased (P<0.05) gamma-GCS protein levels in all three fetal organs studied. CONCLUSION These results demonstrate that the fetal response to maternal hypoxia may be organ specific. The increase in fetal liver glutathione via upregulation of gamma-GCS may be an important adaptive response to prolonged hypoxic stress.
Collapse
Affiliation(s)
- Chien Oh
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | | | | | | | | |
Collapse
|
29
|
Qin LQ, Wang Y, Xu JY, Kaneko T, Sato A, Wang PY. One-day dietary restriction changes hepatic metabolism and potentiates the hepatotoxicity of carbon tetrachloride and chloroform in rats. TOHOKU J EXP MED 2007; 212:379-87. [PMID: 17660703 DOI: 10.1620/tjem.212.379] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Although dietary restriction (DR) is common in modern society, research about hepatic metabolism and the hepatotoxicity induced by DR has been conducted less intensively than that induced by fasting. In the present study, we fed male Wistar rats at five levels of food intake for one day, including conventional feeding (60 kcal), three of DR (45, 30, and 15 kcal), and fasting (0 kcal), and observed the metabolic changes of hepatic cytochrome P450 2E1(CYP2E1) and the hepatotoxicity of chloroform (CHCl(3)) and carbon tetrachloride (CCl(4)). The CYP2E1 content was significantly increased in 15 kcal-food and fasting groups. The hepatic glutathione (GSH) content, which protects the liver from hepatotoxic agents, was depleted in 15 kcal-food and fasting groups. After the challenge by CHCl(3) and CCl(4), the activities of aspartate aminotransferase and alanine aminotransferase, marker enzymes for liver damage, were elevated remarkably at all food groups. Moreover, their activities increased significantly in DR groups, in comparison to the corresponding 60 kcal-food group. After the challenge, the hepatic GSH content was also depleted significantly in 15 kcal-food and fasting groups. CHCl(3) was cleared by hepatic metabolism about 8-10 times faster than that of CCl(4). Similarly, the areas under the blood concentration-time curve of CCl(4) was as much as twice that of the corresponding CHCl(3). In conclusion, when food was restricted to less than half of conventional amount, hepatic metabolism was affected and the hepatotoxicity induced by CCl(4) or CHCl(3) was augmented by, at least in part, CYP2E1 induction and GSH depletion.
Collapse
Affiliation(s)
- Li-Qiang Qin
- Department of Nutrition and Food Hygiene, School of Radiation Medicine and Public Health, Soochow University, Suzhou, China.
| | | | | | | | | | | |
Collapse
|
30
|
Morozova N, Khrapko K, Panee J, Liu W, Harney JW, Berry MJ. Glutathione depletion in hippocampal cells increases levels of H and L ferritin and glutathione S-transferase mRNAs. Genes Cells 2007; 12:561-7. [PMID: 17535247 DOI: 10.1111/j.1365-2443.2007.01074.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glutathione plays an essential role in maintaining cellular redox balance, protecting cells from oxidative stress and detoxifying xenobiotic compounds. Glutathione depletion has been implicated in neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. Cells of neuronal origin are acutely sensitive to glutathione depletion, providing an avenue for studying the mechanisms invoked for neuronal survival in response to oxidant challenge. We investigated the changes in mRNA profile in HT22 hippocampal cells following administration of homocysteic acid (HCA), a glutathione-depleting drug. We report that HCA treatment of HT22 murine hippocampal cells increases the levels of the mRNAs encoding at least three proteins involved in protection from oxidant injury, the mRNAs encoding heavy (H) and light (L) ferritin and glutathione S-transferase (GST).
Collapse
Affiliation(s)
- Nadya Morozova
- Thyroid Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | | | | | | | | | | |
Collapse
|
31
|
Colomb V, Petit J, Matheix-Fortunet H, Hecketsweiler B, Kaeffer N, Lerebours E, Colin R, Lemeland JF. Influence of antibiotics and food intake on liver glutathione and cytochrome P-450 in septic rats. Br J Nutr 2007. [DOI: 10.1079/bjn19950012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Experimental sepsis in rats induces a restriction in spontaneous food intake and a drop in liver glutathione, cytochrome P-450 (P-450) and aminopyrine demethylase (AD) activity. The present study was designed to assess the effects of antibiotics alone or when combined with food deprivation on these variables. Eighty-nine male Sprague-Dawley rats were assigned to six groups: control (C), acute infection (experimental pyelonephritis, I), acute infection with antibiotics and food givenad lib. (IA), control with antibiotics (CA), acute infection with antibiotics pair-fed to I (IAR), and sham-operated pair-fed to I (SR). Liver glutathione, P-450 and AD activities were reduced by 45·2, 79·8 and 41·2% respectively in group I. Glutathione and AD significantly increased only in those infected rats given antibiotics and allowed free access to food. P-450 did not normalize within the study period in infected rats receiving antibiotics and food repletion. The risk of drug hepatotoxicity in acute septic states is therefore closely related to the nutritional status. From this point of view, nutritional support is almost as important as treatment of infection.
Collapse
|
32
|
Jakoby WB. The glutathione S-transferases: a group of multifunctional detoxification proteins. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 46:383-414. [PMID: 345769 DOI: 10.1002/9780470122914.ch6] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The physiological roles of the glutathione S-transferases, by whatever name, seem to result in detoxification. As is true of albumin, members of this group of proteins bind an enormous number of compounds that appear to have in common only hydrophobic topography; the binding of bilirubin is an example of a major function common to all higher species. If the ligand bears a sufficiently electrophilic center, it will be attacked by the nucleophile GSH; such compounds would be the substrates of the enzyme. And should such a ligand be extraordinarily reactive--as, for example, some of the epoxide carcinogens generated by the cytochrome P450-linked, mixed-function oxidases, or even 1-chloro-2,4-dinitrobenzene--then reaction may occur either with GSH or irreversibly with the transferase itself. By reason of the wide distribution and high intracellular concentration of these proteins, there appears to be sufficient enzyme for all three roles in detoxification.
Collapse
|
33
|
Gilbert HF. Molecular and cellular aspects of thiol-disulfide exchange. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 63:69-172. [PMID: 2407068 DOI: 10.1002/9780470123096.ch2] [Citation(s) in RCA: 251] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- H F Gilbert
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030
| |
Collapse
|
34
|
Sorensen M, Sanz A, Gómez J, Pamplona R, Portero-Otín M, Gredilla R, Barja G. Effects of fasting on oxidative stress in rat liver mitochondria. Free Radic Res 2006; 40:339-47. [PMID: 16517498 DOI: 10.1080/10715760500250182] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
While moderate caloric restriction has beneficial effects on animal health state, fasting may be harmful. The present investigation was designed to test how fasting affects oxidative stress, and to find out whether the effects are opposite to those previously found in caloric restriction studies. We have focused on one of the main determinants of aging rate: the rate of mitochondrial free radical generation. Different parameters related to lipid and protein oxidative damage were also analyzed. Liver mitochondria from rats subjected to 72 h of fasting leaked more electrons per unit of O(2) consumed at complex III, than mitochondria from ad libitum fed rats. This increased leak led to a higher free radical generation under state 3 respiration using succinate as substrate. Regarding lipids, fasting altered fatty acid composition of hepatic membranes, increasing the double bond and the peroxidizability indexes. In accordance with this, we observed that hepatic membranes from the fasted animals were more sensitive to lipid peroxidation. Hepatic protein oxidative damage was also increased in fasted rats. Thus, the levels of oxidative modifications, produced either indirectly by reactive carbonyl compounds (N(epsilon)-malondialdehyde-lysine), or directly through amino acid oxidation (glutamic and aminoadipic semialdehydes) were elevated due to the fasting treatment in both liver tissue and liver mitochondria. The current study shows that severe food deprivation increases oxidative stress in rat liver, at least in part, by increasing mitochondrial free radical generation during state 3 respiration and by increasing the sensitivity of hepatic membranes to oxidative damage, suggesting that fasting and caloric restriction have different effects on liver mitochondrial oxidative stress.
Collapse
Affiliation(s)
- M Sorensen
- Danish Center for Molecular Gerontology, University of Aarhus, Department of Molecular Biology, 8000 Aarhus, Denmark
| | | | | | | | | | | | | |
Collapse
|
35
|
McMillan JM, McMillan DC. S-Adenosylmethionine but not glutathione protects against galactosamine-induced cytotoxicity in rat hepatocyte cultures. Toxicology 2006; 222:175-84. [PMID: 16564122 DOI: 10.1016/j.tox.2006.02.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 02/13/2006] [Accepted: 02/17/2006] [Indexed: 10/25/2022]
Abstract
A gradual but extensive depletion of hepatic GSH has long been known to accompany development of galactosamine-induced hepatotoxicity in rats, and some protection from liver injury has been observed after administration of sulfhydryl-donating compounds. Although these observations support a key role for GSH in the underlying mechanism, the impact of GSH depletion and repletion on the hepatotoxic response to galactosamine is unclear. To investigate the role of GSH in galactosamine-induced liver injury, we examined the effect of modulating GSH content on galactosamine toxicity in rat primary hepatocyte cultures. Galactosamine (4 mM) cytotoxicity was assessed by release of lactate dehydrogenase into the culture medium, and hepatocellular GSH content was measured by HPLC with electrochemical detection. The data indicated that prior depletion of GSH with either diethyl maleate or buthionine sulfoximine significantly enhanced galactosamine toxicity; however, addition of GSH-ester or alternate sulfur nucleophiles at various times during the incubation did not abrogate toxicity. In contrast, co-addition of S-adenosylmethionine (SAMe) with galactosamine exerted a marked protective effect without significantly altering hepatocyte GSH content. These data suggest that GSH depletion is not directly involved in the sequelae for galactosamine-induced hepatotoxicity, and raise the possibility that SAMe may have hepatoprotective effects that are not dependent on its ability to enhance GSH synthesis.
Collapse
Affiliation(s)
- Joellyn M McMillan
- Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston, SC 29425, USA.
| | | |
Collapse
|
36
|
Chen ZH, Yoshida Y, Saito Y, Sekine A, Noguchi N, Niki E. Induction of adaptive response and enhancement of PC12 cell tolerance by 7-hydroxycholesterol and 15-deoxy-delta(12,14)-prostaglandin J2 through up-regulation of cellular glutathione via different mechanisms. J Biol Chem 2006; 281:14440-5. [PMID: 16565077 DOI: 10.1074/jbc.m600260200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Increasing evidence suggests an adaptive response induced by reactive oxygen species and other physiologically existing oxidative stimuli. We have recently reported that a variety of lipid peroxidation products at sublethal concentrations could induce adaptive response and enhance PC12 cell tolerance, although the detailed underlying molecular mechanisms have not been clearly clarified. In the present study, we found that both 7-hydroxycholesterol (7-OHCh) and 15-deoxy-delta(12,14)-prostaglandin J2 (15d-PGJ2) at sublethal concentrations significantly increased the cellular GSH as well as the enzyme activity of glutamate-cysteine ligase (GCL), the rate-limiting enzyme of GSH synthesis. Depletion of cellular GSH by buthionine sulfoximine completely abolished the adaptive response. Interestingly, treatment with 15d-PGJ2 significantly increased the gene expression of both subunits of GCL in an NF-E2-related factor 2 (Nrf2)-dependent manner, whereas neither 7-OHCh induced any considerable changes on the GCL gene expression nor did the Nrf2-small interfering RNA treatment exert any appreciable effects on the GSH elevation and subsequent adaptive response induced by 7-OHCh. These results demonstrate that the adaptive response induced by both 7-OHCh and 15d-PGJ2 is mediated similarly through the up-regulation of GSH but via different mechanisms.
Collapse
Affiliation(s)
- Zhi-Hua Chen
- Human Stress Signal Research Center, National Institute of Advanced Industrial Science and Technology, 1-8-31, Midorigaoka, Ikeda, Osaka, 563-8577, Japan.
| | | | | | | | | | | |
Collapse
|
37
|
Zaidi SMKR, Al-Qirim TM, Banu N. Effects of antioxidant vitamins on glutathione depletion and lipid peroxidation induced by restraint stress in the rat liver. Drugs R D 2005; 6:157-65. [PMID: 15869319 DOI: 10.2165/00126839-200506030-00004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND AND AIM Stress as a cofactor has been reported to affect the progression and severity of several diseases. The influence of stress on the liver is of interest from the clinical point of view because stress plays a potential role in aggravating liver diseases in general and hepatic inflammation in particular, probably through generation of reactive oxygen species. The present study was undertaken to investigate the potential of the antioxidant vitamins A (retinol), E (tocopherol) and C (ascorbic acid) individually and in combination (vitamin E + C) to modulate restraint stress-induced oxidative changes. These effects were determined by measuring changes in hepatic levels of free radical scavenging enzymes such as superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase, as well as levels of total glutathione (GSH), malondialdehyde (MDA), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). METHODS Immobilisation was achieved by placing the animals in wire mesh cages of their size. The rats were orally administered vitamins A, E and C individually and in combination (E + C) prior to and after 6 hours of immobilisation stress exposure. The hepatic levels of SOD, GST, catalase, GSH and MDA were determined by spectrophotometric methods. Liver SOD activity was assayed by monitoring the amount of enzyme required to inhibit autoxidation of pyrogallol by 50%. Hepatic GST was monitored by following the increase in absorbance at 340 nm of CDNB-GSH conjugate generated due to GST catalysis between GSH and CDNB. Catalase activity in liver tissues was determined using peroxidase as the substrate. Lipid peroxidation was measured by determining the level of thiobarbituric acid reactive substances. ALT and AST were determined by commercial kits. RESULTS Six hours of immobilisation stress caused a decrease in liver levels of SOD (p = 0.001), catalase (p = 0.031), GST (p = 0.021) and GSH (0.013), while levels of MDA (p = 0.0015), AST (p = 0.05) and ALT (p = 0.046) were increased compared with non-stressed control rats. Both pre-vitamin stress and post-vitamin stress treatments either alone or in combination were associated with increased normalisation of these parameters towards control values, with post-vitamin treatment being the more effective of the two. Vitamins E and C individually were found to be more effective in restoring the endogenous antioxidant system than vitamin A. The combined vitamin (E + C) post-stress treatment was found to be effective but not additive in combating hepatic oxidative stress. The beneficial effects of these vitamin treatments were also reflected in reversions of altered AST and ALT levels towards their control values. CONCLUSION Vitamins E or C alone or in combination can be given as prophylactic/therapeutic supplements for combating scavenging free radicals generated in liver tissue. This approach may reduce oxidative stress caused by diseases such as cirrhosis.
Collapse
Affiliation(s)
- S M Kashif R Zaidi
- Department of Biochemistry, Faculty of Life Science, Aligarh Muslim University, Aligarh, India
| | | | | |
Collapse
|
38
|
Salehi P, Churchill TA. The influence of short-term fasting on the quality of small bowel graft preservation. Cryobiology 2005; 50:83-92. [PMID: 15710372 DOI: 10.1016/j.cryobiol.2004.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Revised: 11/24/2004] [Accepted: 11/30/2004] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Donor nutritional status may be a determinant of small bowel (SB) quality following storage. In this study, we investigated the effect of donor nutritional status and a proven nutrient-rich preservation solution on graft quality following cold storage. METHODS Rats were fasted (12-14 h) or non-fasted. SB (n=6) was flushed vascularly with modified University of Wisconsin (UW) solution and flushed luminally with UW or an amino acid-rich (AA) solution as follows: Fasted. UWV, none; UWL, UW solution; AAL, AA solution. Non-fasted. UWV, none; UWL, UW solution; AAL, AA solution. Energetics, peroxidation (malondialdehyde; MDA), glutathione and histology were assessed over 24 h at 4 degrees C. RESULTS Energetics (ATP, ATP/ADP, and energy charge) were significantly higher in AAL (fasted and non-fasted) groups than other groups. However, there were no differences in energetics parameters between fasted and non-fasted animals in all groups. MDA was higher in fasted groups than non-fasted tissues; interestingly, AAL values were up to 10-fold lower than other groups. Higher glutathione levels were detected in non-fasted AAL tissues. Mucosal integrity was markedly superior in luminally treated tissues (UWL and AAL) in fasted and non-fasted states. Most noteably, AAL tissues from fasted animals exhibited grade 2 injury (villus clefting), whereas normal mucosa was observed in non-fasted tissues (grade 0). CONCLUSION Luminal flushing and a nutrient-rich preservation solution improve energetics, oxidative stress, and mucosal integrity during storage. Poorer donor nutritional status does not affect energetics throughout storage, but causes mucosal injury as a result of increased oxidative stress, even after a brief period of donor fasting.
Collapse
Affiliation(s)
- Payam Salehi
- Surgical-Medical Research Institute, 1074 Dentistry-Pharmacy Building, University of Alberta, Edmonton, Alta., Canada T6G 2N8
| | | |
Collapse
|
39
|
Richie JP, Komninou D, Leutzinger Y, Kleinman W, Orentreich N, Malloy V, Zimmerman JA. Tissue glutathione and cysteine levels in methionine-restricted rats. Nutrition 2004; 20:800-5. [PMID: 15325691 DOI: 10.1016/j.nut.2004.05.009] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Previously, we demonstrated that lifelong methionine (Met) restriction (MR) increases lifespan, decreases the incidence of aging-related diseases, increases blood glutathione (GSH) levels, and prevents loss of GSH during aging in rats. Our present objective was to elucidate the effects of MR on GSH metabolism and transport by determining the time course and nature of GSH and cysteine changes in blood and other tissues in young and mature rats. METHODS Male F-344 rats were placed on control (0.86% Met) or MR (0.17% Met) defined amino acid diets at age 7 wk and killed at different times thereafter. MR was also initiated in adult (12-mo-old) rats. RESULTS Throughout the first 2 mo of MR, blood GSH levels increased 84% and liver GSH decreased 66% in relation to controls. After this period, liver GSH levels remained constant through at least 6 mo. GSH levels also decreased in the pancreas (80%) and kidney (22%) but remained unchanged in other tissues examined after 11 wk of MR. The increase in blood GSH was evident as soon as 1 wk after initiating MR and reached a plateau by 6 wk. A similar increase in erythrocyte GSH levels was observed when MR was administered to mature adult rats. Fasting decreased liver GSH in controls but had no further effect in MR animals. By 1 mo, cysteine levels had decreased in all tissues except brain. CONCLUSION These results suggest that adaptive changes occur in the metabolism of Met, cysteine, and/or GSH as a result of MR in young and adult rats. These early metabolic changes lead to conservation of GSH levels in most extrahepatic tissues and increased GSH in erythrocytes by depleting liver GSH to a critical level.
Collapse
Affiliation(s)
- John P Richie
- Division of Epidemiology and Cancer Susceptibility, American Health Foundation Cancer Center, Institute for Cancer Prevention, Valhalla, NY 10595, USA.
| | | | | | | | | | | | | |
Collapse
|
40
|
Zenger F, Russmann S, Junker E, Wüthrich C, Bui MH, Lauterburg BH. Decreased glutathione in patients with anorexia nervosa. Risk factor for toxic liver injury? Eur J Clin Nutr 2004; 58:238-43. [PMID: 14749742 DOI: 10.1038/sj.ejcn.1601772] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To investigate glutathione and amino acids related to glutathione metabolism in patients with anorexia nervosa in order to test the hypothesis that these patients exhibit a deficiency of glutathione and therefore might be at an increased risk of developing toxic liver injury. DESIGN Controlled observatory study and case report. SETTING University Hospital. SUBJECTS Subjects included 11 female patients with anorexia nervosa and 12 healthy female controls. INTERVENTIONS Determination of fasting free and total glutathione, homocysteine, vitamins B(6) and B(12) and folic acid in plasma. RESULTS A 14-y-old patient with a body mass index of 12.6 kg/m(2) presented with markedly elevated transaminases (ALAT >50 x upper limit of normal), and paracetamol was detected in her blood. Patients with anorexia nervosa exhibited lower circulating concentrations of free cysteine (8.9+/-1.5 vs 12.0+/-1.4 micromol/l) and free and total glutathione (5.0+/-1.3 vs 7.1+/-1.2 and 11.2+/-3.8 vs 16.2+/-5.0 micromol/l, respectively). The plasma concentrations of homocysteine (17.5+/-4.9 vs 12.0+/-3.8 micromol/l) and also of glycine (194+/-37 vs 143+/-41 micromol/l) and glutamine (422+/-51 vs 353+/-51 micromol/l) were significantly higher in patients with anorexia nervosa who were not deficient in folic acid, vitamin B(6) and B(12). CONCLUSIONS Lower plasma concentrations of glutathione suggest lower intracellular concentrations of the tripeptide. Higher homocysteine, glycine and glutamine concentrations point to a decreased utilization of these amino acids for glutathione synthesis and an impairment of trans-sulfuration. Consequently, the capacity of patients with anorexia nervosa to detoxify electrophilic metabolites and reactive oxygen species via glutathione may be impaired.
Collapse
Affiliation(s)
- F Zenger
- Department of Clinical Pharmacology, University of Bern, Switzerland
| | | | | | | | | | | |
Collapse
|
41
|
Serviddio G, Pereda J, Pallardó FV, Carretero J, Borras C, Cutrin J, Vendemiale G, Poli G, Viña J, Sastre J. Ursodeoxycholic acid protects against secondary biliary cirrhosis in rats by preventing mitochondrial oxidative stress. Hepatology 2004; 39:711-20. [PMID: 14999689 DOI: 10.1002/hep.20101] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ursodeoxycholic acid (UDCA) improves clinical and biochemical indices in primary biliary cirrhosis and prolongs survival free of liver transplantation. Recently, it was suggested that the cytoprotective mechanisms of UDCA may be mediated by protection against oxidative stress, which is involved in the development of cirrhosis induced by chronic cholestasis. The aims of the current study were 1) to identify the mechanisms involved in glutathione depletion, oxidative stress, and mitochondrial impairment during biliary cirrhosis induced by chronic cholestasis in rats; and 2) to determine the mechanisms associated with the protective effects of UDCA against secondary biliary cirrhosis. The findings of the current study indicate that UDCA partially prevents hepatic and mitochondrial glutathione depletion and oxidation resulting from chronic cholestasis. Impairment of biliary excretion was accompanied by decreased steady-state hepatic levels of gamma-glutamyl cysteine synthetase and gamma-cystathionase messenger RNAs. UDCA treatment led to up-regulation of gamma-glutamyl cysteine synthetase in animals with secondary biliary cirrhosis and prevented the marked increases in mitochondrial peroxide production and hydroxynonenal-protein adduct production that are observed during chronic cholestasis. A population of damaged and primarily apoptotic hepatocytes characterized by dramatic decreases in mitochondrial cardiolipin levels and membrane potential as well as phosphatidylserine exposure evolves in secondary biliary cirrhosis. UDCA treatment prevents the growth of this population along with the decreases in mitochondrial cardiolipin levels and membrane potential that are induced by chronic cholestasis. In conclusion, UDCA treatment enhances the antioxidant defense mediated by glutathione; in doing so, this treatment prevents cardiolipin depletion and cell injury in animals with secondary biliary cirrhosis.
Collapse
Affiliation(s)
- Gaetano Serviddio
- Department of Medical and Occupational Sciences, University of Foggia, Foggia, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Sugimoto M, Saiki Y, Zhang D, Kawai F. Cloning and characterization of preferentially expressed genes in an aluminum-tolerant mutant derived from Penicillium chrysogenum IFO4626. FEMS Microbiol Lett 2004; 230:137-42. [PMID: 14734176 DOI: 10.1016/s0378-1097(03)00886-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
cDNAs expressed preferentially in an Al-tolerant microorganism were isolated by subtraction hybridization with cDNAs of Al-sensitive Penicillium chrysogenum IFO4626 as driver cDNA and cDNAs of the Al-tolerant mutant derived from the wild cells by UV irradiation as tester cDNA. Northern blot analysis revealed that mRNA levels of six genes were increased significantly in the Al-tolerant mutant after exposure to Al stress when compared with the wild cells. Two genes accumulated in both the presence and absence of Al stress and four genes were induced by Al stress in the Al-tolerant mutant. cDNA fragments were amplified by rapid amplification of cDNA ends and sequenced to obtain full-length cDNAs of the six genes. Two genes were novel or predicted ones and the others showed significant homology to known genes, ADP/ATP translocase, enolase, cysteine synthase, and glucoamylase, which are induced by environmental stresses in prokaryotic and eukaryotic cells. These enzyme activities increased in the Al-tolerant mutant when compared to those in the wild cells, showing that not only the levels of gene expression but also the levels of enzyme activities increased in the Al-tolerant mutant.
Collapse
Affiliation(s)
- Manabu Sugimoto
- Research Institute for Bioresources, Okayama University, 2-20-1 Chuo, Kurashiki, Okayama, Japan.
| | | | | | | |
Collapse
|
43
|
Zaragozá R, García C, Rus AD, Pallardó FV, Barber T, Torres L, Miralles VJ, Viña JR. Inhibition of liver trans-sulphuration pathway by propargylglycine mimics gene expression changes found in the mammary gland of weaned lactating rats: role of glutathione. Biochem J 2003; 373:825-34. [PMID: 12723969 PMCID: PMC1223532 DOI: 10.1042/bj20030387] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2003] [Revised: 04/11/2003] [Accepted: 05/01/2003] [Indexed: 01/11/2023]
Abstract
In the lactating mammary gland, weaning produces mitochondrial cytochrome c release and nuclear DNA fragmentation, as determined by gel electrophoresis. This is followed by a significant decrease in lactation. Weaning for 2 h produces an early induction of the tumour suppressor/transcription factor p53, whereas the oncoprotein c-Jun and c-Jun N-terminal kinase are elevated after 24 h of weaning when compared with controls. The expression of p21(cip1) and p27(kip1), cyclin-dependent kinase inhibitors, was significantly higher in weaned rats when compared with control lactating rats. All the changes mentioned above also happen in the lactating mammary gland when propargylglycine, an inhibitor of the liver trans-sulphuration pathway, is administered. This effect is partially reversed by N -acetylcysteine administration. The administration of buthionine sulphoximine, an irreversible inhibitor of gamma-glutamylcysteine synthetase, to lactating rats produces a decrease in GSH levels and changes in protein concentrations and gene transcripts similar to those in rats with impaired trans-sulphuration pathway. These data suggest that the inter-tissue flux of GSH is an important mechanism of L-cysteine delivery to the lactating mammary gland and emphasize the importance of this physiological event in maintaining the gene expression required to sustain lactation.
Collapse
Affiliation(s)
- Rosa Zaragozá
- Departamento de Bioquímica y Biología Molecular, Facultades de Medicina y Farmacia, Universidad de Valencia, Avda Blasco Ibañez 17, 46010 Valencia, Spain
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Bobyn PJ, Franklin JL, Wall CM, Thornhill JA, Juurlink BHJ, Paterson PG. The effects of dietary sulfur amino acid deficiency on rat brain glutathione concentration and neural damage in global hemispheric hypoxia-ischemia. Nutr Neurosci 2002; 5:407-16. [PMID: 12509070 DOI: 10.1080/1028415021000055952] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Primary brain injury in stroke is followed by an excitotoxic cascade, oxidative stress and further neural damage. Glutathione is critical and depleted in oxidative stress. Since cysteine is limiting in glutathione synthesis, this study investigated the effect of dietary sulfur amino acid (SAA) deficiency on neural damage in a rat model of global hemispheric hypoxia-ischemia (GHHI). Animals were fed with SAA deficient ("deficient") or control diet for 3 days, subjected to right common carotid artery ligation and hypoxia, and diet continued for 3 more days. Histologically evaluated neural damage at 7 days post hypoxia-ischemia was greater in "deficient" rats, shown by mean (+/- SEM) global and hippocampal grid scores of 2.5 +/- 0.7 and 34.9 +/- 9.3%, respectively, vs. controls' scores of 0.1 +/- 0.1 and 0.1 +/- 0.1%, respectively. Mean brain (+/- SEM) reduced glutathione was not different between groups at 6h post hypoxia-ischemia, but was decreased in "deficient" animals 3 days later in neocortex (1.46 micromoles/g wet weight +/- 0.05 vs. 1.67 +/- 0.04 in controls) and thalamus (1.60 micromoles/g wet weight +/- 0.05 vs. 1.78 +/- 0.03 in controls). Administration of a cysteine precursor to "deficient" animals did not ameliorate neural damage. These findings suggest that well-nourished but not "deficient" animals tolerate a mild brain insult. The decline in brain glutathione in the "deficient" animals may be one of several contributing mechanisms.
Collapse
Affiliation(s)
- P Joan Bobyn
- College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Sask., S7N 5C9, Canada
| | | | | | | | | | | |
Collapse
|
45
|
Tsuchiya K, Kirima K, Yoshizumi M, Houchi H, Tamaki T, Mason RP. The role of thiol and nitrosothiol compounds in the nitric oxide-forming reactions of the iron-N-methyl-d-glucamine dithiocarbamate complex. Biochem J 2002; 367:771-9. [PMID: 12141947 PMCID: PMC1222930 DOI: 10.1042/bj20020310] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2002] [Revised: 07/05/2002] [Accepted: 07/26/2002] [Indexed: 11/17/2022]
Abstract
The object of the present study is to investigate whether the physiologically dominant thiol compounds such as GSH and cysteine or their nitrosothiol compounds affect the formation of the iron- N -methyl-D-glucamine dithiocarbamate [(MGD)(2)Fe(2+)]-nitric oxide complex. The present study provided experimental evidence that physiological concentrations of GSH (approx. 5 mM) and L-cysteine (approx. 0.5 mM) accelerated the formation of the (MGD)(2)Fe(2+)-NO complex from nitrite by two and three times respectively. The rate constants for the reduction of (MGD)(3)Fe(3+) to (MGD)(2)Fe(2+) by GSH and cysteine were calculated as 1.3 and 2.0x10(2) M(-1).s(-1) respectively. Furthermore, depletion of GSH was demonstrated in PC12 cells, and thiol compounds enhanced the formation of reactive oxygen species by the (MGD)(2)Fe(2+) complex by accelerating its redox turnover. The main effect of the physiological concentration of thiols was the reduction of (MGD)(3)Fe(3+). S -nitrosoglutathione spontaneously reacted with (MGD)(2)Fe(2+) to produce the (MGD)(2)Fe(2+)-NO complex with a 1:2 stoichiometry. In fact, (MGD)(2)Fe(2+) was as good an indicator of nitrosothiols as it was of NO itself. The present study elucidates the difficulties of utilizing the (MGD)(2)Fe(2+) complex for the quantification of NO in biological samples, especially in vivo.
Collapse
Affiliation(s)
- Koichiro Tsuchiya
- Department of Pharmacology, University of Tokushima School of Medicine, Tokushima 770-8503, Japan.
| | | | | | | | | | | |
Collapse
|
46
|
Miñana JB, Gómez-Cambronero L, Lloret A, Pallardó FV, Del Olmo J, Escudero A, Rodrigo JM, Pellíin A, Viña JR, Viña J, Sastre J. Mitochondrial oxidative stress and CD95 ligand: a dual mechanism for hepatocyte apoptosis in chronic alcoholism. Hepatology 2002; 35:1205-14. [PMID: 11981771 DOI: 10.1053/jhep.2002.32969] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Apoptosis plays an important role in the progression of alcohol-induced liver disease to cirrhosis. Oxidative stress is an early event in the development of apoptosis. The major aim of this study was to study the conditions in which oxidative stress occurs in chronic alcoholism and its relationship with apoptosis of hepatocytes. We have found that oxidative stress is associated with chronic ethanol consumption in humans and in rats, in the former independently of the existence of alcohol-induced liver disease. Ethanol or acetaldehyde induces apoptosis in hepatocytes isolated from alcoholic rats, but not in those from control rats. Inhibition of aldehyde dehydrogenase, but not of cytochrome P450 2E1, prevents ethanol-induced cell death. Ethanol-induced apoptosis is caused by increased reactive oxygen species (ROS) driven by increased availability of the reduced form of nicotinamide-adenine dinucleotide (NADH) owing to mitochondrial acetaldehyde metabolism and it is prevented by blocking the opening of mitochondrial permeability transition (MPT) pores with cyclosporine A. Inhibition of nitric oxide (NO) synthase or addition of antioxidant vitamins C and E completely prevented ethanol-induced apoptosis. Mitochondrial oxidative stress, which occurs during chronic alcoholism, renders hepatocytes susceptible to apoptosis. On the other hand, the CD95 ligand expression was up-regulated by acetaldehyde. In conclusion, ethanol induces apoptosis via 2 different pathways: MPT and up-regulation of the expression of CD95-Fas ligand. The overproduction of ROS by mitochondria, driven by acetaldehyde metabolism, is a common trigger of both mechanisms.
Collapse
Affiliation(s)
- Juan B Miñana
- Departamento de Fisiología, Facultad de Medicina, Universitat de València, Valencia, Spain
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
|
48
|
Viña JR, Giménez A, Corbacho A, Puertes IR, Borrás E, García C, Barber T. Blood sulfur-amino acid concentration reflects an impairment of liver transsulfuration pathway in patients with acute abdominal inflammatory processes. Br J Nutr 2001; 85:173-8. [PMID: 11242485 DOI: 10.1079/bjn2000237] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Whole-blood free amino acids were measured in a control group made up of eight healthy women fasted for 12 h and also in eight patients with acute pancreatitis, five patients with acute cholecystitis and seven patients with acute appendicitis. Blood was withdrawn immediately on admission to hospital and again 3 d later following a controlled peripheral parenteral nutrition diet; this is with the exception of the appendicitis group. l-Cystathionine and l-methionine concentrations were significantly higher in pancreatitis and appendicitis patients when compared with controls. In the pancreatitis and cholecystitis patients, l-serine concentration was also significantly higher when compared with controls. The l-homocysteine concentration was significantly higher only in the appendicitis group when compared with the control group. l-Cystine concentration was unchanged in all the patients studied when compared with control subjects. The l-methionine : l-cystine ratio was significantly higher and the l-glutamine : l-cystine ratio was significantly lower in all the patients when compared with controls. The blood S-amino acid pattern reflects an impairment in liver transsulfuration pathway during acute abdominal processes. This work supports the idea that the l-methionine : l-cystine and l-glutamine : l-cystine ratios can be taken as good markers to evaluate the S-amino acid metabolism and suggests the importance of using N-acetylcysteine as a required nutrient in these situations.
Collapse
Affiliation(s)
- J R Viña
- Dpto Bioquímica y Biología Molecular, Facultades de Medicina y Farmacia, Universidad de Valencia, Spain.
| | | | | | | | | | | | | |
Collapse
|
49
|
Affiliation(s)
- S C Lu
- Department of Medicine, University of Southern California School of Medicine, Los Angeles 90033, USA
| |
Collapse
|
50
|
VIANNA DE OLIVEIRA IM, PAULO RHYD, FUJIMORI E. Efeito da restrição energética na atividade hepática da gama-glutamiltranspeptidase e nos níveis de glutationa. REV NUTR 2000. [DOI: 10.1590/s1415-52732000000100007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Avaliou-se o efeito da restrição energética aguda (crescimento pós-desmame) e crônica (lactantes desnutridas desde o período pré-natal e seus filhotes) na atividade da gama-glutamiltranspeptidase e nos níveis de glutationa. O consumo da dieta foi ad libitum (controle) ou com restrição de 30% (desnutrido), tendo-se conduzido dois ensaios, um de desnutrição aguda e outro de desnutrição crônica. A restrição aguda provocou redução significativa no ganho ponderal dos ratos em crescimento, mas as mães cronicamente desnutridas ganharam significativamente mais peso/filhote, pois apresentaram menor número de filhotes. Não foram observadas alterações significativas nos níveis de glutationa, na atividade da gama-glutamiltranspeptidase e mesmo na concentração de proteína hepática sob o efeito da restrição energética, aguda ou crônica. Menor desequilíbrio no perfil de aminoácidos plasmáticos e na síntese protéica, conseqüente à desnutrição energética e não à protéica, pode justificar estes resultados.
Collapse
|