Advance Access Publication

American Journal of Respiratory and Critical Care Medicine, 2004

Chronic neutrophilic inflammation leads to oxidative damage, which may play an important role for the pathogenesis of cystic fibrosis lung disease. Bronchoalveolar lavage levels of the antioxidant glutathione are diminished in cystic fibrosis patients.

Journal of cystic fibrosis : official journal of the European Cystic Fibrosis Society, 2015

In cystic fibrosis (CF) the defective CF transmembrane conductance regulator protein may be responsible for the impaired transport of glutathione (GSH), the first line defense of the lung against oxidative stress. The aim of this single-blind, randomized, placebo-controlled trial was to evaluate the effect of inhaled GSH in patients with CF. 54 adult and 51 pediatric patients were randomized to receive inhaled GSH or placebo twice daily for 12months. Twelve month treatment with inhaled GSH did not achieve our predetermined primary outcome measure of 15% improvement in FEV1%. Only in patients with moderate lung disease, 3, 6 and 9months therapy with GSH resulted in a statistically significant increase of FEV1 values from the baseline. Moreover GSH therapy improved 6-minute walking test in pediatric population. GSH was well tolerated by all patients. Inhaled GSH has slight positive effects in CF patients with moderate lung disease warranting further study. ClinicalTrials.gov; No.: NCT...

Biochemical pharmacology, 1984

Thirty-minute perfusion of isolated rabbit lungs with a Krebs-Ringer bicarbonate buffer containing 420 @f paraquat (PQ) or nitrofurantoin (NF) resulted in increases in lung oxidized glutathione (GSSG) content of 589 and 2656%, respectively, over control levels. The degree of glutathione efflux was also increased with both agents, i.e. 77 and 238% above control leakage for PQ and NF respectively. The pulmonary toxicity of both compounds is known to be heightened by conditions of hyperoxia(O2). Ventilation of lungs with 95% Or-5% CO2 did not, in itself, significantly alter glutathione efflux, GSH or GSSG levels. However, ventilation with 95% 0r5% CO* increased lung GSSG levels in PQ-perfused lungs 225% over PQ-air-perfused lungs, a combined effect not observed with NF-02, wherein mean GSSG levels were only 72% of that observed with NF-air. Glutathione efflux in PQ-OZ-treated lungs declined somewhat (20%) compared to that observed with PQ-air, but a significant increase in the amount of glutathione efflux was seen with NF-Or-treated lungs, i.e. 120 and 310%, respectively, over that attributable to NF or O2 alone. Although the biochemical mechanisms of toxicity of these compounds are thought to be very similar, the disparate degree of GSH oxidation observed with equimolar levels of PQ and NF may indicate differences in reactivity towards glutathione and other lung s~~ydryl pools. The stim~ation of the oxidative effects of PQ and NF on lung GSH due to hyperoxic ventilation may be related to the reported 02 enhancement of their toxicity.

American Journal of Respiratory Cell and Molecular Biology, 1995

Cells in most culture media use cystine as the primary source of the cysteine precursor needed for glutathione (GSH) synthesis. As a result, GSH levels in many cultured cells may be limited by the rate of uptake of cystine into cells. We have shown that incubation with extracellular GSH can result in the reaction of GSH with cystine to generate cysteine, and that bovine pulmonary artery endothelial cells and lung type II epithelial cells transported cysteine more efficiently than cystine. Cystine transport was not affected by the presence of GSH. In cells incubated with GSH in RPMI-1640 there was a cystine-dependent increase in intracellular GSH levels. The increases in GSH were not prevented by the presence of acivicin, an inhibitor of they -glutamyl transpeptidase reaction. Incubation with oxidized glutathione (GSSG) did not result in significant increases in intracellular GSH levels. We conclude that a primary mechanism by which extracellular GSH may increase intracellular GSH levels in cultured cells is by reducing cystine to cysteine, which is then rapidly transported and used as a substrate for intracellular GSH synthesis. Multiple factors control intracellular glutathione (GSH) levels. Adenosine triphosphate-dependent-y-glutamylcysteine synthetase, the rate-limiting enzyme in the GSH synthesis pathway, is subject to feedback inhibition by GSH (1,2). Alternatively, aSH synthesis may be limited by the availability of substrate (1, 3-6), glutamate, cysteine, or glycine. Glutamate and glycine are rarely rate limiting (5, 7). However, cysteine may be limiting, particularly in cell cultures (3, 7). Cysteine is primarily taken up by a transport system shared with serine and alanine (system ASC) (5) and can also be obtained by reduction of cystine, which is transported into many cells by a sodium-independent transport system (x-c) shared with glutamate (3, 5-8). In addition, they -glutamyl transpeptidase reaction may be used to break down extracellular GSH and transport the resultant amino acids into the cell for use in the resynthesis ofGSH (9, 10). Extracellular GSH reacts with the membranebound enzyme, whereupon they -glutamyl moiety is transferred to an amino acid acceptor. In the presence of excess cysteine,-y-glutamylcysteine can be formed, which could be

Molecular Aspects of Medicine, 2009

Glutathione (γ-glutamyl-cysteinyl-glycine, GSH) is the most abundant intracellular antioxidant thiol and is central to redox defense during oxidative stress. GSH metabolism is tightly regulated and has been implicated in redox signaling and also in protection against environmental oxidant-mediated injury. Changes in the ratio of the reduced and disulfide form (GSH/GSSG) can affect signaling pathways that participate in a broad array of physiological responses from cell proliferation, autophagy and apoptosis to gene expression that involve H 2 O 2 as a second messenger. Oxidative stress due to oxidant/antioxidant imbalance and also due to environmental oxidants is an important component during inflammation and respiratory diseases such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, acute respiratory distress syndrome, and asthma. It is known to activate multiple stress kinase pathways and redox sensitive transcription factors such as Nrf2, NF-κB and AP-1, which differentially regulate the genes for pro-inflammatory cytokines as well as the protective antioxidant genes. Understanding the regulatory mechanisms for the induction of antioxidants, such as GSH, versus pro-inflammatory mediators at sites of oxidant-directed injuries may allow for the development of novel therapies which will allow pharmacological manipulation GSH synthesis during inflammation and oxidative injury. This article features the current knowledge about the role of GSH in redox signaling, GSH biosynthesis and particularly the regulation of transcription factor Nrf2 by GSH and downstream signaling during oxidative stress and inflammation in various pulmonary diseases. We also discussed the current therapeutic clinical trials using GSH and other thiol compounds, such as N-acetyl-L-cysteine, fudosteine, carbocysteine, erdosteine in environment-induced airways disease.

AJP: Lung Cellular and Molecular Physiology, 2007

In patients with chronic obstructive pulmonary disease (COPD), an imbalance between oxidants and antioxidants is acknowledged to result in disease development and progression. Cigarette smoke (CS) is known to deplete total glutathione (GSH + GSSG) in the airways. We hypothesized that components in the gaseous phase of CS may irreversibly react with GSH to form GSH derivatives that cannot be reduced (GSX), thereby causing this depletion. To understand this phenomenon, we investigated the effect of CS on GSH metabolism and identified the actual GSX compounds. CS and H2O2 (control) deplete reduced GSH in solution [Δ = −54.1 ± 1.7 μM ( P < 0.01) and −39.8 ± 0.9 μM ( P < 0.01), respectively]. However, a significant decrease of GSH + GSSG was observed after CS (Δ = −75.1 ± 7.6 μM, P < 0.01), but not after H2O2. Exposure of A549 cells and primary bronchial epithelial cells to CS decreased free sulfhydryl (-SH) groups (Δ = −64.2 ± 14.6 μM/mg protein, P < 0.05) and irreversibly m...

Biochimica et Biophysica Acta (BBA) - General Subjects, 2011

Background: Oxidative stress in an important hallmark of asthma and much research has therefore focused on the predominant antioxidant in the lungs, namely the tripeptide glutathione. Major conclusions: In lung samples of patients with asthma increased levels of glutathione are typically observed, which appear to relate to the level of pulmonary inflammation and are therefore regarded as an adaptive response to the associated oxidative stress. Also in blood samples increased total GSH levels have been reported, representing the systemic inflammatory component of the disease. In addition, a number of the antioxidant enzymes involved in the maintenance of the GSH/GSSG ratio as well as enzymes that utilize GSH have been found to be altered in the lungs and blood of asthmatics and will be summarized in this review. Very few studies have however linked enzymatic alterations to GSH levels or found that either of these correlated with disease severity. Some animal studies have started to investigate the pathophysiological role of GSH biochemistry in asthma and have yielded surprising results. Important in this respect is the physiological role of the GSH redox equilibrium in determining the outcome of immune responses, which could be deregulated in asthmatics and contribute to the disease. Scope of review: Clinical data as well as animal and cell culture studies regarding these aspects of GSH in the context of asthma will be summarized and discussed in this review. This article is part of a Special Issue entitled: Biochemistry of Asthma.

2001

Inflammatory lung diseases are characterized by chronic inflammation and oxidant/antioxidant imbalance, a major cause of cell damage. The development of an oxidant/antioxidant imbalance in lung inflammation may activate redox-sensitive transcription factors such as nuclear factor-kB, and activator protein-1 (AP-1), which regulate the genes for pro-inflammatory mediators and protective antioxidant genes. Glutathione (GSH), a ubiquitous tripeptide thiol, is a vital intra-and extracellular protective antioxidant against oxidative/nitrosative stresses, which plays a key role in the control of pro-inflammatory processes in the lungs. Recent findings have suggested that GSH is important in immune modulation, remodelling of the extracellular matrix, apoptosis and mitochondrial respiration. The rate-limiting enzyme in GSH synthesis is c-glutamylcysteine synthetase (c-GCS). The human c-GCS heavy and light subunits are regulated by AP-1 and antioxidant response elements and are modulated by oxidants, phenolic antioxidants, growth factors, and inflammatory and anti-inflammatory agents in lung cells. Alterations in alveolar and lung GSH metabolism are widely recognized as a central feature of many inflammatory lung diseases such as idiopathic pulmonary fibrosis, acute respiratory distress syndrome, cystic fibrosis and asthma. The imbalance and/or genetic variation in antioxidant c-GCS and pro-inflammatory versus antioxidant genes in response to oxidative stress and inflammation in some individuals may render them more susceptible to lung inflammation. Knowledge of the mechanisms of GSH regulation and balance between the release and expression of pro-and anti-inflammatory mediators could lead to the development of novel therapies based on the pharmacological manipulation of the production as well as gene transfer of this important antioxidant in lung inflammation and injury. This review describes the redox control and involvement of nuclear factor-kB and activator protein-1 in the regulation of cellular glutathione and c-glutamylcysteine synthetase under conditions of oxidative stress and inflammation, the role of glutathione in oxidant-mediated susceptibility/tolerance, c-glutamylcysteine synthetase genetic susceptibility and the potential therapeutic role of glutathione and its precursors in protecting against lung oxidant stress, inflammation and injury.

Frontiers in pharmacology, 2014

Asthma is characterized by airway inflammation. Inflammation is associated with oxidant stress. Airway epithelial cells are shielded from this stress by a thin layer of lung lining fluid (LLF) which contains an abundance of the antioxidant glutathione. LLF glutathione metabolism is regulated by γ-glutamyl transferase (GGT). Loss of LLF GGT activity in the mutant GGT(enu1) mouse causes an increase in baseline LLF glutathione content which is magnified in an IL-13 model of allergic airway inflammation and protective against asthma. Normal mice are susceptible to asthma in this model but can be protected with acivicin, a GGT inhibitor. GGT is a target to treat asthma but acivicin toxicity limits clinical use. GGsTop is a novel GGT inhibitor. GGsTop inhibits LLF GGT activity only when delivered through the airway. In the IL-13 model, mice treated with IL-13 and GGsTop exhibit a lung inflammatory response similar to that of mice treated with IL-13 alone. But mice treated with IL-13 and G...

European Respiratory Journal, 2014

The Journal of Alternative and Complementary Medicine, 2013

Purpose: Glutathione depletion has been documented in several disease states, and exogenous administration has been hypothesized to have therapeutic potential for some conditions. In an effort to reach target tissues of the sinuses and central nervous system (CNS), glutathione is being prescribed as an intranasal spray, although no literature exists to support this mode of administration. The objective of this study was to describe patientreported outcomes in a population of individuals who have been prescribed intranasal reduced glutathione, (in)GSH. Methods: A survey was designed to assess individuals' perception of tolerability, adverse events, and health benefits associated with (in)GSH use. Using a pharmacy database, 300 individuals were randomly selected to receive a survey; any individual who had received one or more prescriptions for (in)GSH between March 2009 and March 2011 was eligible for participation. Results: Seventy (70) individuals returned the survey (23.3% response rate) from 20 different states. Reported indications for (in)GSH prescriptions were multiple chemical sensitivity (MCS) (n = 29), allergies/sinusitis (n = 25), Parkinson disease (PD) (n = 7), Lyme disease (n = 3), fatigue (n = 2), and other (n = 10). Of the respondents, 78.8% (n = 52) reported an overall positive experience with (in)GSH, 12.1% (n = 8) reported having experienced adverse effects, and 62.1% (n = 41) reported having experienced health benefits attributable to (in)GSH use. Over 86% of respondents considered the nasal spray to be comfortable and easy to administer. Conclusions: This is the first study to evaluate patient-reported outcomes among individuals across the country who have been prescribed (in)GSH. The majority of survey respondents considered (in)GSH to be effective and without significant adverse effects. (in)GSH should be further evaluated as a method of treating respiratory and CNS diseases where free-radical burden is a suspected contributor to disease progression.

BioFactors, 2003

Molecules , 2021

This study aimed to review and critically appraise the current methodological issues undermining the suitability of the measurement of serum/plasma glutathione, both in the total and reduced form, as a measure of systemic oxidative stress in chronic obstructive pulmonary disease (COPD). Fourteen relevant articles published between 2001 and 2020, in 2003 subjects, 1111 COPD patients, and 892 controls, were reviewed. Nine studies, in 902 COPD patients and 660 controls, measured glutathione (GSH) in the reduced form (rGSH), while the remaining five, in 209 COPD patients and 232 controls, measured total GSH (tGSH). In the control group, tGSH ranged between 5.7 and 7.5 µmol/L, whilst in COPD patients, it ranged between 4.5 and 7.4 µmol/L. The mean tGSH was 6.6 ± 0.9 µmol/L in controls and 5.9 ± 1.4 µmol/L in patients. The concentrations of rGSH in the control group showed a wide range, between 0.47 and 415 µmol/L, and a mean value of 71.9 ± 143.1 µmol/L. Similarly, the concentrations of rGSH in COPD patients ranged between 0.49 and 279 µmol/L, with a mean value of 49.9 ± 95.9 µmol/L. Pooled tGSH concentrations were not significantly different between patients and controls (standard mean difference (SMD) = −1.92, 95% CI −1582 to 0.0219; p = 0.057). Depending on whether the mean concentrations of rGSH in controls were within the accepted normal range of 0.5-5.0 µmol/L, pooled rGSH concentrations showed either a significant (SMD = −3.8, 95% CI −2.266 to −0.709; p < 0.0001) or nonsignificant (SMD = −0.712, 95% CI −0.627 to 0.293; p = 0.48) difference. These results illustrate the existing and largely unaddressed methodo-logical issues in the interpretation of the serum/plasma concentrations of tGSH and rGSH in COPD.

Clinical <html_ent glyph="@amp;" ascii="&amp;"/> Experimental Allergy, 2002

Background The bronchial epithelium is exposed to reactive oxygen species (ROS) derived from cigarette smoke, air pollutants and activated leucocytes. Glutathione (GSH) prevents ROS-mediated loss of cell function, tissue injury and in¯ammation, and its synthesis is regulated by gglutamylcysteine synthetase (g-GCS). However, the capacity of bronchial epithelial cells to adapt to oxidative stress and the mechanisms involved are not known. Objective To investigate the effects of oxidative stress on the regulation of GSH synthesis in human bronchial epithelial (NCI-H292) cells.

American Journal of Physiology-Lung Cellular and Molecular Physiology, 2015

Oxidant-mediated tissue injury is key to the pathogenesis of acute lung injury. Glutathione- S-transferases (GSTs) are important detoxifying enzymes that catalyze the conjugation of glutathione with toxic oxidant compounds and are associated with acute and chronic inflammatory lung diseases. We hypothesized that attenuation of cellular GST enzymes would augment intracellular oxidative and metabolic stress and induce lung cell injury. Treatment of murine lung epithelial cells with GST inhibitors, ethacrynic acid (EA), and caffeic acid compromised lung epithelial cell viability in a concentration-dependent manner. These inhibitors also potentiated cell injury induced by hydrogen peroxide (H2O2), tert-butyl-hydroperoxide, and hypoxia and reoxygenation (HR). SiRNA-mediated attenuation of GST-π but not GST-μ expression reduced cell viability and significantly enhanced stress (H2O2/HR)-induced injury. GST inhibitors also induced intracellular oxidative stress (measured by dihydrorhodamine...