Activity Of Glutathione-dependent Enzymes Research Articles

Clustering patients with late-life depression by blood glutathione-dependent enzymatic activities for stratification of a heterogeneous group

IntroductionWe have previously found significant alterations in activities of glutathione dependent enzymes in blood cells of patients with late-life depression (LLD) compared with age-matched controls.ObjectivesThe revealing subgroups of LLD patients by glutathione-metabolism enzymes’ activities in blood cells using cluster analysis.Methods LLD patients (n=101) of 60-86 age (69 patients with recurrent depression (RD), 23 with bipolar disorder (BD) and 9 patients with a single depressive episode (DE)) were assessed by Hamilton depression rating scale (HAMD-17), and Hamilton Anxiety Rating Scale (HARS). Activity levels of glutathione reductase (GR) and glutathione S-transferase (GST) were determined in patients’ platelets (-pl) and erythrocytes (-er). The control group consisted of 51 peoples 55-84 years old without mental pathology. Cluster analysis module of the STATISTICA software was used for clustering the patients by baseline blood parameters.Results Three clusters of patients were obtained: C1, n=39, C2, n=31, C3, n=31, differing significantly in all biochemical parameters (Kruskal-Wallis test, p<0.001), except GST. When compared with control group by Mann-Whitney test, GST-pl, GST-er, and GR-er were significantly decreased in C1; GST-er was significantly increased in C2; GST-pl, GR-pl, and GR-er were significantly decreased in C3. Several significant correlations were found between the measured parameters and scores by HDRS or HAMD-17. In C1, baseline activity of GST-er correlated with total scores by HAMD-17 (R=0.335, p=0.043) after treatment. In C2, baseline activity of GR-er correlated with total scores by HARS (R=-0.376, p=0,037) after treatment and GR-pl correlated with delta scores by HAMD-17 under the treatment (R=0.484, p=0.006). No significant correlations were found in C3. Patients with BD distributed significantly unevenly between C1, C2, and C3, with significantly more BD patients clustering in C1 (61%) compared with C2 and C3 (Yetes-corrected Chi-square =7.73, p=0.0054), whereas patients with RD and DE distributed evenly.Conclusions Patterns of activity levels for glutathione-dependent enzymes in patients with BD differ from those in patients with RD and DE. Significant correlations of the measured biochemical parameters with scores by HDRS or HAMD-17 assessed after the treatment and evidenced for the treatment efficacy seem to be promising biomarkers for further evaluation of the treatment efficacy in heterogeneous group of LLD patients using the proposed approach to their stratification into subgroups.Disclosure of InterestNone Declared

Dynamics of the content of reactive oxygen species and the state of the glutathione system in the oral cavity during subchronic intoxication wuth the fungicide thiram and its antioxidant correction.

Thiram is a dithiocarbamate derivative, which is used as a fungicide for seed dressing and spraying during the vegetation period of plants, and also as an active vulcanization accelerator in the production of rubber-based rubber products. In this study the content of reactive oxygen species (ROS) and the state of the glutathione system have been investigated in the oral fluid and gum tissues of adult male Wistar rats treated with thiram for 28 days during its administration with food at a dose of 1/50 LD50. Thiram induced formation of ROS in the oral cavity; this was accompanied by an imbalance in the ratio of reduced and oxidized forms of glutathione due to a decrease in glutathione and an increase in its oxidized form as compared to the control. Thiram administration caused an increase in the activity of glutathione-dependent enzymes (glutathione peroxidase, glutathione transferase, and glutathione reductase). However, the time-course of enzyme activation in the gum tissues and oral fluid varied in dependence on the time of exposure to thiram. In the oral fluid of thiram-treated rats changes in the antioxidant glutathione system appeared earlier. The standard diet did not allow the glutathione pool to be fully restored to physiological levels after cessation of thiram intake. The use of exogenous antioxidants resviratrol and an Echinacea purpurea extract led to the restoration of redox homeostasis in the oral cavity.

Proinflammatory activity of monocytes and activity of glutathione-dependent enzymes in red blood cells in women with depressive conditions

To search for possible connections between the anti-inflammatory activity of monocytes (PAM) and the activity of glutathione metabolic enzymes: glutathione reductase (GR) and glutathione-S-transferase (GT) in patients with depressive states (DS) within various mental pathologies, as well as between the studied biological parameters and clinical condition of patients. Sixty-one women, aged 18-56 years, with DC were examined before and after treatment. Symptom severity was assessed using the Positive and Negative Syndrome Scale (PANSS) and the Hamilton Depressive Symptom Rating Scale (HDRS-21). The control group included 23 women of the corresponding age without mental pathology. Biological parameters were assessed in the peripheral blood of patients and healthy people. Patients with a high level of PAM compared to the control (p<0.001) (subgroup 1, n=31) and with a low (at the control level) level (subgroup 2, n=30) were identified. In the subgroup 1, the values of GR and GT were significantly lower than in patients of subgroup 2 (p<0.05 and p<0.01, respectively). Negative correlations between the level of PAM before treatment and GR before and after treatment were revealed in patients who responded to treatment (r=-0.67; p=0.0041; r=-0.76; p=0.0001). The results may indicate the inverse relationship between the level of PAM and the activity of GR and GT, which are involved in the pathogenesis of DC, and can also serve as criteria for assessing the response of patients to treatment.

Alterations in the activity of glutathione-dependent enzymes in erythrocytes of patients with acute pancreatitis of varying severity

Alterations in the activity of glutathione-dependent enzymes in erythrocytes of patients with acute pancreatitis of varying severity

AUT-M enterosorbent stabilizes glutathione system in vincristine-treated rats with dimethylhydrazine-induced colon cancer

Colorectal cancer is one of the leading causes of mortality in the world. The search for new methods of therapy for this disease that could correct the state of oxidative stress during the development of neoplasms is up to date. The aim of this work was to study the level of reduced glutathione and the activity of glutathione-dependent enzymes in the development of 1,2 dimethylhydrazine-induced colon cancer in rats while treated with vincristine and the use of enterosorbent. To induce carcinogenesis, dimethylhydrazine was administered to male rats subcutaneously for 30 weeks at a dose of 7.2 mg/kg of body weight. The rats with induced colon cancer received entorosorbent per os at a dose of 0.2 g per 100 g of body weight daily for 21 days. After detoxification therapy, the rats were administered cytostatic vincristine daily at a dose of 0.23 mg/kg for 14 days. A decrease in the content of reduced glutathione, the activity of glutathione reductase and glutathione peroxidase in the blood and liver tissue of rats with colorectal cancer was established. The use of enterosorbent­ AUT-M was shown to be effective in stabilizing the indicators of the glutathione system in rats with induced colon cancer. Cytostatic vincristine did not significantly affect the change of the studied indicators, confirming the effectiveness of previous sorption measures. Keywords: blood, colorectal cancer, entorosorbent, glutathione, glutathione peroxidase, glutathione reductase, liver, vincristine

Environmental relevant concentrations of polystyrene nanoplastics and lead co-exposure triggered cellular cytotoxicity responses and underlying mechanisms in Eisenia fetida

Heavy metal pollution of soils and the widespread use of plastics have caused environmental problems worldwide. Nanoplastics (NPs) contaminants in water and soil environments can adsorb heavy metals, thereby affecting the bioavailability and toxicity of heavy metals. In this paper, the effect of co-exposure of polystyrene microspheres with 100 nm particle size and lead acetate (Pb) on the Eisenia fetida coelomocytes was investigated. The environmental concentration of NPs used was 0.01 mg/L and the concentration of Pb ranged from 0.01 to 1 mg/L, and the exposed cells were incubated at 298 k for 24 h. Our study demonstrated that exposure of cells to environmental relevant concentrations of NPs did not significantly affect the cytotoxicity of Pb exposure. It was shown that co-exposure induced cellular production of reactive oxygen species (ROS, increased to 134.4 %) disrupted the antioxidant system of earthworm body cavity cells, activated superoxide dismutase and catalase (CAT), produced reduced glutathione, and inhibited glutathione-dependent enzyme (GST) activity (Reduced to 64 %). Total antioxidant capacity (T-AOC) is first enhanced against ROS due to the stress of NPs and Pb. When the antioxidant reserves of cells are exhausted, the antioxidant capacity will decrease. The level of malondialdehyde, a biomarker of eventual lipid peroxidation, increased to 231.7 %. At the molecular level, due to co-exposure to NPs and Pb, CAT was loosely structured and the secondary structure is misfolded, which was responsible for exacerbating oxidative damage in E. fetida coelomocytes. The findings of this study have significant implications for the toxicological interaction and future risk assessment of co-contamination of NPs and Pb in the environment.

Time-dependent changes in oxidative stress biomarkers and activities of lysosomal and antioxidant enzymes in hepatic tissue of rainbow trout (Oncorhynchus mykiss Walbaum) following vaccination against Yersinia ruckeri

Abstract This study analyzed time-dependent effects of vaccination against Y. ruckeri on the oxidative mechanism underlying those effects by detecting relevant lipid peroxidation (2-thiobarbituric acid reactive substances, TBARS) and protein oxidation biomarkers [aldehydic and ketonic derivatives of oxidatively modified proteins (OMP)], antioxidant defenses [activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), total antioxidant capacity (TAC)], as well as activities of lysosomal functioning [alanyl aminopeptidase (AAP), leucyl aminopeptidase (LAP), acid phosphatase (AcP), and β-N-acetylglucosaminidase (NAG)] in hepatic tissue of rainbow trout, Oncorhynchus mykiss (Walbaum) following anti-Y. ruckeri vaccination in the first, second, and sixth months. A concentrated vaccine with Y. ruckeri strains was enclosed in fish feed and was administered three times every other day. Rainbow trout from each group were euthanized 31, 61, and 181 days following vaccination, and hepatic tissue was sampled for analysis. In the current study, vaccination against Y. ruckeri resulted in a no statistically significant change in TBARS levels, while aldehydic and ketonic derivatives of OMP in hepatic tissue decreased, especially after the first and second months following immunization. Moreover, the activities of glutathione-dependent enzymes increased, especially after the first and sixth months. The highest TAC levels were observed two and six months after vaccination. It has been shown that vaccination-related oxidative stress in hepatic tissue is involved in adaptive responses through the temporary mobilization of antioxidant and lysosomal enzymes in rainbow trout. The present study showed the effect of vaccination on lysosome membrane permeability for carbohydrate cleavage after the development of immunity against Yersinia, whereas antioxidant defence was reduced. Our results confirmed that the concept of preserving antioxidant enzyme function after vaccination was also evident when CAT, GR, and GPx activities either increased or were unchanged following vaccination.

Heavy metal(loid) effect on multi-biomarker responses in apex predator: Novel assays in the monitoring of white stork nestlings

The goal of the present study was to investigate differences in biomarker responses related to metal(loid)s in white stork (Ciconia ciconia) nestling's blood from continental Croatia. To achieve this, a battery of biomarkers that can be affected by environmental pollutants, including metal(loid)s, was assessed (esterase activity, fluorescence–based oxidative stress biomarkers, metallothionein levels, glutathione–dependent enzyme activity). The research was conducted during the white stork breeding season in diverse areas (a landfill, industrial and agricultural sites, and an unpolluted area). White storks' nestlings near the landfill exhibited reduced carboxylesterase (CES) activity, elevated glutathione (GSH) concentration, as well as high Pb content in the blood. Increased As and Hg concentrations in blood were attributable to environmental contamination in agricultural area and an assumed unpolluted area, respectively. Furthermore, agricultural practices appeared to affect CES activity, as well as elevate Se levels. In addition to the successful implementation of biomarkers, present research showed that agricultural areas and a landfill are areas with increased metal(loid) levels possibly causing adverse effects on the white storks. This first–time heavy metal and metalloid analyses in the white stork nestlings from Croatia point to the necessary monitoring and future assessments of pollution impact to prevent irreversible adverse effects.

Вплив мексидолу на глутатіонову систему мозку щурів при моделюванні хвороби Паркінсона

We studied the effects of mexidol (3-oxy-6-methyl-2-ethylpiridine succinate) on the antioxidant glutathione system in rat brain mitochondria in experimental Parkinson’s disease induced by rotenone administration. Wistar rats were divided into the following groups of 6 in each: I - intact rats (control); II - rotenone (3 mg/kg per day) was injected subcutaneously for 2 weeks; III - after rotenone intoxication, mexidol (50 mg/kg per day) was injected intraperitoneally for 2 weeks. In the suspension of brain mitochondria, the activity of NADH dehydrogenase (complex I of the mitochondrial respiratory chain), content of the active products of 2-thiobarbituric acid (TBA-AP), the reduced (GSH) and oxidized (GSSG) glutathione amounts, the activity of glutathione-dependent enzymes: glutathione peroxidase (GP) and glutathione reductase (GR) as well as NADH+-isocitrate-dehydrogenase activity (NADPH+- ICDH) were measured. The activity and protein expression of MnSOD and GP in rat brain mitochondria were estimated. Treatment of rats with mexidol led to a weakening of oxidative processes in brain mitochondria in comparison with rats exposed to rotenone intoxication. It was shown that intraperitoneal injections of mexidol led to a decrease in the TBA-AP and in the GSSG content and to an increase in GSH/GSSG ratio in comparison with rotenone intoxication. It was also registered an increase in the activity of NADH-dehydrogenase. Such changes indicated a weakening of the mitochondrial oxidative processes intensity. Treatment of rats with mexidol promoted an increase in GSH content, GR and NADPH+-ICDH activities in brain mitochondria in comparison with rotenone administration. Treatment with mexidol resulted to an increased activity and protein expression of GP and MnSOD. We conclude that mexidol reduced the rotenone-induced damage of rat brain mitochondria increasing the action of glutathione-dependent and NADPH+-generating enzymes.

Expression of glutation enzymes in splenic tissue is influenced by thiosemicarbazide derivatives

The administration of new Schiff heterocyclic bases and their copper (II) complexes, thiosemicarbazide derivatives induces various influences on the activity of glutathione-dependent enzymes in splenic tissue. The selective action of the studied compounds on the expression of glutathione enzymes is evident, which is manifested by a tendency of insignificant decrease of glutathione reductase (GR) and glutathione peroxidase (GPO), insignificant increase of glutathione-S-transferase (GST) and marked depression of glutaredoxin levels. The slight increase of GST under the action of the studied compounds can be considered as a protective reaction aimed at stagnating the intensity of peroxide processes and supporting the activity of the glutathione cycle, and decreased the activity of glutaredoxin denotes their antiproliferative, cytostatic effect. Further studies are needed to evaluate the mechanisms of action of the investigated compounds on the activity of glutathione-dependent enzymes in other biosystems and animal experiments, to assess the practical importance of the obtained results.

Association of genetic variants in the GPX1 and GPX4 genes with the activities of glutathione-dependent enzymes, their interaction with smoking and the risk of acute pancreatitis

Genetic factors and tobacco smoke exposure can be associated with an increased risk of acute pancreatitis (AP). The pathogenesis of AP is associated with intensive oxidative stress. Glutathione peroxidase (GPx) is one of many enzymes involved in the neutralization of free radicals. This study aimed to investigate the impact of SNP rs1050450 in the GPX1 gene and rs713041 in the GPX4 gene on the activity of total GPx in a group of AP patients and healthy subjects. It was found that AP can contribute to decreased GPx activity (in plasma and erythrocyte lysate) accompanied by an increased glutathione reductase (GR) activity and decreased glutathione (GSH) concentration in two groups, non-smokers and smokers. A decreased GPx activity in erythrocyte lysate of AP patients compared to healthy subjects was associated with the occurrence of the CC genotype for SNP rs1050450. It was noted an increased GPx activity and decreased GR activity in erythrocytes of non-smoking AP patients with the TT genotype compared to subjects with the CC and TC genotype for SNP rs713041. However, in the group of smoking AP patients with this genotype, GR activity was elevated compared to non-smokers, which was accompanied by increased GSH concentration. These results can indicate that smoking in the course of AP can change the involvement of antioxidants in dependence on the genotype for the examined SNPs. The CC genotype for SNP rs1050450 and the TT genotype for rs713041 increases the risk of AP recurrence, which may be associated with increased MDA concentration.

Glutathione-dependent system in the blood of gastric cancer patients with various tumor histotypes and prevalence of the disease

Purpose of the study. Exploring the erythrocyte glutathione system functioning in patients with gastric cancer in a comparative aspect, depending on tumor histotype and disease prevalence.Patients and methods. The study included 89 patients with gastric cancer, divided into 6 groups depending on the histotype of the tumor. Separately, the results of the study were analyzed in patients with T4 status according to TNM and in patients at stage 4. The content of reduced glutathione and the activity of glutathione-dependent enzymes in the erythrocytes of the patients' blood were studied by conventional spectrophotometric methods. Statistical processing of the results was carried out using the Statistika 6.0 software package according to the Student's t-test and the nonparametric Wilcoxon-Mann-Whitney test for two independent samples.Results. An increase in the content of glutathione was revealed in patients with gastric cancer compared with the group without oncopathology. The maximum increase was observed in patients with low-grade adenocarcinoma - by 42.5 %, while in signet ring cell carcinoma (SRCC) there was only a tendency to increase by 17.8 %. Glutathione reductase activity was decreased in adenocarcinoma by 23.4-26.2 % and did not change in SRCC. The activity of the antioxidant enzymes glutathione peroxidase and glutathione transferase was increased in all groups, and especially in SRCC - by 76 % and 23-29 %, respectively. In patients with the T4 status and at stage IV of the process, a lower activity of the studied glutathione-dependent enzymes was revealed in comparison with all other groups of patients.Conclusions. The data obtained indicate a greater functional potential of the glutathione system in SRCC. A significant increase in glutathione transferase activity at a sufficiently high level of reduced glutathione can contribute to the development of treatment resistance in SRCC patients.

Indoxyl sulfate, homocysteine, and antioxidant capacities in patients at different stages of chronic kidney disease.

BACKGROUND/OBJECTIVESIncreased levels of uremic toxins and decreased antioxidant capacity have a significant impact on the progression of chronic kidney disease (CKD). However, it remains unclear whether they interact with each other to mediate the damage of kidney function. The purpose of this study was to investigate whether uremic toxins (i.e., homocysteine and indoxyl sulfate [IS]), as well as glutathione-dependent antioxidant enzyme activities are dependently or independently associated with kidney function during different stages of CKD patients.SUBJECTS/METHODSOne hundred thirty-two patients diagnosed with CKD at stages 1 to 5 participated in this cross-sectional study.RESULTSPatients who had reached an advanced CKD stage experienced an increase in plasma uremic toxin levels, along with decreased glutathione peroxidase (GSH-Px) activity. Plasma homocysteine, cysteine, and IS concentrations were all positively associated with each other, but negatively correlated to GSH-Px activity levels after adjusting for potential confounders in all CKD patients. Although plasma homocysteine, cysteine, IS, and GSH-Px levels were significantly associated with kidney function, only plasma IS levels still had a significant association with kidney function after these parameters were simultaneously adjusted. In addition, plasma IS could interact with GSH-Px activity to be associated with kidney function.CONCLUSIONSIS plays a more dominant role than homocysteine and GSH-Px activity in relation to kidney function.

Content of Carbonyl Compounds and Parameters of Glutathione Metabolism in Men with Type 1 Diabetes Mellitus at Preclinical Stages of Diabetic Nephropathy.

The content of carbonyl compounds (methylglyoxal and TBA-reactive substances) and components of the glutathione system (activities of glutathione-dependent enzymes, content of oxidized and reduced glutathione) and their interrelationships were studied in men of young reproductive age with type 1 diabetes mellitus at the stages of normo- and microalbuminuria. In patients with normoalbuminuria, the level of methylglyoxal, reduced and oxidized glutathione, and glutathione reductase activity were increased and the content of TBA-reactive substances was decreased. In the group with microalbuminuria, an increase in content of methylglyoxal and activity of glutathione-dependent enzymes relative to the control values were observed; the content of TBA-reactive substances was increased and glutathione reductase activity was decreased relative to the group with normoalbuminuria. In patients with microalbuminuria, a strong correlation between the mean glomerular filtration rate and the blood level of methylglyoxal was revealed.

Alcohol dehydrogenase 1 and NAD(H)-linked methylglyoxal oxidoreductase reciprocally regulate glutathione-dependent enzyme activities in Candida albicans.

Glutathione reductase (Glr1) activity controls cellular glutathione and reactive oxygen species (ROS). We previously demonstrated two predominant methylglyoxal scavengers-NAD(H)-linked methylglyoxal oxidoreductase (Mgd1) and alcohol dehydrogenase 1 (Adh1)-in glutathione-depleted γ-glutamyl cysteinyl synthetase-disrupted Candida albicans. However, experimental evidence for Candida pathophysiology lacking the enzyme activities of Mgd1 and Adh1 on glutathione-dependent redox regulation remains unclear. Herein, we have aimed to demonstrate that glutathione-dependent enzyme activities coupled with cellular ROS changes is regulated by methylglyoxal accumulation in Δmgd1/Δadh1 double disruptants. Δmgd1/Δadh1 showed severe growth defects and G1-phase cell cycle arrest. The observed complementary and reciprocal methylglyoxal-oxidizing and methylglyoxalreducing activities between Δmgd1 and Δadh1 were not always exhibited in Δmgd1/Δadh1. Although intracellular accumulation of methylglyoxal and pyruvate was shown in all disruptants, to a greater or lesser degree, methylglyoxal was particularly accumulated in the Δmgd1/Δadh1 double disruptant. While cellular ROS significantly increased in Δmgd1 and Δadh1 as compared to the wild-type, Δmgd1/Δadh1 underwent a decrease in ROS in contrast to Δadh1. Despite the experimental findings underlining the importance of the undergoing unbalanced redox state of Δmgd1/Δadh1, glutathione-independent antioxidative enzyme activities did not change during proliferation and filamentation. Contrary to the significantly lowered glutathione content and Glr1 enzyme activity, the activity staining-based glutathione peroxidase activities concomitantly increased in this mutant. Additionally, the enhanced GLR1 transcript supported our results in Δmgd1/Δadh1, indicating that deficiencies of both Adh1 and Mgd1 activities stimulate specific glutathione-dependent enzyme activities. This suggests that glutathione-dependent redox regulation is evidently linked to C. albicans pathogenicity under the control of methylglyoxal-scavenging activities.

Basic components of glutathion system in rat erythrocytes under conditions of toxic damage on the background of an alimental protein lack

The article is devoted to the study of the main components of the glutathione system under conditions of toxic damage against the background of nutritional protein deficiency: the content of reduced and oxidized glutathione with the determination of the GSH/GSSG ratio, the activity of glutathione-dependent enzymes – glutathione peroxidase, glutathione transferase, glutathione reductase, and glucose-6-phosphate dehydrogenase. The concentration of reduced glutathione in the erythrocyte hemolysate was studied using Elman's reagent after deproteinization of the samples. Glutathione transferase activity was determined by the rate of formation of glutathione S conjugates by reacting reduced glutathione with a substrate of 1-chloro-2.4-dinitrobenzene. Glutathione peroxidase activity was evaluated by the formation of oxidized glutathione. The activity of glutathione reductase in erythrocytes was determined by the method, is based on measuring the oxidation rate of NADPH+H+, which is recorded by decreasing absorption at a wavelength of 340 nm. A decrease in the ratio of GSH/GSSG in rat erythrocytes under conditions of toxic damage against a nutritional deficiency of protein is indicated by a functional shift in the thiol-disulfide balance towards increased use of the reduced form of glutathione for antioxidant protection. It was established that toxic damage is a key factor in reducing the level of glutathione transferase against the background of an increase in glutathione peroxidase activity in rat erythrocytes, the activation of which probably prevents the progression of LPO processes. At the same time, under conditions of toxic damage, against the background of alimentary protein deficiency, a decrease in glutathione reductase and glucose-6-phosphate dehydrogenase activity is observed, which leads to blocking of the first stage of glucose-6-phosphate metabolism in the pentose phosphate cycle, resulting in a decrease in the amount of NADPH and, accordingly reduced glutathione.

Glutathione system in the blood of gastric cancer patients with various tumor histotypes and prevalence of the disease.

e16534 Background: The role of oxidative stress in tumor growth and the multifaceted functional significance of glutathione have led to an interest in studying the components of the glutathione-dependent system in gastric cancer (GC), which occupies a leading position in cancer incidence and mortality. The aim of this work was to study the functioning of the glutathione system in the red blood cells of patients with gastric cancer in a comparative aspect depending on the histotype of the tumor and the prevalence of the disease. Methods: The study included 89 patients with GC divided into 6 groups depending on the histotype of the tumor. Separately, the results of the study were analyzed in patients with T4 status according to TNM and in patients with stage IV cancer. The content of reduced glutathione and the activity of glutathione-dependent enzymes were studied by conventional spectrophotometric methods in the red blood cells of patients. Statistical processing of the results was performed using the Statistika 6.0 program with Student’s t-test for two independent groups. Results: An increase in the content of glutathione in patients with GC compared with the group without oncopathology was revealed. The maximum increase was observed in patients with low-grade adenocarcinoma - by 42.5%, while in signet ring cell cancer (SRCC) there was only a tendency to increase by 17.8%. Glutathione reductase activity was reduced in adenocarcinoma by 23.4-26.2% and did not change in SRCC. The activity of the antioxidant enzymes glutathione peroxidase and glutathione transferase was increased in all groups and especially in SRCC - by 76% and 23-29%, respectively. In patients with T4 status and at stage 4 of the process, lower activity of the studied glutathione-dependent enzymes was revealed compared with all other groups of patients. Conclusions: The data indicate a greater functional potential of the glutathione system in SRCC. A significant increase in the activity of glutathione transferase with a sufficiently high level of reduced glutathione contributes to the development of treatment resistance in patients with SRCC.

The effect of dicarbonyl stress on the development of kidney dysfunction in metabolic syndrome \u2013 a transcriptomic and proteomic approach

Background and aimsDicarbonyl stress plays an important role in the pathogenesis of microvascular complications that precede the formation of advanced glycation end products, and contributes to the development of renal dysfunction. In renal cells, toxic metabolites like methylglyoxal lead to mitochondrial dysfunction and protein structure modifications.In our study, we investigated the effect of methylglyoxal on metabolic, transcriptomic, metabolomic and proteomic profiles in the context of the development of kidney impairment in the model of metabolic syndrome.Materials and methodsDicarbonyl stress was induced by intragastric administration of methylglyoxal (0.5 mg/kg bw for 4 weeks) in a strain of hereditary hypertriglyceridaemic rats with insulin resistance and fatty liver.ResultsMethylglyoxal administration aggravated glucose intolerance (AUC0–120p < 0.05), and increased plasma glucose (p < 0.01) and insulin (p < 0.05). Compared to controls, methylglyoxal-treated rats exhibited microalbuminuria (p < 0.01). Targeted proteomic analysis revealed increases in urinary secretion of pro-inflammatory parameters (MCP-1, IL-6, IL-8), specific collagen IV fragments and extracellular matrix proteins. Urine metabolomic biomarkers in methylglyoxal-treated rats were mainly associated with impairment of membrane phospholipids (8-isoprostane, 4-hydroxynonenal).Decreased levels of glutathione (p < 0.01) together with diminished activity of glutathione-dependent antioxidant enzymes contributed to oxidative and dicarbonyl stress. Methylglyoxal administration elevated glyoxalase 1 expression (p < 0.05), involved in methylglyoxal degradation. Based on comparative transcriptomic analysis of the kidney cortex, 96 genes were identified as differentially expressed (FDR < 0.05). Network analysis revealed an over-representation of genes related to oxidative stress and pro-inflammatory signalling pathways as well as an inhibition of angiogenesis suggesting its contribution to renal fibrosis.ConclusionOur results support the hypothesis that dicarbonyl stress plays a key role in renal microvascular complications. At the transcriptome level, methylglyoxal activated oxidative and pro-inflammatory pathways and inhibited angiogenesis. These effects were further supported by the results of urinary proteomic and metabolomic analyses.

Glutathione-dependent enzyme activities of peripheral blood mononuclear cells decrease during the winter season compared with the summer in normal-weight and severely obese adolescents

Oxidative stress-related inflammation is known to play a vital role in obesity-associated cardiovascular disease, contributing to the early stages of the pathology as well as during its development. Therefore, it is of great interest to understand how obesity-induced stress modulates antioxidant enzyme activity during puberty. To this end, 27 severely obese adolescents (body mass index > 30, z-score > 3.7) were recruited from a paediatric weight management centre. Eighteen were recruited during the summer and nine in the winter. All underwent a 4-month weight loss programme consisting in diet and physical activity. Twenty normal-weight age-matched adolescents were recruited from the same geographical area to serve as controls. Blood samples were extracted, and antioxidant enzyme activities were determined in peripheral blood mononuclear cells (PBMCs) and erythrocytes. The enzymes studied included catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase. Severely obese adolescents presented lower PBMC-glutathione reductase activity than their corresponding normal-weight counterparts. In addition, glutathione-dependent activities tended to be lower in both groups during the winter compared with summer. These changes coincided with differences in circulating vitamin D levels. Results may suggest that season-dependent factors such as vitamin D could affect glutathione-dependent activities in severely obese as well as in normal-weight adolescents.

The Role of Redox Proteins in Arresting Proliferation of Breast Epithelial Cells Under Oxidative Stress

Background: Redox status imbalance against the backdrop of oxidative stress development underlies the pathogenesis of a whole range of diseases. Many intracellular proteins contain free thiol groups and undergo redox regulation which is one of the key processes in controlling cell proliferation. Thioredoxin and glutaredoxin are involved in maintaining intracellular redox homeostasis and act as candidates in regulating proliferation. This provides prospects for future development of methods for diagnosis and targeted therapy of socially sensitive diseases accompanied by oxidative stress. The aim of the study is to reveal the role of redox proteins in molecular mechanisms of regulating HBL-100 breast epithelial cell proliferation under the effect of roscovitine, a cell cycle inhibitor. Materials and methods: Two research groups were formed. They included HBL-100 human breast epithelial cells incubated in the presence and absence of 20 mcM roscovitine for 18 hours. The intracellular thioredoxin levels were determined using Western blot analysis with specific monoclonal antibodies. Distribution of the cells among cell cycle phases were evaluated by flow cytometry. The activity of glutathione reductase, glutathione peroxidase, and thioredoxin reductase were measured by spectrophotometry. Results: Under the effect of roscovitine in the HBL-100 cells, cell cycle arrest in the G2/М phases occurred and oxidative stress developed. In the meantime, the decrease in the thioredoxin and glutaredoxin concentrations was registered along with the change in the functional activity of glutathione-dependent enzymes. Conclusions: Application of roscovitine, a cell cycle inhibitor, allowed creating a model of oxidative stress in the breast epithelial cells against the backdrop of inhibited cell proliferation. We identified that thioredoxin and glutaredoxin contributed to impairment of cell cycle progression. It points at a possibility to regulate cell proliferation by modulating the functional features of cellular redox-dependent proteins in different pathologies accompanied by oxidative stress.