Aerobic organisms require oxygen for respiration but must simultaneously cope with oxidative damages inherently linked with this molecule. Unicellular amoeboflagellates of the genus Naegleria, containing both free-living species and opportunistic parasites, thrive in aerobic environments. However, they are also known to maintain typical features of anaerobic organisms. Here, we describe the mechanisms of oxidative damage mitigation in Naegleria gruberi and focus on the molecular characteristics of three noncanonical proteins interacting with oxygen and its derived reactive forms. We show that this protist expresses hemerythrin, protoglobin, and an aerobic-type rubrerythrin, with spectral properties characteristic of the cofactors they bind. We provide evidence that protoglobin and hemerythrin interact with oxygen in vitro and confirm the mitochondrial localization of rubrerythrin by immunolabeling. Our proteomic analysis and immunoblotting following heavy metal treatment revealed upregulation of hemerythrin, while rotenone treatment resulted in an increase in rubrerythrin protein levels together with a vast upregulation of alternative oxidase. Our study provided new insights into the mechanisms employed by N. gruberi to cope with different types of oxidative stress and allowed us to propose specific roles for three unique and understudied proteins: hemerythrin, protoglobin, and rubrerythrin.

• MeSH
• hemerythrin metabolismus   MeSH
• kyslík metabolismus   MeSH
• Naegleria * metabolismus   MeSH
• oxidační stres MeSH
• proteomika MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Insects, like other organisms, must deal with a wide variety of potentially challenging environmental factors during the course of their life. An important example of such a challenge is the phenomenon of oxidative stress. This review summarizes the current knowledge on the role of adipokinetic hormones (AKH) as principal stress responsive hormones in insects involved in activation of anti-oxidative stress response pathways. Emphasis is placed on an analysis of oxidative stress experimentally induced by various stressors and monitored by suitable biomarkers, and on detailed characterization of AKH's role in the anti-stress reactions. These reactions are characterized by a significant increase of AKH levels in the insect body, and by effective reversal of the markers-disturbed by the stressors-after co-application of the stressor with AKH. A plausible mechanism of AKH action in the anti-oxidative stress response is discussed as well: this probably involves simultaneous employment of both protein kinase C and cyclic adenosine 3',5'-monophosphate pathways in the presence of extra and intra-cellular Ca(2+) stores, with the possible involvement of the FoxO transcription factors. The role of other insect hormones in the anti-oxidative defense reactions is also discussed.

• MeSH
• hmyz metabolismus   MeSH
• hmyzí hormony metabolismus   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   metabolismus   MeSH
• oligopeptidy metabolismus   MeSH
• oxidační stres * MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Motivation. Our previous study showed differences in the atherosclerosis phenotype between Lithuanian and Swedish men that could be influenced by complementary factors, namely oxidation processes and/or oxidative stress. The goal of this study was to evaluate the mainstream biological pathways inducing and maintaining the atherosclerotic process by analyzing genetic biomarkers particularly in inflammatory and metabolic pathways where the main focus is laid on the oxidation process. Methods. There were 32 families recruited for the study and clinical as well as biochemical analyses were performed. For genetic analysis 150 SNPs in 89 genes were selected in order to construct a microarray based on Arrayed Primer Extension (APEX) genotyping technology. Genotyping was carried out in 28 families and transmission disequilibrium test (TDT), siblingTDT (STDT), and combined analysis were performed. Results. Clinical and biochemical analysis revealed that probands with premature CAD were more likely to have diabetes mellitus, arterial hypertension, dyslipidemia and were male with high body mass index. Genetic analysis showed six SNPs statistically significantly associated with the atherosclerosis phenotype in the candidate genes ITGA2, IL1B, ALOX5A, OR13G1, MMP9 and NFKB1. These genes belong to different biological pathways: trombocyte adhesion and vessel damage, inflammation response, cholesterol and lypoxygenase metabolic pathway and nutrition. Conclusions. Generalized clinical, biochemical, bioinformatical and candidate genes’ association results support our hypothesis and indicate that the oxidation process may be of key importance in the formation of atherosclerosis.

• MeSH
• ateroskleróza * genetika   MeSH
• biochemická analýza krve MeSH
• fenotyp MeSH
• genetické testování * MeSH
• genotyp MeSH
• klinické laboratorní techniky MeSH
• lidé MeSH
• oxidační stres * genetika   MeSH
• statistika jako téma MeSH
• tělesné váhy a míry MeSH
• výpočetní biologie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

Oxidační stres je odpovědný nejenom za poškození průdušek a plicního parenchymu, ale podstatnou částí se podílí i na systémových dopadech CHOPN (chronické obstrukční plicní nemoci), často klinicky vyjádřených. Nejvýznamnější příčinou CHOPN je kouření cigaret. Dnes víme, že zanechání kouření cigaret modifikuje průběh onemocnění. Neprokázal se pozitivní efekt inhalačních kortikosteroidů na zánětlivé procesy u CHOPN. Hlavní léčebnou modalitou je bronchodilatační léčba a plicní rehabilitace a jejich včasné nasazení po stanovení správné diagnózy. Probíhají klinické studie zaměřené na ovlivnění oxidačního stresu, zjišťuje se například vliv erdosteinu. Není zatím jasné, zda antioxidancia zabrání přechodu prosté chronické bronchitidy do chronické obstrukční plicní nemoci.

Chronic obstructive pulmonary disease (COPD) is defined by fixed airflow limitation associated with an abnormal pulmonary and systemic inflammatory response of the lungs to cigarette smoke. A better understanding of the origin and consequences of systemic inflammation and oxidative stress, and of potential therapies, will most likely lead to better care of patients with COPD. The role of antioxidants is analysed. The main treatment options are inhaled bronchodilatators and pulmonary rehabilitation with smoking cessation. There are only limited indications for inhaled glucocorticosteroids.

• MeSH
• antioxidancia terapeutické užití   MeSH
• bronchodilatancia terapeutické užití   MeSH
• chronická obstrukční plicní nemoc diagnóza   etiologie   farmakoterapie   MeSH
• hormony kůry nadledvin terapeutické užití   MeSH
• kouření škodlivé účinky   MeSH
• lidé MeSH
• oxidační stres imunologie   účinky léků   MeSH
• oxygenoterapie využití   MeSH
• thiofeny terapeutické užití   MeSH
• thioglykoláty terapeutické užití   MeSH
• volné radikály škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

We determined the susceptibility to oxidative stress and assessed the four virulence factors of the 38 Candida glabrata clinical isolates originating from two teaching hospitals in Slovakia. All the isolates were susceptible to hydrogen peroxide, diamide, and 7-chlorotetrazolo[5,1-c]benzo[1,2,4]triazine (CTBT) inducing an increased formation of reactive oxygen species in fungal cells. The mean relative cell surface hydrophobicity (CSH) of isolates was 21.9, ranging from 1.92 to 56.96. All isolates showed biofilm formation. A high biofilm formation was observed among 60.5% of isolates. Positive correlations were observed between biofilm formation and moderate values of CSHs. The 76.3% and 84.2% of isolates displayed varying degrees of proteinase and phospholipase activity, respectively. These results demonstrate a differential distribution of factors contributing to virulence of C. glabrata clinical isolates and point to their significance in pathogenesis that would be targeted by novel antifungals.

• MeSH
• biofilmy růst a vývoj   MeSH
• Candida glabrata účinky léků   izolace a purifikace   patogenita   fyziologie   MeSH
• diamid toxicita   MeSH
• faktory virulence metabolismus   MeSH
• fosfolipasy metabolismus   MeSH
• fyziologický stres MeSH
• hydrofobní a hydrofilní interakce MeSH
• kandidóza mikrobiologie   MeSH
• lidé MeSH
• nemocnice fakultní MeSH
• oxidační stres MeSH
• oxidancia toxicita   MeSH
• peroxid vodíku toxicita   MeSH
• proteasy metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• triaziny toxicita   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Slovenská republika MeSH

Spx is a Bacillus subtilis transcription factor that interacts with the alpha subunits of RNA polymerase. It can activate the thiol stress response regulon and interfere with the activation of many developmental processes. Here, we show that Spx is a central player orchestrating the heat shock response by up-regulating relevant stress response genes as revealed by comparative transcriptomic experiments. Moreover, these experiments revealed the potential of Spx to inhibit transcription of translation-related genes. By in vivo and in vitro experiments, we confirmed that Spx can inhibit transcription from rRNA. This inhibition depended mostly on UP elements and the alpha subunits of RNA polymerase. However, the concurrent up-regulation activity of stress genes by Spx, but not the inhibition of translation related genes, was essential for mediating stress response and antibiotic tolerance under the applied stress conditions. The observed inhibitory activity might be compensated in vivo by additional stress response processes interfering with translation. Nevertheless, the impact of Spx on limiting translation becomes apparent under conditions with high cellular Spx levels. Interestingly, we observed a subpopulation of stationary phase cells that contains raised Spx levels, which may contribute to growth inhibition and a persister-like behaviour of this subpopulation during outgrowth.

• MeSH
• Bacillus subtilis účinky léků   enzymologie   účinky záření   MeSH
• fyziologický stres * MeSH
• genetická transkripce MeSH
• oxidační stres * MeSH
• proteosyntéza MeSH
• reakce na tepelný šok * MeSH
• regulace genové exprese u bakterií * MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cieľ: Cieľom štúdie bolo vyhodnotenie vplyvu 6 kultivačných médií (komplexné – 5, minerálne – 1) na tvorbu biofilmu a na odpoveď na oxidačný stres u Pseudomonas aeruginosa (3 kmene) a Vibrio cholerae non-O1 (3 kmene). Metodika: Tvorbu biofilmu sme kvantitatívne vyhodnotili testom absorpcie kryštálovej violete. Odpoveď baktérií na oxidačný stres vyvolaný peroxidom vodíka sme hodnotili ako zónu vyčírenia obklopujúcu disky po 24 hodinovej inkubácii pri 37 °C. Výsledky: Najvyššiu tvorbu biofilmu u obidvoch bakteriálnych druhov sme zistili po kultivácii v tryptónovo-sójovom médiu (TSM), resp. v tryptónovo-sójovom médiu obohatenom o 8 % glukózy ( TSM +GL), najnižšiu v minerálnom médiu (MM). Kmene V. cholerae non-O1 boli v priemere 1,4- 3,4 krát citlivejšie v odpovedi na oxidačný stres v závislosti na médiu v porovnaní s kmeňmi P. aeruginosa. Zloženie kultivačného média výrazne neovplyvnilo reakciu vibrií na oxidačný stres vyvolaný H2O2 na rozdiel od P. aeruginosa. Najvyššiu rezistenciu na H2O2 u P. aeruginosa v priemere sme zistili po kultivácii v peptónovej vode, najcitlivejšie boli bunky po kultivácii v TSM + GL a v MM. Záver: Zloženie kultivačného média ovplyvnilo tvorbu biofilmu u obidvoch bakteriálnych druhov a výraznejšie ovplyvnilo aj odpoveď na oxidačný stres u P. aeruginosa.

Objective: To evaluate the effect of six culture media (five complex and one mineral) on biofilm formation and response to oxidative stress in Pseudomonas aeruginosa (3 strains) and Vibrio cholerae non-O1 (3 strains). Methods: Biofilm formation was quantitatively determined by a crystal violet absorption assay. The bacterial response to oxidative stress evoked by hydrogen peroxide was visualized as a zone of clearing around the disc after 24 h incubation at 37°C. Results: For both of the bacterial species studied, biofilm formation was the highest after cultivation in tryptone soya broth (TSM) or in TSM supplemented with 8% glucose (TSM+GL), being the lowest in mineral medium (MM). V. cholerae non O1 strains were 1.4 to 4.3 times more responsive on average to oxidative stress depending on culture medium as compared with P. aeruginosa strains. The culture medium had no significant effect on H2O2 evoked by response to oxidative stress in vibrios in contrast to P. aeruginosa. In P. aeruginosa, the highest mean resistance to H2O2 was observed after cultivation in peptone water while the most sensitive cells were found after incubation in TSM+GL and MM. Conclusion: The culture medium composition influnced biofilm formation in both of the bacterial species tested and had a considerable effect on response to oxidative stress in P. aeruginosa.

• MeSH
• biofilmy růst a vývoj   MeSH
• financování organizované MeSH
• kultivační média MeSH
• kultivační techniky metody   využití   MeSH
• oxidační stres účinky léků   MeSH
• peroxid vodíku škodlivé účinky   MeSH
• Pseudomonas aeruginosa izolace a purifikace   růst a vývoj   MeSH
• Vibrio cholerae O1 izolace a purifikace   růst a vývoj   MeSH

Tellurite resistance gene clusters have been identified in numerous pathogenic bacteria, including clinical isolates of Escherichia coli. The rareness of tellurium in host organisms and the noncontaminated environment raises a question about the true functionality of tellurite resistance gene clusters in pathogenesis and their possible contribution to bacterial fitness. The study aims to point out the beneficial effects of the tellurite resistance gene cluster of pathogenic bacteria to survive in ROS-rich environments. Here, we analysed the bacterial response to oxidative stress conditions with and without tellurite resistance gene clusters, which are composed of terWY1XY2Y3 and terZABCDEF genes. By measuring the levels of protein carbonylation, lipid peroxidation, and expression changes of oxidative stress genes upon oxidative stress, we propose a tellurite resistance gene cluster contribution to the elimination of oxidative damage, potentially increasing fitness and resistance to reactive oxygen species during macrophage attack. We have shown a different beneficial effect of various truncated versions of the tellurite resistance gene cluster on cell survival. The terBCDEF genes increased the survival of E. coli strain MC4100 by 13.21%, terW and terZABCDEF by 10.09%, and terWY1XY2Y3 and terZABCDEF by 25.57%, respectively. The ability to survive tellurite treatment is the most significant at 44.8% in wild clinical strain KL53 compared to laboratory strain E. coli MC4100 due to a complete wild-type plasmid presence.

• MeSH
• Escherichia coli * MeSH
• multigenová rodina MeSH
• oxidační stres MeSH
• telur * farmakologie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

Due to the growing number of applications of cadmium oxide nanoparticles (CdO NPs), there is a concern about their potential deleterious effects. The objective of our study was to investigate the effect of CdO NPs on the immune response, renal and intestine oxidative stress, blood antioxidant defence, renal fibrotic response, bone density and mineral content. Six-week-old female ICR mice were exposed to CdO NPs for 6 weeks by inhalation (particle size: 9.82 nm, mass concentration: 31.7 μg CdO/m3, total deposited dose: 0.195 μg CdO/g body weight). CdO NPs increased percentage of thymus CD3e+CD8a+ cells and moderately enhanced splenocyte proliferation and production of cytokines and chemokines. CdO NPs elevated pro-fibrotic factors (TGF-β2, α-SMA and collagen I) in the kidney, and concentrations of AGEs in the intestine. The ratio of GSH and GSSG in blood was slightly reduced. Exposure to CdO NPs resulted in 10-fold higher Cd concentration in tibia bones. No differences were found in bone mass density, mineral content, bone area values, bone concentrations of Ca, P, Mg and Ca/P ratio. Our findings indicate stimulation of immune/inflammatory response, oxidative stress in the intestine, starting fibrotic response in kidneys and accumulation of CdO NPs in bones of mice.

• MeSH
• aplikace inhalační MeSH
• buněčná imunita účinky léků   MeSH
• cytokiny metabolismus   MeSH
• fibróza chemicky indukované   MeSH
• kovové nanočástice aplikace a dávkování   toxicita   MeSH
• ledviny účinky léků   patologie   MeSH
• lymfatické uzliny účinky léků   MeSH
• myši inbrední ICR MeSH
• oxidační stres účinky léků   MeSH
• oxidy aplikace a dávkování   toxicita   MeSH
• slezina účinky léků   MeSH
• sloučeniny kadmia aplikace a dávkování   toxicita   MeSH
• střeva účinky léků   MeSH
• thymus účinky léků   MeSH
• tibie účinky léků   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

In this study, the effect of chloramine T (Chl-T) on the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione S-transferase (GST); the levels of reduced (GSH) and oxidised glutathione (GSSG) and their ratios; and also membrane lipid peroxidation (LPO) levels in Phanerochaete chrysosporium were investigated in a dose- (0.25-1 mmol/L) and time-dependent (1.5-9 h) manner. The highest SOD activity was observed in 0.5 mmol/L Chl-T at 6th hour as 1.48-fold of its control. The observed highest level in CAT activities was 4.6-fold of control in 0.5 and 0.75 mmol/L at the 6th hour. The GSH levels that were over the control showed decreasing tendency from the beginning of incubation, except 0.25 mmol/L. In contrast with GSH level variations, GSSG levels reached 10.0-fold of its control by showing increasing tendency with the increases in concentration and time. While the GSH/GSSG ratios were over the control at 0.25 mmol/L during all incubation, they fell under the control values at the earlier hours of incubation with the increasing concentrations of Chl-T. Glutathione-related enzymes GSH-Px, GR and GST were also induced with Chl-T treatment, and the highest activities were 3.29-, 7.5- and 6.56-fold of their controls, respectively. On the other hand, the increases in LPO levels with increasing concentration and time up to 5.27-fold of its control showed that the inductions observed in antioxidant system could not prevent the Chl-T-based oxidative stress.

• MeSH
• antioxidancia metabolismus   MeSH
• časové faktory MeSH
• chloraminy farmakologie   MeSH
• glutathion metabolismus   MeSH
• glutathionperoxidasa MeSH
• glutathionreduktasa MeSH
• glutathiontransferasa MeSH
• katalasa metabolismus   MeSH
• oxidace-redukce účinky léků   MeSH
• oxidační stres fyziologie   MeSH
• oxidancia farmakologie   MeSH
• peroxidace lipidů účinky léků   MeSH
• Phanerochaete účinky léků   enzymologie   metabolismus   MeSH
• superoxiddismutasa metabolismus   MeSH
• tosylové sloučeniny farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Publikační typ
• časopisecké články MeSH