An antioxidant role for catecholate siderophores in Salmonella

2013 ◽  
Vol 454 (3) ◽  
pp. 543-549 ◽  
Author(s):  
Maud E. S. Achard ◽  
Kaiwen W. Chen ◽  
Matthew J. Sweet ◽  
Rebecca E. Watts ◽  
Kate Schroder ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ferric Iron ◽  
Iron Acquisition ◽  
Oxygen Species ◽  
Functional Studies ◽  
Host Pathogen Interaction ◽  
Host Pathogen ◽  
Very High ◽  
Full Protection

Iron acquisition is an important aspect of the host–pathogen interaction. In the case of Salmonella it is established that catecholate siderophores are important for full virulence. In view of their very high affinity for ferric iron, functional studies of siderophores have been almost exclusively focused on their role in acquisition of iron from the host. In the present study, we investigated whether the siderophores (enterobactin and salmochelin) produced by Salmonella enterica sv. Typhimurium could act as antioxidants and protect from the oxidative stress encountered after macrophage invasion. Our results show that the ability to produce siderophores enhanced the survival of Salmonella in the macrophage mainly at the early stages of infection, coincident with the oxidative burst. Using siderophore biosynthetic and siderophore receptor mutants we demonstrated that salmochelin and enterobactin protect S. Typhimurium against ROS (reactive oxygen species) in vitro and that siderophores must be intracellular to confer full protection. We also investigated whether other chemically distinct siderophores (yersiniabactin and aerobactin) or the monomeric catechol 2,3-dihydroxy-benzoate could provide protection against oxidative stress and found that only catecholate siderophores have this property. Collectively, the results of the present study identify additional functions for siderophores during host–pathogen interactions.

scholarly journals Vitamin E-Coated Dialyzer Inhibits Oxidative Stress

2017 ◽  
Vol 44 (4) ◽  
pp. 288-293 ◽  
Author(s):  
Shiho Yamadera ◽  
Yuya Nakamura ◽  
Masahiro Inagaki ◽  
Isao Ohsawa ◽  
Hiromichi Gotoh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin E ◽  
Synthetic Polymer ◽  
Intracellular Reactive Oxygen Species ◽  
Ros Production ◽  
Oxygen Species ◽  
In Vitro Methods ◽  
Stress Effects ◽  
Intracellular Ros

Aim: To examine the effects of vitamin E-coated dialyzer on oxidative stress in vitro. Methods: A dialyzer with a synthetic polymer membrane (APS-11SA) and vitamin E-coated dialyzer (VPS-11SA) were connected to a blood tubing line, and U937 cells were circulated in the device. The circulating fluid was collected at 1, 2, 5, 10, 25, and 50 cycles, which are estimated numbers of passes through the dialyzer. Intracellular reactive oxygen species (ROS) production, malondialdehyde (MDA), and Cu/Zn-superoxide dismutase (SOD) were quantified. Results: Intracellular ROS production was increased in the first cycle by APS-11SA and was decreased throughout the experiment by VPS-11SA. Intracellular ROS production in the VPS-11SA device was lower, and MDA levels were decreased. MDA levels were lower during VPS-11SA processing than during APS-11SA processing. Cu/Zn-SOD levels remained unchanged. Conclusion: Our results highlight anti-oxidative-stress effects of a vitamin E-coated dialyzer.

Hyperglycemia Induces Generation of Reactive Oxygen Species and Accelerates Apoptotic Cell Death in Salivary Gland Cells

Pathobiology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Naoyuki Matsumoto ◽  
Daisuke Omagari ◽  
Ryoko Ushikoshi-Nakayama ◽  
Tomoe Yamazaki ◽  
Hiroko Inoue ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Salivary Gland ◽  
Tissue Injury ◽  
Ros Production ◽  
Oxygen Species ◽  
Saliva Secretion ◽  
Salivary Gland Tissue ◽  
Gland Tissue

<b><i>Introduction:</i></b> Type-2 diabetes mellitus (T2DM) is associated with several systemic vascular symptoms and xerostomia. It is considered that hyperglycemia-induced polyuria and dehydration cause decreased body-water volume, leading to decreased saliva secretion and, ultimately, xerostomia. In T2DM, increased production of reactive oxygen species (ROS) causes tissue damage to vascular endothelial cells as well as epithelial tissue, including pancreas and cornea. Hence, a similar phenomenon may occur in other tissues and glands in a hyperglycemic environment. <b><i>Methods:</i></b> Salivary gland tissue injury was examined, using T2DM model mouse (db/db). Transferase‐mediated dUTP nick‐end labeling (TUNEL) was conducted to evaluate tissue injury. The levels of malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine, Bax/Bcl-2 ratio were measured as indicator of oxidative stress. Moreover, in vitro ROS production and cell injury was evaluated by mouse salivary gland-derived normal cells under high-glucose condition culture. <b><i>Results:</i></b> In vivo and in vitro analysis showed a higher percentage of TUNEL-positive cells and higher levels of MDA and 8-hydroxy-2′-deoxyguanosine in salivary gland tissue of db/db mice. This suggests damage of saliva secretion-associated lipids and DNA by hyperglycemic-induced oxidative stress. To analyze the mechanism by which hyperglycemia promotes ROS production, mouse salivary gland-derived cells were isolated. The cell culture with high-glucose medium enhanced ROS production and promotes apoptotic and necrotic cell death. <b><i>Conclusion:</i></b> These findings suggest a novel mechanism whereby hyperglycemic-induced ROS production promotes salivary gland injury, resulting in hyposalivation.

Oxidative injury of coronary venular endothelial cells depletes intracellular glutathione and induces HSP 70 mRNA

1995 ◽  
Vol 268 (4) ◽  
pp. H1651-H1658 ◽  
Author(s):  
M. M. Aucoin ◽  
R. Barhoumi ◽  
D. T. Kochevar ◽  
H. J. Granger ◽  
R. C. Burghardt
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Vascular Endothelium ◽  
Heat Shock Protein 70 ◽  
Ischemia Reperfusion ◽  
Oxygen Species ◽  
Hsp 70 ◽  
Intracellular Glutathione ◽  
Myocardial Ischemia Reperfusion

Vascular endothelium is one of the first tissues exposed to reactive oxygen species produced during myocardial ischemia-reperfusion. Bovine coronary venular endothelial cells (CVEC) were evaluated for intracellular glutathione (GSH) levels and heat shock protein 70 (HSP 70) mRNA and protein during in vitro oxidative stress. CVEC were incubated with 0.01875 U/ml xanthine oxidase (XO) and 0.5 mM hypoxanthine (HX) for 30 min and then allowed to recover for 0, 1, 2, or 3 h. Relative GSH levels were determined by evaluation of monochlorobimane fluorescence. GSH fluorescence was significantly lower in CVEC treated with XO+HX for 30 min than in controls. GSH fluorescence was also decreased in heat-shocked CVEC. After oxidative stress, GSH levels were higher than in controls at 1 h, but by 2 or 3 h after treatment, GSH fluorescence fell below control values. HSP 70 mRNA was induced in CVEC by a 30-min treatment with XO+HX exposure. These data suggest that CVEC respond to oxidative stress by reducing intracellular GSH levels and inducing HSP 70 mRNA, although significant increases in HSP 70 protein were not detected at the time points tested.

scholarly journals Oxymatrine Ameliorates Memory Impairment in Diabetic Rats by Regulating Oxidative Stress and Apoptosis: Involvement of NOX2/NOX4

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yongpan Huang ◽  
Xinliang Li ◽  
Xi Zhang ◽  
Jiayu Tang
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Brain Injury ◽  
Western Blotting ◽  
Caspase 3 ◽  
Memory Function ◽  
Diabetic Rats ◽  
Oxygen Species ◽  
Expression Levels

Oxymatrine (OMT) is the major quinolizidine alkaloid extracted from the root of Sophora flavescens Ait and has been shown to exhibit a diverse range of pharmacological properties. The aim of the present study was to investigate the role of OMT in diabetic brain injury in vivo and in vitro. Diabetic rats were induced by intraperitoneal injection of a single dose of 65 mg/kg streptozotocin (STZ) and fed a high-fat and high-cholesterol diet. Memory function was assessed using a Morris water maze test. A SH-SY5Y cell injury model was induced by incubation with glucose (30 mM/l) to simulate damage in vitro. The serum fasting blood glucose, insulin, serum S100B, malondialdehyde (MDA), and superoxide dismutase (SOD) levels were analyzed using commercial kits. Morphological changes were observed using Nissl staining and electron microscopy. Cell apoptosis was assessed using Hoechst staining and TUNEL staining. NADPH oxidase (NOX) and caspase-3 activities were determined. The effects of NOX2 and NOX4 knockdown were assessed using small interfering RNA. The expression levels of NOX1, NOX2, and NOX4 were detected using reverse transcription-quantitative PCR and western blotting, and the levels of caspase-3 were detected using western blotting. The diabetic rats exhibited significantly increased plasma glucose, insulin, reactive oxygen species (ROS), S-100B, and MDA levels and decreased SOD levels. Memory function was determined by assessing the percentage of time spent in the target quadrant, the number of times the platform was crossed, escape latency, and mean path length and was found to be significantly reduced in the diabetic rats. Hyperglycemia resulted in notable brain injury, including histological changes and apoptosis in the cortex and hippocampus. The expression levels of NOX2 and NOX4 were significantly upregulated at the protein and mRNA levels, and NOX1 expression was not altered in the diabetic rats. NOX and caspase-3 activities were increased, and caspase-3 expression was upregulated in the brain tissue of diabetic rats. OMT treatment dose-dependently reversed behavioral, biochemical, and molecular changes in the diabetic rats. In vitro, high glucose resulted in increases in reactive oxygen species (ROS), MDA levels, apoptosis, and the expressions of NOX2, NOX4, and caspase-3. siRNA-mediated knockdown of NOX2 and NOX4 decreased NOX2 and NOX4 expression levels, respectively, and reduced ROS levels and apoptosis. The results of the present study suggest that OMT alleviates diabetes-associated cognitive decline, oxidative stress, and apoptosis via NOX2 and NOX4 inhibition.

scholarly journals mTOR Inhibition Rejuvenates the Aging Gingival Fibroblasts through Alleviating Oxidative Stress

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yiru Xia ◽  
Mengjun Sun ◽  
Yufeng Xie ◽  
Rong Shu
Keyword(s):  
Oxidative Stress ◽  
Poor Response ◽  
Control Group ◽  
Oxygen Species ◽  
Gingival Fibroblasts ◽  
Periodontal Pathogens ◽  
Mtor Inhibition ◽  
Mechanistic Target Of Rapamycin ◽  
Beta Galactosidase

The aging periodontium may be vulnerable to periodontal pathogens and poor response to inflammation and susceptible to tumorigenesis. Human gingival fibroblasts (hGFs) through continuously replicative culture served as an in vitro surrogate for aging. To investigate the effects of the mechanistic target of rapamycin (mTOR) inhibition on the aging gingiva, we stimulated the high-passage hGFs with rapamycin (20 nmol/L) for 3 days and 30 days. The cellular and biological changes were examined by immunofluorescence, real-time PCR, ELISA, Western blotting, and flow cytometry. The data demonstrated that the inhibition of mTOR signaling led to fewer senescence-associated beta-galactosidase- (SA-β-Gal-) positive cells, delayed the onset of senescence, preserved the capability of proliferation, and lowered the expression levels of relevant senescence-associated markers, such as p16INK4a, p21CIP1a, interleukin-6 (IL-6), and IL-8. In addition, when infected by prominent periodontal pathogens, Porphyromonas gingivalis (ATCC 33277), rapamycin-pretreated groups decreased the expression of inflammatory cytokines (IL-6 and IL-8) compared with the control group. mTOR inhibition upregulated the gene expression of antioxidant components (Cat, Sod2, and Prdx3; P<0.05) and consequently neutralized the excessive reactive oxygen species (ROS). In conclusion, our results indicated that mTOR inhibition might rejuvenate the aging gingiva to some extent and relieve inflammation through eliminating oxidative stress.

72 Protective Effects of C-Phycocyanin on the Developmental Competence of Porcine Parthenotes

2018 ◽  
Vol 30 (1) ◽  
pp. 174
Author(s):  
Y.-J. Niu ◽  
N.-H. Kim ◽  
X.-S. Cui
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Membrane Potential ◽  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Developmental Competence ◽  
Oxygen Species ◽  
Blastocyst Formation

C-Phycocyanin (CP) is a biliprotein enriched in blue-green algae that is known to possess antioxidant, anti-apoptosis, anti-inflammatory, and radical-scavenging properties in somatic cells. However, the protective effect of CP on porcine embryo developmental competence in vitro remains unclear. In the present study, we investigated the effect of CP on the development of porcine early embryos as well as its underlying mechanisms exposing them to H2O2 to induce oxidative stress. The levels of reactive oxygen species, mitochondrial membrane potential, apoptosis, DNA damage, and autophagy in the blastocysts were observed by staining with 2′,7′-dichlorodihydrofluorescein diacetate (H2DCF-DA), 5,5′,6,6’-tetrachloro-1,1′,3,3′-tetraethyl-imidacarbocyanine iodide (JC-1), terminal deoxynucleotidyl transferase-mediated 2′-deoxyuridine 5′-triphosphate (dUTP) nick-end labelling (TUNEL), anti-cytochrome c, and anti-γH2A.X (Ser139), respectively. Colocalization assay of mitochondria and cytochrome c of blastocysts were staining with MitoTracker Red CMXRos and anti-cytochrome c. All data were subjected to one-way ANOVA. Different concentrations of CP (1, 2, 5, 8, 10 µg mL−1) were added to porcine zygote medium 5 (PZM-5, l-glutamine concentration of PZM-3 was modified from 1 to 2 mM) during in vitro culture. The results showed that 5 µg mL−1 CP significantly increased blastocyst formation (62.5 ± 2.1 v. 52.7 ± 2.4; P < 0.05) and hatching rate (10.9 ± 1.9 v. 36.6 ± 5.2; P < 0.05) compared with controls. Blastocyst formation (53.1 ± 2.3 v. 40.1 ± 2.3; P < 0.05) and quality were significantly increased in the 50 µM H2O2 treatment group following 5 µg mL−1 CP addition. C-Phycocyanin prevented the H2O2-induced compromise of mitochondrial membrane potential, release of cytochrome c from the mitochondria, and generation of reactive oxygen species. Furthermore, apoptosis, DNA damage level, and autophagy in the blastocysts were attenuated by supplementation of CP in the H2O2-induced oxidative injury group compared with that in controls. These results suggest that CP has beneficial effects on the development of porcine parthenotes by attenuating mitochondrial dysfunction and oxidative stress.

scholarly journals A novel stress-inducible CmtR-ESX3-Zn2+ regulatory pathway essential for survival of Mycobacterium bovis under oxidative stress

2020 ◽  
Vol 295 (50) ◽  
pp. 17083-17099
Author(s):  
Xiaohui Li ◽  
Liu Chen ◽  
Jingjing Liao ◽  
Jiechen Hui ◽  
Weihui Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Mycobacterium Bovis ◽  
Reactive Oxygen ◽  
Negative Regulator ◽  
Oxygen Species ◽  
Bacterial Survival ◽  
Regulatory Pathway ◽  
Host Pathogen Interaction ◽  
Redox Sensor

Reactive oxygen species (ROS) are an unavoidable host environmental cue for intracellular pathogens such as Mycobacterium tuberculosis and Mycobacterium bovis; however, the signaling pathway in mycobacteria for sensing and responding to environmental stress remains largely unclear. Here, we characterize a novel CmtR-Zur-ESX3-Zn2+ regulatory pathway in M. bovis that aids mycobacterial survival under oxidative stress. We demonstrate that CmtR functions as a novel redox sensor and that its expression can be significantly induced under H2O2 stress. CmtR can physically interact with the negative regulator Zur and de-represses the expression of the esx-3 operon, which leads to Zn2+ accumulation and promotion of reactive oxygen species detoxication in mycobacterial cells. Zn2+ can also act as an effector molecule of the CmtR regulator, using which the latter can de-repress its own expression for further inducing bacterial antioxidant adaptation. Consistently, CmtR can induce the expression of EsxH, a component of esx-3 operon involved in Zn2+ transportation that has been reported earlier, and inhibit phagosome maturation in macrophages. Lastly, CmtR significantly contributes to bacterial survival in macrophages and in the lungs of infected mice. Our findings reveal the existence of an antioxidant regulatory pathway in mycobacteria and provide novel information on stress-triggered gene regulation and its association with host–pathogen interaction.

Supplementation of kaempferol to in vitro maturation medium regulates oxidative stress and enhances subsequent embryonic development in vitro

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 59-64
Author(s):  
Yuhan Zhao ◽  
Yongnan Xu ◽  
Yinghua Li ◽  
Qingguo Jin ◽  
Jingyu Sun ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Treated Group ◽  
Control Group ◽  
Oxygen Species

SummaryKaempferol (KAE) is one of the most common dietary flavonols possessing biological activities such as anticancer, anti-inflammatory and antioxidant effects. Although previous studies have reported the biological activity of KAE on a variety of cells, it is not clear whether KAE plays a similar role in oocyte and embryo in vitro culture systems. This study investigated the effect of KAE addition to in vitro maturation on the antioxidant capacity of embryos in porcine oocytes after parthenogenetic activation. The effects of kaempferol on oocyte quality in porcine oocytes were studied based on the expression of related genes, reactive oxygen species, glutathione and mitochondrial membrane potential as criteria. The rate of blastocyst formation was significantly higher in oocytes treated with 0.1 µm KAE than in control oocytes. The mRNA level of the apoptosis-related gene Caspase-3 was significantly lower in the blastocysts derived from KAE-treated oocytes than in the control group and the mRNA expression of the embryo development-related genes COX2 and SOX2 was significantly increased in the KAE-treated group compared with that in the control group. Furthermore, the level of intracellular reactive oxygen species was significantly decreased and that of glutathione was significantly increased after KAE treatment. Mitochondrial membrane potential (ΔΨm) was increased and the activity of Caspase-3 was significantly decreased in the KAE-treated group compared with that in the control group. Taken together, these results suggested that KAE is beneficial for the improvement of embryo development by inhibiting oxidative stress in porcine oocytes.

scholarly journals Can C-phycocyanin be used as a sperm protector?

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
Emma Gabriela Antonio Marcos ◽  
O. Monroy Hermosillo ◽  
E. Cortés Barberena ◽  
E. Rodríguez Tobón ◽  
J. G. Rivera Martínez ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Sus Scrofa ◽  
Antioxidant Properties ◽  
Medical Applications ◽  
Protein Supplement ◽  
Oxygen Species ◽  
Short Term ◽  
Progressive Motility ◽  
Sus Scrofa Domesticus

C-phycocyanin (C-PC) is a biocompound extracted from Arthrospira maxima. It is a chromophore-protein complex, with antioxidant properties. Its ability to prevent oxidative stress allows for diverse medical applications. This study evaluates the use of C-PC as a protein supplement and an antioxidant for in-vitro sperm preservation in a short-term extender. Viability, progressive motility, DNA damage and percentage of reactive oxygen species where assessed in Swine (Sus scrofa domesticus) sperm stored for up to 72 hours at 4 °C. Treatments with C-PC had the following concentrations: 0, 34.5, 69, 138 and 207 μg mL−1. Progressive motility and percentage of sperm with undamaged DNA were unchanged (20%) after storage for 48 hours using the 138 μg mL C-PC concentration−1.

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