scholarly journals The antioxidant drug N-acetylcysteine abolishes SOS-mediated mutagenesis produced by fluoroquinolones in bacteria

2018 ◽  
Author(s):  
Ana I. Rodríguez-Rosado ◽  
Estela Ynés Valencia ◽  
Alexandro Rodríguez-Rojas ◽  
Coloma Costas ◽  
Rodrigo S. Galhardo ◽  
...  
Keyword(s):  
Dna Polymerases ◽  
Sos Response ◽  
Oxygen Species ◽  
Relative Contribution ◽  
Intracellular Ros ◽  
Induced Mutagenesis ◽  
Resistant Mutants ◽  
Bacterial Mutagenesis ◽  
Antioxidant Molecule ◽  
Shed Light

AbstractCertain antibiotics, particularly fluoroquinolones, induce the mutagenic SOS response and increase the levels of intracellular reactive oxygen species (ROS), which have been associated with antibiotic lethality. Both SOS and ROS promote bacterial mutagenesis, fueling the emergence of resistant mutants during antibiotic treatments. However, the relative contribution of ROS and SOS on this antibioticmediated mutagenesis is currently unknown. We used the antioxidant molecule N-acetylcysteine (NAC) to study the contribution of ROS on the SOS response and the mutagenesis mediated by the fluoroquinolone anti-biotic ciprofloxacin (CIP). We show that NAC is able to reduce intracellular ROS levels, as well as the SOS response caused by treatment with subinhibitory concentrations of CIP, without affecting its anti-bacterial activity. This effect reduces anti-bioticinduced mutagenesis to levels comparable to a translesion synthesis DNA-polymerases deficient strain, suggesting that ROS play a major role in SOS-induced mutagenesis. Collectively, our results shed light on the mechanisms underlying antibioticinduced mutagenesis and open the possibility for the use of NAC as adjuvant in antibiotic therapy to hinder the development of antibiotic resistance.

scholarly journals Targeting Autophagy to Counteract Obesity-Associated Oxidative Stress

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 102
Author(s):  
Federico Pietrocola ◽  
José Manuel Bravo-San Pedro
Keyword(s):  
Oxidative Stress ◽  
Oxygen Species ◽  
Alcoholic Fatty Liver ◽  
Redox Biology ◽  
Obesity Therapy ◽  
Treatment Of Obesity ◽  
Novel Therapeutic Strategies ◽  
Alcoholic Fatty Liver Disease ◽  
Shed Light

Reactive oxygen species (ROS) operate as key regulators of cellular homeostasis within a physiological range of concentrations, yet they turn into cytotoxic entities when their levels exceed a threshold limit. Accordingly, ROS are an important etiological cue for obesity, which in turn represents a major risk factor for multiple diseases, including diabetes, cardiovascular disorders, non-alcoholic fatty liver disease, and cancer. Therefore, the implementation of novel therapeutic strategies to improve the obese phenotype by targeting oxidative stress is of great interest for the scientific community. To this end, it is of high importance to shed light on the mechanisms through which cells curtail ROS production or limit their toxic effects, in order to harness them in anti-obesity therapy. In this review, we specifically discuss the role of autophagy in redox biology, focusing on its implication in the pathogenesis of obesity. Because autophagy is specifically triggered in response to redox imbalance as a quintessential cytoprotective mechanism, maneuvers based on the activation of autophagy hold promises of efficacy for the prevention and treatment of obesity and obesity-related morbidities.

scholarly journals PRDX1 is essential for the viability and maintenance of reactive oxygen species in chicken DT40

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Takahito Moriwaki ◽  
Akari Yoshimura ◽  
Yuki Tamari ◽  
Hiroyuki Sasanuma ◽  
Shunichi Takeda ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Intracellular Signaling ◽  
Reactive Oxygen ◽  
Fine Tuning ◽  
Oxygen Species ◽  
Ros Homeostasis ◽  
Intracellular Ros ◽  
Chromosomal Breaks ◽  
Dt40 Cells

Abstract Background Peroxiredoxin 1 (PRDX1) is a member of a ubiquitous family of thiol peroxidases that catalyze the reduction of peroxides, including hydrogen peroxide. It functions as an antioxidant enzyme, similar to catalase and glutathione peroxidase. PRDX1 was recently shown act as a sensor of reactive oxygen species (ROS) and play a role in ROS-dependent intracellular signaling pathways. To investigate its physiological functions, PRDX1 was conditionally disrupted in chicken DT40 cells in the present study. Results The depletion of PRDX1 resulted in cell death with increased levels of intracellular ROS. PRDX1-depleted cells did not show the accumulation of chromosomal breaks or sister chromatid exchange (SCE). These results suggest that cell death in PRDX1-depleted cells was not due to DNA damage. 2-Mercaptoethanol protected against cell death in PRDX1-depleted cells and also suppressed elevations in ROS. Conclusions PRDX1 is essential in chicken DT40 cells and plays an important role in maintaining intracellular ROS homeostasis (or in the fine-tuning of cellular ROS levels). Cells deficient in PRDX1 may be used as an endogenously deregulated ROS model to elucidate the physiological roles of ROS in maintaining proper cell growth.

scholarly journals FRI0370 DUAL OXIDASE MATURATION FACTOR 1 POSITIVELY REGULATES RANKL-INDUCED OSTEOCLASTOGENESIS VIA ACTIVATING REACTIVE OXYGEN SPECIES PRODUCTION AND TRAF6-MEDIATED SIGNALING

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 782.2-782
Author(s):  
C. H. Lee ◽  
C. H. Chung ◽  
Y. J. Choi ◽  
W. H. Yoo ◽  
J. Y. Kim ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Osteoclast Differentiation ◽  
Reactive Oxygen ◽  
Mouse Bone Marrow ◽  
Ros Production ◽  
Oxygen Species ◽  
Maturation Factor ◽  
Intracellular Ros ◽  
Dual Oxidase ◽  
Rankl Stimulation

Background:Reactive oxygen species (ROS) are one of the significant factors of chemical or physical cell signaling in a wide variety of cell types including skeletal cells. Receptor activator of NF-βB ligand (RANKL) induces generation of intracellular ROS, which act as second messengers in RANKL-mediated osteoclastogenesis. Dual oxidase maturation factor 1 (Duoxa1) was first identified as aDrosophilaNumb-interacting protein (NIP), and has been associated with the maturation of ROS generating enzymes including dual oxidases (Duox1 and Duox2). In the progression of osteoclast differentiation using mouse bone marrow-derived macrophages (BMMs), we identified that only Duoxa1 level showed an effective change upon RANKL stimulation, but not Duox1, Duox2, and Duoxa2.Objectives:we hypothesized that Duoxa1 could independently act as a second messenger for RANKL stimulation and regulate ROS production during osteoclast differentiation.Methods:Using siRNA or retrovirus transduction and knockdown of Duoxa1 via siRNAResults:Duoxa1 level gradually increased during RANKL-induced osteoclast differentiation. We found that Duoxa1 regulated RANKL-stimulated osteoclast formation and bone resorption positively. knockdown of Duoxa1 via siRNA decreased the RANKL-induced ROS production. During Duoxa1-related control of osteoclastogenesis, activation of tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6)-mediated early signaling molecules including MAPKs, Akt, IβB, Btk, and PLC 2 was affected, which sequentially modified the mRNA or protein expression levels of key transcription factors in osteoclastogenesis, such as c-Fos and NFATc1, as well as mRNA expression of osteoclast-specific markers including OSCAR, ATP6v0d2, and CtsK.Conclusion:Overall, our data indicate that Duoxa1 plays a crucial role in osteoclastogenesis via regulating RANKL-induced intracellular ROS production and activating TRAF6-mediated signaling.Disclosure of Interests:None declared

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.

scholarly journals Use of Thiols in the Treatment of COVID-19: Current Evidence

Lung ◽  
2021 ◽  
Author(s):  
Mario Cazzola ◽  
Paola Rogliani ◽  
Sundeep Santosh Salvi ◽  
Josuel Ora ◽  
Maria Gabriella Matera
Keyword(s):  
Oxidative Stress ◽  
Influenza Virus Infection ◽  
Current Evidence ◽  
Low Molecular Weight ◽  
Oxygen Species ◽  
Cytokine Storm ◽  
Antioxidant Defences ◽  
Antioxidant Molecule ◽  
Novel Therapeutic

AbstractThere is a possible role for oxidative stress, a state characterized by an altered balance between the production of free radicals or reactive oxygen species (ROS) and antioxidant defences, in coronavirus disease 2019 (COVID-19), the genesis of which is quite complex. Excessive oxidative stress could be responsible for the alveolar damage, thrombosis, and red blood cell dysregulation observed in COVID-19. Apparently, deficiency of glutathione (GSH), a low-molecular-weight thiol that is the most important non-enzymatic antioxidant molecule and has the potential to keep the cytokine storm in check, is a plausible explanation for the severe manifestations and death in COVID-19 patients. Thiol drugs, which are considered mucolytic, also possess potent antioxidant and anti-inflammatory properties. They exhibit antibacterial activity against a variety of medically important bacteria and may be an effective strategy against influenza virus infection. The importance of oxidative stress during COVID-19 and the various pharmacological characteristics of thiol-based drugs suggest a possible role of thiols in the treatment of COVID-19. Oral and intravenous GSH, as well as GSH precursors such as N-acetylcysteine (NAC), or drugs containing the thiol moiety (erdosteine) may represent a novel therapeutic approach to block NF-kB and address the cytokine storm syndrome and respiratory distress observed in COVID-19 pneumonia patients

Reactive oxygen species formation in the transition to hypoxia in skeletal muscle

2005 ◽  
Vol 289 (1) ◽  
pp. C207-C216 ◽  
Author(s):  
Li Zuo ◽  
Thomas L. Clanton
Keyword(s):  
Reactive Oxygen Species ◽  
Skeletal Muscle ◽  
Acute Hypoxia ◽  
Low Frequency ◽  
Metabolic Stress ◽  
Reactive Oxygen ◽  
Fluorescence Signal ◽  
Oxygen Species ◽  
Peroxidase Mimic ◽  
Intracellular Ros

Many tissues produce reactive oxygen species (ROS) during reoxygenation after hypoxia or ischemia; however, whether ROS are formed during hypoxia is controversial. We tested the hypothesis that ROS are generated in skeletal muscle during exposure to acute hypoxia before reoxygenation. Isolated rat diaphragm strips were loaded with dihydrofluorescein-DA (Hfluor-DA), a probe that is oxidized to fluorescein (Fluor) by intracellular ROS. Changes in fluorescence due to Fluor, NADH, and FAD were measured using a tissue fluorometer. The system had a detection limit of 1 μM H2O2 applied to the muscle superfusate. When the superfusion buffer was changed rapidly from 95% O2 to 0%, 5%, 21%, or 40% O2, transient elevations in Fluor were observed that were proportional to the rise in NADH fluorescence and inversely proportional to the level of O2 exposure. This signal could be inhibited completely with 40 μM ebselen, a glutathione peroxidase mimic. After brief hypoxia exposure (10 min) or exposure to brief periods of H2O2, the fluorescence signal returned to baseline. Furthermore, tissues loaded with the oxidized form of the probe (Fluor-DA) showed a similar pattern of response that could be inhibited with ebselen. These results suggest that Fluor exists in a partially reversible redox state within the tissue. When Hfluor-loaded tissues were contracted with low-frequency twitches, Fluor emission and NADH emission were significantly elevated in a way that resembled the hypoxia-induced signal. We conclude that in the transition to low intracellular Po2, a burst of intracellular ROS is formed that may have functional implications regarding skeletal muscle O2-sensing systems and responses to acute metabolic stress.

Mutagenesis and More: umuDC and the Escherichia coli SOS Response

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1599-1610 ◽  
Author(s):  
Bradley T Smith ◽  
Graham C Walker
Keyword(s):  
Escherichia Coli ◽  
Dna Damage ◽  
Cellular Response ◽  
Sos Response ◽  
Posttranslational Regulation ◽  
E Coli ◽  
Sos Mutagenesis ◽  
Induced Mutagenesis ◽  
Mechanistic Basis ◽  
Increase Cell Survival

Abstract The cellular response to DNA damage that has been most extensively studied is the SOS response of Escherichia coli. Analyses of the SOS response have led to new insights into the transcriptional and posttranslational regulation of processes that increase cell survival after DNA damage as well as insights into DNA-damage-induced mutagenesis, i.e., SOS mutagenesis. SOS mutagenesis requires the recA and umuDC gene products and has as its mechanistic basis the alteration of DNA polymerase III such that it becomes capable of replicating DNA containing miscoding and noncoding lesions. Ongoing investigations of the mechanisms underlying SOS mutagenesis, as well as recent observations suggesting that the umuDC operon may have a role in the regulation of the E. coli cell cycle after DNA damage has occurred, are discussed.

Activation of the JAK-STAT pathway by reactive oxygen species

1998 ◽  
Vol 275 (6) ◽  
pp. C1640-C1652 ◽  
Author(s):  
Amy R. Simon ◽  
Usha Rai ◽  
Barry L. Fanburg ◽  
Brent H. Cochran
Keyword(s):  
Reactive Oxygen Species ◽  
Mammalian Cells ◽  
Reactive Oxygen ◽  
Buthionine Sulfoximine ◽  
Early Response ◽  
Carcinoma Cells ◽  
Oxygen Species ◽  
Intracellular Ros ◽  
Diphenylene Iodonium ◽  
Stat Pathway

Reactive oxygen species (ROS) play an important role in the pathogenesis of many human diseases, including the acute respiratory distress syndrome, Parkinson’s disease, pulmonary fibrosis, and Alzheimer’s disease. In mammalian cells, several genes known to be induced during the immediate early response to growth factors, including the protooncogenes c- fos and c- myc, have also been shown to be induced by ROS. We show that members of the STAT family of transcription factors, including STAT1 and STAT3, are activated in fibroblasts and A-431 carcinoma cells in response to H2O2. This activation occurs within 5 min, can be inhibited by antioxidants, and does not require protein synthesis. STAT activation in these cell lines is oxidant specific and does not occur in response to superoxide- or nitric oxide-generating stimuli. Buthionine sulfoximine, which depletes intracellular glutathione, also activates the STAT pathway. Moreover, H2O2stimulates the activity of the known STAT kinases JAK2 and TYK2. Activation of STATs by platelet-derived growth factor (PDGF) is significantly inhibited by N-acetyl-l-cysteine and diphenylene iodonium, indicating that ROS production contributes to STAT activation in response to PDGF. These findings indicate that the JAK-STAT pathway responds to intracellular ROS and that PDGF uses ROS as a second messenger to regulate STAT activation.

Effect of extracellular Mg2+ on ROS and Ca2+ accumulation during reoxygenation of rat cardiomyocytes

2001 ◽  
Vol 280 (1) ◽  
pp. H344-H353 ◽  
Author(s):  
Mohammad N. Sharikabad ◽  
Kirsten M. Østbye ◽  
Torstein Lyberg ◽  
Odd Brørs
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Flow Cytometry ◽  
Lactate Dehydrogenase ◽  
Superoxide Anion ◽  
Oxygen Species ◽  
No Donor ◽  
Rat Cardiomyocytes ◽  
Intracellular Ros ◽  
Ldh Release

The effects of Mg2+ on reactive oxygen species (ROS) and cell Ca2+ during reoxygenation of hypoxic rat cardiomyocytes were studied. Oxidation of 2′,7′-dichlorodihydrofluorescein (DCDHF) to dichlorofluorescein (DCF) and of dihydroethidium (DHE) to ethidium (ETH) within cells were used as markers for intracellular ROS levels and were determined by flow cytometry. DCDHF/DCF is sensitive to H2O2 and nitric oxide (NO), and DHE/ETH is sensitive to the superoxide anion (O2 −·), respectively. Rapidly exchangeable cell Ca2+ was determined by 45Ca2+uptake. Cells were exposed to hypoxia for 1 h and reoxygenation for 2 h. ROS levels, determined as DCF fluorescence, were increased 100–130% during reoxygenation alone and further increased 60% by increasing extracellular Mg2+concentration to 5 mM at reoxygenation. ROS levels, measured as ETH fluorescence, were increased 16–24% during reoxygenation but were not affected by Mg2+. Cell Ca2+ increased three- to fourfold during reoxygenation. This increase was reduced 40% by 5 mM Mg2+, 57% by 10 μM 3,4-dichlorobenzamil (DCB) (inhibitor of Na+/Ca2+ exchange), and 75% by combining Mg2+ and DCB. H2O2 (25 and 500 μM) reduced Ca2+ accumulation by 38 and 43%, respectively, whereas the NO donor S-nitroso- N-acetyl-penicillamine (1 mM) had no effect. Mg2+ reduced hypoxia/reoxygenation-induced lactate dehydrogenase (LDH) release by 90%. In conclusion, elevation of extracellular Mg2+ to 5 mM increased the fluorescence of the H2O2/NO-sensitive probe DCF without increasing that of the O2 −·-sensitive probe ETH, reduced Ca2+ accumulation, and decreased LDH release during reoxygenation of hypoxic cardiomyocytes. The reduction in LDH release, reflecting the protective effect of Mg2+, may be linked to the effect of Mg2+ on Ca2+ accumulation and/or ROS levels.

337 MITOCHONDRIA AND REACTIVE OXYGEN SPECIES IN PREBUPERTAL LAMB OOCYTES BEFORE AND AFTER IN VITRO MATURATION

2010 ◽  
Vol 22 (1) ◽  
pp. 325
Author(s):  
M. E. Dell'Aquila ◽  
B. Ambruosi ◽  
R. Guastamacchia ◽  
F. Binetti ◽  
E. Ciani ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Female Reproductive Tract ◽  
Nuclear Chromatin ◽  
Oxygen Species ◽  
Intracellular Ros ◽  
Before And After ◽  
Group A ◽  
Group B

Juvenile in vitro embryo transfer (JIVET) reduces the generation interval and increases the rate of genetic gain. The developmental competence of in vitro-produced embryos is strictly related to oocyte quality. Oxidative stress in the oocyte is an emerging problem in reproductive in vitro technologies, due to the gas atmosphere used to incubate oocytes and the lack of physiological defense mechanisms available in the female reproductive tract. The major source of reactive oxygen species (ROS) is represented by mitochondria where ROS are produced during oxidative phosphorylation. The aim of the present study was to analyze mitochondria and ROS in ovine prepubertal oocytes before and after IVM in order to clarify their suitability in JIVET programs. Cumulus-oocyte complexes from the ovaries of 38 slaughtered prepubertal (less than 8 months of age) lambs of the Comisana breed were analyzed at retrieval (group A) or after IVM (group B; Ambruosi et al. 2009 Theriogenology 71, 1093-1104). After cumulus cell removal, all oocytes underwent nuclear chromatin, mitochondria and ROS evaluation by confocal analysis of fluorescence distribution and intensity. Hoechst 33258 and Mitotracker Orange CMTM Ros (Molecular Probes Inc., Eugene, OR) were used to label nuclear chromatin and mitochondria (Ambruosi et al. 2009) and 2′,7′-dichloro-dihydro-fluorescein diacetate was used for ROS labelling (Hashimoto et al. 2000 Mol. Reprod. Dev. 57, 353-360). Out of 65 oocytes from group A, 38 oocytes with regular size (>130 μm in diameter), morphology and nuclear chromatin at the GV stage were selected for analysis. One-hundred-thirty-eight oocytes underwent IVM (group B). Nuclear maturation rate (metaphase II with 1st polar body extruded) was 54%, 75/138. All MII oocytes were used for analysis. Significantly higher rate of oocytes from group B showed heterogeneous (large aggregates, clusters, pericortical, perinuclear) mitochondrial (mt) distribution pattern than oocytes from group A (55%, 41/75 v. 29%, 11/38, respectively; P < 0.05) which showed uniform distribution of small mt aggregates. Fluorescent intensity of mt labeling did not differ between groups (43.05 ± 16.15 v. 45.89 ± 10.36, for group A and B respectively; NS). In most of the oocytes from both groups, intracellular ROS were distributed in small or large aggregates (35/38, 92% and 62/75, 83%). No statistical difference was observed for intracellular ROS levels between oocytes from group A (66.36 ± 13.2) and group B (72.84 ± 20.63; NS). The culture conditions used in this study provided normal mt distribution and intracellular ROS levels. Qualitative and quantitative evaluation of mitochondria and intracellular ROS could be useful to improve in vitro culture methods in ovine prepubertal oocytes.

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