Plasma from Patients with Rheumatoid Arthritis Reduces Nitric Oxide Synthesis and Induces Reactive Oxygen Species in A Cell-Based Biosensor

Rheumatoid arthritis (RA) has been associated with a higher risk of developing cardiovascular (CV) diseases. It has been proposed that systemic inflammation plays a key role in premature atherosclerosis development, and is therefore crucial to determine whether systemic components from RA patients promotes endothelial cell-oxidative stress by affecting reactive oxygen species (ROS) and nitric-oxide (NO) production. The aim of this study was to evaluate whether plasma from RA patients impair NO synthesis and ROS production by using the cell-line ECV-304 as a biosensor. NO synthesis and ROS production were measured in cells incubated with plasma from 73 RA patients and 52 healthy volunteers by fluorimetry. In addition, traditional CV risk factors, inflammatory molecules and disease activity parameters were measured. Cells incubated with plasma from RA patients exhibited reduced NO synthesis and increased ROS production compared to healthy volunteers. Furthermore, the imbalance between NO synthesis and ROS generation in RA patients was not associated with traditional CV risk factors. Our data suggest that ECV-304 cells can be used as a biosensor of systemic inflammation-induced endothelial cell-oxidative stress. We propose that both NO and ROS production are potential biomarkers aimed at improving the current assessment of CV risk in RA.

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Intracellular Sources of ROS/H2O2 in Health and Neurodegeneration: Spotlight on Endoplasmic Reticulum

Cells ◽

10.3390/cells10020233 ◽

2021 ◽

Vol 10 (2) ◽

pp. 233

Author(s):

Tasuku Konno ◽

Eduardo Pinho Melo ◽

Joseph E. Chambers ◽

Edward Avezov

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Hydrogen Peroxide ◽

Endoplasmic Reticulum ◽

Neurodegenerative Diseases ◽

Antioxidative Enzymes ◽

Redox Reactions ◽

Ros Production ◽

Oxygen Species ◽

Specific Target

Reactive oxygen species (ROS) are produced continuously throughout the cell as products of various redox reactions. Yet these products function as important signal messengers, acting through oxidation of specific target factors. Whilst excess ROS production has the potential to induce oxidative stress, physiological roles of ROS are supported by a spatiotemporal equilibrium between ROS producers and scavengers such as antioxidative enzymes. In the endoplasmic reticulum (ER), hydrogen peroxide (H2O2), a non-radical ROS, is produced through the process of oxidative folding. Utilisation and dysregulation of H2O2, in particular that generated in the ER, affects not only cellular homeostasis but also the longevity of organisms. ROS dysregulation has been implicated in various pathologies including dementia and other neurodegenerative diseases, sanctioning a field of research that strives to better understand cell-intrinsic ROS production. Here we review the organelle-specific ROS-generating and consuming pathways, providing evidence that the ER is a major contributing source of potentially pathologic ROS.

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The role of oxidative/nitrosative stress in pathogenesis of paracetamol-induced toxic hepatitis

Medicinski pregled ◽

10.2298/mpns1012827r ◽

2010 ◽

Vol 63 (11-12) ◽

pp. 827-832 ◽

Cited By ~ 7

Author(s):

Tatjana Radosavljevic ◽

Dusan Mladenovic ◽

Danijela Vucevic ◽

Rada Jesic-Vukicevic

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Reactive Oxygen Species ◽

Liver Injury ◽

Kupffer Cells ◽

Reactive Oxygen ◽

Oxygen Species ◽

Severe Liver ◽

Hepatocellular Necrosis

Introduction. Paracetamol is an effective analgesic/antipyretic drug when used at therapeutic doses. However, the overdose of paracetamol can cause severe liver injury and liver necrosis. The mechanism of paracetamol-induced liver injury is still not completely understood. Reactive metabolite formation, depletion of glutathione and alkylation of proteins are the triggers of inhibition of mitochondrial respiration, adenosine triphosphate depletion and mitochondrial oxidant stress leading to hepatocellular necrosis. Role of oxidative stress in paracetamol-induced liver injury. The importance of oxidative stress in paracetamol hepatotoxicity is controversial. Paracetamol induced liver injury cause the formation of reactive oxygen species. The potent sources of reactive oxygen are mitochondria, neutrophils, Kupffer cells and the enzyme xatnine oxidase. Free radicals lead to lipid peroxidation, enzymatic inactivation and protein oxidation. Role of mitochondria in paracetamol-induced oxidative stress. The production of mitochondrial reactive oxygen species is increased, and the glutathione content is decreased in paracetamol overdose. Oxidative stress in mitochondria leads to mito?chondrial dysfunction with adenosine triphosphate depletion, increase mitochondrial permeability transition, deoxyribonu?cleic acid fragmentation which contribute to the development of hepatocellular necrosis in the liver after paracetamol overdose. Role of Kupffer cells in paracetamol-induced liver injury. Paracetamol activates Kupffer cells, which then release numerous cytokines and signalling molecules, including nitric oxide and superoxide. Kupffer cells are important in peroxynitrite formation. On the other hand, the activated Kupffer cells release anti-inflammatory cytokines. Role of neutrophils in paracetamol-induced liver injury. Paracetamol-induced liver injury leads to the accumulation of neutrophils, which release lysosomal enzymes and generate superoxide anion radicals through the enzyme nicotinamide adenine dinucleotide phosphate oxidase. Hydrogen peroxide, which is influenced by the neutrophil-derived enzyme myeloperoxidase, generates hypochlorus acid as a potent oxidant. Role of peroxynitrite in paracetamol-induced oxidative stress. Superoxide can react with nitric oxide to form peroxynitrite, as a potent oxidant. Nitrotyrosine is formed by the reaction of tyrosine with peroxynitrite in paracetamol hepatotoxicity. Conclusion. Overdose of paracetamol may produce severe liver injury with hepatocellular necrosis. The most important mechanisms of cell injury are metabolic activation of paracetamol, glutathione depletion, alkylation of proteins, especially mitochondrial proteins, and formation of reactive oxygen/nitrogen species.

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

Pathobiology ◽

10.1159/000512639 ◽

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

Introduction: 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. Methods: 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. Results: 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. Conclusion: These findings suggest a novel mechanism whereby hyperglycemic-induced ROS production promotes salivary gland injury, resulting in hyposalivation.

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Abstract 316: Effects of Inhibiting of Inducible Nitric Oxide Synthase in the Pathophysiology of Experimental Preeclampsia

Hypertension ◽

10.1161/hyp.60.suppl_1.a316 ◽

2012 ◽

Vol 60 (suppl_1) ◽

Author(s):

Lorena M Amaral ◽

Ana Carolina T Palei ◽

Lucas C Pinheiro ◽

Jonas T Sertorio ◽

Danielle A Guimaraes ◽

...

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Reactive Oxygen Species ◽

Mean Arterial Pressure ◽

Arterial Pressure ◽

Inducible Nitric Oxide Synthase ◽

Inos Expression ◽

Oxygen Species ◽

Oxide Synthase ◽

Inducible Nitric Oxide

The pathophysiology of preeclampsia (PE) is not entirely known. However, increased oxidative stress possibly leading to impaired nitric oxide activity has been implicated in the critical condition. Increased oxidative stress with increased levels of highly reactive species including superoxide may generate peroxynitrite. We examined the role of inducible nitric oxide synthase (iNOS) and oxidative stress in the reduced uterine perfusion pressure (RUPP) preeclampsia experimental model. METHODS: RUPP was induced in wistar rats. Pregnant rats in the RUPP group had their aortic artery clipped at day 14 of gestation. After a midline incision, a silver clip (0.203 mm) was placed around the aorta above the iliac bifurcation; silver clips (0.100 mm) were also placed on branches of both the right and left ovarian arteries that supply the uterus. Sham-operated (pregnant control rats) and RUPP rats were treated with oral vehicle or 1 mg/kg/day 1400W (iNOS inhibitor) for 5 days. Mean arterial pressure (MAP) and plasma levels of thiobarbituric acid-reactive species (TBARS) and total radical-trapping antioxidant potential (TRAP) were measured determined. Aortic iNOS expression (Western blotting) and reactive oxygen species (ROS; assessed by fluorescence microscopy with dihydroethidium-DHE) were measured. We found increased mean arterial pressure in RUPP compared with pregnant control rats (MAP= 128±1 vs. 100±1.8 mmHg, respectively; P<0.05) and 1400W exerted antihypertensive effects (MAP= 114±2 vs.128±1 mmHg in RUPP treated and untreated rats, respectively; P<0.05). Higher reactive oxygen species (ROS) concentrations were found in RUPP compared with pregnant control rats (7.1±0.5 vs. 5.1±0.5 arbitrary units (A.U.), respectively; P<0.05) and 1400W decreased ROS production to 5.8±0.02 A.U. in RUPP treated rats, P<0.05. In addition, 1400W attenuated iNOS expression in RUPP rats (0.29±0.02 vs. 0.55±0.8 A.U. in RUPP treated and untreated rats, respectively; P<0.01) and had no effects on plasma TBARS and TRAP levels. Our results suggest that 1400w exerts antihypertensive effects in the RUPP model and suppresses ROS formation. Supported by FAPESP,Cnpq.

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Induction of inducible nitric oxide synthase increases the production of reactive oxygen species in RAW264.7 macrophages

Bioscience Reports ◽

10.1042/bsr20090048 ◽

2010 ◽

Vol 30 (4) ◽

pp. 233-241 ◽

Cited By ~ 33

Author(s):

Kai Zhao ◽

Zhen Huang ◽

Hongling Lu ◽

Juefei Zhou ◽

Taotao Wei

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Nitric Oxide Synthase ◽

Reactive Oxygen ◽

Inos Expression ◽

Raw264.7 Cells ◽

Ros Production ◽

Oxygen Species ◽

Raw264.7 Macrophages ◽

Oxide Synthase

Macrophages produce a large volume of ROS (reactive oxygen species) through respiratory burst. However, the influence of iNOS [inducible NOS (nitric oxide synthase)] activation on ROS production remains unclear. In the present study, the kinetic generation of ROS in RAW264.7 murine macrophages was monitored by chemiluminescence. PMA induces a robust chemiluminescence in RAW264.7 cells, suggesting PKC (protein kinase C)-related assembly and activation of NOX (NADPH oxidase). The effects of iNOS induction on ROS production were examined. Induction of iNOS expression in RAW264.7 cells with LPS (lipopolysaccharide; 1 μg/ml) causes a significant increase in PMA-induced chemiluminescence, which could be enhanced by the NOS substrate, L-arginine, and could be abolished by the NOS inhibitor, L-NNA (NG-nitro-L-arginine). Further experiments reveal that induction of iNOS expression enhances the PMA-stimulated phosphorylation of the p47phox subunit of NOX, and promotes the relocalization of cytosolic p47phox and p67phox subunits to the membrane. Inhibition of PKCζ by its myristoylated pseudosubstrate significantly decreased the PMA-stimulated phosphorylation of the p47phox in LPS-pretreated cells, suggesting that PKCζ is involved in the iNOS-dependent assembly and activation of NOX. Taken together, the present study suggests that the induction of iNOS upregulates the PMA-induced assembly of NOX and leads to the enhanced production of ROS via a PKCζ-dependent mechanism.

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Reactive Oxygen Species (ROS) Metabolism and Nitric Oxide (NO) Content in Roots and Shoots of Rice (Oryza sativa L.) Plants under Arsenic-Induced Stress

Agronomy ◽

10.3390/agronomy10071014 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1014 ◽

Cited By ~ 1

Author(s):

Ernestina Solórzano ◽

Francisco J. Corpas ◽

Salvador González-Gordo ◽

José M. Palma

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Reactive Oxygen Species ◽

Oryza Sativa ◽

Oryza Sativa L ◽

Reactive Oxygen ◽

Oxygen Species ◽

Antioxidative Systems ◽

Ros Metabolism ◽

As Stress

Arsenic (As) is a highly toxic metalloid for all forms of life including plants. Rice is the main food source for different countries worldwide, although it can take up high amounts of As in comparison with other crops, showing toxic profiles such as decreases in plant growth and yield. The induction of oxidative stress is the main process underlying arsenic toxicity in plants, including rice, due to an alteration of the reactive oxygen species (ROS) metabolism. The aim of this work was to gain better knowledge on how the ROS metabolism and its interaction with nitric oxide (NO) operate under As stress conditions in rice plants. Thus, physiological and ROS-related biochemical parameters in roots and shoots from rice (Oryza sativa L.) were studied under 50 μM arsenate (AsV) stress, and the involvement of the main antioxidative systems and NO in the response of plants to those conditions was investigated. A decrease of 51% in root length and 27% in plant biomass was observed with 50 μM AsV treatment, as compared to control plants. The results of the activity of superoxide dismutase (SOD) isozymes, catalase, peroxidase (POD: total and isoenzymatic), and the enzymes of the ascorbate–glutathione cycle, besides the ascorbate and glutathione contents, showed that As accumulation provoked an overall significant increase of most of them, but with different profiles depending on the plant organ, either root or shoot. Among the seven identified POD isozymes, the induction of the POD-3 in shoots under As stress could help to maintain the hydrogen peroxide (H2O2) redox homeostasis and compensate the loss of the ascorbate peroxidase (APX) activity in both roots and shoots. Lipid peroxidation was slightly increased in roots and shoots from As-treated plants. The H2O2 and NO contents were enhanced in roots and shoots against arsenic stress. In spite of the increase of most antioxidative systems, a mild oxidative stress situation appears to be consolidated overall, since the growth parameters and those from the oxidative damage could not be totally counteracted. In these conditions, the higher levels of H2O2 and NO suggest that signaling events are simultaneously occurring in the whole plant.

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Kallistatin attenuates endothelial apoptosis through inhibition of oxidative stress and activation of Akt-eNOS signaling

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00591.2010 ◽

2010 ◽

Vol 299 (5) ◽

pp. H1419-H1427 ◽

Cited By ~ 49

Author(s):

Bo Shen ◽

Lin Gao ◽

Yi-Te Hsu ◽

Grant Bledsoe ◽

Makato Hagiwara ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Endothelial Cells ◽

Endothelial Cell ◽

Oxygen Species ◽

Phosphatidylinositol 3 Kinase ◽

Reactive Oxygen Species Formation ◽

Endothelial Apoptosis ◽

Species Formation ◽

Tnf Α

Kallistatin is a regulator of vascular homeostasis capable of controlling a wide spectrum of biological actions in the cardiovascular and renal systems. We previously reported that kallistatin inhibited intracellular reactive oxygen species formation in cultured cardiac and renal cells. The present study was aimed to investigate the role and mechanisms of kallistatin in protection against oxidative stress-induced vascular injury and endothelial cell apoptosis. We found that kallistatin gene delivery significantly attenuated aortic superoxide formation and glomerular capillary loss in hypertensive DOCA-salt rats. In cultured endothelial cells, kallistatin suppressed TNF-α-induced cellular apoptosis, and the effect was blocked by the pharmacological inhibition of phosphatidylinositol 3-kinase and nitric oxide synthase (NOS) and by the knockdown of endothelial NOS (eNOS) expression. The transduction of endothelial cells with adenovirus expressing dominant-negative Akt abolished the protective effect of kallistatin on endothelial apoptosis and caspase activity. In addition, kallistatin inhibited TNF-α-induced reactive oxygen species formation and NADPH oxidase activity, and these effects were attenuated by phosphatidylinositol 3-kinase and NOS inhibition. Kallistatin also prevented the induction of Bim protein and mRNA expression by oxidative stress. Moreover, the downregulation of forkhead box O 1 (FOXO1) and Bim expression suppressed TNF-α-mediated endothelial cell death. Furthermore, the antiapoptotic actions of kallistatin were accompanied by Akt-mediated FOXO1 and eNOS phosphorylation, as well as increased NOS activity. These findings indicate a novel role of kallistatin in the protection against vascular injury and oxidative stress-induced endothelial apoptosis via the activation of Akt-dependent eNOS signaling.

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Paraquat Modulates Immunological Function in Bone Marrow-Derived Macrophages

10.21203/rs.3.rs-407029/v1 ◽

2021 ◽

Author(s):

Piyarat Srinont ◽

Jaroon Wandee ◽

Worapol Angwanich

Keyword(s):

Nitric Oxide ◽

Reactive Oxygen Species ◽

Bone Marrow ◽

Cell Death ◽

Cell Viability ◽

Inducible Nitric Oxide Synthase ◽

Ros Production ◽

Oxygen Species ◽

Oxide Synthase ◽

Inducible Nitric Oxide

Abstract Paraquat (PQ) is an herbicide commonly used worldwide. This herbicide is known to alter the human and animal immune systems. Many reports indicated that PQ impacts immune cell viability and functions. However, the underlying mechanism critical is still unknown. Therefore, the aim of this study was to evaluate effects of PQ on free radical production, oxidative stress, cell death, and pro-inflammatory gene expression of murine bone marrow-derived macrophages (BMDMs) from female C57BL/6NJcl mice in vitro. BMDMs were incubated with PQ at 0, 200, 400 µM for 24 h. Intracellular reactive oxygen species (ROS) production, apoptosis, cell viability, nitric oxide, inducible nitric oxide synthase (iNOS), and IL-6 expression of murine BMDMs were measured. The results revealed that PQ treatments led to decrease the cell viability and induced apoptotic cell death in a dose-dependent manner. Additionally, PQ induced reactive oxygen species (ROS) generation. The mRNA expression level of pro-inflammatory mediator gene IL-6 and inducible nitric oxide synthase (iNOS) were elevated, while the level of lipid peroxides (MDA) production was unaltered by PQ treatment. Interestingly, PQ led to a decrease in nitric oxide production depends on its concentration. These phenomena indicated that PQ increased cellular ROS production which induced apoptosis, and the herbicide triggers production of iNOS and IL-6 in murine BMDMs.

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The Characterization of TA-289, a Novel Antifungal from Fusarium sp.

10.26686/wgtn.16992670 ◽

2021 ◽

Author(s):

◽

Natelle C H Quek

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Cell Cycle ◽

Cell Death ◽

Reactive Oxygen ◽

Chemical Diversity ◽

Mitochondrial Morphology ◽

Ros Production ◽

Oxygen Species ◽

Wild Type

Natural products offer vast structural and chemical diversity highly sought after in drug discovery research. Saccharomyces cerevisiae makes an ideal model eukaryotic organism for drug mode-of-action studies owing to ease of growth, sophistication of genetic tools and overall homology to higher eukaryotes. Equisetin and a closely related novel natural product, TA-289, are cytotoxic to fermenting yeast, but seemingly less so when yeast actively respire. Cell cycle analyses by flow cytometry revealed a cell cycle block at S-G2/M phase caused by TA-289; previously described oxidative stress-inducing compounds causing cell cycle delay led to further investigation in the involvement of equisetin and TA-289 in mitochondrial-mediated generation of reactive oxygen species. Chemical genomic profiling involving genome-wide scans of yeast deletion mutant strains for TA-289 sensitivity revealed sensitization of genes involved in the mitochondria, DNA damage repair and oxidative stress responses, consistent with a possible mechanism-of-action at the mitochondrion. Flow cytometric detection of reactive oxygen species (ROS) generation caused by TA-289 suggests that the compound may induce cell death via ROS production. The generation of a mutant strain resistant to TA-289 also displayed resistance to a known oxidant, H2O2, at concentrations that were cytotoxic to wild-type cells. The resistant mutant displayed a higher basal level of ROS production compared to the wild-type parent, indicating that the resistance mutation led to an up-regulation of antioxidant capacity which provides cell survival in the presence of TA-289. Yeast mitochondrial morphology was visualized by confocal light microscopy, where it was observed that cells treated with TA-289 displayed abnormal mitochondria phenotypes, further indicating that the compound is acting primarily at the mitochondrion. Similar effects observed with equisetin treatment suggest that both compounds share the same mechanism, eliciting cell death via ROS production in the mitochondrial respiratory chain.

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Comparative Reactive Oxygen Species (ROS) Content among Various Flavored Disposable Vape Bars, including Cool (Iced) Flavored Bars

Toxics ◽

10.3390/toxics9100235 ◽

2021 ◽

Vol 9 (10) ◽

pp. 235

Author(s):

Shaiesh Yogeswaran ◽

Thivanka Muthumalage ◽

Irfan Rahman

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Health Effects ◽

Reactive Oxygen ◽

Ros Production ◽

Oxygen Species ◽

Aerosol Generator ◽

Pulmonary Cells ◽

Single Puff ◽

Insight Into

Studies have shown that aerosols generated from flavored e-cigarettes contain Reactive Oxygen Species (ROS), promoting oxidative stress-induced damage within pulmonary cells. Our lab investigated the ROS content of e-cigarette vapor generated from disposable flavored e-cigarettes (vape bars) with and without nicotine. Specifically, we analyzed vape bars belonging to multiple flavor categories (Tobacco, Minty Fruit, Fruity, Minty/Cool (Iced), Desserts, and Drinks/Beverages) manufactured by various vendors and of different nicotine concentrations (0–6.8%). Aerosols from these vape bars were generated via a single puff aerosol generator; these aerosols were then individually bubbled through a fluorogenic solution to semi-quantify ROS generated by these bars in H2O2 equivalents. We compared the ROS levels generated by each vape bar as an indirect determinant of their potential to induce oxidative stress. Our results showed that ROS concentration (μM) within aerosols produced from these vape bars varied significantly among different flavored vape bars and identically flavored vape bars with varying nicotine concentrations. Furthermore, our results suggest that flavoring chemicals and nicotine play a differential role in generating ROS production in vape bar aerosols. Our study provides insight into the differential health effects of flavored vape bars, in particular cool (iced) flavors, and the need for their regulation.

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