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

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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Extracellular Reactive Oxygen Species (ROS) Production in Fresh Donkey Sperm Exposed to Reductive Stress, Oxidative Stress and NETosis

Antioxidants ◽

10.3390/antiox10091367 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1367

Author(s):

Iván Yánez-Ortiz ◽

Jaime Catalán ◽

Yentel Mateo-Otero ◽

Marta Dordas-Perpinyà ◽

Sabrina Gacem ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Hydrogen Peroxide ◽

Selection Process ◽

Reactive Oxygen ◽

Polymorphonuclear Neutrophils ◽

Ros Production ◽

Oxygen Species ◽

Oxidative Stresses ◽

Stress Oxidative

Jenny shows a large endometrial reaction after semen influx to the uterus with a large amount of polymorphonuclear neutrophils (PMN) migrating into the uterine lumen. PMN act as a sperm selection mechanism through phagocytosis and NETosis (DNA extrudes and, together with proteins, trap spermatozoa). While a reduced percentage of spermatozoa are phagocytosed by PMN, most are found to be attached to neutrophil extracellular traps (NETs). This selection process together with sperm metabolism produces a large amount of reactive oxygen species (ROS) that influence the reproductive success. The present study aimed to determine the extracellular ROS production in both sperm and PMN. With this purpose, (1) donkey sperm were exposed to reductive and oxidative stresses, through adding different concentrations of reduced glutathione (GSH) and hydrogen peroxide (H2O2), respectively; and (2) PMN were subjected to NETosis in the presence of the whole semen, sperm, seminal plasma (SP) or other activators such as formyl-methionyl-leucyl-phenylalanine (FMLP). Extracellular ROS production (measured as H2O2 levels) was determined with the Amplex® Red Hydrogen Peroxide/Peroxidase Assay Kit. Donkey sperm showed more resilience to oxidative stress than to the reductive one, and GSH treatments led to greater H2O2 extracellular production. Moreover, not only did SP appear to be the main inducer of NETosis in PMN, but it was also able to maintain the extracellular H2O2 levels produced by sperm and NETosis.

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Nordihydroguaiaretic Acid Attenuates the Oxidative Stress-Induced Decrease of CD33 Expression in Human Monocytes

Oxidative Medicine and Cellular Longevity ◽

10.1155/2013/375893 ◽

2013 ◽

Vol 2013 ◽

pp. 1-14 ◽

Cited By ~ 7

Author(s):

Silvia Guzmán-Beltrán ◽

José Pedraza-Chaverri ◽

Susana Gonzalez-Reyes ◽

Fernando Hernández-Sánchez ◽

Ulises E. Juarez-Figueroa ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Hydrogen Peroxide ◽

Antioxidant Activity ◽

Oxidant Stress ◽

Nordihydroguaiaretic Acid ◽

Larrea Tridentata ◽

Ros Production ◽

Oxygen Species ◽

Human Monocytes

Nordihydroguaiaretic acid (NDGA) is a natural lignan with recognized antioxidant and beneficial properties that is isolated fromLarrea tridentata. In this study, we evaluated the effect of NDGA on the downregulation of oxidant stress-induced CD33 in human monocytes (MNs). Oxidative stress was induced by iodoacetate (IAA) or hydrogen peroxide (H2O2) and was evaluated using reactive oxygen species (ROS) production, and cell viability. NDGA attenuates toxicity, ROS production and the oxidative stress-induced decrease of CD33 expression secondary to IAA or H2O2in human MNs. It was also shown that NDGA (20 μM) attenuates cell death in the THP-1 cell line that is caused by treatment with either IAA or H2O2. These results suggest that NDGA has a protective effect on CD33 expression, which is associated with its antioxidant activity in human MNs.

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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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Novel Antioxidant Properties of Doxycycline

International Journal of Molecular Sciences ◽

10.3390/ijms19124078 ◽

2018 ◽

Vol 19 (12) ◽

pp. 4078 ◽

Cited By ~ 9

Author(s):

Dahn Clemens ◽

Michael Duryee ◽

Cleofes Sarmiento ◽

Andrew Chiou ◽

Jacob McGowan ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Hydrogen Peroxide ◽

Chronic Inflammation ◽

Antioxidant Properties ◽

Antibacterial Properties ◽

Reactive Oxygen ◽

Protein Adducts ◽

Oxygen Species ◽

Free System

Doxycycline (DOX), a derivative of tetracycline, is a broad-spectrum antibiotic that exhibits a number of therapeutic activities in addition to its antibacterial properties. For example, DOX has been used in the management of a number of diseases characterized by chronic inflammation. One potential mechanism by which DOX inhibits the progression of these diseases is by reducing oxidative stress, thereby inhibiting subsequent lipid peroxidation and inflammatory responses. Herein, we tested the hypothesis that DOX directly scavenges reactive oxygen species (ROS) and inhibits the formation of redox-mediated malondialdehyde-acetaldehyde (MAA) protein adducts. Using a cell-free system, we demonstrated that DOX scavenged reactive oxygen species (ROS) produced during the formation of MAA-adducts and inhibits the formation of MAA-protein adducts. To determine whether DOX scavenges specific ROS, we examined the ability of DOX to directly scavenge superoxide and hydrogen peroxide. Using electron paramagnetic resonance (EPR) spectroscopy, we found that DOX directly scavenged superoxide, but not hydrogen peroxide. Additionally, we found that DOX inhibits MAA-induced activation of Nrf2, a redox-sensitive transcription factor. Together, these findings demonstrate the under-recognized direct antioxidant property of DOX that may help to explain its therapeutic potential in the treatment of conditions characterized by chronic inflammation and increased oxidative stress.

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Caffeic Acid - Potential Antioxidant in Cultured Human Retinal Pigment Epithelial Cells

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Agriculture ◽

10.15835/buasvmcn-agr:4010 ◽

1970 ◽

Vol 66 (2) ◽

Author(s):

Dumitriţa RUGINǍ ◽

Adela PINTEA ◽

Raluca PÂRLOG ◽

Andreea VARGA

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Hydrogen Peroxide ◽

Protective Effect ◽

Caffeic Acid ◽

Reactive Oxygen ◽

Oxygen Species ◽

Antioxidant Defence ◽

Rpe Cells ◽

In Cells

Oxidative stress causes biological changes responsible for carcinogenesis and aging in human cells. The retinal pigmented epithelium is continuously exposed to oxidative stress. Therefore reactive oxygen species (ROS) and products of lipid peroxidation accumulate in RPE. Neutralization of ROS occurs in retina by the action of antioxidant defence systems. In the present study, the protective effect of caffeic acid (3,4-dihydroxy cinnamic acid), a dietary phenolic compound, has been examined in normal and in oxidative stress conditions (500 µM peroxide oxygen) in cultures human epithelial pigment retinal cells (Nowak, M. et al.). The cell viability, the antioxidant enzymes activity (CAT, GPx, SOD) and the level of intracellular reactive oxygen species (ROS) were determined. Exposure to l00 µM caffeic acid for 24 h induced cellular changes indicating the protective effect of caffeic acid in RPE cells. Caffeic acid did not show any cytotoxic effect at concentrations lower than 200 μM in culture medium. Treatment of RPE cells with caffeic acid causes an increase of catalase, glutathione peroxidase and superoxide dismutase activity, especially in cells treated with hydrogen peroxide. Caffeic acid causes a decrease of ROS level in cells treated with hydrogen peroxide. This study proved that caffeic acid or food that contain high levels of this phenolic acid may have beneficial effects in prevention of retinal diseases associated with oxidative stress by improving antioxidant defence systems.

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BV-2 Microglial Cells Respond to Rotenone Toxic Insult by Modifying Pregnenolone, 5α-Dihydroprogesterone and Pregnanolone Levels

Cells ◽

10.3390/cells9092091 ◽

2020 ◽

Vol 9 (9) ◽

pp. 2091 ◽

Cited By ~ 1

Author(s):

Rossella Avallone ◽

Chiara Lucchi ◽

Giulia Puja ◽

Alessandro Codeluppi ◽

Monica Filaferro ◽

...

Keyword(s):

Mass Spectrometry ◽

Reactive Oxygen Species ◽

Liquid Chromatography ◽

Tandem Mass Spectrometry ◽

Neurodegenerative Diseases ◽

Culture Medium ◽

Microglial Cells ◽

Tandem Mass ◽

Ros Production ◽

Oxygen Species

Neuroinflammation, whose distinctive sign is the activation of microglia, is supposed to play a key role in the development and progression of neurodegenerative diseases. The aim of this investigation was to determine levels of neurosteroids produced by resting and injured BV-2 microglial cells. BV-2 cells were exposed to increasing concentrations of rotenone to progressively reduce their viability by increasing reactive oxygen species (ROS) production. BV-2 cell viability was significantly reduced 24, 48 and 72 h after rotenone (50–1000 nM) exposure. Concomitantly, rotenone (50–100 nM) determined a dose-independent augmentation of ROS production. Then, BV-2 cells were exposed to a single, threshold dose of rotenone (75 nM) to evaluate the overtime release of neurosteroids. In particular, pregnenolone, pregnenolone sulfate, progesterone, 5α-dihydroprogesterone (5α-DHP), allopregnanolone, and pregnanolone, were quantified in the culture medium by liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis. BV-2 cells synthesized all the investigated neurosteroids and, after exposure to rotenone, 5αDHP and pregnanolone production was remarkably increased. In conclusion, we found that BV-2 cells not only synthesize several neurosteroids, but further increase this production following oxidative damage. Pregnanolone and 5α-DHP may play a role in modifying the progression of neuroinflammation in neurodegenerative diseases.

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Distinct Signaling Pathways Respond to Arsenite and Reactive Oxygen Species in Schizosaccharomyces pombe

Eukaryotic Cell ◽

10.1128/ec.4.8.1396-1402.2005 ◽

2005 ◽

Vol 4 (8) ◽

pp. 1396-1402 ◽

Cited By ~ 38

Author(s):

Miguel A. Rodríguez-Gabriel ◽

Paul Russell

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Hydrogen Peroxide ◽

Schizosaccharomyces Pombe ◽

Stress Responses ◽

Biological Effects ◽

Reactive Oxygen ◽

Oxygen Species ◽

Increased Risk ◽

Risk Of Cancer

ABSTRACT Exposure to certain metal and metalloid species, such as arsenic, cadmium, chromium, and nickel, has been associated with an increased risk of cancer in humans. The biological effects of these metals are thought to result from induction of reactive oxygen species (ROS) and inhibition of DNA repair enzymes, although alterations in signal transduction pathways may also be involved in tumor development. To better understand metal toxicity and its connection to ROS, we have compared the effects of arsenite and hydrogen peroxide in wild-type and mutant strains of the fission yeast Schizosaccharomyces pombe. An atf1Δ pap1Δ strain, which is defective in two transcription factors that control stress responses, is extremely sensitive to hydrogen peroxide but not to arsenite. A strain that lacks the transcription factor Zip1 has the opposite relationship. Spc1 (Sty1) mitogen-activated protein kinase (MAPK), a homologue of mammalian p38 MAPK, and the upstream MAPK kinase (MAPKK) Wis1 are essential for survival of both arsenite and hydrogen peroxide. Inactivation of two MAPKK kinases, Win1 and Wis4, almost completely eliminates Spc1 activation by arsenite, yet these cells survive arsenite treatment. The two-component phosphorelay protein Mcs4, which acts upstream of Win1 and Wis4 and is required for Spc1 activation in response to oxidative stress, is not required for Spc1 activation in response to arsenite. We conclude that the toxic effects of arsenic are not strongly connected to oxidative stress and that although Spc1 is activated by arsenic exposure, the basal activity of Spc1 is largely sufficient for the survival of arsenic.

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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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