scholarly journals Efficiency of the four proteasome subtypes to degrade ubiquitinated or oxidized proteins

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joanna Abi Habib ◽  
Etienne De Plaen ◽  
Vincent Stroobant ◽  
Dusan Zivkovic ◽  
Marie-Pierre Bousquet ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mammalian Cells ◽  
Catalytic Subunits ◽  
Protein Tau ◽  
Oxidized Proteins ◽  
Ubiquitinated Proteins ◽  
Selective Degradation ◽  
Disordered Protein ◽  
Partial Dissociation

Abstract The proteasome is responsible for selective degradation of proteins. It exists in mammalian cells under four main subtypes, which differ by the combination of their catalytic subunits: the standard proteasome (β1–β2–β5), the immunoproteasome (β1i–β2i–β5i) and the two intermediate proteasomes (β1–β2–β5i and β1i–β2–β5i). The efficiency of the four proteasome subtypes to degrade ubiquitinated or oxidized proteins remains unclear. Using cells expressing exclusively one proteasome subtype, we observed that ubiquitinated p21 and c-­myc were degraded at similar rates, indicating that the four 26S proteasomes degrade ubiquitinated proteins equally well. Under oxidative stress, we observed a partial dissociation of 26S into 20S proteasomes, which can degrade non-ubiquitinated oxidized proteins. Oxidized calmodulin and hemoglobin were best degraded in vitro by the three β5i-containing 20S proteasomes, while their native forms were not degraded. Circular dichroism analyses indicated that ubiquitin-independent recognition of oxidized proteins by 20S proteasomes was triggered by the disruption of their structure. Accordingly, β5i-containing 20S proteasomes degraded unoxidized naturally disordered protein tau, while 26S proteasomes did not. Our results suggest that the three β5i-containing 20S proteasomes, namely the immunoproteasome and the two intermediate proteasomes, might help cells to eliminate proteins containing disordered domains, including those induced by oxidative stress.

scholarly journals Blue laser light inhibits biofilm formation in vitro and in vivo by inducing oxidative stress

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Katia Rupel ◽  
Luisa Zupin ◽  
Giulia Ottaviani ◽  
Iris Bertani ◽  
Valentina Martinelli ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Biofilm Formation ◽  
Mammalian Cells ◽  
Bacterial Infections ◽  
Laser Light ◽  
Therapeutic Potential ◽  
Blue Laser ◽  
Data Set

Abstract Resolution of bacterial infections is often hampered by both resistance to conventional antibiotic therapy and hiding of bacterial cells inside biofilms, warranting the development of innovative therapeutic strategies. Here, we report the efficacy of blue laser light in eradicating Pseudomonas aeruginosa cells, grown in planktonic state, agar plates and mature biofilms, both in vitro and in vivo, with minimal toxicity to mammalian cells and tissues. Results obtained using knock-out mutants point to oxidative stress as a relevant mechanism by which blue laser light exerts its anti-microbial effect. Finally, the therapeutic potential is confirmed in a mouse model of skin wound infection. Collectively, these data set blue laser phototherapy as an innovative approach to inhibit bacterial growth and biofilm formation, and thus as a realistic treatment option for superinfected wounds.

Release of glutathione from erythrocytes and other markers of oxidative stress in carbon monoxide poisoning

1997 ◽  
Vol 82 (5) ◽  
pp. 1424-1432 ◽  
Author(s):  
Stephen R. Thom ◽  
Melissa Kang ◽  
Donald Fisher ◽  
Harry Ischiropoulos
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Carbon Monoxide Poisoning ◽  
Thiobarbituric Acid ◽  
Nitric Oxide Synthase Inhibitor ◽  
Oxidized Proteins ◽  
Markers Of Oxidative Stress ◽  
Synthase Inhibitor

Thom, Stephen R., Melissa Kang, Donald Fisher, and Harry Ischiropoulos. Release of glutathione from erythrocytes and other markers of oxidative stress in carbon monoxide poisoning. J. Appl. Physiol. 82(5): 1424–1432, 1997.—Rats exposed to CO in a manner known to cause oxidative stress in brain exhibited a twofold increase in plasma levels of oxidized proteins, thiobarbituric acid-reactive substances (TBARS), oxidized glutathione (GSSG), and reduced glutathione (GSH). Changes were neither directly related to hypoxic stress from carboxyhemoglobin nor significantly influenced by circulating platelets or neutrophils. Treatment with the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester inhibited elevations in GSH and GSSG but not changes in oxidized proteins or TBARS, suggesting that two oxidative mechanisms may be operating in this model and that GSH and GSSG elevations involved nitric oxide-derived oxidants. Elevations of blood GSH and GSSG occurred at different anatomic sites, indicating that no single organ was the source of the increased peptides. Animals that underwent exchange transfusion with a hemoglobin-containing saline solution did not exhibit elevations in GSH and GSSG, suggesting that blood-borne cells released these peptides in response to oxidative stress. In in vitro studies, erythrocytes, but not platelets and leukocytes, responded to oxidative stress from peroxynitrite by releasing GSH, whereas no release was observed in response to nitric oxide or superoxide. Glucose, maltose, and cytochalasin B, agents that protect extracellular components of the hexose transport protein complex from oxidative stress, prevented GSH release. The data indicate that nitric oxide-derived oxidants are involved in CO-mediated oxidative stress within the vascular compartment and that elevations of several compounds may be useful for identifying exposures to CO likely to precipitate brain injury.

scholarly journals Discovering Antioxidant Molecules in the Archaea Domain: Peroxiredoxin Bcp1 fromSulfolobus solfataricusProtects H9c2 Cardiomyoblasts from Oxidative Stress

Archaea ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Carmen Sarcinelli ◽  
Gabriella Fiorentino ◽  
Elio Pizzo ◽  
Simonetta Bartolucci ◽  
Danila Limauro
Keyword(s):  
Oxidative Stress ◽  
Mammalian Cells ◽  
Sulfolobus Solfataricus ◽  
Thioredoxin Reductase ◽  
H9c2 Cells ◽  
H9c2 Cardiomyoblasts ◽  
Ph Conditions ◽  
Induced Apoptosis ◽  
Antioxidant Effects

Peroxiredoxins (Prxs) are ubiquitous thiol peroxidases that are involved in the reduction of peroxides. It has been reported that prokaryotic Prxs generally show greater structural robustness than their eukaryotic counterparts, making them less prone to inactivation by overoxidation. This difference has inspired the search for new antioxidants from prokaryotic sources that can be used as possible therapeutic biodrugs. Bacterioferritin comigratory proteins (Bcps) of the hyperthermophilic archaeonSulfolobus solfataricusthat belong to the Prx family have recently been characterized. One of these proteins, Bcp1, was chosen to determine its antioxidant effects in H9c2 rat cardiomyoblast cells. Bcp1 activity was measuredin vitrounder physiological temperature and pH conditions that are typical of mammalian cells; the yeast thioredoxin reductase (yTrxR)/thioredoxin (yTrx) reducing system was used to evaluate enzyme activity. A TAT-Bcp1 fusion protein was constructed to allow its internalization and verify the effect of Bcp1 on H9c2 rat cardiomyoblasts subjected to oxidative stress. The results reveal that TAT-Bcp1 is not cytotoxic and inhibits H2O2-induced apoptosis in H9c2 cells by reducing the H2O2content inside these cells.

scholarly journals Alleviate Effect of Pomegranate Peel Extract in Ameliorating Fluoride-Induced Cytotoxicity, Oxidative Stress in Tetrahymena pyriformis Model

2021 ◽  
Vol 12 (3) ◽  
pp. 3710-3724
Keyword(s):  
Oxidative Stress ◽  
Mammalian Cells ◽  
Antioxidant Properties ◽  
Tetrahymena Pyriformis ◽  
Punica Granatum ◽  
Redox Status ◽  
Total Phenolic ◽  
Pomegranate Peel ◽  
Peel Extract

Fluoride is a major oligo element found in nature, at excessive amounts can cause enormous harm in mammalian cells. Fruits peel, considered most often as a waste of juice processing, could play an important role in attenuating metal cytotoxicity. The present study evaluated the effect of pomegranate peel (Punica granatum. L) methanolic extract (PPE) on the Fluoride-induced toxicity and redox status in the protozoa Tetrahymena pyriformis. Polyphenols of peel extract were extracted using methanol and characterized by spectrophotometric methods, total phenolic content (TPC), total flavonoids content (TFC), and in vitro, antioxidant properties were assessed using the Folin-Ciocalteu method and DPPH, ABTS, and FRAP. Pomegranate peel is a rich source of phenolic compounds TP (223.21 ± 15 mg GAE/g dw), TF (52.12 ± 1.36 mg Qu/g dw) and showed high antioxidant properties DPPH (EC50 0.043 ± 0.06 mg/ml), ABTS (EC50 0.06 ± 0.01 mg/ml) and FRAP (1.47 ± 0.01 mg AA equivalents/g dw). Cells were incubated with fluoride alone and in combination with PPE. NaF (0.8 mM) significantly decreased the cell viability, induced oxidative stress by decreasing antioxidants enzyme activities, and increased intracellular fluoride content. Treatment with NaF in combination with PPE decreases CAT, SOD, and GPx activities and alleviates GSH content. These findings suggest that pomegranate peel biomolecules may have a protective effect against fluoride induced-toxicity.

scholarly journals From Past to Present: The Link Between Reactive Oxygen Species in Sperm and Male Infertility

Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 616 ◽  
Author(s):  
Ana Izabel Silva Balbin Villaverde ◽  
Jacob Netherton ◽  
Mark A. Baker
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Male Infertility ◽  
Mammalian Cells ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Signalling Molecules ◽  
Function Impairment ◽  
Enzymatic Mechanisms

Reactive oxygen species (ROS) can be generated in mammalian cells via both enzymatic and non-enzymatic mechanisms. In sperm cells, while ROS may function as signalling molecules for some physiological pathways, the oxidative stress arising from the ubiquitous production of these compounds has been implicated in the pathogenesis of male infertility. In vitro studies have undoubtedly shown that spermatozoa are indeed susceptible to free radicals. However, many reports correlating ROS with sperm function impairment are based on an oxidative stress scenario created in vitro, lacking a more concrete observation of the real capacity of sperm in the production of ROS. Furthermore, sample contamination by leukocytes and the drawbacks of many dyes and techniques used to measure ROS also greatly impact the reliability of most studies in this field. Therefore, in addition to a careful scrutiny of the data already available, many aspects of the relationship between ROS and sperm physiopathology are still in need of further controlled and solid experiments before any definitive conclusions are drawn.

Detection of phospholipid oxidation in oxidatively stressed cells by reversed-phase HPLC coupled with positive-ionization electroscopy MS

2001 ◽  
Vol 355 (2) ◽  
pp. 449-457 ◽  
Author(s):  
Corinne M. SPICKETT ◽  
Nicola RENNIE ◽  
Helen WINTER ◽  
Laura ZAMBONIN ◽  
Laura LANDI ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Direct Injection ◽  
Biological Tissues ◽  
Reversed Phase ◽  
Membrane Lipid ◽  
Oxidized Phospholipids ◽  
Reversed Phase Hplc

Measurement of lipid peroxidation is a commonly used method of detecting oxidative damage to biological tissues, but the most frequently used methods, including MS, measure breakdown products and are therefore indirect. We have coupled reversed-phase HPLC with positive-ionization electrospray MS (LC-MS) to provide a method for separating and detecting intact oxidized phospholipids in oxidatively stressed mammalian cells without extensive sample preparation. The elution profile of phospholipid hydroperoxides and chlorohydrins was first characterized using individual phospholipids or a defined phospholipid mixture as a model system. The facility of detection of the oxidized species in complex mixtures was greatly improved compared with direct-injection MS analysis, as they eluted earlier than the native lipids, owing to the decrease in hydrophobicity. In U937 and HL60 cells treated in vitro with t-butylhydroperoxide plus Fe2+, lipid oxidation could not be observed by direct injection, but LC-MS allowed the detection of monohydroperoxides of palmitoyl-linoleoyl and stearoyl-linoleoyl phosphatidylcholines. The levels of hydroperoxides observed in U937 cells were found to depend on the duration and severity of the oxidative stress. In cells treated with HOCl, chlorohydrins of palmitoyloleoyl phosphatidylcholine were observed by LC-MS. The method was able to detect very small amounts of oxidized lipids compared with the levels of native lipids present. The membrane-lipid profiles of these cells were found to be quite resistant to damage until high concentrations of oxidants were used. This is the first report of direct detection by LC-MS of intact oxidized phospholipids induced in cultured cells subjected to oxidative stress.

scholarly journals Lost in the Crowd: How Does Human 8-Oxoguanine DNA Glycosylase 1 (OGG1) Find 8-Oxoguanine in the Genome?

2020 ◽  
Vol 21 (21) ◽  
pp. 8360
Author(s):  
Ostiane D’Augustin ◽  
Sébastien Huet ◽  
Anna Campalans ◽  
Juan Pablo Radicella
Keyword(s):  
Oxidative Stress ◽  
Mammalian Cells ◽  
Excision Repair ◽  
Current Knowledge ◽  
Dna Glycosylase ◽  
Base Modification ◽  
Dna Lesion ◽  
Efficient Detection ◽  
Base Excision

The most frequent DNA lesion resulting from an oxidative stress is 7,8-dihydro-8-oxoguanine (8-oxoG). 8-oxoG is a premutagenic base modification due to its capacity to pair with adenine. Thus, the repair of 8-oxoG is critical for the preservation of the genetic information. Nowadays, 8-oxoG is also considered as an oxidative stress-sensor with a putative role in transcription regulation. In mammalian cells, the modified base is excised by the 8-oxoguanine DNA glycosylase (OGG1), initiating the base excision repair (BER) pathway. OGG1 confronts the massive challenge that is finding rare occurrences of 8-oxoG among a million-fold excess of normal guanines. Here, we review the current knowledge on the search and discrimination mechanisms employed by OGG1 to find its substrate in the genome. While there is considerable data from in vitro experiments, much less is known on how OGG1 is recruited to chromatin and scans the genome within the cellular nucleus. Based on what is known of the strategies used by proteins searching for rare genomic targets, we discuss the possible scenarios allowing the efficient detection of 8-oxoG by OGG1.

Terminalia ferdinandiana, a traditional medicinal plant of Australia, alleviates hydrogen peroxide induced oxidative stress and inflammation, in vitro

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Mridusmita Chaliha ◽  
Yasmina Sultanbawa
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Medicinal Plant ◽  
Mammalian Cells ◽  
Cell Types ◽  
Inflammatory Activity ◽  
Ros Production ◽  
Anti Inflammatory ◽  
Terminalia Ferdinandiana

AbstractBackgroundOxidative stress and inflammation are the underlying factors in many chronic debilitating diseases and commonly intertwined. Terminalia ferdinandiana is a traditional medicinal plant, endemic to Australia and is a rich source of many bioactive phytochemicals such as ellagic acid (EA) with known antioxidant capacity.MethodsWe investigated the in vitro antioxidant and anti-inflammatory activity of an aqueous food grade EA enriched (EAE) extract of T. ferdinandiana. Caco-2 and KERTr cell lines were treated with EAE or pure EA (used as reference control), followed by the exposure to hydrogen peroxide (H2O2). Levels of reactive oxygen species (ROS) production and gene expression of molecular markers associated with oxidative stress and inflammation were monitored.ResultsSignificant reduction in ROS production was observed in both cell types treated with 100 or 200 µg/mL EA or EAE. Treatment of cells with EAE or EA showed upregulation of mRNA expression of the antioxidative gene superoxide dismutase (SOD)-2 and downregulated the expression of inducible nitric oxide synthase (iNOS), soluble cell adhesion molecule (sICAM), and cyclooxygenase (COX)-2. Neither EAE nor EA had any effect on the constitutively expressed COX1.ConclusionsThe antioxidant and anti-inflammatory activity of T. ferdinandiana extract on mammalian cells exposed to H2O2 suggests the potential of using this traditional medicinal plant in preventing oxidative damage and inflammation related diseases.

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

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