Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).
A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.
Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.
A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.
Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.
The N-acetyl derivative of CYSTEINE. It is used as a mucolytic agent to reduce the viscosity of mucous secretions. It has also been shown to have antiviral effects in patients with HIV due to inhibition of viral stimulation by reactive oxygen intermediates.
Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.
Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
The voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.
A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.
Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+
Nitrogenous products of NITRIC OXIDE synthases, ranging from NITRIC OXIDE to NITRATES. These reactive nitrogen intermediates also include the inorganic PEROXYNITROUS ACID and the organic S-NITROSOTHIOLS.
An excited state of molecular oxygen generated photochemically or chemically. Singlet oxygen reacts with a variety of biological molecules such as NUCLEIC ACIDS; PROTEINS; and LIPIDS; causing oxidative damages.
An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.
Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.
The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.
The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.
Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.
The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.
A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
A cell line derived from cultured tumor cells.
Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.
An enzyme catalyzing the oxidation of 2 moles of glutathione in the presence of hydrogen peroxide to yield oxidized glutathione and water. EC 1.11.1.9.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
The relationship between the dose of an administered drug and the response of the organism to the drug.
A botanical insecticide that is an inhibitor of mitochondrial electron transport.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Established cell cultures that have the potential to propagate indefinitely.
A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
A colorimetric reagent for iron, manganese, titanium, molybdenum, and complexes of zirconium. (From Merck Index, 11th ed)
Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.
A large increase in oxygen uptake by neutrophils and most types of tissue macrophages through activation of an NADPH-cytochrome b-dependent oxidase that reduces oxygen to a superoxide. Individuals with an inherited defect in which the oxidase that reduces oxygen to superoxide is decreased or absent (GRANULOMATOUS DISEASE, CHRONIC) often die as a result of recurrent bacterial infections.
Cytochromes of the c type that are found in eukaryotic MITOCHONDRIA. They serve as redox intermediates that accept electrons from MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III and transfer them to MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX IV.
A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)
Elements of limited time intervals, contributing to particular results or situations.
Proteins encoded by the mitochondrial genome or proteins encoded by the nuclear genome that are imported to and resident in the MITOCHONDRIA.
A synthetic naphthoquinone without the isoprenoid side chain and biological activity, but can be converted to active vitamin K2, menaquinone, after alkylation in vivo.
Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)
The mitochondria of the myocardium.
Relatively complete absence of oxygen in one or more tissues.
A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 9. Isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
A family of ubiquitously-expressed peroxidases that play a role in the reduction of a broad spectrum of PEROXIDES like HYDROGEN PEROXIDE; LIPID PEROXIDES and peroxinitrite. They are found in a wide range of organisms, such as BACTERIA; PLANTS; and MAMMALS. The enzyme requires the presence of a thiol-containing intermediate such as THIOREDOXIN as a reducing cofactor.
Porphyrins which are combined with a metal ion. The metal is bound equally to all four nitrogen atoms of the pyrrole rings. They possess characteristic absorption spectra which can be utilized for identification or quantitative estimation of porphyrins and porphyrin-bound compounds.
A condition of decreased oxygen content at the cellular level.
A family of intracellular CYSTEINE ENDOPEPTIDASES that play a role in regulating INFLAMMATION and APOPTOSIS. They specifically cleave peptides at a CYSTEINE amino acid that follows an ASPARTIC ACID residue. Caspases are activated by proteolytic cleavage of a precursor form to yield large and small subunits that form the enzyme. Since the cleavage site within precursors matches the specificity of caspases, sequential activation of precursors by activated caspases can occur.
Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
The appearance of carbonyl groups (such as aldehyde or ketone groups) in PROTEINS as the result of several oxidative modification reactions. It is a standard marker for OXIDATIVE STRESS. Carbonylated proteins tend to be more hydrophobic and resistant to proteolysis.
A nucleoside consisting of the base guanine and the sugar deoxyribose.
The metabolic process of all living cells (animal and plant) in which oxygen is used to provide a source of energy for the cell.
The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)
A basic-leucine zipper transcription factor that was originally described as a transcriptional regulator controlling expression of the BETA-GLOBIN gene. It may regulate the expression of a wide variety of genes that play a role in protecting cells from oxidative damage.
Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)
A poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
The dialdehyde of malonic acid.
Ubiquitous, inducible, nuclear transcriptional activator that binds to enhancer elements in many different cell types and is activated by pathogenic stimuli. The NF-kappa B complex is a heterodimer composed of two DNA-binding subunits: NF-kappa B1 and relA.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins.
Splitting the DNA into shorter pieces by endonucleolytic DNA CLEAVAGE at multiple sites. It includes the internucleosomal DNA fragmentation, which along with chromatin condensation, are considered to be the hallmarks of APOPTOSIS.
A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.
A mitogen-activated protein kinase subfamily that regulates a variety of cellular processes including CELL GROWTH PROCESSES; CELL DIFFERENTIATION; APOPTOSIS; and cellular responses to INFLAMMATION. The P38 MAP kinases are regulated by CYTOKINE RECEPTORS and can be activated in response to bacterial pathogens.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
The process by which chemical compounds provide protection to cells against harmful agents.
Sulfhydryl acylated derivative of GLYCINE.
Hydrogen-donating proteins that participates in a variety of biochemical reactions including ribonucleotide reduction and reduction of PEROXIREDOXINS. Thioredoxin is oxidized from a dithiol to a disulfide when acting as a reducing cofactor. The disulfide form is then reduced by NADPH in a reaction catalyzed by THIOREDOXIN REDUCTASE.
A direct-acting oxidative stress-inducing agent used to examine the effects of oxidant stress on Ca(2+)-dependent signal transduction in vascular endothelial cells. It is also used as a catalyst in polymerization reactions and to introduce peroxy groups into organic molecules.
A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Chemical agents that uncouple oxidation from phosphorylation in the metabolic cycle so that ATP synthesis does not occur. Included here are those IONOPHORES that disrupt electron transfer by short-circuiting the proton gradient across mitochondrial membranes.
Chelating agent and inhibitor of cellular respiration.
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
A ubiquitous stress-responsive enzyme that catalyzes the oxidative cleavage of HEME to yield IRON; CARBON MONOXIDE; and BILIVERDIN.
Highly specialized EPITHELIAL CELLS that line the HEART; BLOOD VESSELS; and lymph vessels, forming the ENDOTHELIUM. They are polygonal in shape and joined together by TIGHT JUNCTIONS. The tight junctions allow for variable permeability to specific macromolecules that are transported across the endothelial layer.
The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).
A GLUTATHIONE dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized.
Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.
Low-molecular-weight end products, probably malondialdehyde, that are formed during the decomposition of lipid peroxidation products. These compounds react with thiobarbituric acid to form a fluorescent red adduct.
Natural product isolated from Streptomyces pilosus. It forms iron complexes and is used as a chelating agent, particularly in the mesylate form.
All of the processes involved in increasing CELL NUMBER including CELL DIVISION.
A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.

Reactive oxygen intermediate-dependent NF-kappaB activation by interleukin-1beta requires 5-lipoxygenase or NADPH oxidase activity. (1/16336)

We previously reported that the role of reactive oxygen intermediates (ROIs) in NF-kappaB activation by proinflammatory cytokines was cell specific. However, the sources for ROIs in various cell types are yet to be determined and might include 5-lipoxygenase (5-LOX) and NADPH oxidase. 5-LOX and 5-LOX activating protein (FLAP) are coexpressed in lymphoid cells but not in monocytic or epithelial cells. Stimulation of lymphoid cells with interleukin-1beta (IL-1beta) led to ROI production and NF-kappaB activation, which could both be blocked by antioxidants or FLAP inhibitors, confirming that 5-LOX was the source of ROIs and was required for NF-kappaB activation in these cells. IL-1beta stimulation of epithelial cells did not generate any ROIs and NF-kappaB induction was not influenced by 5-LOX inhibitors. However, reintroduction of a functional 5-LOX system in these cells allowed ROI production and 5-LOX-dependent NF-kappaB activation. In monocytic cells, IL-1beta treatment led to a production of ROIs which is independent of the 5-LOX enzyme but requires the NADPH oxidase activity. This pathway involves the Rac1 and Cdc42 GTPases, two enzymes which are not required for NF-kappaB activation by IL-1beta in epithelial cells. In conclusion, three different cell-specific pathways lead to NF-kappaB activation by IL-1beta: a pathway dependent on ROI production by 5-LOX in lymphoid cells, an ROI- and 5-LOX-independent pathway in epithelial cells, and a pathway requiring ROI production by NADPH oxidase in monocytic cells.  (+info)

Hyperoxia induces the neuronal differentiated phenotype of PC12 cells via a sustained activity of mitogen-activated protein kinase induced by Bcl-2. (2/16336)

We previously reported that rat pheochromocytoma PC12 cells express the neuronal differentiated phenotype under hyperoxia through the production of reactive oxygen species (ROS). In the present study, we found that in this phenotype, Bcl-2, an apoptosis inhibitor, affects mitogen-activated protein (MAP)-kinase activity, which is known as a key enzyme of the signal-transduction cascade for differentiation. When PC12 cells were cultured under hyperoxia, a rapid increase in MAP-kinase activity, including that of both p42 and p44, was observed. Although the activity level then decreased quickly, activity higher than the control level was observed for 48 h. PD98059, an inhibitor of MAP kinase, suppressed the hyperoxia-induced neurite extensions, suggesting the involvement of MAP-kinase activity in the mechanism of differentiation induced by ROS. An elevation of Bcl-2 expression was observed after culturing PC12 cells for 24 h under hyperoxia. This Bcl-2 elevation was not affected by treatment with PD98059, suggesting that it did not directly induce neurite extension under hyperoxia. However, the blockade of the Bcl-2 elevation by an antisense oligonucleotide inhibited the sustained MAP-kinase activity and neurite extensions under hyperoxia. Further, in PC12 cells highly expressing Bcl-2, the sustained MAP-kinase activity and neurite extensions under hyperoxia were enhanced. These results suggested that MAP kinase is activated through the production of ROS, and the subsequent elevation of Bcl-2 expression sustains the MAP-kinase activity, resulting in the induction of the neuronal-differentiation phenotype of PC12 cells under hyperoxia.  (+info)

The Pseudomonas aeruginosa secretory product pyocyanin inactivates alpha1 protease inhibitor: implications for the pathogenesis of cystic fibrosis lung disease. (3/16336)

Alpha1 Protease inhibitor (alpha1PI) modulates serine protease activity in the lung. Reactive oxygen species inactivate alpha1PI, and this process has been implicated in the pathogenesis of a variety of forms of lung injury. An imbalance of protease-antiprotease activity is also detected in the airways of patients with cystic fibrosis-associated lung disease who are infected with Pseudomonas aeruginosa. P. aeruginosa secretes pyocyanin, which, through its ability to redox cycle, induces cells to generate reactive oxygen species. We tested the hypothesis that redox cycling of pyocyanin could lead to inactivation of alpha1PI. When alpha1PI was exposed to NADH and pyocyanin, a combination that results in superoxide production, alpha1PI lost its ability to form an inhibitory complex with both porcine pancreatic elastase (PPE) and trypsin. Similarly, addition of pyocyanin to cultures of human airway epithelial cells to which alpha1PI was also added resulted in a loss of the ability of alpha1PI to form a complex with PPE or trypsin. Neither superoxide dismutase, catalase, nor dimethylthiourea nor depletion of the media of O2 to prevent formation of reactive oxygen species blocked pyocyanin-mediated inactivation of alpha1PI. These data raise the possibility that a direct interaction between reduced pyocyanin and alpha1PI is involved in the process. Consistent with this possibility, pretreatment of alpha1PI with the reducing agent beta-mercaptoethanol also inhibited binding of trypsin to alpha1PI. These data suggest that pyocyanin could contribute to lung injury in the P. aeruginosa-infected airway of cystic fibrosis patients by decreasing the ability of alpha1PI to control the local activity of serine proteases.  (+info)

Inflammatory cell-mediated tumour progression and minisatellite mutation correlate with the decrease of antioxidative enzymes in murine fibrosarcoma cells. (4/16336)

We isolated six clones of weakly tumorigenic fibrosarcoma (QR) from the tumorigenic clone BMT-11 cl-9. The QR clones were unable to grow in normal C57BL/6 mice when injected s.c. (1x10(5) cells). However, they formed aggressive tumours upon co-implantation with a 'foreign body', i.e. a gelatin sponge, and the rate of tumour take ranged from 8% to 58% among QR clones. The enhanced tumorigenicity was due to host cell-mediated reaction to the gelatin sponge (inflammation). Immunoblot analysis and enzyme activity assay revealed a significant inverse correlation between the frequencies of tumour formation by QR clones and the levels of manganese superoxide dismutase (Mn-SOD, P<0.005) and glutathione peroxidase (GPchi, P<0.01) in the respective tumour clones. Electron spin resonance (ESR) revealed that superoxide-scavenging ability of cell lysates of the QR clone with high level of Mn-SOD was significantly higher than that with low level of the antioxidative enzyme in the presence of potassium cyanide, an inhibitor for copper-zinc superoxide dismutase (CuZn-SOD) (P<0.001). Minisatellite mutation (MSM) induced by the inflammatory cells in tumour cells were investigated by DNA fingerprint analysis after QR clones had been co-cultured with gelatin-sponge-reactive cells. The MSM rate was significantly higher in the subclones with low levels of Mn-SOD and GPchi (P<0.05) than in the subclones with high levels of both enzymes. The MSM of the subclones with low levels of both enzymes was inhibited in the presence of mannitol, a hydroxyl radical scavenger. The content of 8-hydroxydeoxyguanosine (8-OHdG) by which the cellular DNA damage caused by active oxygen species can be assessed was significantly low in the tumours arising from the QR clone with high levels of Mn-SOD and GPchi even if the clone had been co-implanted with gelatin sponge, compared with the arising tumour from the QR clone with low levels of those antioxidative enzymes (P<0.001). In contrast, CuZn-SOD and catalase levels in the six QR clones did not have any correlation with tumour progression parameters. These results suggest that tumour progression is accelerated by inflammation-induced active oxygen species particularly accompanied with declined levels of intracellular antioxidative enzymes in tumour cells.  (+info)

Reactive oxygen species play an important role in the activation of heat shock factor 1 in ischemic-reperfused heart. (5/16336)

BACKGROUND: The myocardial protective role of heat shock protein (HSP) has been demonstrated. Recently, we reported that ischemia/reperfusion induced a significant activation of heat shock factor (HSF) 1 and an accumulation of mRNA for HSP70 and HSP90. We examined the role of reactive oxygen species (ROSs) in the induction of stress response in the ischemic-reperfused heart. METHODS AND RESULTS: Rat hearts were isolated and perfused with Krebs-Henseleit buffer by the Langendorff method. Whole-cell extracts were prepared for gel mobility shift assay using oligonucleotides containing the heat shock element. Induction of mRNA for HSP70 and HSP90 was examined by Northern blot analysis. Repetitive ischemia/reperfusion, which causes recurrent bursts of free radical generation, resulted in burst activation of HSF1, and this burst activation was significantly reduced with either allopurinol 1 mmol/L (an inhibitor of xanthine oxidase) or catalase 2x10(5) U/L (a scavenger of H2O2). Significant activation of HSF1 was observed on perfusion with buffer containing H2O2 150 micromol/L or xanthine 1 mmol/L plus xanthine oxidase 5 U/L. The accumulation of mRNA for HSP70 or HSP90 after repetitive ischemia/reperfusion was reduced with either allopurinol or catalase. CONCLUSIONS: Our findings demonstrate that ROSs play an important role in the activation of HSF1 and the accumulation of mRNA for HSP70 and HSP90 in the ischemic-reperfused heart.  (+info)

Methemoglobin formation by hydroxylamine metabolites of sulfamethoxazole and dapsone: implications for differences in adverse drug reactions. (6/16336)

Differences in the incidence of adverse drug reactions to trimethoprim-sulfamethoxazole and dapsone may result from differences in the formation, disposition, toxicity, and/or detoxification of their hydroxylamine metabolites. In this study, we examine whether differences in the biochemical processing of sulfamethoxazole hydroxylamine (SMX-NOH) and dapsone hydroxylamine (DDS-NOH) by erythrocytes [red blood cells (RBCs)] contribute to this differential incidence. The methemoglobin (MetHgb)-forming capacity of both metabolites was compared after a 60-min incubation with washed RBCs from four healthy human volunteers. DDS-NOH was significantly more potent (P =.004) but equally efficacious with SMX-NOH in its ability to form MetHgb. The elimination of potential differences in disposition by lysing RBCs did not change the MetHgb-forming potency of either hydroxylamine. At pharmacologically relevant concentrations, greater reduction to the parent amine occurred with DDS-NOH. Maintenance of MetHgb-forming potency was dependent on recycling with glutathione, but no difference in cycling efficiency was observed between DDS-NOH and SMX-NOH. In contrast, the pharmacodynamics of hydroxylamine-induced MetHgb formation were not changed by pretreatment with the glucose 6-phosphate dehydrogenase inhibitor epiandrosterone or by compounds that alter normal antioxidant enzyme activity. Methylene blue, which stimulates NADPH-dependent MetHgb reductase activity, decreased MetHgb levels but did not alter the differential potency of these hydroxylamines. DDS-NOH was also significantly more potent when incubated with purified human hemoglobin A0. Collectively, these data suggest that the inherently greater reactivity of DDS-NOH with hemoglobin, the greater conversion of DDS-NOH to its parent amine, and potential differences in disposition of hydroxylamine metabolites may contribute to the preferential development of dapsone-induced hemotoxicity and sulfamethoxazole-induced hypersensitivity reactions.  (+info)

Mechanisms and mediators in coal dust induced toxicity: a review. (7/16336)

Chronic inhalation of coal dust can cause several lung disorders, including simple coal workers pneumoconiosis (CWP), progressive massive fibrosis (PMF), chronic bronchitis, lung function loss, and emphysema. This review focuses on the cellular actions and interactions of key inflammatory cells and target cells in coal dust toxicity and related lung disorders, i.e. macrophages and neutrophils, epithelial cells, and fibroblasts. Factors released from or affecting these cells are outlined in separate sections, i.e. (1) reactive oxygen species (ROS) and related antioxidant protection mechanisms, and (2) cytokines, growth factors and related proteins. Furthermore, (3) components of the extracellular matrix (ECM), including the modifying role of ROS, cytokines, proteases and antiproteases are discussed in relation to tissue damage and remodelling in the respiratory tract. It is recognised that inhaled coal dust particles are important non-cellular and cellular sources of ROS in the lung, and may be significantly involved in the damage of lung target cells as well as important macromolecules including alpha-1-antitrypsin and DNA. In vitro and in vivo studies with coal dusts showed the up-regulation of important leukocyte recruiting factors, e.g. Leukotriene-B4 (LTB4), Platelet Derived Growth Factor (PDGF), Monocyte Chemotactic Protein-1 (MCP-1), and Tumor Necrosis Factor-alpha (TNF alpha), as well as the neutrophil adhesion factor Intercellular Adhesion Molecule-1 (ICAM-1). Coal dust particles are also known to stimulate the (macrophage) production of various factors with potential capacity to modulate lung cells and/or extracellular matrix, including O2-., H2O2, and NO, fibroblast chemoattractants (e.g. Transforming Growth Factor-beta (TGF beta), PDGF, and fibronectin) and a number of factors that have been shown to stimulate and/or inhibit fibroblast growth or collagen production such as (TNF alpha, TGF beta, PDGF, Insulin Like Growth Factor, and Prostaglandin-E2). Further studies are needed to clarify the in vivo kinetics and relative impact of these factors.  (+info)

1,25-Dihydroxyvitamin D3 enhances the susceptibility of breast cancer cells to doxorubicin-induced oxidative damage. (8/16336)

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the hormonal form of vitamin D, has anticancer activity in vivo and in vitro. Doxorubicin exerts its cytotoxic effect on tumor cells mainly by two mechanisms: (a) generation of reactive oxygen species (ROS); and (b) inhibition of topoisomerase II. We studied the combined cytotoxic action of 1,25(OH)2D3 and doxorubicin on MCF-7 breast cancer cells. Pretreatement with 1,25(OH)2D3 resulted in enhanced cytotoxicity of doxorubicin. The average enhancing effect after a 72-h pretreatment with 1,25(OH)2D3 (10 nM) followed by a 24-h treatment with 1 microg/ml doxorubicin was 74+/-9% (mean +/- SE). Under these experimental conditions, 1,25(OH)2D3 on its own did not affect cell number or viability. 1,25(OH)2D3 also enhanced the cytotoxic activity of another ROS generating quinone, menadione, but did not affect cytotoxicity induced by the topoisomerase inhibitor etoposide. The antioxidant N-acetylcysteine slightly reduced the cytotoxic activity of doxorubicin but had a marked protective effect against the combined action of 1,25(OH)2D3 and doxorubicin. These results indicate that ROS are involved in the interaction between 1,25(OH)2D3 and doxorubicin. 1,25(OH)2D3 also increased doxorubicin cytotoxicity in primary cultures of rat cardiomyocytes. Treatment of MCF-7 cells with 1,25(OH)2D3 alone markedly reduced the activity, protein, and mRNA levels of the cytoplasmic antioxidant enzyme Cu/Zn superoxide dismutase, which indicated that the hormone inhibits its biosynthesis. This reduction in the antioxidant capacity of the cells could account for the synergistic interaction between 1,25(OH)2D3 and doxorubicin and may also suggest increased efficacy of 1,25(OH)2D3 or its analogues in combination with other ROS-generating anticancer therapeutic modalities.  (+info)

During pneumococcal pneumonia, NADPH oxidase-derived reactive oxygen species are redundant for host defense but limit neutrophil recruitment and survival. Decreased NADPH oxidase-dependent reactive oxygen species production is well tolerated and improves disease outcome during pneumococcal pneumonia by removing neutrophils from the tight constraints of reactive oxygen species-mediated regulation.. ...
TY - JOUR. T1 - Activation of mitogen-activated protein kinases by lysophosphatidylcholine- induced mitochondrial reactive oxygen species generation in endothelial cells. AU - Watanabe, Nobuo. AU - Zmijewski, Jaroslaw W.. AU - Takabe, Wakako. AU - Umezu-Goto, Makiko. AU - Le Goffe, Claire. AU - Sekine, Azusa. AU - Landar, Aimee. AU - Watanabe, Akira. AU - Aoki, Junken. AU - Arai, Hiroyuki. AU - Kodama, Tatsuhiko. AU - Murphy, Michael P.. AU - Kalyanaraman, Raman. AU - Darley-Usmar, Victor M.. AU - Noguchi, Noriko. PY - 2006/5. Y1 - 2006/5. N2 - Lysophosphatidylcholine (lysoPC) evokes diverse biological responses in vascular cells including Ca2+ mobilization, production of reactive oxygen species, and activation of the mitogen-activated protein kinases, but the mechanisms linking these events remain unclear. Here, we provide evidence that the response of mitochondria to the lysoPC-dependent increase in cytosolic Ca2+ leads to activation of the extracellular signal-regulated kinase (ERK) ...
Asthma is a chronic inflammatory airway disease induced by many environmental factors. The inhalation of allergens and pollutants promote the reactive oxygen species (ROS) production leading to airway inflammation, hyper-responsiveness and remodeling in allergic asthma. The effects of asthma medications on ROS production are unclear. The present study investigated the anti-ROS effects of current asthma medications including inhaled corticosteroid (ICS; budesonide and fluticasone), leukotriene receptor antagonist (LTRA; montelukast), long acting β2 agonists (LABAs; salmeterol and formoterol) and a new extra-LABA (indacaterol). The human monocyte cell line THP-1 cells were pre-treated with different concentrations of the asthma medications at different time-points after hydrogen peroxide (H2O2) stimulation. H2O2 production was measured with DCFH-DA by flow cytometry. Montelukast, fluticasone and salmeterol suppressed H2O2-induced ROS production. Indacaterol enhanced H2O2-induced ROS production.
Ontology: biological process Synonyms: narrow: inhibition by organism of defense-related host active oxygen species production exact: downregulation by organism of defense-related host AOS production exact: down regulation by organism of defense-related host metabolic burst exact: down-regulation by organism of defense-related host oxidative burst exact: negative regulation by organism of defense-related host reactive oxidative species production exact: negative regulation by organism of defense-related host reactive oxygen intermediate production exact: negative regulation by organism of defense-related host respiratory burst exact: negative regulation by organism of defense-related host ROI production exact: negative regulation by organism of defense-related host ROS production Definition: Any process by which an organism stops, prevents or reduces the frequency, rate or extent of the production of reactive oxygen species as part of the defense response of the host organism. The host is ...
Toyokuni, S. (1999), Reactive oxygen species-induced molecular damage and its application in pathology. Pathology International, 49: 91-102. doi: 10.1046/j.1440-1827.1999.00829.x ...
Mitochondria are the major cellular producers of reactive oxygen species (ROS), and mitochondrial ROS production increases steeply with increased proton-motive force. The uncoupling proteins (UCP1, UCP2, and UCP3) and adenine nucleotide translocase induce proton leak in response to exogenously added fatty acids, superoxide, or lipid peroxidation products. Mild uncoupling by these proteins may provide a negative feedback loop to decrease proton-motive force and attenuate ROS production. Using wild-type and Ucp3(-/-) mice, we found that native UCP3 actively lowers the rate of ROS production in isolated energized skeletal muscle mitochondria, in the absence of exogenous activators. The estimated specific activity of UCP3 in lowering ROS production was 90 to 500 times higher than that of the adenine nucleotide translocase. The mild uncoupling hypothesis was tested by measuring whether the effect of UCP3 on ROS production could be mimicked by chemical uncoupling. A chemical uncoupler mimicked the ...
Dysregulation of apoptosis is a prime hallmark of leukemia. Therefore, drugs which restore the sensitivity of leukemic cells to apoptotic stimuli are promising candidates in the treatment of leukemia. The main objective of this dissertation was to examine the antileukemic effect of sanguinarine, in vitro, and to further examine the signaling mechanisms that may be involved. This study demonstrates that in human leukemic cells, sanguinarine activates a caspase-dependent apoptotic cell death pathway that is characterized by reactive oxygen species-dependent ceramide generation, and subsequent inhibition of Akt signaling pathway. In addition, sanguinarine also induces reactive oxygen species-dependent glutathione depletion and activation of extracellular signal-regulated kinase1/2. Moreover, inhibition of reactive oxygen species generation, using reactive oxygen species scavengers and antioxidants, significantly abrogates sanguinarine-induced ceramide generation, Akt dephosphorylation, extracellular signal
Figure 4: Effect of CAgNCs on ROS production in V. tapetis cells. Intracellular ROS generation was determined by the flow cytometry using H2DCFDA. A: concentration dependent ROS production; B: time dependant ROS production ...
The Impact of Various Reactive Oxygen Species on the Formation of Neutrophil Extracellular Traps. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
In this study PI3-kinase was found to play a role in regulating NADPH oxidase-generated superoxide in platelets, altering the bioactivity of platelet NO that contributes to platelet disaggregation. The progressive reversal of aggregation following initial aggregation as the result of PI3-kinase inhibition in stimulated platelets is consistent with the findings of previous studies.2 Given that disaggregation resulting from PI3-kinase inhibition in TRAP-stimulated platelets correlated with a dose-dependent inhibition of the integrin GPIIb-IIIa activation,2 the activation of PI3-kinase is considered essential for maintaining GPIIb-IIIa in its activated state to sustain aggregation. Likewise, the ability of NO donors to induce platelet disaggregation has been linked to the diminished activation of GPIIb-IIIa and fibrinogen binding.29 The stimulation of platelets induces a conformational change in GPIIb-IIIa (inside-out signaling) leading to the binding of soluble fibrinogen and the onset of platelet ...
Reactive oxygen species (ROS) are constantly generated and eliminated in the biological system, and play important roles in a variety of normal biochemical functions and abnormal pathological processes (16). Mitochondria are considered the major source of cellular ROS (and are likely to play a significant role in ROS stress in cancer cells (17). Although, increased ROS stress in cancer cells may provide therapeutic strategies by further increasing ROS to kill cancer cells using pharmacological agents (18), ROS take part in survival signal activation and under persistent endogenous ROS stress cells become resistant (19). In the present study E2 was shown that be able to increased OVCAR-3 cell proliferation, which is evident by increased cell viability. It also induced intracellular ROS generation in a dose dependent manner. Interestingly, the optimal dose of E2 which was most effective on cell viability, caused the highest ROS generation in these cell. On the other hand, treatment of cells with ...
AIMS/HYPOTHESIS: The aim of this study was to perform a detailed analysis of cytokine toxicity in the new human EndoC- H1 beta cell line. METHODS: The expression profile of the antioxidative enzymes in the new human EndoC- H1 beta cells was characterised and compared with that of primary beta cells in the human pancreas. The effects of proinflammatory cytokines on reactive oxygen species formation, insulin secretory responsiveness and apoptosis of EndoC- H1 beta cells were determined. RESULTS: EndoC- H1 beta cells were sensitive to the toxic action of proinflammatory cytokines. Glucose-dependent stimulation of insulin secretion and an increase in the ATP/ADP ratio was abolished by proinflammatory cytokines without induction of IL-1 expression. Cytokine-mediated caspase-3 activation was accompanied by reactive oxygen species formation and developed more slowly than in rodent beta cells. Cytokines transiently increased the expression of unfolded protein response genes, without inducing endoplasmic ...
In the present study, we have demonstrated that the function of both BKCa and SKCa channels in uterine arteries of pregnant animals is suppressed by heightened oxidative stress during chronic hypoxia. Our results suggest that chronic hypoxia-induced oxidative stress exerts its adverse effect on KCa channel-mediated relaxations of uterine arteries through suppressing steroid hormone-induced upregulation of KCa channel activities. These findings provide strong evidence that heightened ROS is a common mechanism to impair BKCa and SKCa channel function in uterine arteries and contributes to the dysfunction of uterine circulation caused by chronic hypoxia during gestation.. Consistent with our previous studies,6 the present finding that both NS1619- and NS309-induced relaxations of uterine arteries were significantly attenuated by chronic hypoxia in pregnant animals, further suggesting that chronic hypoxia downregulates both BKCa and SKCa channel activities. However, the molecular mechanisms ...
Background: During myocardial ischemia/reperfusion injury, a burst of reactive oxygen species (ROS) is considered to occur at the onset of reperfusion and cause cardiomyocyte death through the loss of mitochondrial membrane potential (ΔΨm), but there are evidences against this concept. We aimed to visualize the dynamic changes of ROS during ischemia/reperfusion in intact rat hearts using two-photon laser scanning microscopy.. Methods and Results: Langendorff-perfused rat hearts were loaded with 5-(and -6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate acetyl-ester and tetramethylrhodamine ethyl-ester, fluorescent indicators of ROS and ΔΨm, respectively. Under the two-photon excitation, spatio-temporal changes of ROS and ΔΨm in response to ischemia/reperfusion were simultaneously monitored at cellular level. As soon as ischemia started, ROS level of each cell began to increase, despite maintained ΔΨm. Importantly, the rate of ROS accumulation during the early phase of ...
OBJECTIVE: To examine the effect of O(2) and the role, and source, of reactive oxygen species (ROS) on pH regulation in articular chondrocytes. METHODS: Cartilage from equine metacarpo/tarsophalangeal joints was digested (collagenase) to isolate chondrocytes and loaded with 2,7-bis-2-(carboxyethyl)-5(6)-carboxylfluorescein, a pH-sensitive fluorophore. O(2) tension was maintained using Eschweiler tonometers and a Wosthoff gas mixer. Cells were exposed to agents which alter ROS levels, mitochondrial inhibitors and/or inhibitors of protein phosphorylation. ROS levels were determined by dichlorofluorescein and mitochondrial membrane potential measured using JC-1. RESULTS: pH homeostasis was dependent on ROS. Na(+)/H(+) exchanger (NHE) activity was inhibited at low O(2) tension (acid efflux reducing from 2.30+/-0.05 to 1.27+/-0.11mMmin(-1) at 1%). NHE activity correlated with ROS levels (r(2)=0.65). ROS levels were increased by antimycin A (with levels at 1% O(2) tension increasing from 59+/-9% of the
We provided evidence in the present report suggesting that treatment of the BEAS-2B cells with continuous low concentration of As3+ induces cell transformation and that the capacity of ROS generation in the transformed cells was severely compromised. Such a reduction in ROS generation seems to be responsible for fast proliferation, anchorage-independent growth, and resistance to As3+ toxicity of the transformed cells. A sustained alternative activation of NF-κB might contribute to the fast and anchorage-independent growth of these cells due to reduced ROS generation. The fast growth of the transformed cells could be reversed by either resuming the ROS production through SOD2/catalase inhibition or gene silencing of NF-κB p105/50.. ROS have long been viewed as major contributors to oxidative injury and DNA damage of tissues or cells (22). A sustained oxidative injury and unrepaired damage on DNA will be carcinogenic due to accumulation of genetic mutations that either activate oncogenes or ...
Scientists have identified a new type of anti-inflammatory compound that may be useful in treating a wide range of conditions, including neurodegenerative and autoimmune diseases. These compounds inhibit the enzyme Nox2, part of a family of enzymes responsible for producing reactive oxygen species.
OBJECTIVE: To obtain further insight into the mechanism underlying the vasodilator effect of nebivolol. Since oxidative inactivation of nitric oxide (NO) is regarded as an important cause of its decreased biological activity, we studied (1) the effect of nebivolol on some oxidative parameters in essential hypertensive patients; (2) the effect of plasma of nebivolol-treated patients on reactive oxygen species production and NO availability in endothelial cells. METHODS: A total of 20 healthy subjects and 20 matched essential hypertensive patients treated with atenolol or nebivolol according to a double-blind, randomized design participated in the study. We measured low-density lipoprotein (LDL) and plasma hydroperoxides, 8-isoprostanes, oxidized LDL, susceptibility of LDL to oxidation (lag phase) and LDL vitamin E and the effect of plasma of nebivolol- and atenolol-treated patients on reactive oxygen species production and NO availability in endothelial cells exposed to oxidative stress. RESULTS: ...
Schoultz I, McKay CM, Graepel R, Phan VC, Wang A, Soderholm J, McKay DM. Indomethacin-induced translocation of bacteria across enteric epithelia is reactive oxygen species-dependent and reduced by vitamin C. Am J Physiol Gastrointest Liver Physiol 303: G536-G545, 2012. First published June 14, 2012; doi:10.1152/ajpgi.00125.2012.-The enteric epithelium must absorb nutrients and water and act as a barrier to the entry of luminal material into the body; this barrier function is a key component of innate immunity. Nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy occurs via inhibition of prostaglandin synthesis and perturbed epithelial mitochondrial activity. Here, the direct effect of NSAIDs [indomethacin, piroxicam (cyclooxygenase 1 and 2 inhibitors), and SC-560 (a cyclooxygenase 1 inhibitor)] on the barrier function of human T84 epithelial cell line monolayers was assessed by transepithelial electrical resistance (TER) and internalization and translocation of a commensal Escherichia ...
Reactive oxygen species are produced during normal ovarian function, and they may also be produced as a result of toxicant metabolism. Our earlier work demonstrated a role for reactive oxygen species in mediating spontaneous apoptosis in follicles deprived of hormonal support and apoptosis caused by exposure to ovarian toxicants. We discovered that reactive oxygen species increased in ovarian follicles cultured without gonadotropin support prior to any increase in endpoints of apoptosis and that follicle stimulating hormone stimulated synthesis of the antioxidant glutathione (GSH) and suppressed the rise in reactive oxygen species. We further showed that GSH depletion in cultured follicles reversed the protective, suppressive effect of follicle stimulating hormone on reactive oxygen species and on apoptosis. This work provides evidence that the protective effects of follicle stimulating hormone are mediated in part via upregulation of GSH synthesis. We also showed that increased generation of ...
Am J Clin Exp Urol 2013;1(1):39-52 www.ajceu.us /ISSN:2330-1910/AJCEU1311005 Original Article Prostate-associated gene 4 (PAGE4) protects cells against stress by elevating p21 and suppressing reactive oxygen species production Yu Zeng1,3, Dong Gao1, John J Kim1,5, Takumi Shiraishi1, Naoki Terada1, Yoshiyuki Kakehi4, Chuize Kong3, Robert H Getzenberg1, Prakash Kulkarni1,2 Department of Urology, The James Buchanan Brady Urological Institute, 2Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland; 3Department of Urology, Institute of Urology, The First Hospital, China Medical University, Shenyang, China; 4Department of Urology, Kagawa University Faculty of Medicine, Kita-gun, Kagawa, Japan; 5Current address: University of California, Berkeley and University of California, San Francisco Graduate Program in Bioengineering, USA 1 Received November 28, 2013; Accepted December 22, 2013; Epub December 25, 2013; Published December 30, 2013 Abstract: Background: It is ...
Visualising reactive oxygen species in live mammals and revealing of ROS-related system. Free Radic Res. 2019 Oct 21;:1-11 Authors: Guo J, Xu H, Liu S, Wang Z, Dai Y, Lu J, Zheng S, Xu D, Zhou J, Ke L, Cheng X, Xu M, Zhang X, Guo Y, Lin Y, Ding W, Gao G, Wang H, Chen Q, Yu X, Chen H, Qin L, Sun X, Li Z, Zheng S, Wang J, Cheng Y, Qiu S, Hu Y, Huang P, Lin C, Wu Q, Li Y, Chen T, Shaw C,...
Low vitality (a component of fatigue) in middle-aged and older adults is an important complaint often identified as a symptom of a disease state or side effect of a treatment. No studies to date have investigated the potential link between dysfunctional mitochondrial ATP production and low vitality. Therefore, we measured a number of cellular parameters related to mitochondrial activity in peripheral blood mononuclear cells (PBMCs) isolated from middle-aged men, and tested for association with vitality. These parameters estimate mitochondrial respiration, reactive oxygen species (ROS) production, and deoxyribonucleotide (dNTP) balance in PBMCs. The population was drawn from the Metropolit cohort of men born in 1953. Vitality level was estimated from the Medical Outcomes Study Short Form 36 (SF-36) vitality scale. We found that vitality score had no association with any of the mitochondrial respiration parameters. However, vitality score was inversely associated with cellular ROS production and ...
Rationale: Cardiac lipotoxicity, characterized by increased uptake, oxidation and accumulation of lipid intermediates, contributes to cardiac dysfunction in obesity and diabetes. However, mechanisms linking lipid overload and mitochondrial dysfunction are incompletely understood. Objective: To elucidate the mechanisms for mitochondrial adaptations to lipid overload in postnatal hearts in vivo. Methods and Results: Using a transgenic mouse model of cardiac lipotoxicity overexpressing long-chain acyl-CoA synthetase 1 in cardiomyocytes, we show that modestly increased myocardial fatty acid uptake leads to mitochondrial structural remodeling with significant reduction in minimum diameter. This is associated with increased palmitoyl-carnitine oxidation and increased reactive oxygen species (ROS) generation in isolated mitochondria. Mitochondrial morphological changes and elevated ROS generation are also observed in palmitate-treated neonatal rat ventricular cardiomyocytes (NRVCs). Palmitate exposure ...
Poster (2013, September 11). Neutrophils (PMNs) produce reactive oxygen species (ROS) to kill pathogenic agents. After appropriate stimulation, leading to the activation of protein kinase C (PKC), the cytosolic subunits of the NADPH ... [more ▼]. Neutrophils (PMNs) produce reactive oxygen species (ROS) to kill pathogenic agents. After appropriate stimulation, leading to the activation of protein kinase C (PKC), the cytosolic subunits of the NADPH oxidase (Nox2) are phosphorylated and translocated to the membrane flavocytochrome b558, forming the active enzyme which produces superoxide anion (O2●-). From O2●- derives H2O2 used by the PMNs myeloperoxidase (MPO) to form strong oxidant species. Many human and animal pathologies with fatal issue are associated with uncontrolled activation of PMNs. The modulation of enzymes implied in ROS production is thus a primary target to manage excessive inflammatory events. For this purpose, we evaluated the effects of NDS27, a water-soluble salt of ...
It is now accepted that small fluctuations in the steady-state concentration of ROS may play a role in intracellular signaling (3,12). Their pivotal role in nutrient sensing is beginning to be considered in the literature since we highlighted their requirement in hypothalamic glucose and lipid sensing (5,6). Here, we expand the question to the gold standard, and the main glucose-sensitive cell type, the pancreatic β-cells. The present results undoubtedly demonstrate that glucose-induced mitochondrial ROS production is an obligatory stimulus for insulin secretion.. In cells, mitochondria are the main source of oxidants. Transient-accelerated electron transport on glucose stimulation generates an H2O2 burst in many cell types, including the β-cells (13). Metabolism of substrates leads to reduced formation of equivalents (NADH and FADH2) that predispose to increased mROS through a direct effect on the electron-transfer chain (14). Preceding studies point to the crucial role of H2O2, which either ...
Traditionally, reactive oxygen species (ROS) have been regarded as toxic by-products of aerobic metabolism. However, in recent years it has become apparent that plants actively produce ROS as signalling molecules. ROS are able to mediate adaptive responses to various environmental stresses as well as processes such as stomatal closure and development. Downstream signalling events that are modulated by ROS include calcium mobilisation, protein phosphorylation and gene expression. This study investigated signalling proteins acting downstream of ROS, in order to understand how ROS are perceived and transduced to elicit such a wide range of responses. To establish a molecular profile provoked by ROS, a microarray experiment of Arabidopsis plants exposed to exogenous H(_2)O(_2) was analysed. Of the 895 differentially expressed transcripts, a substantial proportion had predicted functions in cell rescue and defence, including heat shock, disease resistance and antioxidant genes. Genes encoding ...
The retina is the most oxygen consuming tissue of the body. for the beneficial actions of antioxidants in preventing or retarding the effect around the retinal degenerative pathologies can be found in their action on reactive oxygen species generated by the ectopic mitochondrial electron transport chain (ETC) coupled to FoF1-ATP synthase in pole OS disks. In fact, if not adequately coupled, the ETC produces reactive oxygen species that, in turn, can act within the polyunsaturated fatty acids which SU11274 the pole OS is rich in. If right, the mechanism put forward here would provide a potential for the molecular basis of therapies with antioxidants for retinal degenerative diseases. Key Terms: Antioxidants, Retinopathy, Oxidative stress Intro The vertebrate retina consists of two types of photoreceptors, rods and cones, which carry out the first step of vision. Both possess a specialised compartment: the outer segment (OS) that is dedicated to phototransduction, SU11274 and the inner segment (Is ...
The production of ROS is known to be increased in diabetic patients (20), and such an increase may contribute to the development of diabetes complications (21,22). In addition, we previously proposed that hyperglycemia-induced ROS production from the mitochondria electron transport chain was a key event in the development of diabetes complications (6,23). In this study, we first confirmed that metformin, which has been reported to exert a possible additional benefit in the prevention of diabetes complications independently of its antihyperglycemic effect (8,24,25), inhibited the hyperglycemia-induced intracellular ROS production as measured by H2DCF-DA and the mtROS production as measured by the MitoTracker Red probe (26). The fluorescence of H2DCF-DA indicates intracellular ROS production (7). In contrast, the reduced MitoTracker Red probe can specifically detect mtROS, since this probe accumulates inside mitochondria and is oxidized predominantly by reactions involving hydrogen peroxide ...
Oxygen is one of the most important molecules on Earth mainly because of the biochemical symmetry of oxygenic photosynthesis and aerobic respiration that can maintain homeostasis within our planet's biosphere. Oxygen can also produce toxic molecules, reactive oxygen species (ROS). ROS play a dual role in biological systems, since they can be either harmful or beneficial to living systems. They can be considered a double-edged sword because at moderate concentrations, nitric oxide (NO•), superoxide anion, and related reactive oxygen species play an important role as regulatory mediators in signalling processes. Many of the ROS-mediated responses actually protect the cells against oxidative stress and re-establish redox homeostasis. On the other hand, overproduction of ROS has the potential to cause damage. In the recent decades, ROS has become a focus of interest in most biomedical disciplines and many types of clinical research. Increasing evidence from research on several diseases ...
Fingerprint Dive into the research topics of Molecular mechanisms of curcumin-induced cytotoxicity: Induction of apoptosis through generation of reactive oxygen species, down-regulation of Bcl-X,sub,L,/sub, and IAP, the release of cytochrome c and inhibition of Akt. Together they form a unique fingerprint. ...
How to measure reactive oxygen species using a specific fluorescent dye/indicato - posted in Biochemistry: When a fluorescent dye/indicator is added to a cell culture to show the ROS in the culture, how can the amount of reactive oxygen species be estimated or determined? Is there an easy method, possibly not costly? Thanks for the responses!
Background: Increasing evidence indicates that mitochondrial-derived reactive oxygen species (ROS) and cellular apoptosis contribute to the pathogenesis of cardiac dysfunction. Mitochondrial thioredoxin (Trx2) is a key protein regulating cellular redox and survival, However, but its role in normal cardiac growth has not been determined.. Methods and Results: We have generated cardiac-specific Trx2 knockout mice (Trx2-cKO) to determine the physiological importance of the Trx2 system in the heart. Trx2-cKO mice developed a spontaneous dilated cardiomyopathy at 1 month of age with increased heart size, fibrosis, reduced ventricular wall thickness, and progressive contractile dysfunction, resulting in death due to heart failure by 4 months of age. Cardiac changes in Trx2-cKO mice were accompanied by disruption of mitochondrial integrity and function, as evident by alterations in mitochondrial number, ultrastructure, membrane potential and ATP production. Increases in ASK1 signaling and ROS ...
Estrogen-mediated high reactive oxygen species (ROS) tolerance plays an important role in driving carcinogenesis. ROS overproduction acts as the significant effector to increase genomic instability...
The aim of this study was to determine the relationship between proliferation inhibition and the production of reactive oxygen species (ROS) induced by Licochalcone A (LCA). Cell viability was evaluated using sulforhodamine B (SRB) assay. Intracellul
Click to launch & play an online audio visual presentation by Dr. Zhi-Qing Zhao on Reactive oxygen species and myocardial apoptosis, part of a collection of online lectures.
Elevated cellular reactive species, which can be produced by diabetic serum conditions such as elevated inflammatory cytokines, lipotoxicity or glucotoxicity contribute to islet beta cell dysfunction and cell death. Cellular pathways that result in beta cell oxidative stress are poorly resolved. In this study, stimulation of human donor islets, primary mouse islets or homogeneous beta cell lines with a cocktail of inflammatory cytokines (TNFα, IL-1β, and INFγ) significantly induced NADPH oxidase-1 (NOX-1) gene expression (p,0.05). This pro-inflammatory cytokine cocktail concomitantly induced loss of islet glucose stimulated insulin response (p,0.05), elevated expression of MCP-1 (p,0.01), increased cellular reactive oxygen species (ROS) and induced cell death. Inhibitors of NADPH oxidase, apocynin and diphenyleneiodonium, and a dual selective NOX1/4 inhibitor, blocked ROS generation (p,0.01) and induction of MCP-1 (p,0.05) by pro-inflammatory cytokines in beta cells. It has previously been ...
The role of miR-451 in certain cardiac diseases was recently reported including ischemia/reperfusion and hypertrophic cardiomyopathy. Oxidative stress is known to involve in the above diseases. Currently the relationship between miR-451 and cardiac oxidative stress is unknown. We thus hypothesize that miR-451 act as a key mediator for cardiac hypertrophy via regulating myocardial ROS level and antioxidant pathways. We first compared the heart/body weight (HW/BW) ratio between age- & gender-matched miR-451 knockout (KO) and wild-type (WT) mice. Increase of HW/BW was found in KO mice (6.1±0.1 vs 4.8±0.1 mg/g in WT, p,0.01). Expression of fetal genes ANF (2.9-fold↑) and β-MHC (4.0-fold↑) was also significantly increased in KO hearts, as well as the ROS level (2.3-fold↑, p,0.05) in KO hearts. Consistently, both the protein expression and activation levels of the oxidation-regulating gene Nrf2 decreased the same extent (~33%↓, p,0.05) in KO hearts. In contrast, the protein expression of ...
Hypothalamus is a key area involved in the control of metabolism and food intake via the integrations of numerous signals (hormones, neurotransmitters, metabolites) from various origins. These factors modify hypothalamic neurons activity and generate adequate molecular and behavioral responses to control energy balance. In this complex integrative system, a new concept has been developed in recent years, that includes reactive oxygen species (ROS) as a critical player in energy balance. ROS are known to act in many signaling pathways in different peripheral organs, but also in hypothalamus where they regulate food intake and metabolism by acting on different types of neurons, including proopiomelanocortin (POMC) and agouti-related protein (AgRP)/neuropeptide Y (NPY) neurons. Hypothalamic ROS release is under the influence of different factors such as pancreatic and gut hormones, adipokines (leptin, apelin,...), neurotransmitters and nutrients (glucose, lipids,...). The sources of ROS production are
Oxidative stress figures prominently in retinal diseases, including diabetic retinopathy, and glaucoma. Ligands for σ1R, a unique transmembrane protein localized to the endoplasmic reticulum, mitochondria, and nuclear and plasma membranes, have profound retinal neuroprotective properties in vitro and in vivo. Studies to determine the mechanism of σ1R-mediated retinal neuroprotection have focused mainly on neurons. Little is known about the effects of σ1R on Müller cell function, yet these radial glial cells are essential for homeostatic support of the retina. Here we investigated whether σ1R mediates the oxidative stress response of Müller cells using wild-type (WT) and σ1R-knockout (σ1RKO) mice. We observed increased endogenous reactive oxygen species (ROS) levels in σ1RKO Müller cells compared to WT, which was accompanied by decreased expression of Sod1, catalase, Nqo1, Hmox1, Gstm6, and Gpx1. The protein levels of SOD1, CAT, NQO1, and GPX1 were also significantly decreased. The ...
We demonstrate in this article that 10 weeks of exposure to concentrated ambient PM2.5 potentiates hypertension in response to AII and alters vasoconstrictor/vasodilator sensitivity. These alterations were accompanied by increased NAD(P)H oxidase and NOS-dependent generation of O2·− and upregulation of the RhoA/ROCK pathway.. Because exposure to PM2.5 alone did not alter BP, we did not pursue additional investigations in the PM2.5 group alone and investigated the impact of PM2.5 in conjunction with AII. An additional reason to examine the effect of PM2.5 in conjunction with AII is prior observations by us and others that suggest that PM2.5 has minimal effects by itself, but actively synergizes with other risk factors to influence outcomes.3,6,9,10 Our data are consistent with this notion and suggest that although PM2.5 by itself had no discernible impact on BP, has an important effect in potentiating it, presumably by sensitizing the vasculature. The AII infusion model is a well ...
Restoring blood flow has been confirmed to be an efficient approach to recover ischemic myocardium (25). However, myocardial reperfusion will elicit an increase in ROS production in cardiomyocytes (26). Some therapeutic drugs, such as rosuvastatin (27), have been available to prevent oxidative stress injury from I/R; however, the therapeutic effects for I/R injury remain unsatisfactory (28). Therefore, it is essential to discover safe and effective therapeutic agents. The present study demonstrated the function of 3S, 3′S-AST in protecting cardiomyocytes from ROS-induced injury in vitro. The results indicated that 3S, 3′S-AST treatment inhibited cardiomyocyte apoptosis and improved antioxidant activity. It was further indicated that 3S, 3′S-AST treatment prevented intracellular ROS generation by reducing the activity of the NKA/Src/Erk1/2/ROS amplification signal transduction pathway.. AST exists in three stereoisomeric forms (3S, 3′S; 3R, 3′R and 3R, 3′S)(29). H. pluvialis-derived ...
Our data show that disulfide bonds between C-terminal cysteines link ASIC1a subunits. This was a surprising discovery because previous data showed that the C terminus was not required to form an ASIC1 structure (4), and we found that C-terminal cysteines were not needed to produce ASIC1a trimers on the cell surface or to generate functional channels. However, the C-terminal cysteines were a target for the oxidant H2O2; it induced inter-subunit links, reducing the amount of ASIC1a present on the cell surface and the H+-activated current.. Our data, combined with previous studies, indicate that H2O2 and other oxidants can regulate ASIC1a in at least 2 ways. Earlier work showed that oxidants decreased current amplitude, and the studies suggested that the modification was in the extracellular or transmembrane domains of ASIC1a (26, 27). We found a similar response to H2O2, an endogenous reactive oxygen species. Because H2O2 inhibited an ASIC1a variant that lacked intracellular cysteines, our data ...
In our studies, we showed that inhibition of LPS-stimulated ROS production in BMDM also selectively inhibited the production of PGD2, but not its isomer PGE2. LPS-induced PGD2 production in BMDM was mediated via H-PGDS isomerase, but not L-PGDS. LPS-induced H-PGDS-mediated PGD2 production was sensitive to and dependent on the NOX-generated ROS in BMDM. In contrast, the LPS-induced PGE2 production in BMDM was ROS independent.. To our knowledge, this is the first report of the role of ROS in differential regulation of LPS-induced PGD2 and PGE2 production. The novel finding of our study is that the modulation of intracellular ROS levels in macrophages could selectively regulate LPS-induced production of PGD2, but not PGE2. Therefore, it is impossible that the ROS or any NOX/ROS inhibitors exert their selective effects on PGD2 production via the modification of COX-2 enzyme in BMDM. If there is any modifications of the COX-2 protein expression or its enzyme activity by the above inhibitors or H2O2, ...
Exposure to radiation can lead to deficits in cognitive function, including impairments in hippocampal-dependent learning and memory. However, not all individuals exposed to irradiation develop cognitive impairments, suggesting the involvement of genetic risk factors. Apolipoprotein E (apoE), a protein important for neuronal repair, might influence susceptibility to developing radiation-induced cognitive impairments. Humans express three major apoE isoforms, apoE2, apoE3 and apoE4. Compared to apoE3, apoE4 increases the risk to develop Alzheimers disease while apoE2 decreases this risk. ApoE4 is also associated with cognitive deficits following neurotrauma. Moreover, deficiency of apolipoprotein E (apoE) in mice worsens cognitive impairments following irradiation. There might also be sex differences in the risk for developing radiation-induced cognitive impairments. In both humans and rodents, females are more susceptible to the effects of irradiation on cognition than males. The neur
Mary Beckman http://sageke.sciencemag.org/cgi/content/abstract/sageke;2001/9/nw30 Key Words: oxidative stress isp-1 reactive oxygen species life-span worm. Abstract: Some people think stress kills--and the image of the businessman nearly popping his jugular isnt all theyre thinking about. Researchers have long pursued the connection between oxidative stress and aging. While generating the adenosine triphosphate that powers the cell, mitochondria also give birth to the byproduct superoxide, a highly reactive oxygen radical that can damage other molecules. To protect the cell, resident enzymes turn superoxide into the slightly less obnoxious peroxide and then into innocuous water--but they dont neutralize it all. Some researchers propose that the havoc wreaked by these reactive oxygen species (ROS) promotes aging (see The Two Faces of Oxygen), based in part on observations that an antioxidant drug and mutations that disrupt global energy-producing activities can extend worm and yeast ...
All living cells produce reactive oxygen species (ROS) as a byproduct of metabolism. ROS are reduced oxygen intermediates that include the superoxide radical (O2−) and the hydroxyl radical (OH•), as well as the non-radical species hydrogen peroxide (H2O2). These ROS are important in the normal functioning of cells, playing a role in signal transduction and the expression of transcription factors. However, when present in excess, ROS can cause damage to proteins, lipids and DNA by reacting with these biomolecules to modify or destroy their intended function. As an example, the occurrence of ROS have been linked to the aging process in humans, as well as several other diseases including Alzheimers, rheumatoid arthritis, Parkinsons, and some cancers. Their potential for damage also makes reactive oxygen species useful in direct protection from invading pathogens, as a defense response to physical injury, and as a mechanism for stopping the spread of bacteria and viruses by inducing programmed ...
Reactive oxygen species (ROSs) play important physiological and physiopathological roles in the cardiovascular system. An imbalance between ROS and antioxidants, termed oxidative stress, can contribute to endothelial dysfunction and cardiovascular remodeling. ROSs have been demonstrated to be increased and to regulate the following main pulmonary vasculature changes that occur at high altitude (hypobaric hypoxia): hypoxic pulmonary vasoconstriction (HPV), pulmonary hypertension, right ventricular hypertrophy (RVH), and ultimately, cardiac failure. Thus, ROS increases are a public health concern for the increasing number of people living or working at high altitudes. ROSs trigger the activation of different metabolic signaling pathways that alter the activity of redox-sensitive transcription factors and translational signals. Consequently, we provide a comprehensive review of the literature on the main factors, sources, and mechanisms of action of ROS and their effects on the cardiovascular system under
Dysfunction of T cells and natural killer (NK) cells has been proposed to determine the course of disease in acute myeloid leukemia (AML), but only limited information is available on the mechanisms of lymphocyte inhibition. We aimed to evaluate to what extent human malignant AML cells use NADPH oxidase-derived reactive oxygen species (ROS) as an immune evasion strategy. We report that a subset of malignant myelomonocytic and monocytic AML cells (French-American-British [FAB] classes M4 and M5, respectively), recovered from blood or BM of untreated AML patients at diagnosis, expressed the NADPH oxidase component gp91(phox). Highly purified FAB M4/M5 AML cells produced large amounts of ROS on activation and triggered poly-[ADP-ribose] polymerase-1-dependent apoptosis in adjacent NK cells, CD4(+) T cells, and CD8(+) T cells. In contrast, immature (FAB class M1) and myeloblastic (FAB class M2) AML cells rarely expressed gp91(phox), did not produce ROS, and did not trigger NK or T-cell apoptosis. ...
Compounds and their stable or reactive metabolites can increase the production of reactive oxygen/nitrogen species (ROS/RNS) in hepatocytes via proposed mechanisms such as the reduction in cellular antioxidants or direct parent compound-mediated or reactive metabolite-mediated interactions. Modest increases in ROS/RNS can trigger activation of caspase enzymes, leading to caspase-mediated hepatocellular apoptosis. Greater increases in ROS/RNS can induce reductions in hepatocellular ATP, in turn disrupting other cellular processes (e.g. mitochondrial electron transport chain activity, bile acid transport) that can ultimately result in necrosis.. The balance of ROS/RNS within DILIsym is determined by the relative contributions of production and clearance. It has been demonstrated that compounds can either directly or via reactive metabolites elicit increases in the hepatocellular production of ROS and RNS, shifting the balance towards accumulation. One such example is acetaminophen, which perturbs ...
Emerging evidence of significant hearing loss occurring shortly after cisplatin administration in cancer patients has stimulated research into the causes and treatment of this side effect. Although the aetiology of cisplatin-induced hearing loss (CIHL) remains unknown, an increasing body of research …
ENGLISH ABSTRACT: Salinity is one of the major limiting abiotic stresses on legume plant yield, leading to early senescence of root nodules. This occurs because of accumulation of reactive oxygen species (ROS) in plant cells under salinity stress. Concurrent with the increase in cellular reactive oxygen species levels is the increase in cellular antioxidants and corresponding antioxidant enzymes. This feature is observed mostly in the shoots and roots of more tolerant genotypes compared to the susceptible genotypes. It is accepted that the mechanism of plant tolerance to stress is dependent upon the response of the antioxidant systems. Most studies carried out on shoot tissues suggest that scavenging of ROS by the plant antioxidant system is modulated by nitric oxide (NO). However, the pathways by which NO mediates such antioxidant responses are not fully understood. For legumes, salinity stress has adverse effects on yield and this is in part due to inhibition of nitrogen fixation in the root ...
Exposure system consisted of two identical apparatuses, each composed of four square coils placed horizontally inside a µ-metal shielding box. The coils were arranged in wound configuration for exposure or in counter wound configuration for sham exposure.The magnetic field direction was perpendicular to the surface of the culture plates ...
Excess reactive oxygen species can cause cellular damage, and are involved in many pathological processes such as inflammation, atherosclerosis and cancer. Reactive oxygen species can be generated by several mechanisms, one of which involves the reaction of xanthine oxidase with xanthine to generate a supero
The underlying mechanisms in the development of diabetic nephropathy are currently unclear and likely consist of a series of dynamic events from the early to late stages of the disease. Diabetic nephropathy is currently without curative treatments and it is acknowledged that even the earliest clinical manifestation of nephropathy is preceded by an established morphological renal injury that is in turn preceded by functional and metabolic alterations. An early manifestation of the diabetic kidney is the development of kidney hypoxia that has been acknowledged as a common pathway to nephropathy.There have been reports of altered mitochondrial function in the diabetic kidney such as altered mitophagy, mitochondrial dynamics, uncoupling and cellular signaling through hypoxia inducible factors and AMP-kinase. These factors are also likely to be intertwined in a complex manner. In this review we discuss how these pathways are connected to mitochondrial production of reactive oxygen species (ROS) and how they
3). The concentration of the enzyme responsible for O2•− production, [E], will vary with organism, tissue, state, age or hormonal status, and may underlie many of the changes in maximum ROS production capacity between tissues [23]; for example, complex I content may explain the different maximum capacities of pigeon and rat heart mitochondria [24].. As the apparent Km of cytochrome oxidase for O2 is very low (,1 μM [25]), changes in [O2] should have little direct effect on mitochondrial function and instead are most likely to interact by affecting O2•− production. The generation of O2•− or H2O2 by isolated respiratory complexes, SMPs (submitochondrial particles) or mitochondria increases when [O2] is raised above the normal atmospheric level of 21% O2, and this increase is roughly proportional to [O2], at least over the lower range of supraphysiological [O2] [4,12,26-28]. Fewer studies have looked at the effects of decreasing [O2], but O2•− production by isolated complex I ...
Several pieces of evidence presented here document that β1Δ/Δ or Dko mice have an uncompensated anemia at homeostasis with signs of ineffective erythropoiesis and shortened RBC survival likely because of their inability to counteract chronic ROS accumulation. As a result, membrane changes through protein oxidation and lipid peroxidation would affect membrane fluidity and stability,3,4 leading to hemolysis. Since a similar picture is not seen in the absence of only α4-integrins ([α4β1;α4β7]−/−) the data would suggest that the absence of other integrin heterodimers in β1Δ/Δ or Dkos alone or in combination are responsible for this phenotype.. Integrins expressed in differentiated erythroid cells (mainly α4β1 and α5β1) and their interactions with fibronectin (Fn) in their ME have been previously emphasized as critical for completing terminal maturation steps.30,40,41 Specifically, on the basis of in vitro studies using fetal liver cells, it was concluded that Epo and Fn regulate ...
Oxidative stress is generally associated with unregulated relationship between free radical production and enzymes responsible for clearing them. Endogenous antioxidant system protects various tissues and cells rendered susceptible to damage by exposure to excessive oxidative milieu. Superoxide dismutase is one of the major enzymes in living systems to regulate endogenous reactive oxygen species (ROS) levels. It partitions highly reactive superoxide radicals into less damaging oxygen or hydrogen peroxide (H2O2). Glutathione peroxidase and catalase are some of the other enzymes which play significant roles in maintaining the equilibrium of free radicals and further decompose H2O2. Catalase mediates decomposition of hydrogen peroxide into O2 and H2O while glutathione peroxidase catalyses reduction of lipid hydroperoxides and hydrogen peroxide to H2O. In the eye, ROS has particularly been implicated in mediating damage to retinal cells and other ocular tissues in diseases such as ocular hypertension, age
The risk on developing cancer increases with age. Moreover, many processes that affect the onset of aging, such as altered proliferation, metabolism and stress resistance, are also frequently deregulated in cancer. The molecular mechanisms that prevent the onset of aging may therefore be partially related to those that suppress carcinogenesis. ... read more Reactive Oxygen Species (ROS) are produced as a byproduct of energy production. ROS are essential for cell cycle progression, however, when ROS levels rise above a threshold, the cellular interior can be damaged through oxidation of proteins and lipids and through induction of DNA breaks. Inherently, excessive ROS accelerate the onset of aging and increase the chance on tumorigenesis. FOXO (Forkhead Box O) transcription factors counteract the excess in cellular ROS by transactivating transcription of the ROS scavenging enzymes. As such, FOXO activity is associated with longevity in model organisms and humans. FOXO signaling in turn can be ...
The function of the brain is dependent upon sufficient supply of glucose for energy metabolism. The glycolytic pathway and Krebs cycle are important in producing ATP for the brain. Brain dysfunction resulting from an external force is known as traumatic brain injury (TBI). TBI is associated with oxidative damage through the production of reactive oxygen/nitrogen species. Reduced energy metabolism is a consequence of TBI. Antioxidants are substances responsible for the inhibition of oxidation. Gamma-glutamylcysteine ethyl ester (GCEE) is an ethyl ester moiety of gamma-glutamylcysteine that exhibits antioxidant activity by increasing glutathione production. Previous studies have demonstrated that the administration of GCEE following TBI has protective effects against protein nitration. This study investigates the enzymatic activity of malate dehydrogenase which has been identified as being nitrated in moderate TBI. To test the hypothesis that the administration of GCEE will normalize enzymatic activity
We will utilize standard toxicologic assessment and high through-put toxicogenomic approaches, to gauge the relative toxicity of PM collected in regions where particles have greater and lesser effects on health outcomes. Project 3 will address potential limitations by integrating state-of-the-art genomic technologies with traditional and complementary toxicologic assessment. To exploit comparisons of pathobiologic cardiopulmonary responses to respirable airborne PM, in Phase I, we will optimize a battery of well-developed in vitro (human) and in vivo (murine) bioassays including multiple cytokines, indicators of reactive oxygen/nitrogen species burden (ROS/RNS), and biomarkers of vascular and cardiac dysfunction for assessing particle toxicity. For this purpose, we will use a set of particles having differing characteristics: standard NIOSH urban PM, Baltimore tunnel PM, ambient Baltimore air PM, New York City air PM. We will use oligonucleotide-based microarrays to address the hypothesis that ...
Endocannabinoids have recently drawn attention as promising anti-cancer agents. We previously observed that anandamide (AEA), one of the representative endocannabinoids, effectively inhibited the proliferation of head and neck squamous cell carcinoma (HNSCC) cell lines in a receptor-independent manner. In this study, using HNSCC cell lines, we examined the anti-cancer effects and the mechanisms of action of docosahexaenoyl ethanolamide (DHEA) and N-arachidonoyl-L-alanine (NALA), which are polyunsaturated fatty acid (PUFA)-based ethanolamides like AEA. DHEA and NALA were found to effectively inhibit HNSCC cell proliferation. These anti-proliferative effects seemed to be mediated in a cannabinoid receptor-independent manner, since the antagonist of cannabinoid receptor-1 (CB1) and vanilloid receptor-1 (VR1), two endocannabinoid receptors, did not reverse the ability of DHEA and NALA to induce cell death. Instead, we observed an increase in reactive oxygen species (ROS) production and a decrease of
Cigarette smoke contains numerous chemical compounds, including abundant reactive oxygen/nitrogen species and aldehydes, and many other carcinogens. Long-term cigarette smoking significantly increases the risk of various lung diseases, including chronic obstructive pulmonary disease and lung cancer, …
Three pairs of parental (ρ+) and established mitochondrial DNA depleted (ρ0) cells, derived from bone, lung and muscle were used to verify the influence of the nuclear background and the lack of efficient mitochondrial respiratory chain on antioxidant defences and homeostasis of intracellular reactive oxygen species (ROS). Mitochondrial DNA depletion significantly lowered glutathione reductase activity, glutathione (GSH) content, and consistently altered the GSH2 : oxidized glutathione ratio in all of the ρ0 cell lines, albeit to differing extents, indicating the most oxidized redox state in bone ρ0 cells. Activity, as well as gene expression and protein content, of superoxide dismutase showed a decrease in bone and muscle ρ0 cell lines but not in lung ρ0 cells. GSH peroxidase activity was four times higher in all three ρ0 cell lines in comparison to the parental ρ+, suggesting that this may be a necessary adaptation for survival without a functional respiratory chain. Taken together, ...
High intake of natural antioxidants (NA) from plant-derived foods and beverages is thought to provide cardiovascular benefits. The endothelium plays a pivotal role in cardiovascular homeostasis, and for this reason, the molecular events resulting from NA actions on endothelial cells (ECs) are actively investigated. Here, we show the direct impact of two NA, coumaric acid and resveratrol, on intracellular reactive oxygen species levels, protein carbonylation, and cell physiology in human ECs. While at lower doses, both NA promoted antioxidant effects, at moderately high doses, NA elicited a dose-dependent pro-oxidant effect, which was followed by apoptosis, cell damage, and phospho-Akt downregulation. NA-induced pro-oxidant effects were counteracted by N-acetyl cysteine and diphenyleneiodonium (DPI), suggesting a role for flavin oxidases in NA-induced toxicity. DPI also prevented NA-induced phospho-Akt downregulation indicating that Akt can work downstream of flavin oxidases in mediating cellular ...
A main feature of cancer cells, when compared to normal ones, is a persistent pro-oxidative state that leads to an intrinsic oxidative stress. Cancer cells have higher levels of reactive oxygen species (ROS) than normal cells, and ROS are, in turn, responsible for the maintenance of the cancer phenotype. Persistent ROS stress may induce adaptive stress responses, enabling cancer cells to survive with high levels of ROS and maintain cellular viability. However, excessive ROS levels render cancer cells highly susceptible to quercetin, one of the main dietary flavonoids. Quercetin depletes intracellular glutathione and increases intracellular ROS to a level that can cause cell death.
A main feature of cancer cells, when compared to normal ones, is a persistent pro-oxidative state that leads to an intrinsic oxidative stress. Cancer cells have higher levels of reactive oxygen species (ROS) than normal cells, and ROS are, in turn, responsible for the maintenance of the cancer phenotype. Persistent ROS stress may induce adaptive stress responses, enabling cancer cells to survive with high levels of ROS and maintain cellular viability. However, excessive ROS levels render cancer cells highly susceptible to quercetin, one of the main dietary flavonoids. Quercetin depletes intracellular glutathione and increases intracellular ROS to a level that can cause cell death.
ABSTRACT: Oceans function as a sink for organochlorine compounds (OCs) such as PCBs and DDTs. Deep-sea fish bioaccumulate OCs to levels 10 to 100 times higher than shallow-water species. OCs induce the cytochrome P450 (CYP) system, the activity of which may increase reactive oxygen species (ROS) production in liver cells. However, the susceptibility of fish to the oxidative stress likely caused by OCs remains unclear. We analysed whether PCB and DDT contamination of roundnose grenadier Coryphaenoides rupestris was associated with higher ethoxyresorufin-O-deethylase (EROD) activity (CYP1A-related), and activities of antioxidant enzymes such as catalase (CAT), superoxide dismutases (SOD) and glutathione peroxidases (GPX). Biological parameters affecting EROD patterns (e.g. gender, ontogeny) were also investigated. Citrate synthase (CS) was used as a proxy for oxidative metabolism, responsible for basal ROS production and recruitment of antioxidant enzymes in liver cells. Hepatic OC levels were ...
BACKGROUND Skin is uniquely vulnerable to damage caused by reactive oxygen species (ROS), which are most commonly produced in response to ultraviolet (UV) light. ROS generated at injury sites play an important role in modulating the inflammatory response. Besides inhibiting Rac, 7,8-dihydro-8-oxo-2-deoxyguanosine (8-oxo-dG) has also shown notable antioxidant action. OBJECTIVE We tested whether 8-oxo-dG could protect skin from UVB-induced damage by scavenging ROS. METHODS HaCaT cells and hairless mice were irradiated with 15 and 180 mJ/cm(2) narrow-spectrum UVB, respectively. ROS generation was detected through incubation with DCFDA and confocal microscopy. Western blot analyses and immunohistochemistry were performed to verify the activities of ERK, JNK, p38, ATF-2, and c-Jun, and the expression of matrix metalloproteinases (MMPs), in UVB-irradiated HaCaT cells and murine skin. Hydrogen peroxide production and protein carbonyl concentrations were measured in UVB-damaged mouse skin. MMP-1 and MMP-9
To keep the integrity of the organism embryonic stem cells (ESC) need to maintain their Rabbit Polyclonal to PSMC6. genomic integrity in response to DNA damage. high levels of endogenous reactive oxygen species (ROS) which can contribute to DNA damage and may arise from high levels of metabolic activity. To potentially counter genomic instability caused A 922500 by DNA damage we find that hESC employ two strategies: First these cells have enhanced levels of DNA repair proteins including those involved in repair of DSBs and they demonstrate elevated nonhomologous end-joining (NHEJ) activity and restoration efficacy one of A 922500 the main pathways for fixing DSBs. Second they may be hypersensitive to DNA damaging providers as evidenced by a high level of apoptosis upon irradiation. Importantly iPSC unlike the parent cells they are derived from mimic hESC in their ROS levels cell cycle profiles restoration protein manifestation and NHEJ restoration effectiveness indicating reprogramming of the ...
Quantum biology is the study of quantum effects on biochemical mechanisms and biological function. We show that the biological production of reactive oxygen species (ROS) in live cells can be influenced by coherent electron spin dynamics, providing a new example of quantum biology in cellular regulation. ROS partitioning appears to be mediated during the activation of molecular oxygen (O2) by reduced flavoenzymes, forming spin-correlated radical pairs (RPs). We find that oscillating magnetic fields at Zeeman resonance alter relative yields of cellular superoxide (O2•âˆ) and hydrogen peroxide (H2O2) ROS products, indicating coherent singlet-triplet mixing at the point of ROS formation. Furthermore, the orientation-dependence of magnetic stimulation, which leads to specific changes in ROS levels, increases either mitochondrial respiration and glycolysis rates. Our results reveal quantum effects in live cell cultures that bridge atomic and cellular levels by connecting ROS partitioning to ...
Our results demonstrate that all complex II inhibitors, despite their different binding sites (Fig. 1) and a wide range of affinities, affected ROS production by the respiratory chain in the same way. All compounds exhibited comparable ambivalent effects when succinate was the predominant substrate: they attenuated ROS production at the level of complex I by reverse electron transfer, whereas they stimulated ROS generation at the Qo site of complex III under conditions of oxidant-induced reduction. In this respect, complex II activity modulates these two respiratory chain complexes (Dröse et al., 2009) that are generally regarded as the main ROS producers within mitochondria (Kowaltowski et al., 2009; Brand, 2010). A common principle exerting these effects seems evident, because we observed a strict correlation between the degree of inhibition and the modulating effects on ROS production for all compounds. Three of the investigated complex II inhibitors have been shown to be cardioprotective in ...
Antioxidant enzymes play a fundamental role in counteracting oxidative stress induced by high glucose. Although mitochondrial superoxide dismutase (SOD2) is the principal defence against the toxicity of superoxide anions, the mechanism of its inactivation in diabetic subjects is still poorly understood. Recently, microRNA-21 has been associated with diabetes, although its function remains unclear. We sought to explore the mechanism underlying defective SOD2 antioxidant response in HUVECs during exposures to constant high glucose and oscillating glucose (as glucose variability model, GV) and the role of miR-21 in increasing the susceptibility to oxidative stress by disrupting reactive oxygen species (ROS) homeostasis. HUVECs exposed for 1 week to constant high glucose and GV were subjected to quantitative electron paramagnetic resonance for ROS measurements. Superoxide anions, SOD2 protein levels and mitochondrial membrane potential (ΔΨm) were also evaluated. Endogenous miR-21 and its putative ROS
TY - JOUR. T1 - Neuroprotective role of retinal SIRT3 against acute photo-stress. AU - Ban, Norimitsu. AU - Ozawa, Yoko. AU - Osada, Hideto. AU - Lin, Jonathan B.. AU - Toda, Eriko. AU - Watanabe, Mitsuhiro. AU - Yuki, Kenya. AU - Kubota, Shunsuke. AU - Apte, Rajendra S.. AU - Tsubota, Kazuo. PY - 2017/12/1. Y1 - 2017/12/1. N2 - SIRT3 is a key regulator of mitochondrial reactive oxygen species as well as mitochondrial function. The retina is one of the highest energy-demanding tissues, in which the regulation of reactive oxygen species is critical to prevent retinal neurodegeneration. Although previous reports have demonstrated that SIRT3 is highly expressed in the retina and important in neuroprotection, function of SIRT3 in regulating reactive oxygen species in the retina is largely unknown. In this study, we investigated the role of retinal SIRT3 in a light-induced retinal degeneration model using SIRT3 knockout mice. We demonstrate that SIRT3 deficiency causes acute reactive oxygen species ...
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These days, several couples are suffering from infertility conditions, which means they are unable to conceive a baby naturally. In this condition, they need to get proper check-up and treatment. Here, in this article you will learn about male infertility and its treatment.. Almost 30% of a male suffer from fertility issues due to several reasons. Poor sperm health leads you to infertility, which is explained as an inability to be a father. Males usually experience poor sperm health due to oxidative stress. To get the right treatment for your fertility conditions, you need to understand what is oxidative stress.. What is oxidative stress?. Sperm cells are delicate and they are constantly exposed to free radical compounds. This only happens when sperm cells travel from the testes toward their final destination, and those free radical compounds are known as reactive oxidative species (ROS). Reactive Oxidative species play an important role in the functioning of sperm cells. But the irregular ...
8-Hydroxy-2-deoxyguanosine (8-OHdG), a marker of oxidative stress, has been recently rediscovered to inhibit Rac1 in neutrophils and macrophages, thereby inhibiting Rac1-linked functions of these cells, including reactive oxygen species production through NADPH oxidase activation, phagocytosis, chemotaxis, and cytokine release. In vascular smooth muscle cells (VSMCs), reactive oxygen species also induce abnormal proliferation and migration leading to progression of atherosclerosis. Based upon the involvement of reactive oxygen species in phagocytic cells and VSMCs during the atherosclerotic process, we hypothesized that 8-OHdG could have antiatherosclerotic action and tested this hypothesis in an experimentally induced atherosclerosis in mice. Partially ligated ApoE knockout mice, a more physiologically relevant model of low and oscillatory flow, developed an advanced lesion in 2 weeks, and orally administered 8-OHdG significantly reduced plaque formation along with reduced superoxide formation, ...
Background/Purpose: Osteoarthritis (OA) is the most common form of arthritis, affecting nearly 10% of the US population. With age and injury, chondrocytes have diminished mitochondrial content and mitochondrial production of ATP contributing to OA pathogenesis. We have previously reported that chondrocytes release ATP, which is converted extracellularly to adenosine and maintains chondrocyte homeostasis via endogenous stimulation of the A2AR. Injured/inflamed chondrocytes have lower ATP levels and release less ATP resulting in diminished extracellular adenosine and A2AR stimulation. Mice and humans lacking the capacity to convert extracellular ATP to adenosine (ecto-5nucleotidase deficient) develop spontaneous OA as do mice lacking A2AR (A2ARKO). We therefore studied the effect of A2AR stimulation on mitochondrial health and function in chondrocytes from WT and A2ARKO mice and in a human chondrocytic cell line. Methods: A human chondrocyte cell line, T/C28-a2, or neonatal chondrocytes isolated ...
In humans, oxidative stress is involved in many diseases, such as atherosclerosis, Parkinsons disease, heart failure, myocardial infarction, Alzheimers disease, fragile X syndrome and chronic fatigue syndrome, but short-term oxidative stress may also be important in prevention of aging by induction of a process named mitohormesis. Reactive oxygen species can be beneficial, as they are used by the immune system as a way to attack and kill pathogens. Reactive oxygen species are also used in cell signaling. This is dubbed redox signaling.. Next week we will discuss the role of antioxidants in combatting oxidative stress.. ...
BACKGROUND: Reduced availability of tetrahydrobiopterin (BH(4)), an essential cofactor of nitric oxide (NO) synthase (NOS), decreases NO production and increases reactive oxygen species. Both mechanisms contribute to atherosclerotic vascular disease. Although acute supplementation of BH(4) improves endothelial dysfunction, the effect of chronic BH(4) in humans is unknown. OBJECTIVE: To investigate the effect of chronic BH(4) supplementation on endothelial function and oxidative stress in hypercholesterolaemia. DESIGN: Randomised double-blind, placebo-controlled trial. SETTING: University Hospital. PATIENTS: 22 hypercholesterolaemic patients (low-density lipoprotein (LDL) |4.5 mmol/l) were randomised to 4 weeks of oral BH(4) (400 mg twice daily) or placebo. Age-matched healthy volunteers served as controls. MAIN OUTCOME MEASURES: Endothelium-dependent and -independent vasodilatation was assessed by venous occlusion plethysmography. To elucidate the mechanisms of BH(4) effect, NO release and superoxide
Mitochondria have emerged recently as effective targets for novel anti-cancer drugs referred to as mitocans. We propose that the molecular mechanism of induction of apoptosis by mitocans, as exemplified by the drug a-tocopheryl succinate, involves generation of reactive oxygen species (ROS). ROS then mediate the formation of disufide bridges between cytosolic Bax monomers, resulting in the formation of mitochondrial outer membrane channels. ROS also cause oxidation of cardiolipin, triggering the release of cytochrome c and its translocation via the activated Bax channels. This model may provide a general mechanism for the action of inducers of apoptosis and anticancer drugs, mitocans, targeting mitochondria via ROS production ...
Their analysis of 10 such studies showed that exposure to EMR from cell phones lowered sperm motility by 8 percent and sperm viability by 9 percent.2Previous studies have also found that cell phone radiation can affect mens sperm count, and the quality and motility of their sperm. One such study, published in PLOS One found. RF-EMR in both the power density and frequency range of mobile phones enhances mitochondrial reactive oxygen species generation by human spermatozoa, decreasing the motility and vitality of these cells while stimulating DNA base adduct formation and, ultimately DNA fragmentation. These findings have clear implications for the safety of extensive mobile phone use by males of reproductive age, potentially affecting both their fertility and the health and wellbeing of their offspring.. During the 2013 discussion Cell Phones & Wi-Fi - Are Children, Fetuses and Fertility at Risk?, leading experts from top universities further reported, There is a direct relationship between ...
The interaction of (Mtb) with sponsor cell death signaling Flumatinib mesylate pathways is characterized by an initial anti-apoptotic phase followed by a pro-necrotic phase to allow for sponsor cell exit of the bacteria. phagocytic cells Mtb resides within a altered phagosomal compartment and IL2RG inhibits apoptotic sponsor cell death. Recent studies possess shown that Mtb eventually translocates from your phagosomal compartment to the cytosol. This event is definitely followed by the induction of necrotic sponsor cell death allowing the bacteria to exit the sponsor cell and infect naive cell populations. Our study adds to this relatively unexplored aspect of Mtb pathogenesis by exposing the transcriptional repressor of Mtb negatively regulates phagosomal escape and sponsor cell necrosis. We furthermore demonstrate the improved necrosis induction from the Mtb mutant strain deficient in required elevated reactive oxygen species levels within sponsor cell mitochondria and reduced activation of ...
Apoptosis is a programmed cell death mechanism to control cell number in tissues and to eliminate individual cells that may lead to disease states. The present study investigates chromium(VI) (Cr(VI))-induced apoptosis and the role of reactive oxygen species (ROS) and p53 in this response. Treatment of human lung epithelial cells (A549) with Cr(VI) caused apoptosis as measured by DNA fragmentation
Viagra as an Adjunctive Cancer Therapy Jacob Schor, ND Published in the May 2007 issue of Naturopathy Doctor News and Review. The majority of the cancer patients in our practice choose to combine standard medical treatment with naturopathic care. Thus, most of these patients will undergo some form of chemotherapy and or radiation therapy. While they undergo these treatments, our primary goal is to make the cancer cells as sensitive to the chosen treatment as possible. On the standard list of supplements that do this are melatonin, vitamin D, green tea, quercetin, curcumin, ellagic acid, resveratrol and so on. As a general rule, we seek substances that either increase Reactive Oxygen Species (ROS) or lower glutathione levels (GSH) in the cancer cells to make them more susceptible to either drug or radiation damage. There is a new addition to our thinking, we now seek to change nitric oxide levels (NO) before and during treatment. This is a potentially amusing suggestion as the easiest way to ...
Although cholesterol circulating systemically is unable to cross the blood brain barrier, an oxidized product 27-hydroxycholesterol (27-OHC) is able to reach the brain. This has been theorized to be a potential link from elevated cholesterol to the risk of Alzheimers disease. Elevated cholesterol may increase reactive oxygen species (ROS) formation which may promote amyloid beta deposits in the brain. There is a lot of data to cover so detailed descriptions are not really the point here but many of the mechanisms have not actually been evaluated in actual patients. The majority of models have been cultured tissues and animal models. These findings have been contradictory and ongoing research is needed to determine if there is a safe and efficacious place for statins in the treatment or prevention of neurodegenerative diseases like Alzheimers disease ...
Cheung, C. Y., McCartney, S. J. and Anseth, K. S. (2008), Synthesis of Polymerizable Superoxide Dismutase Mimetics to Reduce Reactive Oxygen Species Damage in Transplanted Biomedical Devices. Adv. Funct. Mater., 18: 3119-3126. doi: 10.1002/adfm.200800566 ...
The reactive oxygen kills the target cells.[5] Reactive oxygen species[edit]. In air and tissue, molecular oxygen (O2) occurs ... and produce radicals and reactive oxygen species (ROS), crucial to the Type II mechanism. These species include singlet oxygen ... The highly-reactive singlet oxygen species (1O2) produced via the Type-II process act near to their site generation and within ... with oxygen to produce singlet oxygen. This species is highly cytotoxic, rapidly attacking any organic compounds it encounters ...
Generation of reactive oxygen species[edit]. Figure 2: Disease Pathways for SDHB mutations. Electron path during normal ... transfer through the SDHB subunit to the Ubiquinone pool are instead transferred to O2 to create Reactive Oxygen Species (ROS) ... The O1 carbonyl oxygen of ubiquinone is oriented at the active site (image 4) by hydrogen bond interactions with Tyr83 of SDHD ... PHD action normally requires oxygen and alpha-ketoglutarate as cosubstrates and ferrous iron and ascorbate as cofactors. ...
Peroxidation and reactive oxygen species[edit]. Next, the free fatty acid is oxygenated along any of several pathways; see the ... Oxidation by either COX or lipoxygenase releases reactive oxygen species (ROS) and the initial products in eicosanoid ... PGH2 has a 5-carbon ring bridged by molecular oxygen. Its derived PGS have lost this oxygen bridge and contain a single, ... The eicosanoid pathways (via lipoxygenase or COX) add molecular oxygen (O2). Although the fatty acid is symmetric, the ...
... kinases present in the ovule control the production of highly reactive derivatives of oxygen called reactive oxygen species ( ... "Reactive oxygen species". Science Direct. Retrieved April 25, 2018.. *^ Johnstone, Adam. Biology: facts & practice for A level ... "Reactive oxygen species mediate pollen tube rupture to release sperm for fertilization in Arabidopsis". Nature Communications. ... In some species, self-fertilisation has persisted over many generations. Capsella rubella is a self-fertilisating species that ...
2004) Generation of reactive oxygen species in the reaction catalyzed by alpha-ketoglutarate dehydrogenase, J. Neurosci. 24, ... 2004) Generation of reactive oxygen species in the reaction catalyzed by alpha-ketoglutarate dehydrogenase, J. Neurosci. 24, ... Oxidative stress is a process characterized by a production of reactive oxygen species (ROS), that are partially reduced ... 2004) Mitochondrial alpha-ketoglutarate dehydrogenase complex generates reactive oxygen species, J. Neurosci. 24, 7779-7788. ...
ROS stands for reactive oxygen species. ROS plays a large role in mediating events through transduction. Cold stress was shown ... Nobuhiro, S., & Miller, R. (2006). Reactive oxygen species and temperature stresses: A delicate balance between signaling and ... Some plants could have genes added to them from other species of plants that have a resistance to a specific stress. Plants ... implanted with these genes would then become transgenic plants because they have the genes from another species of plant in ...
... perhaps because of reactive oxygen species (complex I can, like complex III, leak electrons to oxygen, forming highly toxic ... Recent investigations suggest that complex I is a potent source of reactive oxygen species.[44] Complex I can produce ... Superoxide is a reactive oxygen species that contributes to cellular oxidative stress and is linked to neuromuscular diseases ... Esterházy D, King MS, Yakovlev G, Hirst J (March 2008). "Production of reactive oxygen species by complex I (NADH:ubiquinone ...
... activation is modulated by reactive oxygen species.[49] Antigen discrimination[edit]. A unique feature of T cells is ... "T cells and reactive oxygen species". Journal of Biomedical Science. 22: 85. doi:10.1186/s12929-015-0194-3. PMC 4608155. PMID ... This process is an important component of central tolerance and serves to prevent the formation of self-reactive T cells that ...
"Reactive Oxygen Species in Plant Cell Death". Plant Physiology. 141 (2): 384-390. doi:10.1104/pp.106.078295. ISSN 1532-2548. ... Tomato plants protect against cold stress with anthocyanins countering reactive oxygen species, leading to a lower rate of cell ... Plants rich in anthocyanins are Vaccinium species, such as blueberry, cranberry, and bilberry; Rubus berries, including black ... Anthocyanins occur in the flowers of many plants, such as the blue poppies of some Meconopsis species and cultivars.[11] ...
Therefore, NADPH prevents reactive oxygen species from accumulating and damaging cells. Excessive activation of the polyol ... Bonnefont-Rousselot, Dominique (2002). "Glucose and reactive oxygen species". Current Opinion in Clinical Nutrition and ... increased concentrations of reactive oxygen species, and decreased concentrations of nitric oxide and glutathione. Each of ...
Corpas FJ, Barroso JB, del Río LA (Apr 2001). "Peroxisomes as a source of reactive oxygen species and nitric oxide signal ... Bonekamp NA, Völkl A, Fahimi HD, Schrader M (2009). "Reactive oxygen species and peroxisomes: struggling for balance". ... reduction of reactive oxygen species - specifically hydrogen peroxide[3] - and biosynthesis of plasmalogens, i.e., ether ... The protein content of peroxisomes varies across species or organism, but the presence of proteins common to many species has ...
... oxygen is a highly reactive molecule that damages living organisms by producing reactive oxygen species.[52] Consequently, ... The use of oxygen as part of the process for generating metabolic energy produces reactive oxygen species.[61] In this process ... Oxygen. ⟶. ⋅. O. 2. −. Superoxide. →. Superoxide. dismutase. H. 2. O. 2. Hydrogen. peroxide. →. Peroxidases. catalase. H. 2. O ... The reactive oxygen species produced in cells include hydrogen peroxide (H2O2), hypochlorous acid (HClO), and free radicals ...
Inside mitochondria, reactive oxygen species (ROS), or free radicals, byproducts of the constant production of adenosine ... DNA damage can be subdivided into two main types: endogenous damage such as attack by reactive oxygen species produced from ... increase in reactive oxygen species (ROS). Replication stress, along with the selection for inactivating mutations in DNA ... induced by endogenously generated reactive oxygen species. For example, increasing the gene dosage of the gene SIR-2, which ...
... triggers reactive oxygen species (ROS). ROS production disrupts protein folding and induces the unfolded protein ...
... perhaps because of reactive oxygen species (complex I can, like complex III, leak electrons to oxygen, forming highly toxic ... Superoxide is a reactive oxygen species that contributes to cellular oxidative stress and is linked to neuromuscular diseases ... Esterházy D, King MS, Yakovlev G, Hirst J (March 2008). "Production of reactive oxygen species by complex I (NADH:ubiquinone ... Murphy MP (January 2009). "How mitochondria produce reactive oxygen species". Biochem. J. 417 (1): 1-13. doi:10.1042/BJ20081386 ...
It is a very important enzyme in protecting the cell from oxidative damage by reactive oxygen species (ROS). Likewise, catalase ... Winterbourn, Christine C.; Kettle, Anthony J.; Hampton, Mark B. (2016-06-02). "Reactive Oxygen Species and Neutrophil Function ... to transfer between the oxygen atoms. The free oxygen atom coordinates, freeing the newly formed water molecule and Fe(IV)=O. ... The production of oxygen can be seen by the formation of bubbles. This easy test, which can be seen with the naked eye, without ...
... the unreduced oxygen molecules in the mitochondrial cortex may accumulate and begin to produce reactive oxygen species. It is ... Reactive oxygen species can damage the DNA and proteins in cells. A majority of them arise in the mitochondria. Deletion of the ... Adam-Vizi V (2005). "Production of reactive oxygen species in brain mitochondria: contribution by electron transport chain and ... Apel K, Hirt H (2004). "Reactive oxygen species: metabolism, oxidative stress, and signal transduction". Annual Review of Plant ...
Belikov, Aleksey V.; Schraven, Burkhart; Simeoni, Luca (1 January 2015). "T cells and reactive oxygen species". Journal of ... T cell activation is modulated by reactive oxygen species. A unique feature of T cells is their ability to discriminate between ... This process is an important component of central tolerance and serves to prevent the formation of self-reactive T cells that ...
Alom-Ruiz SP, Anilkumar N, Shah AM (2008). "Reactive oxygen species and endothelial activation". Antioxid Redox Signal. 10 (6 ... April 2016). "Mitochondrial Reactive Oxygen Species Mediate Lysophosphatidylcholine-Induced Endothelial Cell Activation". ...
Its role is to prevent the interaction of the intermediate with molecular oxygen to produce reactive oxygen species (ROS). The ... January 2003). "Architecture of succinate dehydrogenase and reactive oxygen species generation". Science. 299 (5607): 700-4. ... Other studies claim that Tyr83 of subunit D is coordinated to a nearby histidine as well as the O1 carbonyl oxygen of ... The O1 carbonyl oxygen of ubiquinone is oriented at the active site (image 4) by hydrogen bond interactions with Tyr83 of ...
Nordberg J, Arnér ES (December 2001). "Reactive oxygen species, antioxidants, and the mammalian thioredoxin system". Free ... plays a central role in humans and is increasingly linked to medicine through their response to reactive oxygen species (ROS). ...
... has been shown to interact with multiple signaling pathways including; ITGB1BP1., reactive oxygen species, cell death, ... "KRIT1 regulates the homeostasis of intracellular reactive oxygen species". PLOS ONE. 5 (7): e11786. doi:10.1371/journal.pone. ...
Role of hypoxia and reactive oxygen species". Reproductive Toxicology (Elmsford, N.Y.). 13 (2): 93-101. ISSN 0890-6238. PMID ...
Mitochondrial SNO-proteins inhibit Complex I of the electron transport chain; modulate mitochondrial reactive oxygen species ( ... Moreover, the biliary secretion of NO species was significantly diminished in UDCA-infused transport mutant [ATP-binding ... it has been proposed that exogenous GSNO could be used to regulate circulating levels of NO and NO-derived species, and GSNO ...
Tomato plants protect against cold stress with anthocyanins countering reactive oxygen species, leading to a lower rate of cell ... Breusegem, Frank Van; Dat, James F. (2006-06-01). "Reactive Oxygen Species in Plant Cell Death". Plant Physiology. 141 (2): 384 ... Anthocyanins have an antioxidant role in plants against reactive oxygen species caused by abiotic stresses, such as ... Anthocyanins occur in the flowers of many plants, such as the famous blue poppies of some Meconopsis species and cultivars. ...
She has written the book Reactive Oxygen Species and the Cardiovascular System, which describes how various oxygen species can ... M., Touyz, Rhian (2012). Reactive oxygen species and the cardiovascular system. Morgan & Claypool. ISBN 9781615043620. OCLC ...
Bergamini, Carlo M.; Gambetti, Stefani; Dondi, Alessia; Cervellati, Carlo (2004). "Oxygen, Reactive Oxygen Species and Tissue ... seemingly as a result of increased generation of reactive oxidative species (ROS). This is a plausible mechanism, as there is a ... "Extrapolating Brain Development from Experimental Species to Humans". NeuroToxicology. 28 (5): 931-37. doi:10.1016/j.neuro. ...
A variety of reactive oxygen species (ROS) are generated by plants during times of stress (biotic and abiotic) including UV ... Sakamoto, M., I. Munemura, R. Tomita, & K. Kobayashi (2008). Reactive oxygen species in leaf abscission signaling. Plant Signal ... This step can occur in a variety of ways depending on the species but always occurs at the abscission zone. Detachment can ... Steps 2 and 3 may occur in either order depending on the species. Resorption involves degrading chlorophyll to extract the ...
positive regulation of reactive oxygen species metabolic process. Источники: Amigo / QuickGO. Профиль экспрессии РНК. ...
The most prevailing mechanism of endothelial dysfunction is an increase in reactive oxygen species, which can impair nitric ... "Mitochondrial Reactive Oxygen Species Mediate Lysophosphatidylcholine-Induced Endothelial Cell Activation". Arteriosclerosis, ...
Belikov AV, Schraven B, Simeoni L. T cells and reactive oxygen species. Journal of Biomedical Science. October 2015, 22: 85. ...
... s are also weak bases, undergoing protonation on the carbonyl oxygen in the presence of Brønsted acids. Ketonium ions (i. ... Acetylacetone (pentane-2,4-dione) is virtually a misnomer (inappropriate name) because this species exists mainly as the ... because they do not have reactive groups like −OH or −Cl attached directly to the carbon atom in the carbonyl group, as in ... The carbonyl group is polar because the electronegativity of the oxygen is greater than that for carbon. Thus, ketones are ...
In vitro modulation of oxidative burst via release of reactive oxygen species from immune cells by extracts of selected ... A genetic diversity study of endangered Psiadia species endemic from Mauritius Island using PCR markers». Biochemical ... Chemical composition and in vitro antimicrobial activities of the essential oils from endemic Psiadia species growing in ...
... this generates free radicals and reactive oxygen species in the skin, which purposefully damage the sebaceous glands and kill C ... The anaerobic bacterial species Cutibacterium acnes (formerly Propionibacterium acnes) contributes to the development of acne, ... acnes by oxidizing its proteins through the formation of oxygen free radicals and benzoic acid. These free radicals likely ...
Lin et al., conducted an experiment in Taiwan that tested the effect of generation of reactive oxygen species on temporary ... Studies[clarification needed] have been done on a variety of animal species, including guinea pigs[13] and dolphins.,[14] rats, ... With the resultant oxygen tension and diminished blood supply reaching the outer hair cells, their response to sound levels is ... The transduction of sounds requires an oxygen supply that will be readily depleted due to the prolonged threshold shifts. ...
Reaction with oxygen Upon reacting with oxygen, alkali metals form oxides, peroxides, superoxides and suboxides. However, the ... Thus, contrary to expectation, caesium is the most reactive of the alkali metals, not francium.[68][37]:1729[87] All known ... These compounds can be described as involving the alkali metals losing electrons to acceptor species and forming monopositive ... The other oxygen compounds are also unstable in water. 2KO2 + 2H2O → 2KOH + H2O2 + O2[145]. Li2O + H2O → 2LiOH. Reaction with ...
The surface of conventional activated carbon is reactive, capable of oxidation by atmospheric oxygen and oxygen plasma[26][27][ ... The large charcoal beds adsorb these gases and retain them while they rapidly decay to non-radioactive solid species. The ... He uses oxygen as an example, wherein the activated carbon would typically adsorb the atmospheric concentration (21%) under ... Shende RV, Mahajani VV (2002). "Wet oxidative regeneration of activated carbon loaded with reactive dye". Waste Management. 22 ...
In contrast, some results point to the formation of anionic palladium species, which would be the real catalysts instead of the ... Vinyl iodides are the most reactive vinyl halides to Pd0 oxidative addition, and their use is therefore most frequent for ... and oxygen promotes the formation of homocoupled acetylenes. Recently, development of air-stable organopalladium catalysts ... which acts as an activated species for the coupling reactions. Cu(I) is a co-catalyst in the reaction, and is used to increase ...
Petersen Shay, K; Moreau, RF; Smith, EJ; Hagen, TM (2008). „Is alpha-lipoic acid a scavenger of reactive oxygen species in vivo ...
More research on this fungal species, Cunninghamella japonica, and others, is likely to appear in the near future.[112] The ... combustion with an amount of oxygen that is not sufficient to convert the biomass completely to carbon dioxide and water.[26] ... "Bioethers are produced by the reaction of reactive iso-olefins, such as iso-butylene, with bioethanol."[55] Bioethers are ... From 1978 to 1996, the US NREL experimented with using algae as a biofuels source in the "Aquatic Species Program".[17] A self- ...
Reactive oxygen species-induced oxidative stress in the development of insulin resistance and hyperandrogenism in polycystic ...
Consequently, compounds containing Si-H bonds are much more reactive than is H2. The strength of the Si-H bond is modestly ... Si has a nominal oxidation number IV in all three species). However, the utility of the oxidation number concept for a covalent ... Oxygen (molecular). *Phosphorus monoxide. *Phosphorus mononitride. *Potassium chloride. *Silicon carbide. *Silicon mononitride ...
Superoxide is one of the main reactive oxygen species in the cell. As a consequence, SOD serves a key antioxidant role. The ... Human white blood cells use enzymes such as NADPH oxidase to generate superoxide and other reactive oxygen species to kill ... Corpas FJ, Barroso JB, del Río LA (Apr 2001). "Peroxisomes as a source of reactive oxygen species and nitric oxide signal ... Reactive oxygen species levels increase with age in these mutant strains and show a similar pattern to the pattern of DNA ...
The major use of quicklime is in the basic oxygen steelmaking (BOS) process. Its usage varies from about 30 to 50 kilograms (65 ... It is noteworthy that CaO is also a separate mineral species, named lime. A pyrometamorphic mineral, it is rare, as it is ... Limestone, which contains less reactive material, is slower to react and may have other disadvantages compared with lime, ...
An ion is a charged species, an atom or a molecule, that has lost or gained one or more electrons. When an atom loses an ... The molecules/atoms of substance in an excited energy state are often much more reactive; that is, more amenable to chemical ... Carl Wilhelm Scheele isolated pure oxygen. ... Most radicals are comparatively reactive, but some, such as ... According to the IUPAC gold book, a chemical reaction is "a process that results in the interconversion of chemical species."[ ...
Respiratory protéin-generated reactive oxygen species as an antimicrobial strategy. Nature Immunology, 26 August 2007. PMID ... Red blood cells do more than just carry oxygen. New findings by NUS team show they aggressively attack bacteria too., The ...
"Regulation of late G1/S phase transition and APC Cdh1 by reactive oxygen species". Molecular and Cellular Biology. 26 (12): ... The bortezomib molecule is in the center colored by atom type (carbon = pink, nitrogen = blue, oxygen = red, boron = yellow), ... This mechanism may depend on an associated water molecule for deprotonation of the reactive threonine hydroxyl. Degradation ... assembly and function lead to reduced proteolytic activities and the accumulation of damaged or misfolded protein species. Such ...
... causing the release of reactive oxygen species. Pathogens also stimulate the macrophage to produce chemokines, which summon ... Elements of the complement cascade can be found in many non-mammalian species including plants, birds, fish, and some species ... Although the exact pathogenic species vary with the infected species, bacteria, fungi, viruses, nematodes, and insects can all ... In other species[edit]. Prokaryotes[edit]. Bacteria (and perhaps other prokaryotic organisms), utilize a unique defense ...
"Reactive Oxygen Species and the Hypomotility of the Gall Bladder as Targets for the Treatment of Gallstones with Melatonin: A ...
... as well as a powerful reducing agent capable of rapidly scavenging a number of reactive oxygen species (ROS). Given that ... By luck, this species did not make its own vitamin C, whereas mice and rats do.[174] In 1912, the Polish biochemist Casimir ... In some species that synthesize ascorbate in the liver (including mammals and perching birds), the glucose is extracted from ... Recent orders of birds and most mammals make ascorbic acid in their liver.[115] A number of species of passerine birds also do ...
In mammals, amino acid sensing and additional signals such as growth factors and reactive oxygen species regulate the activity ...
... through the PI3K pathway or through reactive oxygen species (ROS)-mediated activation of the STAT3 pathway.[11] Downstream ... Synthesis occurs due to external stimuli such as thrombin, low oxygen tension, or other cytokines and growth factors.[20] ... "An antibody reactive with domain 4 of the platelet-derived growth factor beta receptor allows BB binding while inhibiting ...
regulation of reactive oxygen species metabolic process. • positive regulation of protein transport. • negative regulation of ... Other factors, such as cell type, concurrent stimulation of other cytokines, or the amount of reactive oxygen species (ROS) can ... On the liver: stimulating the acute phase response, leading to an increase in C-reactive protein and a number of other ...
... he proposed a new molecular structure for sarsasapogenin where the side chain was chemically reactive due to the two oxygen ... Species of the genus Dioscorea contain diosgenin: a saponin similar to the structure of sarsasapogenin found in beth root. In ...
Several species of macrofungi accumulate vanadium (up to 500 mg/kg in dry weight).[7] Vanadium-dependent bromoperoxidase ... All the elements of the group are reactive metals with a high melting points (1910 °C, 2477 °C, 3017 °C). The reactivity is not ... Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium ... decavanadate and oxovanadates are species that potentially have many biological activities and that have been successfully used ...
... mitochondrial reactive oxygen species production, and membrane fatty acid composition". J Gerontol A Biol Sci Med Sci. 61 (8): ... The life extension varies for each species, but on average there was a 30-40% increase in life span in both mice and rats.[28] ... In preliminary research, some non-human species on calorie restriction diets without malnutrition may exhibit slowing of the ...
Liu SQ, Bhatnagar A, Ansari NH, Srivastava SK (August 1993). "Identification of the reactive cysteine residue in human placenta ... 1.1.3: oxygen acceptor. *Glucose oxidase. *L-gulonolactone oxidase. *Xanthine oxidase. 1.1.4: disulfide as acceptor. *Vitamin K ...
Obat-obatan yang memakan reactive oxygen species, menolak apoptosis, atau menolak inhibit excitatory neurotransmitters telah ... Hyperbaric oxygen therapy telah dipelajari sebagai kemungkinan perlindungan, tetapi akhir-akhir ini dipikirkan bahwa terapi ini ... Bennett, MH; Weibel, S; Wasiak, J; Schnabel, A; French, C; Kranke, P (12 November 2014). "Hyperbaric oxygen therapy for acute ...
... a reactive oxygen species that damages DNA. These defenses limit the population of infected flies. ... SpeciesEdit. The tsetse genus is generally split into three groups of species based on a combination of distributional, ... Species affected. Trypanosoma agents. Distribution. Glossina vectors. Sleeping sickness - chronic form. humans. T. brucei ... Some species, such as T. theileri, do not seem to cause any health problems except perhaps in animals that are already sick.[16 ...
Discusses reactive oxygen species which are involved in a broad range of biological processes. Reactive Oxygen Species in ... 10 Reactive Oxygen Species and Antioxidants: A Continuous Scuffle within the Cell 187. Supriya Tiwari. 11 Quenching of Reactive ... 8 Reactive Oxygen Species and Response of the Calvin-Benson Cycle: An Overview 157. Shivam Yadav and Neelam Atri. 9 Role of ... Reactive Oxygen Species in Plants. Boon Or Bane - Revisiting the Role of ROS. Singh, Vijay Pratap / Singh, Samiksha / Tripathi ...
These compounds inhibit the enzyme Nox2, part of a family of enzymes responsible for producing reactive oxygen species. ... New anti-inflammatory drugs pinch off reactive oxygen species at the source Drugs target Nox2 enzyme directly instead of acting ... These compounds inhibit the enzyme Nox2, part of a family of enzymes responsible for producing reactive oxygen species (ROS). ... New anti-inflammatory drugs pinch off reactive oxygen species at the source. Emory Health Sciences ...
Kourie JI: Interaction of reactive oxygen species with ion transport mechanisms. Am J Physiol275 :C1 -C24,1998. ... Carriere A, Carmona MC, Fernandez Y, Rigoulet M, Wenger RH, Pénicaud L, Casteilla L: Mitochondrial reactive oxygen species ... Mitochondrial Reactive Oxygen Species Are Obligatory Signals for Glucose-Induced Insulin Secretion. ... Studies on the mitochondrial generation of reactive oxygen species (ROS) generally focus on chronic nutrient exposure. Here, we ...
Toyokuni, S. (1999), Reactive oxygen species-induced molecular damage and its application in pathology. Pathology International ...
Negative regulator of reactive oxygen species (ROS) that limits ROS production by phagocytes during inflammatory response, ... Negative regulator of reactive oxygen speciesAdd BLAST. 674. Amino acid modifications. Feature key. Position(s). Description ... Negative regulator of reactive oxygen species (ROS) that limits ROS production by phagocytes during inflammatory response, ... sp,Q86YC3,NRROS_HUMAN Negative regulator of reactive oxygen species OS=Homo sapiens GN=NRROS PE=1 SV=1 ...
Zhi-Qing Zhao on Reactive oxygen species and myocardial apoptosis, part of a collection of online lectures. ... Reactive oxygen species and myocardial apoptosis. *Dr. Zhi-Qing Zhao - Emory University, USA ... Zhao, Z. (2007, October 1). Reactive oxygen species and myocardial apoptosis [Video file]. In The Biomedical & Life Sciences ...
The production of reactive oxygen species (ROS), via consumption of oxygen in a so-called oxidative burst, is one of the ... Reactive Oxygen Species Signaling in Response to Pathogens Message Subject (Your Name) has sent you a message from Plant ... Reactive Oxygen Species Signaling in Response to Pathogens. Miguel Angel Torres, Jonathan D.G. Jones, Jeffery L. Dangl ... Apel K, Hirt H (2004) Reactive oxygen species: metabolism, oxidative stress, and signal transduction. Annu Rev Plant Biol 55: ...
Many algal species have been shown to not only produce reactive oxygen species under normal conditions but to increase ... The products of this subsequent reduction of molecular oxygen are what are referred to as reactive oxygen species. Thus, the ... All living cells produce reactive oxygen species (ROS) as a byproduct of metabolism. ROS are reduced oxygen intermediates that ... Reactive oxygen species in natural waters". In Christopher S. Foote. Active oxygen in chemistry. London: Blackie Acad. & ...
Reactive oxygen species (ROSs) are oxidants produced in both health and disease by various processes, for example, from the ... Nader-Djalal N, Knight PR III, Thusu K, et al: Reactive oxygen species contribute to oxygen related lung injury after acid ... Reactive Oxygen Species Nitric Oxide Acute Lung Injury Acute Respiratory Distress Syndrome Xanthine Oxidase These keywords were ... Reactive oxygen species (ROSs) are oxidants produced in both health and disease by various processes, for example, from the ...
Reactive oxygen species are indispensable in ovulation. Ketty Shkolnik, Ari Tadmor, Shifra Ben-Dor, Nava Nevo, Dalia Galiani, ... Reactive oxygen species are indispensable in ovulation. Ketty Shkolnik, Ari Tadmor, Shifra Ben-Dor, Nava Nevo, Dalia Galiani, ... Reactive oxygen species are indispensable in ovulation. Ketty Shkolnik, Ari Tadmor, Shifra Ben-Dor, Nava Nevo, Dalia Galiani, ... 1986) Reactive oxygen species: Production and role in the kidney. Am J Physiol 251:F765-F776. ...
Reactive oxygen species generation and disposal in the mitochondria. Primary sources of ROS occur from the transfer of ... Signal transduction by reactive oxygen species.. Finkel T1.. Author information. 1. Center for Molecular Medicine, National ... Although historically viewed as purely harmful, recent evidence suggests that reactive oxygen species (ROS) function as ... Cysteine biochemistry allows for redox-dependent signaling. Specific reactive cysteine (Cys) residues within target proteins ...
T cell apoptosis and reactive oxygen species. David A. Hildeman,1 Thomas Mitchell,2 John Kappler,3,4,5,6 and Philippa Marrack3, ... Reactive oxygen species regulate activation-induced T cell apoptosis. Immunity. 1999. 10:735-744. View this article via: PubMed ... Tumor necrosis factor and reactive oxygen species cooperative cytotoxicity is mediated via inhibition of NF-kappaB. Mol. Med. ... Increased formation of reactive oxygen species due to glucose depletion in primary cultures of rat thymocytes inhibits ...
The reduction of oxygen to water proceeds via one electron at a time. In the mitochondrial respiratory chain, Complex IV ( ... Mitochondrial formation of reactive oxygen species J Physiol. 2003 Oct 15;552(Pt 2):335-44. doi: 10.1113/jphysiol.2003.049478. ... it is a precursor of most other reactive oxygen species, and it also becomes involved in the propagation of oxidative chain ... This review describes the main mitochondrial sources of reactive species and the antioxidant defences that evolved to prevent ...
Play media Reactive oxygen species (ROS) are chemically reactive chemical species containing oxygen. Examples include peroxides ... "Upsides and downsides of reactive oxygen species for cancer: the roles of reactive oxygen species in tumorigenesis, prevention ... Oxidative stress Oxygen toxicity Polyphenol antioxidants Pro-oxidant Reactive nitrogen species Reactive oxygen species ... The reduction of molecular oxygen (O2) produces superoxide (•O− 2) and is the precursor of most other reactive oxygen species: ...
... Lun Zhang,1 Jiahui Li,1 Liang Zong,1 Xin Chen,1 Ke Chen,1 ... Lun Zhang, Jiahui Li, Liang Zong, et al., "Reactive Oxygen Species and Targeted Therapy for Pancreatic Cancer," Oxidative ...
... are chemically reactive molecules containing oxygen. There is an on-going debate to the extent that such chemicals are harmful ... Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen. There is an on-going debate to the extent ... Reactive Oxygen Species (ROS) have long been known to be a component of the killing response of immune cells to microbial ... Detoxification of reactive oxygen species is paramount to the survival of all life forms. There are also reports that suggest ...
Reactive oxygen and nitrogen species in the renal ischemia/reperfusion injury.. Rodriguez F1, Bonacasa B, Fenoy FJ, Salom MG. ...
There exist two opposing perspectives regarding reactive oxygen species (ROS) and their roles in angiogenesis and ... Reactive Oxygen Species and Mitochondrial Dynamics: The Yin and Yang of Mitochondrial Dysfunction and Cancer Progression ... Aldosari, S.; Awad, M.; Harrington, E.O.; Sellke, F.W.; Abid, M.R. Subcellular Reactive Oxygen Species (ROS) in Cardiovascular ... "Subcellular Reactive Oxygen Species (ROS) in Cardiovascular Pathophysiology." Antioxidants 7, no. 1: 14. ...
Assays for Reactive Oxygen Species. Reactive oxygen species (ROS) are chemically reactive molecules that contain oxygen. ROS ... A New Luminescent Assay for Detection of Reactive Oxygen Species. Sarah Duellman, John Shultz, Gediminas Vidugiris, and James ... The ROS-Glo™ H2O2 Assay measures changes in the level of reactive oxygen species in cultured mammalian cells. The assay can ... 2012) Reactive oxygen and nitrogen species generation, antioxidant defenses and β-cell function: A critical role for amino ...
However, unaccustomed and/or exhaustive exercise can generate excessive reactive oxygen species (ROS), leading to oxidative ... However, unaccustomed and/or exhaustive exercise can generate excessive reactive oxygen species (ROS), leading to oxidative ... Redox Mechanism of Reactive Oxygen Species in Exercise. Feng He1†, Juan Li2†, Zewen Liu3,4†, Chia-Chen Chuang4,5, Wenge Yang6‡ ... Citation: He F, Li J, Liu Z, Chuang C-C, Yang W and Zuo L (2016) Redox Mechanism of Reactive Oxygen Species in Exercise. Front ...
It can provoke the generation of reactive oxygen species and activate unfolded protein response (UPR) signaling pathways. SAR ... It can provoke the generation of reactive oxygen species and activate unfolded protein response (UPR) signaling pathways. SAR ... Acetylcysteine(N-acetyl-l-cysteine) is a ROS(reactive oxygen species) inhibitor that antagonizes the activity of proteasome ... Acetylcysteine(N-acetyl-l-cysteine) is a ROS(reactive oxygen species) inhibitor that antagonizes the activity of proteasome ...
High levels of reactive oxygen species (ROS) are observed in chronic human diseases such as neurodegeneration, Crohns disease ... Reactive oxygen species promote TNFalpha-induced death and sustained JNK activation by inhibiting MAP kinase phosphatases. Cell ... Mitochondrial reactive oxygen species drive proinflammatory cytokine production. Edwina Naik, Vishva M. Dixit ... Reactive oxygen species activity and lipid peroxidation in Helicobacter pylori associated gastritis: relation to gastric ...
... and singlet oxygen (1O2). Reactive oxygen species possess a huge impact influencing the cellular function which at lower ... Reactive oxygen species has short life-time due to its high reactivity and thus its detection has always been a challenge. ... system such as respiration and oxidative burst are known to be associated with the generation of reactive oxygen species (ROS ... Different techniques have been applied for detection and quantification of varied ROS and their reactive intermediates during ...
... in the oxygen evolution reaction (OER) in comparison with their crystalline counterpart, rutile-type IrO2, by focusing on the ... Reactive oxygen species in iridium-based OER catalysts V. Pfeifer, T. E. Jones, S. Wrabetz, C. Massué, J. J. Velasco Vélez, R. ... of this reactive species is not solely a property of the metal but is intimately tied to the electronic structure of oxygen. We ... As such, we expect this species to play the critical role of the electrophilic oxygen involved in O-O bond formation in the ...
Oxygen and reactive oxygen species in cartilage degradation: friends or foes? Osteoarthritis Cartilage. 13:643-654. ... Reactive oxygen species induce chondrocyte hypertrophy in endochondral ossification. Kozo Morita, Takeshi Miyamoto, Nobuyuki ... The role of reactive oxygen species in homeostasis and degradation of cartilage. Osteoarthritis Cartilage. 11:747-755. ... Reactive oxygen species induce chondrocyte hypertrophy in endochondral ossification. Kozo Morita, Takeshi Miyamoto, Nobuyuki ...
... Yang Sun,1,2 Sachiko Ito,1 ... Beyond that, acrolein can cause oxidative stress and generate reactive oxygen species (ROS) [8]. Although the mechanisms are ... showed that acrolein produced reactive oxygen species (ROS) in mast cells [7]. ... developing the pulmonary damage with inflammation and increase of reactive oxygen species (ROS). Conversely, the integrality of ...
... such as those related to reactive oxygen species (ROS), have been implicated in various retinal and optic nerve disorders. Many ... Oxidative injuries, such as those related to reactive oxygen species (ROS), have been implicated in various retinal and optic ...
Keywords: Mycobacterium tuberculosis, reactive oxygen species, reactive nitrogen species, microarray, nitric oxide, hydrogen ... The response of Mycobacterium tuberculosis to reactive oxygen and nitrogen species. Martin I. Voskuil1,2,3*, Iona L. Bartek1, ... Macrophages produce antimicrobial reactive oxygen and nitrogen species (ROS and RNS) via NADPH oxidase (NOX2/gp91phox) and ... The response of Mycobacterium tuberculosis to reactive oxygen and nitrogen species. Front. Microbio. 2:105. doi: 10.3389/fmicb. ...
These findings indicate that isoalantolactone induces reactive oxygen species-dependent apoptosis in prostate cancer cells via ... that the apoptosis-inducing effect of isoalantolactone in prostate cancer cells is mediated by reactive oxygen species. ... reactive oxygen species prostate cancer; isoalantolactone; apoptosis; reactive oxygen species ... Reactive Oxygen Species Mediate Isoalantolactone-Induced Apoptosis in Human Prostate Cancer Cells. Azhar Rasul 1,2,†, Jun Di 3 ...
It not only possesses reactive oxygen species (ROS) catalytic ability in aqueous solution, by synergizing the Cu clusters with ... It not only possesses reactive oxygen species (ROS) catalytic ability in aqueous solution, by synergizing the Cu clusters with ... A binuclear copper-substituted phosphomolybdate with reactive oxygen species catalytic ability and antimicrobial activity ... A binuclear copper-substituted phosphomolybdate with reactive oxygen species catalytic ability and antimicrobial activity X. Ma ...
... singlet oxygen, ozone, and nitrogen monoxide and dioxide free radicals, is an area of intense research. This volume covers (1) ... Reactive oxygen species (ROS) which include free radicals, peroxides, ... Reactive oxygen species (ROS) which include free radicals, peroxides, singlet oxygen, ozone, and nitrogen monoxide and dioxide ...
Reactive oxygen species (ROSs) play important physiological and physiopathological roles in the cardiovascular system. An ... Reactive Oxygen Species at High Altitude (Hypobaric Hypoxia) on the Cardiovascular System, Reactive Oxygen Species (ROS) in ... Reactive Oxygen Species at High Altitude (Hypobaric Hypoxia) on the Cardiovascular System, Reactive Oxygen Species (ROS) in ... In the cardiovascular system, reactive oxygen species (ROSs) and reactive nitrogen species (RNSs) play important physiological ...
Discovered only within the last fifty years, reactive oxygen species (ROS) are oxygen derived free radicals found in both intra ... The Plasmalemmal Na/K-ATPase: An Amplifier for Reactive Oxygen Species? Kyle D Maxwell, Preeya T Shah and Joseph I Shapiro* ... 1999) Intracellular reactive oxygen species mediate the linkage of Na+/K+-ATPase to hypertrophy and its marker genes in cardiac ... Liu J, Kennedy DJ, Yan Y, Shapiro JI (2012) Reactive Oxygen Species Modulation of Na/K-ATPase Regulates Fibrosis and Renal ...
2006) Oxygen sensing by mitochondria at complex III: the paradox of increased reactive oxygen species during hypoxia. Exp. ... 2007) Response of mitochondrial reactive oxygen species generation to steady-state oxygen tension: implications for hypoxic ... How mitochondria produce reactive oxygen species. Michael P. Murphy. Biochemical Journal Jan 01, 2009, 417 (1) 1-13; DOI: ... 1998) Mitochondrial reactive oxygen species trigger hypoxia-induced transcription. Proc. Natl. Acad. Sci. U.S.A. 95:11715-11720 ...
... caesia on reactive oxygen species (ROS) and reactive nitrogen species (RNS) and it showed significant activity in a dose ... containing oxygen, known as reactive oxygen species (ROS), are the most biologically significant free radicals. ROS include the ... Curcuma caesia, antioxidants, reactive oxygen species, total phenols. Free radicals, which are molecules with unpaired ... Scavenging activity of Curcuma caesia rhizome against reactive oxygen and nitrogen species. Orient Pharm Exp Med 2011;11:221-8. ...
2004) Involvement of reactive oxygen species in Toll-like receptor 4-dependent activation of NF-kappa B. J Immunol 172:2522- ... Reactive oxygen species-independent activation of the IL-1β inflammasome in cells from patients with chronic granulomatous ... Reactive oxygen species-independent activation of the IL-1β inflammasome in cells from patients with chronic granulomatous ... Reactive oxygen species-independent activation of the IL-1β inflammasome in cells from patients with chronic granulomatous ...
Modulation of the response to cisplatin by nitric oxide and reactive oxygen species in melanoma cells. Author(s). Anderson, ... Because inflammatory products such as NO and reactive oxygen species (ROS) are associated with the genesis and evolution of ... Altogether, our findings illustrate the complexity of the regulation of signaling components by oxidative species of distinct ... cancer, we hypothesized that these oxidative species may regulate key components of the response of melanoma to cisplatin. ...
  • Traditionally, reactive oxygen species (ROS) have been regarded as toxic by-products of aerobic metabolism. (bl.uk)
  • Reactive oxygen species, or ROS, are produced by the body as a byproduct of metabolism. (scienmag.com)
  • These extracellular highly reactive oxygen species (ROS) cause many biological effects such as destruction of bacterial cells, parasites and tumor cells, promoting inflammation and modulating the immune reaction (Fig. 1). (bmglabtech.com)
  • During this process, oxygen is converted into superoxide anions, hydrogen peroxide, monomolecular oxygen and hydroxyl c radicals by means of several kinds of phagocytic cells (e.g. neutrophil, eosinophil and basophil leucocytes, macrophages). (bmglabtech.com)
  • In addition, oxidant-induced damage to DNA, 17β-estradiol-generated ROS can induce lipid peroxidation and oxygen radical-mediated oxidation of amino acid residues of proteins to carbonyl-containing moieties ( 9 ). (intjcancermanag.com)
  • Enhanced levels of reactive oxygen species occur during atherogenesis and foster progression of vascular inflammation. (nih.gov)
  • The role of mitochondrial reactive oxygen species in pH regulation in articular chondrocytes. (ox.ac.uk)
  • OBJECTIVE: To examine the effect of O(2) and the role, and source, of reactive oxygen species (ROS) on pH regulation in articular chondrocytes. (ox.ac.uk)
  • This production of mitochondrial reactive oxygen species (mROS)-transient because H 2 O 2 -inactivating enzymes rapidly quench it before a damage to the physiological conditions of the cell occurs-is now recognized as an intracellular messenger ( 3 , 4 ). (diabetesjournals.org)
  • The aim of this study was to determine the relationship between proliferation inhibition and the production of reactive oxygen species (ROS) induced by Licochalcone A (LCA). (iospress.com)
  • One of the consequences associated to mitochondrial dysfunction is the production of reactive oxygen species (ROS). (figshare.com)
  • These parameters estimate mitochondrial respiration, reactive oxygen species (ROS) production, and deoxyribonucleotide (dNTP) balance in PBMCs. (au.dk)
  • Lysophosphatidylcholine (lysoPC) evokes diverse biological responses in vascular cells including Ca 2+ mobilization, production of reactive oxygen species, and activation of the mitogen-activated protein kinases, but the mechanisms linking these events remain unclear. (elsevier.com)
  • The researchers found that Ciprofloxacin had an immunosuppresive effect on T-cells, inhibited the production of ROS (Reactive Oxygen Species) and were anti-inflammatory. (floxiehope.com)
  • Taken together, these data suggest a role for mitochondrially generated reactive oxygen species and Ca 2+ to the redox cell signaling pathways, leading to ERK activation and adaptation of the pathological stress mediated by oxidized lipids such as lysoPC. (elsevier.com)
  • NADPH is needed to reduce the oxygen which is bonded to membrane-based cytochromes. (bmglabtech.com)
  • Generation of reactive oxygen species in murine macrophages.To assess the influence of mono-MP on the generation of intracellular oxidative stress in macrophages, C2′,7′-dichlorodihydrofluorescin-diacetate experiments were performed. (nih.gov)
  • These compounds inhibit the enzyme Nox2, part of a family of enzymes responsible for producing reactive oxygen species (ROS). (eurekalert.org)
  • Studies on the mitochondrial generation of reactive oxygen species (ROS) generally focus on chronic nutrient exposure. (diabetesjournals.org)
  • The neutrophil senses a dramatic increase in reactive oxygen species as it gets closer to the wound site, and this triggers the shutdown of the migration of the cell,' said Jingsong Xu, assistant professor of pharmacology in the UIC College of Medicine and corresponding author on the paper. (scienmag.com)
  • Since superoxide is also moderately reactive towards trace metals and dissolved organic matter, any remaining superoxide is thought to be removed from the water column through reactions with these species. (wikipedia.org)
  • All living cells produce reactive oxygen species (ROS) as a byproduct of metabolism. (wikipedia.org)
  • 2 Although the actual cause of this endothelial damage is not well-known, neutrophils, through their ability to produce reactive oxygen species (ROS), have been implicated as likely candidates. (ahajournals.org)
  • Recent studies have revealed that vascular cells can produce reactive oxygen species (ROS) through NAD(P)H oxidase, which may be involved in vascular injury. (diabetesjournals.org)
  • However, numerous methods of slowing aging in short-lived animals involve increases in the rate at which mitochondria produce reactive oxygen species. (fightaging.org)
  • Our work highlights the need to take a nuanced view of the role of reactive oxygen species, as they are necessary when they are present at the right place and right time. (eurekalert.org)
  • Testing the predictions of the Mitochondrial Free Radical Theory of Ageing (MFRTA) has provided a deep understanding of the role of reactive oxygen species (ROS) and mitochondria in the ageing process. (fightaging.org)
  • Role of reactive oxygen species in cell signalling pathways. (syromonoed.com)
  • To investigate the role of reactive oxygen species (ROS) and its mechanism on cytotoxicity of moxifloxacin and benzalkonium chloride (BAK) on human corneal epithelial cells (HCECs). (arvojournals.org)
  • NSAIDs have been shown to induce reactive oxygen species (ROS) in different cell types including cardiac and cardiovascular related cells. (hindawi.com)
  • ZnO NPs was found to induce reactive oxygen species (ROS) generation, oxidative stress and activities of caspase-3 & caspase-9 in a dose- and time dependent manner. (omicsonline.org)
  • Recent observations demonstrate that BRAF inhibitors induce reactive oxygen species (ROS) in melanoma cells. (jcancer.org)
  • as well as the non-radical species hydrogen peroxide (H2O2). (wikipedia.org)
  • Superoxide dismutases (SOD) are a class of enzymes that catalyze the dismutation of superoxide into oxygen and hydrogen peroxide. (wikipedia.org)
  • In animals, reactive oxygen species (ROS), such as hydrogen peroxide (H 2 O 2 ), superoxide ion, and nitric oxide (NO) are well-recognized triggers of cell death ( Jabs, 1999 ). (plantphysiol.org)
  • Methods and Results -We examined both the effects of lysophosphatidylcholine (LPC) and hydrogen peroxide (H 2 O 2 ), a donor of reactive oxygen species, as major components of moxLDL and their interactions with 5HT on VSMC proliferation. (ahajournals.org)
  • Hydrogen gas (H 2 ) has potential as eliminating highly reactive ROS. (ersjournals.com)
  • Accumulating evidence suggests that AngII stimulates intracellular formation of reactive oxygen species (ROS) such as the superoxide anion and hydrogen peroxide. (asnjournals.org)
  • Good" ROS being low reactivity ROS (i.e. superoxide or hydrogen peroxide) produced at specific places, at specific times and in moderate amounts and "Bad" ROS being highly reactive ROS (or low reactive ROS as hydrogen peroxide or superoxide produced at high concentrations) generated continuously and unspecifically. (fightaging.org)
  • Superoxide and its derivatives such as hydrogen peroxide (H 2 O 2 ) and ·OH, which collectively are referred to as reactive oxygen species (ROS), are released into the phagosome and are essential in the killing of the ingested pathogen ( 39 , 70 ). (asm.org)
  • The pro-inflammatory cytokines negatively impacted the cells' viability, markedly increased reactive oxygen species production, and down-regulated markers specific to BAT such as UCP-1 and β-Klotho. (nexcelom.com)
  • Mitochondria serve as the cell's powerhouse and supply energy for producing force, but this process also makes reactive oxygen species as a by-product. (eurekalert.org)
  • Reactive oxygen species (ROSs) are oxidants produced in both health and disease by various processes, for example, from the phagocytic respiratory burst, during mitochondrial aerobic respiration, and as a by-product of both ischemia and reper-fusion. (springer.com)
  • It is extremely reactive, and it's a great oxidizing agent. (duke.edu)
  • The results of the study suggest that DCA-induced developmental toxic effects in zebrafish embryos are associated with production of reactive oxygen species in those embryos. (nih.gov)
  • NADPH oxidase activity is believed to be essential to microbial host defense for a wide range of pulmonary pathogens, although excessive production of reactive oxygen species may contribute to lung injury. (pubmedcentralcanada.ca)
  • Significance: Excessive production of reactive oxygen species (ROS) has been linked to neurodegenerative diseases (NDs), and therefore, many scientific works were published on the impact of ROS on the development of prevalent NDs, such as Alzheimer's (AD) and Parkinson's disease (PD). (thisisms.com)
  • Sepsis and endotoxemia induce the production of reactive oxygen species (ROS). (asahq.org)
  • Baicalein could prevent lysoPC-induced cell death, production of reactive oxygen species (ROS), and increase of intracellular calcium concentration in H9c2 cardiomyoctes. (biomedcentral.com)
  • Reactive oxygen species (ROSs) play important physiological and physiopathological roles in the cardiovascular system. (intechopen.com)
  • The buried active site minimizes, but does not completely prevent, such a side reaction pathway, allowing some reactive oxygen species (ROS) to be produced under physiological conditions ( 10 , 11 ). (sciencemag.org)
  • This compilation opens with a comprehensive review of heavy metals involves the unifying theme of electron transfer (ET), reactive oxygen species (ROS) and oxidative stress (OS) applied to toxicity, which often arises from pollution. (novapublishers.com)
  • Aim] The pulmonary toxicity of high concentration of oxygen during mechanical ventilation relates to reactive oxygen species (ROS). (ersjournals.com)
  • Effects of vitamin E on reactive oxygen species-mediated 2,3,7,8-tetrachlorodi-benzo-p-dioxin toxicity in rat testis. (biomedsearch.com)
  • Infection with this bacterium leads to induction of oxidative stress and an increased level of reactive oxygen species in its mosquito host. (pnas.org)
  • Specific reactive cysteine (Cys) residues within target proteins can be covalently modified by oxidative stress. (nih.gov)
  • The viral core and nonstructural protein 3 proteins were shown to be responsible for the inhibition of DNA repair, mediated by NO and reactive oxygen species. (jimmunol.org)
  • The effect of arsenic is largely achieved through both direct binding of arsenic to proteins and induction of reactive oxygen species (ROS) during the oxidation-reduction reaction of the trivalent arsenic and pentavalent arsenic compounds. (aacrjournals.org)
  • The effects of oxidized dextrans of different molecular weight on reactive oxygen species production and transmembrane mitochondrial potential of macrophages and neutrophils have been studied in vivo and in vitro. (sigmaaldrich.com)
  • Decreased NADPH oxidase-dependent reactive oxygen species production is well tolerated and improves disease outcome during pneumococcal pneumonia by removing neutrophils from the tight constraints of reactive oxygen species-mediated regulation. (pubmedcentralcanada.ca)
  • Neutrophils kill microorganisms, using both reactive oxygen species (ROS) and granule-associated proteases ( 7 , 8 ). (pubmedcentralcanada.ca)
  • Extra- and intracellular formation of reactive oxygen species by human neutrophils in the presence of pheniramine, chlorpheniramine and brompheniramine. (nel.edu)
  • Jancinová I, Drábiková A, Nosál' A, Holománová A, Extra- and intracellular formation of reactive oxygen species by human neutrophils in the presence of pheniramine, chlorpheniramine and brompheniramine. (nel.edu)
  • We observed LPS induced oxygen bursts in macrophages by confocal microscopic analysis and fluorometer measurement over a time scale of several hours,' says Lee. (nanowerk.com)
  • Oxidation of these specific and reactive cysteine residues in turn can lead to the reversible modification of enzymatic activity. (nih.gov)
  • Tremendous effort has been devoted towards elucidating the fundamental reasons for the higher activity of hydrated amorphous Ir III/IV oxyhydroxides (IrO x ) in the oxygen evolution reaction (OER) in comparison with their crystalline counterpart, rutile-type IrO 2 , by focusing on the metal oxidation state. (rsc.org)
  • We propose that the dynamic nature of the Ir framework in amorphous IrO x imparts the flexibility in Ir oxidation state required for the formation of this active electrophilic oxygen. (rsc.org)
  • Photosystem II (PSII), a unique membrane-bound oxidoreductase, catalyzes light-driven oxidation of water to molecular oxygen. (sciencemag.org)
  • 2 It is also known that the oxidation of LDL ultimately leads to the generation of reactive oxygen species (ROS) and the conversion of phosphatidylcholine (PC) to lysophosphatidylcholine (LPC). (ahajournals.org)
  • The cytoplasmic reactive oxygen species were mostly found in mitochondria, while extracellular ones were localized in aperture zones of intine, as well as in the solution surrounding pollen grains in vitro. (deepdyve.com)
  • The content of extracellular reactive oxygen species decreased after superoxide dismutase (100 units per ml) and diphenylene iodonium (100 µM), which indicates NADPH oxidase as one of possible producent of them. (deepdyve.com)
  • In conditions of suppression of extracellular reactive oxygen species production (100 µM diphenilene iodonium) or their promoted removal (after addition of 10 to 100 µM ascorbic acid), the number of germinating pollen grains increased. (deepdyve.com)
  • The result is evidence of the significance of processes of generation/removal of extracellular reactive oxygen species for pollen germination. (deepdyve.com)
  • The mechanism of farnesol (FOH)-induced growth inhibition of Saccharomyces cerevisiae was studied in terms of its promotive effect on generation of reactive oxygen species (ROS). (asm.org)
  • These findings indicate that p90RSK activation is critical for reactive oxygen species-mediated inhibition of voltage-gated K + channel activity and leads to prolongation of cardiac repolarization. (ahajournals.org)
  • The aim of this study was to investigate the role of neutrophil-derived reactive oxygen species on endothelial cell dysfunction in preeclampsia. (ahajournals.org)
  • The purpose of this study was to investigate the occurrence of reactive oxygen species and peroxynitrite in the vestibular organ of the guinea pig following inoculation with bacterial lipopolysaccharide (LPS). (diva-portal.org)
  • On the basis of these data, it can be concluded that NO together with O-2, which form more reactive peroxynitrite, may be the most important pathogenic agents in LPS-induced labyrinthitis in the guinea pig. (diva-portal.org)
  • Many diseases and pathological conditions, including ischemia/reperfusion (I/R) injury, are the consequence of the actions of reactive oxygen species (ROS). (aspetjournals.org)
  • It is an efficient electron transfer catalyst from a number of organic substrates to molecular oxygen (O2), constructing quinoprotein model reactions. (selleckchem.com)
  • Our experiments show that administration of broad-range scavengers of oxidative species into the ovarian bursa of mice, hormonally induced to ovulate, significantly reduced the rate of ovulation. (pnas.org)
  • Because inflammatory products such as NO and reactive oxygen species (ROS) are associated with the genesis and evolution of cancer, we hypothesized that these oxidative species may regulate key components of the response of melanoma to cisplatin. (mit.edu)
  • Altogether, our findings illustrate the complexity of the regulation of signaling components by oxidative species of distinct natures. (mit.edu)