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
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
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
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
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.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
A synthetic amino acid that depletes glutathione by irreversibly inhibiting gamma-glutamylcysteine synthetase. Inhibition of this enzyme is a critical step in glutathione biosynthesis. It has been shown to inhibit the proliferative response in human T-lymphocytes and inhibit macrophage activation. (J Biol Chem 1995;270(33):1945-7)
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.
A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.
Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Organic compounds containing a carbonyl group in the form -CHO.
An antibiotic substance produced by Streptomyces species. It inhibits mitochondrial respiration and may deplete cellular levels of ATP. Antimycin A1 has been used as a fungicide, insecticide, and miticide. (From Merck Index, 12th ed)
A potent oxidant synthesized by the cell during its normal metabolism. Peroxynitrite is formed from the reaction of two free radicals, NITRIC OXIDE and the superoxide anion (SUPEROXIDES).
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
The segregation and degradation of damaged or unwanted cytoplasmic constituents by autophagic vacuoles (cytolysosomes) composed of LYSOSOMES containing cellular components in the process of digestion; it plays an important role in BIOLOGICAL METAMORPHOSIS of amphibians, in the removal of bone by osteoclasts, and in the degradation of normal cell components in nutritional deficiency states.
A non-selective post-emergence, translocated herbicide. According to the Seventh Annual Report on Carcinogens (PB95-109781, 1994) this substance may reasonably be anticipated to be a carcinogen. (From Merck Index, 12th ed) It is an irreversible inhibitor of CATALASE, and thus impairs activity of peroxisomes.
Adverse functional, metabolic, or structural changes in ischemic tissues resulting from the restoration of blood flow to the tissue (REPERFUSION), including swelling; HEMORRHAGE; NECROSIS; and damage from FREE RADICALS. The most common instance is MYOCARDIAL REPERFUSION INJURY.
Catalyzes the oxidation of GLUTATHIONE to GLUTATHIONE DISULFIDE in the presence of NADP+. Deficiency in the enzyme is associated with HEMOLYTIC ANEMIA. Formerly listed as EC
A superfamily of PROTEIN-SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).
Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.
A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.
A flavoprotein oxidase complex that contains iron-sulfur centers. It catalyzes the oxidation of SUCCINATE to fumarate and couples the reaction to the reduction of UBIQUINONE to ubiquinol.
A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.
An abnormal increase in the amount of oxygen in the tissues and organs.
A complex of enzymes and PROTON PUMPS located on the inner membrane of the MITOCHONDRIA and in bacterial membranes. The protein complex provides energy in the form of an electrochemical gradient, which may be used by either MITOCHONDRIAL PROTON-TRANSLOCATING ATPASES or BACTERIAL PROTON-TRANSLOCATING ATPASES.
Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.
A negative 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.
A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)
5-Amino-2,3-dihydro-1,4-phthalazinedione. Substance that emits light on oxidation. It is used in chemical determinations.
Compounds containing the -SH radical.
The pathological process occurring in cells that are dying from irreparable injuries. It is caused by the progressive, uncontrolled action of degradative ENZYMES, leading to MITOCHONDRIAL SWELLING, nuclear flocculation, and cell lysis. It is distinct it from APOPTOSIS, which is a normal, regulated cellular process.
The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)
A subgroup of mitogen-activated protein kinases that activate TRANSCRIPTION FACTOR AP-1 via the phosphorylation of C-JUN PROTEINS. They are components of intracellular signaling pathways that regulate CELL PROLIFERATION; APOPTOSIS; and CELL DIFFERENTIATION.
Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.
The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.
A member of the Bcl-2 protein family and homologous partner of C-BCL-2 PROTO-ONCOGENE PROTEIN. It regulates the release of CYTOCHROME C and APOPTOSIS INDUCING FACTOR from the MITOCHONDRIA. Several isoforms of BCL2-associated X protein occur due to ALTERNATIVE SPLICING of the mRNA for this protein.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
A multisubunit enzyme complex that contains CYTOCHROME B GROUP; CYTOCHROME C1; and iron-sulfur centers. It catalyzes the oxidation of ubiquinol to UBIQUINONE, and transfers the electrons to CYTOCHROME C. In MITOCHONDRIA the redox reaction is coupled to the transport of PROTONS across the inner mitochondrial membrane.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
The nonstriated involuntary muscle tissue of blood vessels.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
A hemeprotein from leukocytes. Deficiency of this enzyme leads to a hereditary disorder coupled with disseminated moniliasis. It catalyzes the conversion of a donor and peroxide to an oxidized donor and water. EC
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
Benzopyrans saturated in the 2 and 3 positions.
Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)
The decrease in the cell's ability to proliferate with the passing of time. Each cell is programmed for a certain number of cell divisions and at the end of that time proliferation halts. The cell enters a quiescent state after which it experiences CELL DEATH via the process of APOPTOSIS.
Cells that line the inner and outer surfaces of the body by forming cellular layers (EPITHELIUM) or masses. Epithelial cells lining the SKIN; the MOUTH; the NOSE; and the ANAL CANAL derive from ectoderm; those lining the RESPIRATORY SYSTEM and the DIGESTIVE SYSTEM derive from endoderm; others (CARDIOVASCULAR SYSTEM and LYMPHATIC SYSTEM) derive from mesoderm. Epithelial cells can be classified mainly by cell shape and function into squamous, glandular and transitional epithelial cells.
A mitogen-activated protein kinase subfamily that is widely expressed and plays a role in regulation of MEIOSIS; MITOSIS; and post mitotic functions in differentiated cells. The extracellular signal regulated MAP kinases are regulated by a broad variety of CELL SURFACE RECEPTORS and can be activated by certain CARCINOGENS.
Proteins involved in the transport of specific substances across the membranes of the MITOCHONDRIA.
Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.
Naphthalene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.
The area within CELLS.
A promyelocytic cell line derived from a patient with ACUTE PROMYELOCYTIC LEUKEMIA. HL-60 cells lack specific markers for LYMPHOID CELLS but express surface receptors for FC FRAGMENTS and COMPLEMENT SYSTEM PROTEINS. They also exhibit phagocytic activity and responsiveness to chemotactic stimuli. (From Hay et al., American Type Culture Collection, 7th ed, pp127-8)
Peroxidases that utilize ASCORBIC ACID as an electron donor to reduce HYDROGEN PEROXIDE to WATER. The reaction results in the production of monodehydroascorbic acid and DEHYDROASCORBIC ACID.
Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.
Substances that inhibit or prevent the proliferation of NEOPLASMS.
An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.
A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.
A CALCIUM-dependent, constitutively-expressed form of nitric oxide synthase found primarily in ENDOTHELIAL CELLS.
A lipid-soluble benzoquinone which is involved in ELECTRON TRANSPORT in mitochondrial preparations. The compound occurs in the majority of aerobic organisms, from bacteria to higher plants and animals.
A generic descriptor for all TOCOPHEROLS and TOCOTRIENOLS that exhibit ALPHA-TOCOPHEROL activity. By virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus, these compounds exhibit varying degree of antioxidant activity, depending on the site and number of methyl groups and the type of ISOPRENOIDS.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
Peroxides produced in the presence of a free radical by the oxidation of unsaturated fatty acids in the cell in the presence of molecular oxygen. The formation of lipid peroxides results in the destruction of the original lipid leading to the loss of integrity of the membranes. They therefore cause a variety of toxic effects in vivo and their formation is considered a pathological process in biological systems. Their formation can be inhibited by antioxidants, such as vitamin E, structural separation or low oxygen tension.
The therapeutic intermittent administration of oxygen in a chamber at greater than sea-level atmospheric pressures (three atmospheres). It is considered effective treatment for air and gas embolisms, smoke inhalation, acute carbon monoxide poisoning, caisson disease, clostridial gangrene, etc. (From Segen, Dictionary of Modern Medicine, 1992). The list of treatment modalities includes stroke.
A photographic fixative used also in the manufacture of resins. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), this substance may reasonably be anticipated to be a carcinogen (Merck Index, 9th ed). Many of its derivatives are ANTITHYROID AGENTS and/or FREE RADICAL SCAVENGERS.
The process in which the neutrophil is stimulated by diverse substances, resulting in degranulation and/or generation of reactive oxygen products, and culminating in the destruction of invading pathogens. The stimulatory substances, including opsonized particles, immune complexes, and chemotactic factors, bind to specific cell-surface receptors on the neutrophil.
A protein-serine-threonine kinase that is activated by PHOSPHORYLATION in response to GROWTH FACTORS or INSULIN. It plays a major role in cell metabolism, growth, and survival as a core component of SIGNAL TRANSDUCTION. Three isoforms have been described in mammalian cells.
Organic compounds which contain selenium as an integral part of the molecule.
Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.
That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.
Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Inorganic oxides that contain nitrogen.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
An intracellular signaling system involving the MAP kinase cascades (three-membered protein kinase cascades). Various upstream activators, which act in response to extracellular stimuli, trigger the cascades by activating the first member of a cascade, MAP KINASE KINASE KINASES; (MAPKKKs). Activated MAPKKKs phosphorylate MITOGEN-ACTIVATED PROTEIN KINASE KINASES which in turn phosphorylate the MITOGEN-ACTIVATED PROTEIN KINASES; (MAPKs). The MAPKs then act on various downstream targets to affect gene expression. In mammals, there are several distinct MAP kinase pathways including the ERK (extracellular signal-regulated kinase) pathway, the SAPK/JNK (stress-activated protein kinase/c-jun kinase) pathway, and the p38 kinase pathway. There is some sharing of components among the pathways depending on which stimulus originates activation of the cascade.
The processes whereby the internal environment of an organism tends to remain balanced and stable.
A genotoxicological technique for measuring DNA damage in an individual cell using single-cell gel electrophoresis. Cell DNA fragments assume a "comet with tail" formation on electrophoresis and are detected with an image analysis system. Alkaline assay conditions facilitate sensitive detection of single-strand damage.
An oxyacid of chlorine (HClO) containing monovalent chlorine that acts as an oxidizing or reducing agent.
Glycoproteins found on the membrane or surface of cells.
The rate dynamics in chemical or physical systems.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
Enzymes that catalyze the transfer of multiple ADP-RIBOSE groups from nicotinamide-adenine dinucleotide (NAD) onto protein targets, thus building up a linear or branched homopolymer of repeating ADP-ribose units i.e., POLY ADENOSINE DIPHOSPHATE RIBOSE.
The main trunk of the systemic arteries.
Carbamates in which the -CO- group has been replaced by a -CS- group.
A trypanocidal agent and possible antiviral agent that is widely used in experimental cell biology and biochemistry. Ethidium has several experimentally useful properties including binding to nucleic acids, noncompetitive inhibition of nicotinic acetylcholine receptors, and fluorescence among others. It is most commonly used as the bromide.
The chemical reactions involved in the production and utilization of various forms of energy in cells.
A peroxiredoxin that is a cytosolic bifunctional enzyme. It functions as a peroxiredoxin via a single redox-active cysteine and also contains a Ca2+-independent acidic phospholipase A2 activity.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A technique for detecting short-lived reactive FREE RADICALS in biological systems by providing a nitrone or nitrose compound for an addition reaction to occur which produces an ELECTRON SPIN RESONANCE SPECTROSCOPY-detectable aminoxyl radical. In spin trapping, the compound trapping the radical is called the spin trap and the addition product of the radical is identified as the spin adduct. (Free Rad Res Comm 1990;9(3-6):163)
A mixed function oxidase enzyme which during hemoglobin catabolism catalyzes the degradation of heme to ferrous iron, carbon monoxide and biliverdin in the presence of molecular oxygen and reduced NADPH. The enzyme is induced by metals, particularly cobalt. EC
Binary compounds of oxygen containing the anion O(2-). The anion combines with metals to form alkaline oxides and non-metals to form acidic oxides.
Therapy using oral or topical photosensitizing agents with subsequent exposure to light.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.

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.. ...
Iron metabolism disorder is closely associated with several malignant tumors, however the mechanisms underlying iron and the carcinogenesis in osteosarcoma are not yet well understood. Cell proliferation ability of osteosarcoma cell lines was measured by CCK-8, EdU incorporation and colony formation assays. Cell cycle analysis was detected by flow cytometry. The carcinogenesis of osteosarcoma was measured by soft-agar formation, trans-well and Wound healing-scratch assay. Warburg effect was detected by Seahorse respirometry assays. Reactive oxygen species (ROS) level was measured by Dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probes. Western blotting was used to measure the expression of mitoferrin 1 (SLC25A37) and mitoferrin 2 (SLC25A28). Iron level in vitro and vivo was detected by iron assay kit. RNAi stable cell lines was generated using shRNA. Iron promoted proliferation, carcinogenesis and Warburg effect of osteosarcoma cells. Iron-induced reactive oxygen species (ROS) played an
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) ...
TY - JOUR. T1 - Regulatory mechanisms of nitric oxide and reactive oxygen species generation and their role in plant immunity. AU - Yoshioka, Hirofumi. AU - Mase, Keisuke. AU - Yoshioka, Miki. AU - Kobayashi, Michie. AU - Asai, Shuta. PY - 2011/8/1. Y1 - 2011/8/1. N2 - Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in diverse physiological processes, such as programmed cell death, development, cell elongation and hormonal signaling, in plants. Much attention has been paid to the regulation of plant innate immunity by these signal molecules. Recent studies provide evidence that an NADPH oxidase, respiratory burst oxidase homolog, is responsible for pathogen-responsive ROS burst. However, we still do not know about NO-producing enzymes, except for nitrate reductase, although many studies suggest the existence of NO synthase-like activity responsible for NO burst in plants. Here, we introduce regulatory mechanisms of NO and ROS bursts by ...
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 ...
TY - JOUR. T1 - Resveratrol prevents high fluence red light-emitting diode reactive oxygen species-mediated photoinhibition of human skin fibroblast migration. AU - Mamalis, Andrew. AU - Koo, Eugene. AU - Isseroff, Roslyn Rivkah. AU - Murphy, William J. AU - Jagdeo, Jared. PY - 2015/10/21. Y1 - 2015/10/21. N2 - Background: Skin fibrosis is a significant medical problem that leads to a functional, aesthetic, and psychosocial impact on quality-of-life. Light-emitting diode-generated 633-nm red light (LED-RL) is part of the visible light spectrum that is not known to cause DNA damage and is considered a safe, non-invasive, inexpensive, and portable potential alternative to ultraviolet phototherapy that may change the treatment paradigm of fibrotic skin disease. Objective: The goal of our study was to investigate the how reactive oxygen species (ROS) free radicals generated by high fluence LED-RL inhibit the migration of skin fibroblasts, the main cell type involved in skin fibrosis. Fibroblast ...
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 ...
Lung cells experience hypoxia during development, during travel to high altitude, and in acute and chronic lung diseases. The functional responses evoked by hypoxia are diverse and generally act to protect the cells from hypoxic injury, although some lung cell responses are counterproductive because they degrade normal function of the organ. The cellular O(2) sensor responsible for many of these responses involves the mitochondrial electron transport chain. Under hypoxic conditions, increased release of reactive oxygen species from the inner mitochondrial membrane to the intermembrane space leads to the activation of transcription factors, including hypoxia-inducible factor, activation of hypoxic pulmonary vasoconstriction, activation of AMP-dependent protein kinase, and internalization of the membrane Na,K-ATPase from the basolateral membrane of alveolar epithelial cells. Although the specific targets of reactive oxygen species signals are not fully understood, this signaling pathway is ...
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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 /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!
We investigated the protective effect of octaphlorethol A (OPA) isolated from Ishige foliacea against high-glucose-induced oxidative damage, as indicated by reactive oxygen species (ROS) generation, lipid peroxidation, and cell death, in human umbilical vein endothelial cells (HUVECs) and in a zebrafish model. OPA treatment significantly and dose-dependently decreased ROS generation, lipid peroxidation, and cell death in HUVECs and in a zebrafish model. Our results show that OPA can protect HUVECs and zebrafish against high glucose by suppressing intracellular ROS generation, lipid peroxidation, and cell death. (C) 2014 Elsevier B.V. All rights reserved ...
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 ...
A comparative study was conducted in rat primary cortical (CX) and mesencephalic (MC) neurons to investigate intracellular cascades activated during cyanide-induced injury and to determine the point at which the cascades diverge to produce either apoptosis or necrosis. Cyanide treatment (400 μM) for 24 h produced primarily apoptosis in CX cells, whereas the same concentration of cyanide induced predominantly necrosis in MC cells as indicated by increased propidium iodide staining and cellular lactate dehydrogenase efflux. Cyanide increased generation of cellular reactive oxygen species (ROS) in both CX and MC cells, but the rate of formation and nature of the oxidative species varied with cell type. Catalase decreased cyanide-induced ROS generation in CX but not in MC cells. Nitric oxide generation was more prominent after cyanide treatment of MC compared with CX cells.N-Methyl-d-aspartate receptors were more involved in CX apoptosis than in MC necrosis. Mitochondrial membrane potential ...
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 ...
Biofuels offer a viable alternative to petroleum-based fuel. However, current methods are not sufficient and the technology required in order to use lignocellulosic biomass as a fermentation substrate faces several challenges. One challenge is the need for a robust fermentative microorganism that can tolerate the inhibitors present during lignocellulosic fermentation. These inhibitors include the furan aldehyde, furfural, which is released as a byproduct of pentose dehydration during the weak acid pretreatment of lignocellulose. In order to survive in the presence of furfural, yeast cells need not only to reduce furfural to the less toxic furan methanol, but also to protect themselves and repair any damage caused by the furfural. Since furfural tolerance in yeast requires a functional pentose phosphate pathway (PPP), and the PPP is associated with reactive oxygen species (ROS) tolerance, we decided to investigate whether or not furfural induces ROS and its related cellular damage in yeast. We
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 ...
Complex I and complex III are the major sites of ROS generation in mitochondria15; however, the site responsible for volatile anesthetic-induced ROS generation remains undefined. The following evidence supports the contention that complex I is a source of isoflurane-induced ROS: isoflurane increases ROS generation with complex I- but not complex II-linked substrates in SMPs (fig. 5); and isoflurane only alters activity of complex I, but not of the other complexes in solubilized mitochondria. However, isoflurane-induced ROS generation in isolated mitochondria was not detected in our experiments when complex I-linked substrates were used. This apparent discrepancy observed in isolated mitochondria compared with submitochondrial particles may have occurred because ROS generated at complex I site are released into the mitochondrial matrix where they rapidly react with manganese superoxide dismutase before interacting with detection reagent in the buffer.15Interestingly, in the presence of rotenone, ...
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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 ...
It is now well accepted that radiation induced bystander effects can occur in cells exposed to media from irradiated cells. The aim of this study was to follow the bystander cells in real time following addition of media from irradiated cells and to determine the effect of inhibiting these signals. A human keratinocyte cell line, HaCaT cells, was irradiated (0.005, 0.05 and 0.5 Gy) with γ irradiation, conditioned medium was harvested after one hour and added to recipient bystander cells. Reactive oxygen species, nitric oxide, Glutathione levels, caspase activation, cytotoxicity and cell viability was measured after the addition of irradiated cell conditioned media to bystander cells. Reactive oxygen species and nitric oxide levels in bystander cells treated with 0.5Gy ICCM were analysed in real time using time lapse fluorescence microscopy. The levels of reactive oxygen species were also measured in real time after the addition of extracellular signal-regulated kinase and c-Jun amino-terminal kinase
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 ...
Most ionizing radiation-induced damage is caused by radical oxygen species (ROS). Some radioprotectors, such as amifostine, exert radioprotective effects by scavenging radical oxygen species. Recent studies show that hydrogen (H) has antioxidant activities that protect the brain and intestine agains …
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
2.1. Glutathione. GSH (L‐γ‐glutamyl‐L‐cysteinyl‐glycine) is a non‐protein thiol that reaches millimolar concentrations in most cell types. Its reduced form (GSH) is biologically active. It functions as an antioxidant defense against reactive oxygen/nitrogen species (ROS/RNS) as also with detoxication enzymes like GSH peroxidases and GSH‐S‐transferases. The GSH/glutathione disulfide is the major redox couple in animal cells.. Mitochondrial protection is exerted by GSH versus radicals and oxidant species by the contribution of a group of nutrients that can directly or indirectly protect mitochondria from oxidative damage and improve mitochondrial function. The protection mecha‐ nism of these molecules prevents the generation of oxidants, scavenging free radicals, or inhibiting oxidant reactivity. Other mechanism includes increasing cofactors of mitochon‐ drial enzymes that increase the kinetic constant of enzyme activity, which represents a pro‐ tecting mechanism from ...
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
I would like to say that my responses are not meant to be inflammatory but thought provoking. This is not an issue which side is right for the sake of argument but rather a journey of learning so people can find their cure. I have read more accounts of people getting well from pharmas than natural remedies. Parasites create a living hell in the body via immune reactions (ROS/RNS) reactive oxygen/nitrogen species, immune shifting, endocrine disturbances, pain etc, than any pharma could ever hope to. Furthermore the ROS/RNS damage tissues (liver, kidney, cell membranes, etc). This is ...
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 ...
Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in
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
Introduction. Oxygen is life sustaining, but its metabolism by organisms is not without consequences. Aerobic metabolism provides energy predominantly through mitochondrial oxidative phosphorylation. This process leads to the formation of by-products known as oxygen free radicals, which are toxic in high quantities. Oxygen toxicity is an intrinsic challenge to aerobic life that also affects spermatozoa, cells essential for the propagation of a species.. Free radicals are molecules with one or more unpaired electron(s). They are unstable, reactive molecules and are able to oxidize nearby molecules to gain an electron, damaging adjacent cells. At physiological levels, free radicals are benefcial and assist in maintaining normal cell function. It is therefore essential that they be maintained at homeostatic levels.. Free radicals come in two main forms: reactive oxygen species (ROS) and reactive nitrogen species (RNS). The superoxide anion (O2−), hydroxyl radical (OH−), peroxyl radical ...
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
TY - JOUR. T1 - Dietary antioxidants and exercise. AU - Powers, Scott K.. AU - DeRuisseau, Keith C.. AU - Quindry, John. AU - Hamilton, Karyn L.. N1 - Funding Information: This work was supported, in part, by grants from the American Heart Association-Florida and the National Institutes of Health awarded to S.K.P.. PY - 2004/1. Y1 - 2004/1. N2 - Muscular exercise promotes the production of radicals and other reactive oxygen species in the working muscle. Growing evidence indicates that reactive oxygen species are responsible for exercise-induced protein oxidation and contribute to muscle fatigue. To protect against exercise-induced oxidative injury, muscle cells contain complex endogenous cellular defence mechanisms (enzymatic and non-enzymatic antioxidants) to eliminate reactive oxygen species. Furthermore, exogenous dietary antioxidants interact with endogenous antioxidants to form a cooperative network of cellular antioxidants. Knowledge that exercise-induced oxidant formation can contribute ...
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 ...
The aim of the present study was to determine whether the endothelial dysfunction associated with CAD (coronary artery disease) and T2D (Type 2 diabetes mellitus) is concomitant with elevated mtROS (mitochondrial reactive oxygen species) production in the endothelium and establish if this, in turn, regulates the activity of endothelial AMPK (AMP-activated protein kinase). We investigated endothelial function, mtROS production and AMPK activation in saphenous veins from patients with advanced CAD. Endothelium-dependent vasodilation was impaired in patients with CAD and T2D relative to those with CAD alone. Levels of mitochondrial H 2 O 2 and activity of AMPK were significantly elevated in primary HSVECs (human saphenous vein endothelial cells) from patients with CAD and T2D compared with those from patients with CAD alone. Incubation with the mitochondria-targeted antioxidant, MitoQ 10 significantly reduced AMPK activity in HSVECs from patients with CAD and T2D but not in cells from patients with ...
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
TY - JOUR. T1 - A critical role for Romo1-derived ROS in cell proliferation. AU - Na, Ah Ram. AU - Chung, Young Min. AU - Lee, Seung Baek. AU - Park, Seon Ho. AU - Lee, Myeong Sok. AU - Yoo, Young Do. N1 - Funding Information: This work was supported by a grant (FG06-2-20) of the 21C Frontier Functional Human Genome Project from the Ministry of Science and Technology in Korea, by a grant (R01-2006-000-10113-0) from the Basic Research Program of the Korea Science and Engineering Foundation, and by a grant (R11-2005-017-01001-0) of the Research Center for Womans Diseases of the KOSEF. Copyright: Copyright 2009 Elsevier B.V., All rights reserved.. PY - 2008/5/2. Y1 - 2008/5/2. N2 - Low levels of endogenous reactive oxygen species (ROS) originating from NADPH oxidase have been implicated in various signaling pathways induced by growth factors and mediated by cytokines. However, the main source of ROS is known to be the mitochondria, and increased levels of ROS from the mitochondria have been ...
Naked mole-rats (NMRs) are the longest-lived rodents, showing minimal aging phenotypes. An unsolved paradox is that NMRs exhibit low intracellular anti-oxidant defence despite minimal aging. Here, we explained a link between these contradicting features by a phenomenon termed senescent cell death - senescence induced cell death in NMR cells due to their inherent vulnerability to reactive oxygen species and unique metabolic system. Generally, the free radical theory of aging, later modified to mitochondrial free radical theory, is the well-known theory of aging mechanism. Intracellular reactive oxygen species (ROS), deriving especially from mitochondria, damages macromolecules such as lipids, DNA, and proteins, and the accumulated damages in tissues are assumed to contribute aging process. Indeed, the mitochondrial ROS production rate is negatively correlated with the maximal lifespan of animal species. However, previous insights on responses of long-lived NMRs to ROS are puzzling: 1) ...
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 ...
AIM To identify and characterize the protective effect that L-carnitine exerted against an oxidative stress in C2C12 cells. METHODS Myoblastic C2C12 cells were treated with menadione, a vitamin K analog that engenders oxidative stress, and the protective effect of L-carnitine (a nutrient involved in fatty acid metabolism and the control of the oxidative process), was assessed by monitoring various parameters related to the oxidative stress, autophagy and cell death. RESULTS Associated with its physiological function, a muscle cell metabolism is highly dependent on oxygen and may produce reactive oxygen species (ROS), especially under pathological conditions. High levels of ROS are known to induce injuries in cell structure as they interact at many levels in cell function. In C2C12 cells, a treatment with menadione induced a loss of transmembrane mitochondrial potential, an increase in mitochondrial production of ROS; it also induces autophagy and was able to provoke cell death. Pre-treatment
The paradoxical role of reactive oxygen species in cell death versus cell survival establishes a delicate balance between chemotherapy efficacy and management of detrimental unwanted effects. cell loss of life in response to both Taxol and cisplatin. We propose that inhibiting the upregulated growth factor-dependent signaling in malignancy cells will target chemo-insensitivity, potentially lowering the necessary dose of the drugs and preventing harmful side effects. strong class=kwd-title Keywords: Lysophosphatidic acid (LPA), Ovarian malignancy, Reactive oxygen varieties (ROS), Chemotherapy, Taxol, Cisplatin Graphical abstract Rabbit Polyclonal to ADAM32 Proliferative signaling happens inside a windows that allows signaling molecules to be reversibly oxidized Z-VAD-FMK small molecule kinase inhibitor and reduced. Chemotherapeutic medicines drive cells toward a higher oxidation state, which is necessary for effective malignancy cell death. The relative side-effect is oxidative harm to normal ...
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
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 ...
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] ...
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 ...
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). ...
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, ...
Oxidative stress occurs when the production of reactive oxygen species (ROS) is greater than their catabolism. ROS production ... reactive oxygen species and cancer cell metabolism". European Journal of Clinical Investigation. 45 Suppl 1: 25-31. doi:10.1111 ... an immunologist's guide to reactive oxygen species". Nature Reviews. Immunology. 13 (5): 349-61. doi:10.1038/nri3423. PMC ... "Reactive oxygen species induced by p66Shc longevity protein mediate nongenomic androgen action via tyrosine phosphorylation ...
Schumacker P (2006). «Reactive oxygen species in cancer cells: Live by the sword, die by the sword». Cancer Cell. 10 (3): 175-6 ... Nordberg J, Arner ES (2001). «Reactive oxygen species, antioxidants, and the mammalian thioredoxin system». Free Radic Biol Med ... Hirst, Judy; King, Martin S.; Pryde, Kenneth R. (2008). «The production of reactive oxygen species by complex I». Biochemical ... Tapia, P (2006). «Sublethal mitochondrial stress with an attendant stoichiometric augmentation of reactive oxygen species may ...
An important internal source of DNA damage in both prokaryotes and eukaryotes is reactive oxygen species (ROS) formed as ... Sakai, A; Nakanishi, M; Yoshiyama, K; Maki, H (2006). "Impact of reactive oxygen species on spontaneous mutagenesis in ... Impaired nutrient supply, such as lack of oxygen or glucose, or impaired production of adenosine triphosphate (ATP) may deprive ... In both prokaryotes and eukaryotes, DNA genomes are vulnerable to attack by reactive chemicals naturally produced in the ...
"Lactate Regulates Rat Male Germ Cell Function through Reactive Oxygen Species". PLoS ONE. 9 (1): e88024. doi:10.1371/journal. ... LDH A that significantly decreases ATP production in tumorous cells as well as increasing production of reactive oxygen species ... It converts pyruvate, the final product of glycolysis, to lactate when oxygen is absent or in short supply, and it performs the ... This mechanism allows tumorous cells to convert the majority of their glucose stores into lactate regardless of oxygen ...
"Sunscreen enhancement of UV-induced reactive oxygen species in the skin". Free Radical Biology and Medicine. 41 (8): 1205-12. ...
Hanson, KM; Gratton, E; Bardeen, CJ (2006). "Sunscreen enhancement of UV-induced reactive oxygen species in the skin". Free ...
... free radicals such as reactive oxygen species).[citation needed] UVA can generate highly reactive chemical intermediates, such ... that was published in 2006, the amount of harmful reactive oxygen species (ROS) was measured in untreated and in sunscreen ... the amount of reactive oxygen species may be increased.[73][63][64][74] The amount of sunscreen that penetrates through the ... "Sunscreen enhancement of UV-induced reactive oxygen species in the skin". Free Radical Biology and Medicine. 41 (8): 1205-1212 ...
Due to its redox-active properties, pyocyanin generates reactive oxygen species. Contents. ... H to induce a redox active cascade to produce reactive oxygen intermediates. This allows P. aeruginosa to have a competitive ... This is done by the generation of reactive oxygen intermediates such as hydrogen peroxide and superoxide which cause oxidative ... In the cystic fibrosis lung, intracellular pyocyanin converts molecular oxygen to the superoxide free radical by oxidizing ...
... free radicals such as reactive oxygen species). UVA can generate highly reactive chemical intermediates, such as hydroxyl and ... that was published in 2006, the amount of harmful reactive oxygen species (ROS) was measured in untreated and in sunscreen ... Hanson Kerry M.; Gratton Enrico; Bardeen Christopher J. (2006). "Sunscreen enhancement of UV-induced reactive oxygen species in ... the amount of reactive oxygen species may be increased.[77][67][68][78] The amount of sunscreen that penetrates through 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 ...
See also: Reactive Oxygen Species. The activity of succinate dehydrogenase (SDH), which interconverts succinate into fumarate ... participates in mitochondrial reactive oxygen species (ROS) production by directing electron flow in the electron transport ... Since PDHs have an absolute requirement for molecular oxygen, this process is suppressed in hypoxia allowing HIF1α to escape ... therefore stabilizing HIF1α and inducing the transcription of HIF1-dependent genes even under normal oxygen conditions. HIF1 is ...
Reactive oxygen speciesEdit. Further information: Oxidative stress and Antioxidant. Molecular oxygen is an ideal terminal ... when electrons transfer directly to oxygen, forming superoxide.[84] As the production of reactive oxygen species by these ... These reactive oxygen species and their reaction products, such as the hydroxyl radical, are very harmful to cells, as they ... To counteract these reactive oxygen species, cells contain numerous antioxidant systems, including antioxidant vitamins such as ...
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 indirect DNA damage is caused by free radicals and reactive oxygen species. Research indicates that the absorption of three ... "Sunscreen enhancement of UV-induced reactive oxygen species in the skin" (PDF). Free Radical Biology & Medicine. 41 (8): 1205- ...
This type of damage is caused by reactive oxygen species that build up in the cell as a by-product of cellular respiration.[9] ... Chen Q, Vazquez EJ, Moghaddas S, Hoppel CL, Lesnefsky EJ (September 2003). "Production of reactive oxygen species by ... These reactive oxygen species are missing an electron, and because they are highly electronegative (have a strong electron pull ...
... metabolism generates reactive oxygen species, which are damaging to cells. During sleep, metabolic rates decrease and reactive ... oxygen species generation is reduced allowing restorative processes to take over. The sleeping brain has been shown to remove ... This restoration takes place mostly during slow-wave sleep, during which body temperature, heart rate, and brain oxygen ... As oxygen levels in the blood drop, the patient then comes out of deep sleep in order to resume breathing. When several of ...
Exposure of colonic cells to high DCA concentrations increase formation of reactive oxygen species, causing oxidative stress, ... Cholic acid, 3α,7α,12α-trihydroxy-5β-cholan-24-oic acid, the most abundant bile acid in humans and many other species, was ... Synthesis of bile acids is a major route of cholesterol metabolism in most species other than humans. The body produces about ... Chenodeoxycholic acid is made by many species, and is the prototypic functional bile acid.[2][3] ...
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 ...
... is thermally stable at temperatures wide over 200 °C, resistant to oxygen and water-tolerant.[1] ... In this process, the strongly coordinating methyl group transfers to the boron to expose a reactive site on zirconium. The ... This reagent has led to the development of immobilised catalyst/activator species; where the catalyst/activator is immobilised ... resulting cationic zirconocene species is stabilised by the non coordinating borane anion. The exposed site on the zirconium ...
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 ...
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 ...
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. ...
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 ...
... 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. ...
The purpose of this chapter is to explore the current understanding of reactive oxygen species involvement in bone ... Reactive oxygen species (ROS) are key signaling molecules that play an important role in the progression of inflammatory ... Reactive Oxygen Species and Bone Fragility, Reactive Oxygen Species (ROS) in Living Cells, Cristiana Filip and Elena Albu, ... Reactive Oxygen Species and Bone Fragility, Reactive Oxygen Species (ROS) in Living Cells, Cristiana Filip and Elena Albu, ...
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. ...
One of them is the free radical theory which postulates that reactive oxygen species (ROS), extremely reactive chemical ... The role of reactive oxygen species and mitochondria in aging].. [Article in Polish] ... are mainly produced by the mitochondrial respiratory chain as a result of electron transport and the reduction of the oxygen ...
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 ...
... J Clin Endocrinol Metab. 2000 Aug;85(8): ...
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. ...
Oxygen toxicity Pro-oxidant Reactive nitrogen species Reactive sulfur species Reactive carbonyl species Reactive oxygen species ... "Upsides and downsides of reactive oxygen species for cancer: the roles of reactive oxygen species in tumorigenesis, prevention ... Reactive oxygen species (ROS) are highly reactive chemical molecules formed due to the electron receptivity of O2. Examples of ... Another type of reactive oxygen species is singlet oxygen (1O2) which is produced for example as byproduct of photosynthesis in ...
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 ...
Cystic fibrosis neutrophils have normal intrinsic reactive oxygen species generation. D. J. McKeon, K. A. Cadwallader, S. Idris ... Cystic fibrosis neutrophils have normal intrinsic reactive oxygen species generation. D. J. McKeon, K. A. Cadwallader, S. Idris ... Cystic fibrosis neutrophils have normal intrinsic reactive oxygen species generation. D. J. McKeon, K. A. Cadwallader, S. Idris ... Receptor-mediated reactive oxygen species generation and shape change in cystic fibrosis (CF) and normal neutrophils. a) ...
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. ...
  • 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. (
  • ROS is a phrase used to describe a number of reactive molecules and free radicals derived from molecular oxygen. (
  • Reactive oxygen species (ROS) which include free radicals, peroxides, singlet oxygen, ozone, and nitrogen monoxide and dioxide free radicals, is an area of intense research. (
  • Discovered only within the last fifty years, reactive oxygen species (ROS) are oxygen derived free radicals found in both intra- and extracellular space. (
  • Common forms of ROS include superoxide anion (O 2 -), hydroxyl radical (OH-), and peroxide (O 2 -2 ), each classified as free radicals, due to the presence of an extra unpaired electron carried in their outer shell, giving each species paramagnetic tendencies. (
  • Free radicals containing oxygen, known as reactive oxygen species (ROS), are the most biologically significant free radicals. (
  • Epidemiological studies have also shown that the consumption of plant foods rich in antioxidants is beneficial to health as it protects against oxidative damage by inhibiting free radicals and reactive oxygen species[ 1 , 13 , 14 ]. (
  • Chronic fluoride exposure generates free radicals, reactive species which leads to redox imbalance, cytotoxicity and hematological damage. (
  • ROS include a number of reactive molecules and free radicals, derived from molecular oxygen, that damage DNA and RNA and oxidize proteins and lipids (lipid peroxidation). (
  • These free radicals have an unpaired electron, creating a highly reactive molecule that will try to obtain an additional electron from wherever it can. (
  • Reactive oxygen species include singlet oxygen, superoxide, and oxygen free radicals. (
  • Candeias LP, Patel KB, Stratford MRL, Wardman P: Free hydroxyl radicals are formed as reaction between the neutrophil derived species superoxide and hypochlorous acid. (
  • ROS include the superoxide and hydroxyl radical, plus derivatives of oxygen that do not contain unpaired electrons, such as hydrogen peroxide, singlet oxygen, and hypochlorous acid. (
  • Although there are no sensors that reversibly monitor the level of reactive oxygen species, this section discusses a number of probes that trap or otherwise react with singlet oxygen, hydroxyl radicals or superoxide. (
  • Also, hydroxyl radical is a reactive species that oxidizes lipids, proteins, and DNA, which results in genomic instability [17]. (
  • These molecules are very reactive and come in many different forms, examples include: H 2 O 2 (hydrogen peroxide), NO (nitric oxide), O 2 - (oxide anion), peroxynitrite (ONOO - ), hydrochlorous acid (HOCl), and hydroxyl radical (OH - ) 1 . (
  • Furthermore, this highly selective chemiluminescent probe does not react with other activated oxygen species such as hydroxyl radical, superoxide or hydrogen peroxide. (
  • Hydroxyl radicals or other reactive oxygen species appear to be involved in this cleavage. (
  • Reactive oxygen species (ROS), including hydrogen peroxide, superoxide anion, and hydroxyl radical, are highly toxic oxidants which are inevitably produced to a certain extent under aerobic conditions. (
  • ROS are composed of a series of oxygen intermediates, including the free radical superoxide anion (·O 2 − ), the nonradical hydrogen peroxide (H 2 O 2 ), the highly reactive hydroxyl free radical (·OH), peroxynitrite (ONOO − ), and singlet oxygen ( 1 O 2 ), in which one of the electrons is raised to an orbital of higher energy with an inversion of spin. (
  • It uses the cell permeant reagent Dichlorodihydrofluorescein-diacetate (H 2 DCFDA), a fluorogenic dye that measures hydroxyl, peroxyl and other reactive oxygen species (ROS) activity within the cell. (
  • Some of the most abundant radicals produced in natural biochemical reactions are reactive oxygen species (ROS) such as hydroxyl, hydroperoxyl and superoxide radicals, and reactive nitrogen species (RNS), such as nitrogen monoxide and peroxynitrite. (
  • H 2 O 2 is readily converted into the aggressive hydroxyl radical by Fenton chemistry, and this extremely reactive radical could be responsible for much of the oxidative damage seen in all of the above disorders. (
  • and singlet oxygen ( 1 O 2 ). (
  • In the laboratory, singlet oxygen is usually generated in one of three ways: photochemically from dioxygen ( 3 O 2 ) using a photosensitizing dye ( Figure 18.2.1 ), chemically by thermal decomposition of a peroxide or dioxetane, or by microwave discharge through an oxygen stream. (
  • Singlet oxygen can be directly detected by its characteristic weak chemiluminescence at 1270 nm. (
  • This heat-stable dye exhibits a quantum yield for singlet oxygen generation in excess of 0.7, as well as high photostability, making it an important agent for both anticancer and antiviral research. (
  • Rose bengal diacetate ( R14000 ) is an efficient, cell-permeant generator of singlet oxygen. (
  • Photoirradiation of merocyanine 540 ( M24571 ) produces both singlet oxygen and other reactive oxygen species, including oxygen radicals. (
  • Before reaction with singlet oxygen, this probe initially exhibits weak blue fluorescence with excitation peaks at 372 and 393 nm and emission peaks at 395 and 416 nm. (
  • In the presence of singlet oxygen, however, it emits a green fluorescence similar to that of fluorescein (excitation/emission maxima ~504/525 nm). (
  • We have observed that the fluorescent product of Singlet Oxygen Sensor Green reagent can degrade with time in some solutions and that Singlet Oxygen Sensor Green reagent can become fluorescent at alkaline pH in the absence of singlet oxygen. (
  • Nevertheless, with the proper controls the intensity of the green-fluorescent signal can be correlated with singlet oxygen concentration, without significant interference from other reactive oxygen species. (
  • Figure 18.2.1 Fluorescence response and specificity of Singlet Oxygen Sensor Green reagent ( S36002 ) to 1 O 2 . (
  • A) Fluorescence measurements were made in a spectrofluorometer using excitation/emission wavelengths of 488/525 nm for solutions containing: 1 µM Singlet Oxygen Sensor Green reagent and 10 µM methylene blue in 100 mM pH 7.5 Tris buffer alone, the singlet oxygen scavenger sodium azide (NaN 3 , 1 mM), or 50% D 2 O, which increases the lifetime of 1 O 2 . (
  • B) Fluorescence measurements were made in a spectrofluorometer using excitation/emission wavelengths of 488/525 nm for solutions of 50 mM pH 7 Tris buffer with 1 mM xanthine containing either 1 µM Singlet Oxygen Sensor Green reagent or dihydrorhodamine 123 ( D632 , D23806 ). (
  • trans -1-(2'-Methoxyvinyl)pyrene ( M7913 ) can be used to detect picomole quantities of singlet oxygen in chemical and biological systems ( Figure 18.2.2 ), making this compound one of the most sensitive singlet oxygen probes currently available. (
  • Figure 18.2.2 Reaction of trans -1-(2'-methoxyvinyl)pyrene ( M7913 ) with singlet oxygen ( 1 O 2 ), yielding a dioxetane intermediate that generates chemiluminescence (CL) upon decomposition to 1-pyrenecarboxaldehyde. (
  • Methyl coelenterazine is a reportedsuperior antioxidant for cells against reactive oxygen species (ROS) such as singlet oxygen and superoxide anion. (
  • and singlet oxygen ( 1 O 2 ), all of which are more reactive than oxygen (O 2 ) itself. (
  • The involvement of oxygen in the near-UV inactivation processes lead investigators to suggest that oxygen reactive species such as singlet oxygen and superoxide anion produced during exposure to near-UV. (
  • Role of reactive oxygen species and p53 in chromium(VI)-induced apoptosis. (
  • The present study investigates chromium(VI) (Cr(VI))-induced apoptosis and the role of reactive oxygen species (ROS) and p53 in this response. (
  • Cr(VI)-induced apoptosis is contributed to ROS generation, resulting from cellular reduction of Cr(VI) as measured by flow cytometric analysis of the stained cells, oxygen consumption, and electron spin resonance spin trapping. (
  • Reactive oxygen species (ROS), which induce apoptosis in cells such as neurons ( 7 ), play critical roles in cell regulation, sometimes as second messengers ( 8 , 9 ). (
  • Isoalantolactone-induced apoptosis is markedly abrogated when the cells were pretreated with N -acetylcysteine (NAC), a specific ROS inhibitor, suggesting that the apoptosis-inducing effect of isoalantolactone in prostate cancer cells is mediated by reactive oxygen species. (
  • These findings indicate that isoalantolactone induces reactive oxygen species-dependent apoptosis in prostate cancer cells via a novel mechanism involving inhibition of survivin and provide the rationale for further in vivo and preclinical investigation of isoalantolactone against human prostate cancer. (
  • Li, X. Reactive Oxygen Species Mediate Isoalantolactone-Induced Apoptosis in Human Prostate Cancer Cells. (
  • Pablo Chapela S, Burgos I, Schiel A, Alonso M, Alberto Stella C. Serum reactive oxygen species and apoptosis markers in septic patients. (
  • Increased extracellular glucose (30 mmol/l) rapidly stimulated generation of intracellular reactive oxygen species (ROS) through NADPH oxidase and mitochondrial pathways and led to activation of proapoptotic p38 mitogen-activated protein kinase and caspase 3 and to apoptosis of conditionally immortalized podocytes in vitro. (
  • The rates of apoptosis and the level of reactive oxygen species (ROS) in rat podocytes were assessed by flow cytometry. (
  • The present study aimed to investigate the anticancer effects and mechanism underlying RSV in CRC cells by conducting Cell Counting Kit‑8, apoptosis, reactive oxygen species (ROS) and western blotting assays. (
  • At a molecular level, DPP-23 targeted the unfolded protein response (UPR) in the endoplasmic reticulum (ER) through the production of reactive oxygen species (ROS) in cancer cells, but not in normal cells, resulting in selective killing of tumor cells via caspase-dependent apoptosis. (
  • The present study synthesized a novel polyphenol conjugate (DPP-23) that produces reactive oxygen species (ROS) in a cancer-selective manner, leading to the stimulation of the unfolded protein response (UPR) and caspase-dependent apoptosis. (
  • All living cells produce reactive oxygen species (ROS) as a byproduct of metabolism. (
  • 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. (
  • However, numerous methods of slowing aging in short-lived animals involve increases in the rate at which mitochondria produce reactive oxygen species. (
  • Nitrogen-containing oxidants such as nitric oxide are called reactive nitrogen species. (
  • Despite the wealth of pre-clinical support for a role for reactive oxygen and nitrogen species (ROS/RNS) in the aetiology of diabetic complications, enthusiasm for antioxidant therapeutic approaches has been dampened by less favourable outcomes in large clinical trials. (
  • What is the Reactive Nitrogen/Oxygen Species Submodel? (
  • 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. (
  • 18,19 Thus, NO can either scavenge O 2 − or be transformed by O 2 − into highly reactive nitrogen intermediates. (
  • In sepsis, ROS and reactive nitrogen species (RNS) are increased, both in circulation and in tissue [14]. (
  • The global ebook reactive oxygen and nitrogen species signaling Scarecrow on access, Genetic Disorders and the Fetus is perhaps nice in a coupling depicted and directed elliptical depth Completing the most utter hands in offshoot, page, and sure guardianship. (
  • If you have at an ebook reactive oxygen and nitrogen species signaling and communication or particular official, you can be the erosulate browser to pave a browser across the gene concerning for discrete or feminine phenomena. (
  • The three efficient items get on IntroductionComputational current ebook reactive oxygen and nitrogen species signaling and communication, British musicals, and the glycogen of crazy and vast verse. (
  • adequately of flowing Cainite books, were the instincts of huge ebook reactive oxygen and nitrogen species signaling and a momentous higher day that were widely proposed by every malformed proof that began achieved numerical, previous, common, or web. (
  • Fluoride enhances generation of reactive oxygen and nitrogen species, oxidizes hemoglobin, lowers antioxidant power and inhibits transmembrane electron transport in isolated human red blood cells. (
  • Treatment of RBC with NaF enhanced the generation of reactive oxygen and nitrogen species. (
  • Reactive oxygen and nitrogen species are involved in a vast range of major diseases including cardiovascular disease, Alzheimer's disease, Parkinson's disease, cancer, multiple sclerosis, autism, and infections. (
  • Reactive oxygen and nitrogen species induce protein and DNA modificati" by Theresa A Freeman, Javad Parvizi et al. (
  • Reactive oxygen and nitrogen species induce protein and DNA modifications driving arthrofibrosis following total knee arthroplasty. (
  • The hypothesis for this study was that disregulated production of reactive oxygen species (ROS) and nitrogen species (RNS) mediates matrix protein and DNA modifications, which result in excessive fibroblastic proliferation. (
  • In normal circumstances, the deleterious effects caused by the highly reactive nature of ROS are balanced by the presence of antioxidants, including glutathione, carotenoids, and antioxidant enzymes such as catalase and glutathione peroxidase. (
  • Consequently, if the magnitude of derived ROS exceeds the host's capacity to detoxify the reactive intermediates--via antioxidants--then the physiological system is said to be under oxidative stress. (
  • Reactive oxygen species elevation is linked to the activation of the Toll pathway, which is essential in mediating the expression of antioxidants to counterbalance oxidative stress. (
  • Oxidative stress: imbalance between reactive oxygen species (ROS) and antioxidants. (
  • Interestingly, reactive oxygen species (ROS) can control both pathways through reciprocal modulation of the main effector molecules FasL and Bcl-2. (
  • Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen. (
  • Reactive oxygen species have opposing effects on roundworm longevity depending on whether these molecules are in the mitochondria or the cytoplasm. (
  • Reactive oxygen species (ROS) are key signaling molecules that play an important role in the progression of inflammatory disorders. (
  • Reactive oxygen species (ROS) are oxygen-containing molecules naturally occurring in both inorganic and biological chemical systems. (
  • Reactive oxygen species (ROS) are highly reactive chemical molecules formed due to the electron receptivity of O2. (
  • Reactive oxygen species are unstable molecules, which contain oxygen as a byproduct of the natural metabolism of oxygen. (
  • These "activated" oxygen molecules can readily react with organic substances by noncatalytic means. (
  • It is believed that the inorganic form of arsenic, especially inorganic trivalent arsenic (As 3+ ), is more carcinogenic and reactive with thiol-containing molecules. (
  • Reactive oxygen species (ROS) are oxygen containing heterogeneous group with chemically reactive ions and molecules [ 6 ]. (
  • 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. (
  • 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. (
  • Role of reactive oxygen species in cell signalling pathways. (
  • High levels of reactive oxygen species (ROS) are observed in chronic human diseases such as neurodegeneration, Crohn's disease, and cancer. (
  • Low levels of reactive oxygen species have been found to have useful and beneficial effects. (
  • ImC obtained from tumor-bearing mice had significantly higher levels of reactive oxygen species (ROS) than ImC isolated from tumor-free animals. (
  • Intracellular levels of reactive oxygen species (ROS) were detected by fluorescent probe 2′,7′-dichlorofluorescein diacetate (DCFH-DA). (
  • Different techniques have been applied for detection and quantification of varied ROS and their reactive intermediates during the past few decades either in vitro and in vivo studies. (
  • H 2 DCFDA (2′,7′-Dichlorodihydrofluorescein diacetate) is a useful fluorogenic reagent to detect reactive oxygen intermediates in cells. (
  • AngII is an important mediator of oxidative stress, and reactive oxygen species (ROS) induced by AngII are chief signal intermediates in several signal transduction pathways involved in renal pathophysiology. (
  • The superoxide anion is formed directly from the one-electron reduction of molecular oxygen. (
  • The superoxide anion ( Reactive oxygen species-Table 18.1 ) may also play a role in regulating normal vascular function. (
  • these "leaky" electrons can quickly interact with molecular oxygen to form superoxide anion, the predominant reactive oxygen species in mitochondria. (
  • Accumulating evidence suggests that AngII stimulates intracellular formation of reactive oxygen species (ROS) such as the superoxide anion and hydrogen peroxide. (
  • NADPH oxidase is involved in the generation of the superoxide anion (·O 2 − ) by the addition of an electron to oxygen. (
  • OH 2 H+ + 2 e− + H2O2 → 2 H2O In a biological context, ROS are formed as a natural byproduct of the normal aerobic metabolism of oxygen and have important roles in cell signaling and homeostasis. (
  • An unregulated imbalance between oxygen metabolism and ROS neutralization can threaten essential cellular macromolecules. (
  • In the course of normal metabolism, oxidizing equivalents or reactive oxygen species (ROS) are generated when oxygen is partially reduced as electrons leak out of the electron transport chain during respiration in mitochondria. (
  • Traditionally, reactive oxygen species (ROS) have been regarded as toxic by-products of aerobic metabolism. (
  • as well as the non-radical species hydrogen peroxide (H2O2). (
  • 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 ). (
  • 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. (
  • Hydrogen gas (H 2 ) has potential as eliminating highly reactive ROS. (
  • 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. (
  • 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 ). (
  • It contains radicals reacting with oxygen to form ROS 6 . (
  • Under these pro-oxidant conditions, highly reactive radicals can damage DNA, RNA, proteins, and lipid components, which may lead to cell death. (
  • In prostate cancer, oxygen radicals are reported to arise from several sources within the cells including the NADPH oxidase (Lim et al . (
  • 2005). Oxygen radicals in this cell line also induce VEGF which can promote angiogenesis (Gao et al . (
  • There are many intracellular sources of reactive oxygen species, including cell mitochondria and NADPH oxidases (NOX enzymes) linked to neutrophils 2 , white blood cells, which produce high levels of ROS as part of their defense role. (
  • The role of NADPH oxidase activation in pneumonia is complex because reactive oxygen species contribute to both microbial killing and regulation of the acute pulmonary infiltrate. (
  • We evaluated the contribution of NADPH oxidase-derived reactive oxygen species to the pathogenesis of pneumococcal pneumonia, addressing both the contribution to microbial killing and regulation of the inflammatory response. (
  • 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. (
  • 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. (
  • 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. (
  • We investigated the progression of five different strains of murine malaria in gp91 phox−/− mice, which lack a functional NADPH oxidase and thus the ability to produce phagocyte-derived reactive oxygen species. (
  • Neutrophils kill microorganisms, using both reactive oxygen species (ROS) and granule-associated proteases ( 7 , 8 ). (
  • Extra- and intracellular formation of reactive oxygen species by human neutrophils in the presence of pheniramine, chlorpheniramine and brompheniramine. (
  • 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. (
  • The induction of reactive oxygen species increases oxidative damage to cellular components and thus contributes to the development of skin cancer 7 . (
  • 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. (
  • Although historically viewed as purely harmful, recent evidence suggests that reactive oxygen species (ROS) function as important physiological regulators of intracellular signaling pathways. (
  • Evidence suggests that reactive oxygen species may modulate cell differentiation, including hematopoietic differentiation involving stem cell production, in both physiological and pathological (disease) conditions 4 . (
  • 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 cell death. (
  • 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. (
  • NSAIDs have been shown to induce reactive oxygen species (ROS) in different cell types including cardiac and cardiovascular related cells. (
  • 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. (
  • Recent observations demonstrate that BRAF inhibitors induce reactive oxygen species (ROS) in melanoma cells. (
  • 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. (
  • Reactive Oxygen Species (ROS) have long been known to be a component of the killing response of immune cells to microbial invasion. (
  • WASHINGTON - Mitochondria help injured muscle cells (myofibers) repair by soaking up calcium that enters from the site of injury and using it to trigger increased production of reactive oxygen species. (
  • Although reactive oxygen species can damage cells when produced in high amounts, according to a study published online Sept. 5, 2017 by Science Signaling and featured on the journal's cover, these oxidative species are crucial signals that start the process of repairing myofiber. (
  • As metabolic by-products within normal physiological processes, such as the mitochondrial electron transport chain, ROS highly reactive nature arms them with the capability to damage surrounding cells-- irrespective of cell type [ 1 - 3 ]. (
  • Mitochondria are an important source of ROS (reactive oxygen species) within most mammalian cells [ 1 - 8 ]. (
  • We then examined neutrophil-mediated oxygen radical damage to human umbilical vein endothelial cells in vitro. (
  • In vivo, reactive oxygen species (ROS) are produced in different pathways, different cells, and in different quantities. (
  • When reactive oxygen species build up at high levels inside cells, also referred to as oxidative stress, they can damage DNA, RNA and proteins, and even cause cell death. (
  • Generation of Reactive Oxygen Species (ROS) and Pro-Inflammatory Signaling in Human Brain Cells in Primary Culture. (
  • To further understand the triggering and participation of ROS-generating species to pro-inflammatory and pathological signaling in human brain cells, in these experiments we studied the effects of 22 different substances (including various common drugs, interleukins, amyloid precursor protein, amyloid peptides and trace metals) at nanomolar concentrations, in a highly sensitive human neuronal-glial (HNG) cell primary co-culture assay. (
  • We report, for the first time, that Ag-specific inhibition of CD8 + T cells by ImC could result from up-regulation of reactive oxygen species (ROS) production by these cells, and that this process is possibly mediated by integrins. (
  • The viability of the cells as well as the levels of O 2 - and highly reactive ROS in the cells was evaluated with or without 2% H 2 . (
  • H 2 O 2 can oxidize chloride to form the reactive hypochlorous acid (HOCl) in cells that express the enzyme myeloperoxidase. (
  • The interactions between molecular damage in cells, repair system activity, the generation of reactive oxygen species (ROS) in mitochondria capable of causing damage, and individual or species longevity are far from simple. (
  • Reactive oxygen species (ROS) were originally thought to only be released by phagocytic cells during their role in host defence. (
  • To detect reactive oxygen species , cells were treated with 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H 2 DCFDA, purchased from Molecular Probes). (
  • 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. (
  • ROS Detection Assay Kit is a highly sensitive and safe assay to measure reactive oxygen species (ROS). (
  • This review describes the main mitochondrial sources of reactive species and the antioxidant defences that evolved to prevent oxidative damage in all the mitochondrial compartments. (
  • Reactive oxygen species (ROSs) play important physiological and physiopathological roles in the cardiovascular system. (
  • PSII produces reactive oxygen species (ROS), responsible for the frequent damage and turnover of this megacomplex that occur under physiological conditions. (
  • 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 ). (
  • Oxidation of these specific and reactive cysteine residues in turn can lead to the reversible modification of enzymatic activity. (
  • 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. (
  • 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. (
  • Photosystem II (PSII), a unique membrane-bound oxidoreductase, catalyzes light-driven oxidation of water to molecular oxygen. (
  • 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). (
  • This increased the oxidation of hemoglobin to yield methemoglobin and oxoferrylhemoglobin, which are inactive in oxygen transport. (
  • Wink DA, Hanbauer I, Krishna MC, DeGraff W, Gamson J, Mitchell JB: Nitric oxide protects against cellular damage and cytotoxicity from reactive oxygen species. (
  • Reactive oxygen species possess a huge impact influencing the cellular function which at lower concentration are known to be involved in the regulation of cell signaling cascades however, its higher production leads to damage of biomolecules such as lipid, proteins and nucleic acid and are well documented to be associated with several biological dysfunction and human diseases. (
  • The production of ROS (reactive oxygen species) by mammalian mitochondria is important because it underlies oxidative damage in many pathologies and contributes to retrograde redox signalling from the organelle to the cytosol and nucleus. (
  • 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. (
  • To identify the source of reactive oxygen species (ROS), our previous publication ( 7 ) showed that ROS is generated from mitochondrial damage-induced oxidative burst, leading to ROS generation. (
  • Reactive oxygen species (ROS)-induced nuclear and mitochondrial DNA damage is associated with the aging process as well as numerous pathologies in humans ( 1 ). (
  • Since this resulted in increased formation of reactive oxygen species, the antioxidative activity of antiallergic drugs was considered to decrease the risk of tissue damage. (
  • Several genetic and biochemical techniques were employed to examine the role of oxygen reactive species in near-UV mediated damage to DNA and membrane components, and to identify endogenous photosensitizers. (
  • It is worth noting that the direct and quantitative measurement of ROS production continues to remain challenging in muscle redox biology due to the reactive nature of ROS as well as the methodological shortcomings. (
  • Novel antioxidative nanotherapeutics in a rat periodontitis model: Reactive oxygen species scavenging by redox injectable gel suppresses alveolar bone resorption. (
  • The cell s net redox state is a balance between oxygen radical synthesis and breakdown, and net ROS generation in prostate cancer has also been reported to develop from downregulated levels or activities of the scavenger enzyme systems catalase, superoxide dismutase I (Zn 2+/Cu 2+ SOD) and II (MN-SOD), and glutathione peroxidase (Chiarugi, 2003). (
  • Specific reactive cysteine (Cys) residues within target proteins can be covalently modified by oxidative stress. (
  • 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. (
  • It can provoke the generation of reactive oxygen species and activate unfolded protein response (UPR) signaling pathways. (
  • 3,6,10 Although the precise mechanisms through which PM 2.5 gains access to the systemic vasculature is still hotly debated, there is increasing evidence that particles in the fine and ultrafine range transgress into the systemic circulation and modulate vascular tone acutely, presumably through reactive oxygen species (ROS)-dependent pathways. (
  • In other words, oxygen toxicity can arise both from uncontrolled production and from the inefficient elimination of ROS by the antioxidant system. (
  • 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. (
  • Aim] The pulmonary toxicity of high concentration of oxygen during mechanical ventilation relates to reactive oxygen species (ROS). (
  • Effects of vitamin E on reactive oxygen species-mediated 2,3,7,8-tetrachlorodi-benzo-p-dioxin toxicity in rat testis. (
  • Infection with this bacterium leads to induction of oxidative stress and an increased level of reactive oxygen species in its mosquito host. (
  • Reactive Oxygen Species and Targeted Therapy for Pancreatic Cancer," Oxidative Medicine and Cellular Longevity , vol. 2016, Article ID 1616781, 9 pages, 2016. (
  • Metabolic processes within the cellular system such as respiration and oxidative burst are known to be associated with the generation of reactive oxygen species (ROS). (
  • ROS (reactive oxygen species) are considered to be a major cause of cellular oxidative stress, linked to neuromuscular diseases and aging. (
  • Different derivatives of H 2 DCFDA are employed for reactive oxygen species measurements as they have specific characteristics: carboxy-H 2 DCFDA displays an improved cellular retention whereas the fluorinated molecule (H 2 DFFDA) proves more stable when exposed to light. (
  • The cellular generation of reactive oxygen species (ROS) has been implicated in contributing to the pathology of human neurological disorders including Alzheimer's disease (AD) and Parkinson's disease (PD). (
  • Cellular oxygen consumption was inhibited immediately upon extracellular addition of FOH, whereas FOH and its possible metabolites failed to directly inhibit any oxidase activities detected with the isolated mitochondrial preparation. (
  • Asiaticoside, the major active principle of Centella asiatica, prevents ultraviolet A-dependent photoaging by suppressing ultraviolet A-induced reactive oxygen species production. (
  • Negative regulator of reactive oxygen species (ROS) that limits ROS production by phagocytes during inflammatory response, thereby playing a role during host defense. (
  • 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 ROS/RNS balance by increasing ROS production via a reactive metabolite. (
  • For instance, alcohol leads to formation of reactive oxygen species during its degradation and induce ROS production by activation of cytochrome P450 enzymes 5 . (
  • 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). (
  • The excessive production of reactive oxygen species (ROS) has been implicated in a variety of disorders, but to date, ROS scavengers have not been widely used for local treatment of inflammation, because they are rapidly eliminated from the inflamed site. (
  • Dihydroethidine and 2′, 7′-dichlorodihydrofluorescein diacetate fluorescent probes were used to assess reactive oxygen species (ROS) production. (
  • 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. (
  • Sepsis and endotoxemia induce the production of reactive oxygen species (ROS). (
  • A change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a reactive oxygen species stimulus. (
  • 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. (
  • The result is evidence of the significance of processes of generation/removal of extracellular reactive oxygen species for pollen germination. (
  • Although there is very little information on the biological generation of ROS in marine surface waters, several species of marine phytoplankton have recently been shown to release significant amounts of ROS into the environment. (
  • Reactive oxygen species generation and disposal in the mitochondria. (
  • This signaling function appears to require the generation of reactive oxygen species (ROS) which, in turn requires the activation of Src and the transactivation of the epithelial growth factor receptor (EGFR). (
  • 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). (
  • reactive oxygen species (ROS) generation. (
  • The results indicated that AGF could inhibit cell proliferation, promote TNF‑α, interleukin‑1β (IL‑1β), and reactive oxygen species (ROS) generation, and increase autophagy in rat podocytes. (
  • Generation of reactive oxygen species has an important role in the induction of cell death by oxaliplatin in combination with autophagy inhibitors. (
  • The absorption of energy causes the chromophore to be electronically excited into the triplet state which leads to subsequent generation of oxygen reactive species within the membrane. (
  • AOX can use reductant in excess of cytochrome pathway capacity, preventing reactive oxygen species (ROS) formation from an over-reduced ubiquinone pool, and thus may be involved in acclimation to oxidative stresses. (
  • The aim of this study was to investigate the role of neutrophil-derived reactive oxygen species on endothelial cell dysfunction in preeclampsia. (
  • The breakdown of glucose produces reactive oxygen species (ROS). (
  • Both drugs increased reactive oxygen species and 8-oxodG levels, and cytotoxicity was decreased by antioxidant pretreatment. (
  • 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). (
  • 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. (
  • Reactive oxygen species has short life-time due to its high reactivity and thus its detection has always been a challenge. (
  • and various peroxides (ROOR') and hydroperoxides (ROOH) ( Reactive oxygen species-Table 18.1 ), as well as for their fluorometric detection in solution. (
  • However, the detection of reactive oxygen species (ROS), is not straightforward. (
  • It is an efficient electron transfer catalyst from a number of organic substrates to molecular oxygen (O2), constructing quinoprotein model reactions. (
  • Formation of reactive oxygen species was determined in vitro using the chemiluminescence method. (
  • 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. (
  • 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. (
  • Altogether, our findings illustrate the complexity of the regulation of signaling components by oxidative species of distinct natures. (
  • The ROS most likely released to the environment are those produced at the cell surface as electrons get "leaked" from the respiratory chain and react with molecular oxygen, O2. (
  • This coelenterazine derivative is membrane-permeant, nontoxic, and highly reactive toward ROS. (
  • As such, we expect this species to play the critical role of the electrophilic oxygen involved in O-O bond formation in the electrocatalytic OER on IrO x . (
  • Previous studies showed that CD36 promotes reactive oxygen species (ROS) formation in mouse models of cerebral and cardiac ischemia. (
  • The optical or electron spin properties of the resulting products can be used as a measure of the presence or quantity of the reactive oxygen species and, in certain cases, can report the kinetics and location of their formation. (
  • Yermakov, I. 2009-12-03 00:00:00 The formation of reactive oxygen species in pollen at the early germination stage, which precedes the formation of the pollen tube, was studied. (
  • The cyanide-resistant alternative oxidase (AOX) of plant mitochondria accepts electrons from the ubiquinone (UQ) pool and uses them to reduce oxygen to water, with no conservation of energy through proton gradient formation. (

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