scholarly journals Identification of a superoxide-generating NADPH oxidase system in human fibroblasts

1991 ◽  
Vol 275 (1) ◽  
pp. 241-245 ◽  
Author(s):  
B Meier ◽  
A R Cross ◽  
J T Hancock ◽  
F J Kaup ◽  
O T G Jones
Keyword(s):  
Nadph Oxidase ◽  
Human Fibroblasts ◽  
Light And Electron Microscopy ◽  
Specific Inhibitor ◽  
Outer Cell ◽  
Oxidase System ◽  
Diphenylene Iodonium ◽  
Outer Cell Membrane ◽  
System 1 ◽  
Generating System

Human fibroblasts have the capacity to release superoxide radicals upon stimulation of an electron transport system similar to the NADPH oxidase of leukocytes. Two components of the NADPH oxidase system, (1) a flavoprotein of 45 kDa which binds diphenylene iodonium (a compound described as a specific inhibitor of the leukocyte NADPH oxidase), and (2) a low-potential cytochrome b, are present in fibroblast membranes. Fibroblasts exhibit these compounds at lower concentrations than do polymorphonuclear leukocytes or B-lymphocytes. The superoxide-generating system is rather uniformly associated with the outer cell membrane, as shown by light and electron microscopy. Superoxide release upon stimulation with various agents was prevented by the addition of micromolar concentrations of diphenylene iodonium, making an NADPH oxidase a likely source.

The feeding site and probable feeding mechanism of the parasitic nematode Capillaria hepatica (Bancroft, 1893)

1974 ◽  
Vol 52 (10) ◽  
pp. 1215-1220 ◽  
Author(s):  
K. A. Wright
Keyword(s):  
Cell Membrane ◽  
Light And Electron Microscopy ◽  
Circulatory System ◽  
Outer Cell ◽  
Feeding Site ◽  
Capillaria Hepatica ◽  
Parenchymal Liver ◽  
Outer Cell Membrane ◽  
Tissue Fluids ◽  
Nucleolar Components

Examination by light and electron microscopy of the tissue surrounding the anterior end of the trichuroid nematode Capillaria hepatica in the liver of its mouse host indicates that the nematode is enclosed by multinucleate cytoplasmic masses originating from parenchymal liver cells. These cytoplasmic masses have desmosomal contacts with adjacent cells. Nuclei often have an irregularly expanded nuclear envelope, greatly increased amounts of heterochromatin or increases in interchromatinic and perichromatinic granules, and segregated nucleolar components. Mitochondria are swollen and endoplasmic reticulum is swollen or vesiculated to varying degrees. The outer cell membrane of the cytoplasmic masses is thrown into extensive irregular folds, but on the surface next to the nematode, no cell membrane can be found. As the nematode's intestinal contents include remnants of cellular materials, it seems likely that the nematode feeds upon the cytoplasm surrounding its anterior region. Unsuccessful attempts to demonstrate the uptake of trypan blue, colloidal gold, or ferritin injected into the host's circulatory system further suggest that this nematode feeds from the induced host reaction rather than from blood or tissue fluids.

scholarly journals High rates of extracellular superoxide generation by cultured human fibroblasts: involvement of a lipid-metabolizing enzyme

1996 ◽  
Vol 318 (3) ◽  
pp. 805-812 ◽  
Author(s):  
Valerie B. O'DONNELL ◽  
Angelo AZZI
Keyword(s):  
Nadph Oxidase ◽  
Human Fibroblasts ◽  
Extracellular Enzyme ◽  
Competitive Inhibitor ◽  
Superoxide Generation ◽  
Diphenylene Iodonium ◽  
Cultured Human Fibroblasts ◽  
Prostaglandin H ◽  
Metabolizing Enzyme ◽  
Hydroperoxyeicosatetraenoic Acid

Expression of NADPH oxidase and low superoxide generation (approx. 0.06 nmol/min per 106 cells) by cytokine- or ionophore-stimulated human fibroblasts is known. However, we here show that these cells also contain an ectoplasmic enzyme, distinct from NADPH oxidase, which can generate superoxide (2.19±0.14 nmol/min per 106 cells) at levels similar to phorbol ester-stimulated monocytes on exogenous NADH addition. Superoxide generation was temperature-dependent, insensitive to chelation (desferal), and had a Km(app)(NADH) of 11.5 µM. Inhibitor studies showed that there was no involvement of NADPH oxidase (diphenylene iodonium, diphenyl iodonium), prostaglandin H synthase (indomethacin), xanthine oxidase (allopurinol), cytochrome P-450 (metyrapone) or mitochondrial respiration (rotenone, antimycin A). NAD+ was a competitive inhibitor, whereas NADPH supported 40% of the rate seen with NADH. No luminescence was observed after the addition of lactate, malate, pyruvate, GSH or l-cysteine. NADH-stimulated superoxide generation was enhanced by the addition of (3–30 µM) arachidonic acid, linoleic acid or (5S)-hydroxyeicosatetraenoic acid [(5S)-HETE] but not palmitic acid, (15S)-hydroperoxyeicosatetraenoic acid [(15S)-HPETE], (15S)-HETE or (12S)-HETE. Several features suggest involvement of an enzyme related to 15-lipoxygenase, and, in support of this, we show superoxide generation and NADH oxidation by recombinant rabbit reticulocyte 15-lipoxygenase. The large amounts of superoxide measured suggest that the fibroblast extracellular enzyme could be a major source of reactive oxygen species after tissue damage.

scholarly journals Bactericidal activity of a superoxide anion-generating system. A model for the polymorphonuclear leukocyte.

1979 ◽  
Vol 149 (1) ◽  
pp. 27-39 ◽  
Author(s):  
H Rosen ◽  
S J Klebanoff
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Bactericidal Activity ◽  
Parent Strain ◽  
Carotenoid Pigments ◽  
Bacterial Killing ◽  
Oxidase System ◽  
System A ◽  
Presence And Absence ◽  
Generating System

The acetaldehyde-xanthine oxidase system in the presence and absence of myeloperoxidase (MPO) and chloride has been employed as a model of the oxygen-dependent antimicrobial systems of the PMN. The unsupplemented xanthine oxidase system was bactericidal at relatively high acetaldehyde concentrations. The bactericidal activity was inhibited by superoxide dismutase (SOD), catalase, the hydroxyl radical (OH.) scavengers, mannitol and benzoate, the singlet oxygen (1O2) quenchers, azide, histidine, and 1,4-diazabicyclo[2,2,2]octane (DABCO) and by the purines, xanthine, hypoxanthine, and uric acid. The latter effect may account for the relatively weak bactericidal activity of the xanthine oxidase system when purines are employed as substrate. A white, carotenoid-negative mutant strain of Sarcina lutea was more susceptible to the acetaldehyde-xanthine oxidase system than was the yellow, carotenoid-positive parent strain. Carotenoid pigments are potent 1O2 quenchers. The xanthine oxidase system catalyzes the conversion of 2,5-diphenylfuran to cis-dibenzoylethylene, a reaction which can occur by a 1O2 mechanism. This conversion is inhibited by SOD, catalase, azide, histidine, DABCO, xanthine, hypoxanthine, and uric acid but is only slightly inhibited by mannitol and benzoate. The addition of MPO and chloride to the acetaldehyde-xanthine oxidase system greatly increases bactericidal activity; the minimal effective acetaldehyde concentration is decreased 100-fold and the rate and extent of bacterial killing is increased. The bactericidal activity of the MPO-supplemented system is inhibited by catalase, benzoate, azide, DABCO, and histidine but not by SOD or mannitol. Thus, the acetaldehyde-xanthine oxidase system which like phagocytosing PMNs generates superoxide (O.2-) and hydrogen peroxide, is bactericidal both in the presence and absence of MPO and chloride. The MPO-supplemented system is considerably more potent; however, when MPO is absent, bactericidal activity is observed which may be mediated by the interaction of H2O2 and O.2- to form OH. and 1O2.

Protein kinase C-α and -δ are required for NADPH oxidase activation in WKYMVm-stimulated IMR90 human fibroblasts

2007 ◽  
Vol 459 (2) ◽  
pp. 288-294 ◽  
Author(s):  
Annalisa Iaccio ◽  
Claudio Collinet ◽  
Nicola Montesano Gesualdi ◽  
Rosario Ammendola
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Nadph Oxidase ◽  
Human Fibroblasts ◽  
Kinase C ◽  
Nadph Oxidase Activation

Topics in Chronic Granulomatous Disease

PEDIATRICS ◽  
1991 ◽  
Vol 88 (1) ◽  
pp. 183-185
Author(s):  
SHIGENOBU UMEKI
Keyword(s):  
Nadph Oxidase ◽  
Chronic Granulomatous Disease ◽  
Host Defense ◽  
Superoxide Anion ◽  
Fungal Infections ◽  
Regulatory Elements ◽  
Granulomatous Disease ◽  
Phagocytic Cells ◽  
Oxidase System ◽  
Membrane Bound

To the Editor.— Such phagocytic cells as neutrophils and macrophages are crucial elements in the host defense against bacterial [See table in the PDF file] and fungal infections. Microbicidal activity depends to a large extent on NADPH oxidase system, which can be activated by stimuli (bacteria, fungi) and which generates the superoxide anion and other highly reactive forms of reduced oxygen.1,2 The neutrophil NADPH oxidase system is composed functionally of membrane-bound catalytic components (which consist of at least two constituents, the low potential cytochrome b5583-5 and flavoprotein5) and soluble cytosolic components6,7 which participate as either catalytic or regulatory elements.

NADPH oxidase promotes NF-κB activation and proliferation in human airway smooth muscle

2002 ◽  
Vol 282 (4) ◽  
pp. L782-L795 ◽  
Author(s):  
Sukhdev S. Brar ◽  
Thomas P. Kennedy ◽  
Anne B. Sturrock ◽  
Thomas P. Huecksteadt ◽  
Mark T. Quinn ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Nadph Oxidase ◽  
Airway Smooth Muscle ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nuclear Factor Κb ◽  
Nicotinamide Adenine ◽  
Phagocytic Cells ◽  
Diphenylene Iodonium ◽  
Reduced Nicotinamide Adenine Dinucleotide

Evidence is rapidly accumulating that low-activity-reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases homologous to that in phagocytic cells generate reactive oxygen species as signaling intermediates in both endothelium and vascular smooth muscle. We therefore explored the possibility of such an oxidase regulating growth of airway smooth muscle (AWSM). Proliferation of human AWSM cells in culture was inhibited by the antioxidants catalase and N-acetylcysteine, and by the flavoprotein inhibitor diphenylene iodonium (DPI). Membranes prepared from human AWSM cells generated superoxide anion (O[Formula: see text]) measured by superoxide dismutase-inhibitable lucigenin chemiluminescence, with a distinct preference for NADPH instead of reduced nicotinamide adenine dinucleotide as substrate. Chemiluminescence was also inhibited by DPI, suggesting the presence of a flavoprotein containing oxidase generating O[Formula: see text] as a signaling molecule for cell growth. Examination of human AWSM cells by reverse transcriptase-polymerase chain reaction consistently demonstrated transcripts with sequences identical to those reported for p22phox. Transfection with p22phoxantisense oligonucleotides reduced human AWSM proliferation. Inhibition of NADPH oxidase activity with DPI prevented serum-induced activation of nuclear factor-κB (NF-κB), and overexpression of a superrepressor form of the NF-κB inhibitor IκBα significantly reduced human AWSM growth. These findings suggest that an NADPH oxidase containing p22phoxregulates growth-factor responsive human AWSM proliferation, and that the oxidase signals in part through activation of the prototypical redox-regulated transcription factor NF-κB.

O2-. release by activated Kupffer cells upon hypoxia-reoxygenation

1991 ◽  
Vol 261 (4) ◽  
pp. G602-G607 ◽  
Author(s):  
B. Rymsa ◽  
J. F. Wang ◽  
H. de Groot
Keyword(s):  
Nadph Oxidase ◽  
Kupffer Cells ◽  
Cell Injury ◽  
Cell Damage ◽  
Primary Cultures ◽  
Time Lag ◽  
Specific Inhibitor ◽  
Significant Difference ◽  
Reoxygenation Injury ◽  
Hypoxia Reoxygenation

Primary cultures of rat liver Kupffer cells generated large amounts of superoxide anion radical (O2-.) when subjected to reoxygenation after a hypoxic period of at least 2 h. O2-. formation reached its maximum rate of approximately 25 nmol/10(6) cells within 1 h after reoxygenation. Two to four hours after reoxygenation, the number of injured cells began to increase and after 10 h approximately 60% of the cells were dead. During the period of O2-. release no significant difference in cell viability was observed between reoxygenated and hypoxically incubated cells, indicating a distinct time lag between O2-. release and onset of cell damage. Addition of diphenyliodonium, a specific inhibitor of the neutrophilic NADPH oxidase, to the Kupffer cells just before reoxygenation diminished both O2-. formation and cell injury up to 70%. Reoxygenation injury was completely prevented when superoxide dismutase and catalase were added immediately before reoxygenation. The results indicate that Kupffer cells subjected to hypoxia-reoxygenation generate a burst of reactive oxygen species and that this kind of "activation," probably by activating the NADPH oxidase, contributes to the self-destruction of the cells.

Role of the Vascular NADH/NADPH Oxidase System in Atherosclerosis

2006 ◽  
Vol 902 (1) ◽  
pp. 241-248 ◽  
Author(s):  
MITSUHIRO YOKOYAMA ◽  
NOBUTAKA INOUE ◽  
SEINOSUKE KAWASHIMA
Keyword(s):  
Nadph Oxidase ◽  
Oxidase System
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