Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.3.1 (NADPH oxidase)
11,281 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

New selenium-containing compounds behave as GPx mimics and protect endothelial cells (HUVEC) from damage upon exposure to 55 microM linoleic acid hydroperoxide or to 200 microM hydrogen peroxide. The simultaneous presence of the GPx mimic and the hydroperoxyde is not necessary, since a pre-treatment of endothelial monolayers with 1 to 10 microM of such compounds, preserves their morphology, their cell density and their longer-term viability. The compounds which are most efficient in this model of oxidative stress also protect endothelial monolayers which have been incubated with an excess (10:1) of polymorphonuclear neutrophils (PMN) and with 1 ng/ml of TNF-alpha, if such monolayers are pre- and co-treated (10 microM). They inhibit the adhesion of activated neutrophils which show-up as polymorphous and very dense particles, in the vicinity of which endothelial alterations can be seen. The inhibition of leucocyte adhesion and that of endothelial activation/alteration have been quantified by means of immunoassays of myeloperoxidase and von Willebrand factor (vWf). The lead-compound BXT-51072 is not a direct inhibitor of the NADPH oxidase of PMN. TNF-alpha alone induces the endothelial release of Interleukin-8 (Il-8) as well as the expression of P- and E-selectin. The extent and the kinetics of inhibition of such processes by compound BXT-51072 would explain several of the effects observed in the presence of PMN. The GPx mimics also inhibit the endothelial production of Il-8 which is induced by Interleukin-1 alpha. Finally, compound BXT-51072 inhibits the endothelial expression of the adhesion factor VCAM-1 which is more slowly induced by TNF-alpha. Such antioxidant catalysts therefore protect endothelial cells from the toxic effects of TNF-alpha through mechanisms which include a down-regulation of cytokines and cell-adhesion factors.
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PMID:[Antioxidant and anti-inflammatory protection of vascular endothelial cells by new synthetic mimics of glutathione peroxidase]. 867 32

microdant stress is involved in the events that accompany endothelial cell expression of adhesion molecules and leukocyte adherence in many disease states, including atherosclerosis. A recently discovered benzo(b)pyran-4-one derivative, S17834 (10 to 50 micromol/L), reduced tumor necrosis factor-stimulated vascular cell adhesion molecule-1 (VCAM) mRNA accumulation and protein expression in human umbilical vein endothelial cells. Intercellular cell adhesion molecule-1 and E-selectin were also inhibited by S17834, but platelet endothelial cell adhesion molecule-1 was not. Adherence of U937 monocytic cells to the endothelial cells as well as to plastic plates coated with soluble VCAM, intercellular cell adhesion molecule-1, P-selectin, and E-selectin was also decreased. Consistent with an antioxidant mechanism of action, S17834 (10 to 50 micromol/L) inhibited tumor necrosis factor-stimulated release of superoxide from endothelial cells measured by cytochrome c reduction. S17834 had no effect on superoxide produced by xanthine oxidase, indicating that rather than by acting as a scavenger of superoxide anion, the drug acts by inhibiting the production of free radicals. Indeed, S17834 inhibited NADPH oxidase activity of endothelial cell membranes. The ability to inhibit superoxide anion production appears to be key in the effect of S17834 on superoxide anion production and VCAM expression, because these actions were mimicked by adenovirus-mediated overexpression of superoxide dismutase. Furthermore, these actions may be relevant in vivo, because S17834 reduced aortic superoxide anion levels by 40% and aortic atherosclerotic lesions by 60% in apolipoprotein E-deficient mice. These results indicate that S17834 inhibits adhesion molecule expression and adherence of leukocytes to endothelial cells as well as aortic atherogenesis and that perhaps these effects can be explained by its ability to inhibit endogenous superoxide anion production.
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PMID:S17834, a new inhibitor of cell adhesion and atherosclerosis that targets nadph oxidase. 1159 29

It is strongly suspected that cytokine-induced gene expression in inflammation is oxidant mediated; however, the intracellular sources of signaling oxidants remain controversial. In inflammatory bowel disease (IBD) proinflammatory cytokines, such as TNF-alpha, trigger gene expression of endothelial adhesion molecules including mucosal addressin cell adhesion molecule-1 (MAdCAM-1). MAdCAM-1 plays an essential role in gut inflammation by governing the infiltration of leukocytes into the intestine. Several groups suggest that endothelial-derived reduced NADP (NADPH) oxidase produces signaling oxidants that control the expression of adhesion molecules (E-selectin, ICAM-1, VCAM-1). In addition to NADPH oxidase, cytochrome P-450 (CYP450) monooxygenases have also been shown to trigger cytokine responses. We found that in high endothelial venular cells (SVEC4-10), multiple inhibitors of CYP450 monooxygenases (SKF-525a, ketoconazole, troleandomycin, itraconazole) attenuated TNF-alpha induction of MAdCAM-1, whereas NADPH oxidase inhibition (PR-39) did not. Conversely, E-selectin, ICAM-1, and VCAM-1 induction requires both NADPH oxidase and CYP450-derived oxidants. We show here that MAdCAM-1 induction may depend exclusively on CYP450-derived oxidants, suggesting that CYP450 blockers might represent a possible novel therapeutic treatment for human IBD.
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PMID:TNF-alpha -induced endothelial cell adhesion molecule expression is cytochrome P-450 monooxygenase dependent. 1238 57

The aim of this study was to quantify the expression of E-selectin, intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vascular endothelial cells (HUVECs) exposed to anoxia/reoxygenation (A/R) in the presence or absence of an inflammatory context (0.1 IU/ml tumor necrosis factor-alpha [TNF-alpha]) and to investigate the effects of two different NADPH inhibitors, apocynin and diphenyleneiodonium (DPI), on the expression of the endothelial cell adhesion molecules. Confluent HUVECs were exposed to anoxia for 3 hours (100% N2), followed by a reoxygenation period of 4 hours. TNF-alpha at 0.1 IU/ml was added to the medium either under normoxic conditions for 7 hours (TNF-alpha) or just before the start of anoxia (A/R + TNF-alpha). Levels of E-selectin, VCAM-1, and ICAM-1 were quantified using specific monoclonal antibodies revealed by an alkaline phosphatase-labeled goat F(ab)'2 fragment against mouse IgG antibody and the fluorescent substrate Attophos. Adhesion experiments were also performed using calcein-labeled U937 leukocytes. HUVECs submitted to A/R overexpressed E-selectin but not VCAM-1 or ICAM-1, whereas TNF-alpha at 0.1 IU/ ml increased the expression of all three adhesion molecules. In endothelial cells subjected to A/R in the presence of TNF-alpha, a synergistic increase of E-selectin expression and a synergistic adhesion of U937 cells was noted. The NADPH oxidase inhibitors apocynin and DPI both decreased significantly the U937 adhesion and the E-selectin overexpression on HUVECs submitted to A/R, TNF-alpha, or A/R + TNF-alpha. These results suggest that E-selectin expression is implicated in the leukocyte adhesion to HUVECs caused by A/R in the presence or absence of an inflammatory context. NADPH oxidase appears to participate in the E-selectin overexpression on HUVECs subjected either to A/R and/or TNF-alpha, suggesting a major role of this enzyme in the ischemia/reperfusion syndrome.
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PMID:Effect of NADPH oxidase inhibition on E-selectin expression induced by concomitant anoxia/reoxygenation and TNF-alpha. 1257 57

Activation of endothelial cell NF-kappaB by interleukin (IL)-1 constitutes an event critical to the progression of the innate immune response. In this context, oxidants have been associated with NF-kappaB activation, although the molecular source and mechanism of targeting have remained obscure. We found that RelA, essential for NF-kappaB activation by IL-1, was associated with the NADPH oxidase adapter protein p47(phox) in yeast two-hybrid, coprecipitation, and in vitro binding studies. RelA and p47-GFP also colocalized in endothelial cells in focal submembranous dorsoventral protrusions. Overexpression of p47(phox) synergized with IL-1beta in the activation of an artificial kappaB-luciferase reporter and specifically augmented IL-1beta-induced RelA transactivation activity. p47(phox) overexpression also greatly increased IL-1beta-stimulated RelA phosphorylation, whereas it had no effect on I-kappaB degradation or on RelA nuclear translocation or kappaB binding. The tandem SH3 domains of p47(phox) were found to associate with a proline-rich mid-region of RelA (RelA-PR) located between the Rel homology and transactivation domains. The RelA-PR peptide blocked interaction of p47(phox) and RelA, and ectopic expression of RelA-PR abrogated IL-1beta-induced transactivation of the NF-kappaB-dependent E-selectin promoter. Further, suppression of NADPH oxidase function through the inhibitor diphenylene iodonium, the superoxide dismutase mimetic Mn(III) tetrakis(4-benzoic acid)porphyrin (MnTBAP), or expression of a dominant interfering mutant of a separate NADPH oxidase subunit (p67(V204A)) decreased IL-1beta-induced E-selectin promoter activation, suggesting that p47(phox) facilitates NF-kappaB activation through linkage with the NADPH oxidase. IL-1beta rapidly increased tyrosine phosphorylation of IL-1 type I receptor-associated proteins, suggesting that oxidants may operate through inactivation of local protein-tyrosine phosphatases in the proximal IL-1beta signaling pathway leading to RelA activation.
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PMID:p47phox participates in activation of RelA in endothelial cells. 1261 29

Endothelial expression of E-selectin is enhanced in diabetic patients with retinopathy, however, the underlying mechanisms are unclear. Therefore, this study was aimed to determine if endothelial expression of E-selectin is stimulated with serum from type 2 diabetic patients with retinopathy, and whether this process is related to NAD(P)H oxidase-derived oxidative stress. Serum was obtained from type 2 diabetic patients with (T2DR) or without (T2DM) retinopathy, and age-matched non-diabetic healthy person (Control). Serum was added to in vitro-grown human coronary artery endothelial cells (HCAEC), after which E-selectin expression, reactive oxygen species (ROS) production, and NAD(P)H oxidase activity were measured. Serum from T2DR induced a significantly higher expression of E-selectin than serum from T2DM and control in association with an enhanced production of ROS in HCAEC. T2DR serum enhanced E-selectin expression in a ROS-dependent manner since this process was significantly attenuated not only by tiron (1 mM), a superoxide scavenger, but also by DPI (10 micromol/L) and apocynin (100 micromol/L), inhibitors of NAD(P)H oxidase. Furthermore, the activity of NADH oxidase was markedly increased by T2DR serum, and this was accompanied by the enhanced membrane translocation of p47phox, a cytosolic subunit of NAD(P)H oxidase. These findings suggest that serum from T2DR induced up-regulation of E-selectin expression in HCAEC, and this process might be dependent on activation of endothelial NADH oxidase via an enhanced membrane translocation of p47phox.
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PMID:NAD(P)H oxidase-stimulating activity of serum from type 2 diabetic patients with retinopathy mediates enhanced endothelial expression of E-selectin. 1634 54

Activation of the vascular endothelium with cytokines such as TNF is widely used to study the role of the vasculature in proinflammatory disease. To gain insight into mechanisms of prolonged vascular endothelial activation we compared changes in gene expression induced by continuous activation in stable tmTNF-expressing cells with changes due to acute TNF challenge in vitro. Affymetrix Genechip analysis was performed on RNA from control, acute and continuous TNF-activated endothelial cells. Only 36% of the significant changes in gene expression were convergent between the acute and continuously activated endothelial cells compared with the control. From the divergently regulated genes, for example the cytokine ENA-78 was specifically induced in chronically activated cells, while E-selectin, a cell adhesion molecule, was upregulated only in acutely activated endothelial cells. Antioxidant SOD gene induction was noted in acute activation, while a regulatory NADPH oxidase subunit was selectively upregulated in continuously activated endothelium in accordance with significant reactive oxygen species induction occurred only in these cells. Accordingly, p38 and ERK1/2, two MAP kinases downstream of reactive oxygen species, were activated in stable transmembrane-spanning precursor (tm) TNF-expressing cells and were refractory to activation with soluble TNF or VEGF. In consequence, the increased p38 MAP kinase activity contributed to increased endothelial cell migration in tmTNF-expressing cells. These data suggest that continuous activation of endothelial cells leads to specific expression and functional changes, consistent with alterations observed in dysfunctional endothelium exposed to or involved in chronic inflammation.
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PMID:Divergent and convergent effects on gene expression and function in acute versus chronic endothelial activation. 1756 77

Glycated human serum albumin (Glc-HSA) has previously been reported (Higai K., et al., 2006) to induce E-selectin expression on human umbilical vein endothelial cells through activation of NADPH oxidase; however, Glc-HSA signaling in monocytes remains obscure. To clarify the influence on human monocyte-derived U937 cells, U937 cells were stimulated with Glc-HSA and glycoaldehyde-dimer-modified HSA (GA-HSA) for 2 h in the absence and presence of the protein kinase C (PKC) inhibitor calphostin and the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC) and NADPH oxidase inhibitor apocynin; interleukin-8 (IL-8) mRNA expression was determined by RT-PCR. As a result, IL-8 mRNA expression in U-937 cells was time- and dose-dependently enhanced by stimulation with Glc-HSA and GA-HSA. Furthermore, promoter activity of the IL-8 reporter gene was enhanced approximately 2-fold by stimulation with Glc-HSA and GA-HSA. Nuclear factor kappaB (NFkappaB) and activator protein-1 (AP-1) reporter genes were also enhanced although CCAAT/enhancer binding protein (C/EBP) was not affected. IL-8 mRNA expression was suppressed by NAC and apocynin but not calphostin in cells stimulated with Glc-HSA; however, its expression in cells stimulated with GA-HSA was suppressed by calphostin but not NAC. These results indicated that IL-8 mRNA expression was upregulated by NFkappaB and AP-1 in U937 cells stimulated with Glc-HSA and GA-HSA, but the signaling pathways were different.
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PMID:Glycated human serum albumin induces interleukin 8 mRNA expression through reactive oxygen species and NADPH oxidase-dependent pathway in monocyte-derived U937 cells. 1791 46

Immune responses in the testis are regulated in a way that provides protection for the developing male germ cells, while permitting qualitatively normal inflammatory responses and protection against infection. In addition, germ cells are potent targets for the growth factors and cytokines which regulate the reproductive process. Our study analyzes for the first time the pattern of expression of several immune-relevant genes in the gonad of a seasonal breeding teleost fish. The immune molecules analyzed include (i) inflammatory molecules, such as interleukin-1b (il1b), il6, tumor necrosis factor-a (tnfa), cyclooxygenase-2 (cox2) and the NADPH oxidase subunit p40(phox) (ncf4 gene); (ii) the anti-inflammatory cytokine transforming growth factor-b1 (tgfb1) and its type 2 receptor tgfbr2; (iii) innate immune receptors, including toll-like receptor 9 (tlr9), tlr5, tlr22 and macrophage-colony stimulating factor receptor (mcsfr); (iv) lymphocyte receptors, such as the beta subunit of T-cell receptor (Tcrb) and the heavy chain of immunoglobulin M (ighm); (v) the anti-bacterial molecules lysozyme (lyz), hepcidin (hamp) and complement component 3 (c3); (vi) the anti-viral molecule myxovirus (influenza) resistance protein (mx); and (vii) molecules related to leukocyte infiltration, including the CC chemokine ccl4, the CXC chemokine il8 and the leukocyte adhesion molecule E-selectin (Sele). Notably, all of them show a pattern of expression that depends on the reproductive stage of the first two reproductive cycles when the fish develop and function as males. Furthermore, we demonstrate that some of these immune-relevant molecules, such as Il1b and Mcsfr, are produced by germ cells (Il1b) and ovarian and testicular somatic cells (Mcsfr). These data suggest that, as occurs in mammals, there is a critical balance between immune molecules and that these may play an essential role in the orchestration of gametogenesis and the maintenance of gonad tissue homeostasis in fish.
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PMID:Pattern of expression of immune-relevant genes in the gonad of a teleost, the gilthead seabream (Sparus aurata L.). 1832 94

Superoxide has been reported to be involved in vascular dysfunction in diabetes. The Ins2(Akita) mouse is an autosomal dominant mutant diabetic model that can serve as an excellent substitute for the Type 1 diabetic mouse model induced by chemical diabetogens. The purpose of the present study was to investigate the role of superoxide on vascular dysfunction using this new diabetic model. Compared with age-matched normal C57BL/6 mice, in Ins2(Akita) diabetic mice arterial superoxide, lipid peroxidation production (1.2 +/- 0.1 vs 17.4 +/- 1.9 mmol/mg tissue, respectively; P < 0.01) and plasma lipid peroxidation production (0.08 +/- 0.02 vs 0.40 +/- 0.03 mmol/L, respectively; P < 0.01) were increased. Meanwhile, expression of vascular adhesion molecule-1, E-selectin and monocyte chemoattractant protein-1 in the aorta and/or plasma was elevated. The contraction of carotid arteries to U46619 in Ins2(Akita) diabetic mice was significantly enhanced compared with control mice (P < 0.05). Tempol (a scavenger of superoxide), apocynin (an inhibitor of NADPH oxidase) and allopurinol (an inhibitor of xanthine oxidase) all not only decreased superoxide in carotid arteries, but also suppressed arterial contractions to U46619 in Ins2(Akita) diabetic mice. Indomethacin, an inhibitor of cyclo-oxygenase, and chelerythrine, an inhibitor of protein kinase C, also suppressed the enhanced vascular contraction. These results suggest that increased arterial superoxide generated from diverse sources may potentiate the contractions of carotid arteries in Ins2(Akita) diabetic mice.
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PMID:Increased superoxide contributes to enhancement of vascular contraction in Ins2(Akita) diabetic mice, an autosomal dominant mutant model. 1878 99


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