Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:1.6.3.1 (NADPH oxidase)
11,281 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Superoxide anions (O(*-)(2)) induce oxidative stress and reduce endothelial NO availability by peroxynitrite formation. In human endothelial cells gp91(phox) was identified as the limiting subunit of the forming NAD(P)H oxidase. Because endothelin-1 (ET-1) is considered as a pro-atherosclerotic stimulus, we analyzed the effect of ET-1 on gp91(phox) expression and O(*-)(2) generation in primary cultures of human umbilical vein endothelial cells (HUVECs). The gp91(phox) mRNA expression was quantified by standard calibrated competitive reverse transcriptase-polymerase chain reaction. ET-1 induces gp91(phox) mRNA expression in HUVEC (max. after 1 h). The induction of gp91(phox) expression was dose-dependent, reaching its maximum at 10 nmol/L ET-1. The increased gp91(phox) expression is mediated by endothelial receptor type B (ET(B)). Furthermore, ET-1 augments O(*-)(2) generation in human endothelial cells as measured by coelenterazine chemiluminescence. These data support a new mechanism: how ET-1 increases oxidative stress in the vessel wall leading to endothelial dysfunction and enhanced susceptibility to atherosclerosis.
...
PMID:Endothelin-1 induces NAD(P)H oxidase in human endothelial cells. 1072 Apr 82

The potent vasoconstrictor peptide endothelin-1 (ET-1) has been implicated in the pathophysiology of atherosclerosis and its complications. Since inflammation of the vessel wall is a hallmark of atherosclerosis, the purpose of the present study was to investigate the influence of ET-1 on cytokine production in human vascular smooth muscle cells (SMC) as a marker of inflammatory cell activation. ET-1 (100 pM - 1 microM) stimulated interleukin-6 (IL-6) secretion from human vascular SMC in a concentration-dependent manner. The ET-A-receptor antagonist BQ-123 (10 microM), but not the ET-B-receptor antagonist BQ-788, inhibited IL-6 release. ET-1 also transiently increased IL-6 mRNA compatible with regulation of IL-6 release at the pretranslational level. Electrophoretic mobility shift assays demonstrated time- and concentration-dependent activation of the proinflammatory transcription factor nuclear factor-kappaB (NF-kappaB) in ET-1-stimulated human vascular SMC. A decoy oligodeoxynucleotide bearing the NF-kappaB binding site inhibited ET-1-stimulated IL-6 release to a great extent suggesting that this transcription factor plays a key role for cytokine production elicited by ET-1. Moreover, the antioxidant pyrrolidine dithiocarbamate (10 microM) inhibited ET-1-induced IL-6 release indicating involvement of reactive oxygen species in ET-1 signaling. ET-1-stimulated IL-6 secretion was also suppressed by diphenylene iodonium (40 microM), an inhibitor of flavon-containing enzymes such as NADH/NADPH oxidase. The results demonstrate the ability of ET-1 to induce an inflammatory response in human vascular SMC. These observations may contribute to a better understanding of the role of ET-1 in inflammatory activation of the vessel wall during atherogenesis.
...
PMID:Endothelin-1 induces interleukin-6 release via activation of the transcription factor NF-kappaB in human vascular smooth muscle cells. 1082 1

Oxidative stress in blood vessels and the kidney in hypertension can be induced by diverse vasoconstrictor mechanisms, including blockade of nitric oxide synthase and activation of angiotensin II type I receptors and thromboxane receptors. It can cause vasoconstriction via bioinactivation of nitric oxide, and by nitric oxide synthase independent mechanisms that include increased generation of endothelin-1 and the effects of superoxide anion and hydrogen peroxide on vascular smooth muscle cells. Oxidative stress can accompany hypertension in many models including the spontaneously hypertensive rat, the angiotensin II-infused rat, renovascular hypertension, the deoxycorticosterone acetate-salt model, and obesity-related hypertension. In the kidney, NADPH oxidase-generating superoxide anion is expressed in the vasculature, interstitium, juxtaglomerular apparatus, and the distal nephron. Much progress has been made in defining the pathways that intervene between agonist stimulation of blood vessels and reactive oxygen species-mediated contractile and renal functional responses in animal models in hypertension.
...
PMID:Reactive oxygen species: roles in blood pressure and kidney function. 1188 72

1. The biosynthesis of endothelin-1 is increased in the diabetic state. So this peptide may cause diabetic vascular complications. We tested this possibility by chronically administering J-104132, a potent orally active mixed antagonist of endothelin A and B (ET(A)/ET(B)) receptors to streptozotocin (STZ)-induced diabetic rats and focusing on changes in endothelial function. 2. The acetylcholine (ACh)-induced endothelium-dependent relaxation was impaired in diabetic rats and this impairment was significantly attenuated following chronic administration of J-104132 (10 mg kg(-1), p.o., daily for 4 weeks). 3. In an in vitro experiment using aortae from diabetic rats, the ACh-induced relaxation was not changed by the presence of J-104132 (3 x 10(-9) M). 4. The expression levels of the mRNA for endothelial nitric oxide synthase was comparable among aortae from the three groups (control, diabetic and chronically J-104132-treated diabetic). 5. The amount of superoxide anion was significantly greater in aortae from diabetic rats than in controls. Chronic J-104132 treatment significantly decreased the level of superoxide anion in diabetic rats. 6. The expression of the p22phox mRNA for the NADH/NADPH oxidase subunit was significantly increased in STZ-induced diabetic rats and this increase was completely prevented by chronic administration of J-104132. 7. These results suggest that in STZ-induced diabetic rats, ET-1 may be directly involved in impairing endothelium-dependent relaxation via increased superoxide-anion production.
...
PMID:Effects of chronic administration of the novel endothelin antagonist J-104132 on endothelial dysfunction in streptozotocin-induced diabetic rat. 1195 96

We examined the mechanism of action of lysophosphatidylcholine (lyso-PC), which is suggested to be involved in the pathogenesis of atherosclerosis and inflamatory disorders, and its interaction with well-known vasoactive compounds such as hydrogen peroxide (H2O2), thromboxane A2 (TX-A2), serotonin (5-HT), angiotensin II (Ang-II), endothelin-1 (ET-1), or urotensin II (U-II) on VSMC proliferation. Growth-arrested rabbit VSMCs were incubated with given concentrations of lyso-PC with H202, TX-A2, 5-HT, Ang-II, ET-1, or U-II. [3H]Thymidine incorporation into DNA was measured as an index of VSMC proliferation. Lyso-PC induced a maximal effect on [3H]thymidine incorporation at a concentration of 15 microM (156%), and its effect was significantly inhibited by the phospholipase C inhibitor U73122 (10 microM), the intracellular antioxidant NAC (400 microM), and the NADPH oxidase inhibitor diphenylene iodonium (1 microM), but not by the MAPK kinase inhibitor (10 microM). H2O2, TX-A2, 5-HT, Ang-II, ET-1, or U-II also stimulated [3H]thymidine incorporation in a dose-dependent manner. A non-mitogenic concentration of lyso-PC (5 microM) significantly potentiated the effect of low concentrations of H2O2 (0.1 microM, 110 to 222%), TX-A2 (5 microM, 120 to 202%), 5-HT (5 microM, 182 to 259%), Ang-II (0.5 microM, 167 to 304%), ET-1 (0.01 microM, 139 to 297%), or U-II (0.025 microM, 120 to 332%) on [3H]thymidine incorporation. The results suggest that lyso-PC acts synergistically with the vasoactive compounds H2O2, TX-A2, 5-HT, Ang-II, ET-1, or U-II in inducing VSMC proliferation, which may play an important role in the progression of atherosclerosis.
...
PMID:Lysophosphatidylcholine potentiates the mitogenic effect of various vasoactive compounds on rabbit aortic smooth muscle cells. 1222 16

An elevated vascular superoxide anion formation has been implicated in the initiation and progression of hypertension and atherosclerosis. In this review, we would like to discuss the generation of superoxide anions by an NADPH oxidase complex in vascular cells. Special focus is on the induction of endothelial NADPH oxidase by proatherosclerotic stimuli. We propose a proatherosclerotic vicious cycle of increased NADPH oxidase-dependent superoxide anion formation, augmented generation and uptake of oxidatively modified low-density lipoprotein, and further potentiation of oxidative stress by oxidized low-density lipoprotein itself, angiotensin II, and endothelin-1 in endothelial cells. Furthermore, novel homologues of NADPH oxidase subunit gp91(phox) are summarized. Future directions of research for a better understanding of the role of NADPH oxidase in the pathogenesis of atherosclerosis and clinical implications are discussed.
...
PMID:NADPH oxidase in endothelial cells: impact on atherosclerosis. 1271 77

High glucose (HG) is the underlying factor contributing to long term complications of diabetes mellitus. The molecular mechanisms transforming the glomerular mesangial cell phenotype to cause nephropathy including diacylglycerol-sensitive protein kinase C (PKC) are still being defined. Reactive oxygen species (ROS) have been postulated as a unifying mechanism for HG-induced complications. We hypothesized that in HG an interaction between ROS generation, from NADPH oxidase, and PKC suppresses mesangial Ca2+ signaling in response to endothelin-1 (ET-1). In primary rat mesangial cells, growth-arrested (48 h) in 5.6 mM (NG) or 30 mm (HG) glucose, the total cell peak [Ca2+]i response to ET-1 (50 nM) was 630 +/- 102 nM in NG and was reduced to 159 +/- 15 nM in HG, measured by confocal imaging. Inhibition of PKC with phorbol ester down-regulation in HG normalized the ET-1-stimulated [Ca2+]i response to 541 +/- 74 nM. Conversely, an inhibitory peptide specific for PKC-zeta did not alter Ca2+ signaling in HG. Furthermore, overexpression of conventional PKC-beta or novel PKC-delta in NG diminished the [Ca2+]i response to ET-1, reflecting the condition observed in HG. Likewise, catalase or p47phox antisense oligonucleotide normalized the [Ca2+]i response to ET-1 in HG to 521 +/- 58 nM and 514 +/- 48 nM, respectively. Pretreatment with carbonyl cyanide m-chlorophenylhydrazone or rotenone did not restore Ca2+ signaling in HG. Detection of increased intracellular ROS in HG by dichlorofluorescein was inhibited by catalase, diphenyleneiodonium, or p47phox antisense oligonucleotide. HG increased p47phox mRNA by 1.7 +/- 0.1-fold as measured by reverse transcriptase-PCR. In NG, H2O2 increased membrane-enriched PKC-beta and -delta, suggesting activation of these isozymes. HG-enhanced immunoreactivity of PKC-delta visualized by confocal imaging was attenuated by diphenyleneiodium chloride. Thus, mesangial cell [Ca2+]i signaling in response to ET-1 in HG is attenuated through an interaction mechanism between NADPH oxidase ROS production and diacylglycerol-sensitive PKC.
...
PMID:High glucose-suppressed endothelin-1 Ca2+ signaling via NADPH oxidase and diacylglycerol-sensitive protein kinase C isozymes in mesangial cells. 1282 78

Deoxycorticosterone acetate (DOCA)-salt hypertension is characterized by low renin/angiotensin but increased arterial superoxide levels. We have recently reported that the arterial endothelin-1 (ET-1) level is increased, resulting in NADPH oxidase activation and superoxide generation. However, the effect of ET-1 on venous superoxide production and its relation to venoconstriction are unknown. The present study tested the hypotheses that ET-1 stimulates venous NADPH oxidase and superoxide via its ET(A) receptors, resulting in enhanced venoconstriction in DOCA-salt hypertensive rats. Treatment with ET-1 (0.01 to 1 nmol/L), but not the selective ET(B) receptor agonist sarafotoxin s6c, of vena cavas of normal rats concentration-dependently increased superoxide levels, an effect that was abolished by the selective ET(A) receptor antagonist ABT-627. Although the ET-1 level was not increased in the vena cava and plasma, both venous NADPH oxidase activity and superoxide levels were significantly higher in DOCA-salt compared with sham rats. Moreover, ET-1 treatment (10(-9) mol/L, 10 minutes) of isolated vena cavas further elevated superoxide levels in DOCA-salt rats only but not sham rats, an effect that was abrogated by the superoxide scavenger tempol. Similarly, ET-1-induced contractions of isolated vena cavas of DOCA-salt but not sham rats were significantly inhibited by tempol. The NADPH oxidase inhibitor apocynin significantly reduced superoxide levels in vena cavas of DOCA-salt rats and in ET-1-treated vena cavas of normal rats. Finally, in vivo ET(A) receptor blockade by ABT-627 significantly lowered venous superoxide levels and blood pressure in DOCA-salt but not sham rats. These results suggest that superoxide contributes to ET-1-induced venoconstriction through an elevated venous NADPH oxidase activity in mineralocorticoid hypertension.
...
PMID:NADPH oxidase-derived superoxide augments endothelin-1-induced venoconstriction in mineralocorticoid hypertension. 1288 92

Although hypertension is a major risk factor for atherosclerosis, its underlying mechanisms remain to be delineated. We have recently reported that both endothelin-1 (ET-1) and vascular cellular adhesion molecule-1 (VCAM-1) levels, key early markers of atherosclerosis, are significantly elevated in carotid arteries of deoxycorticosterone acetate (DOCA)-salt hypertensive rats, a model known for its suppressed plasma renin levels. This study tested the hypothesis that ET-1 augments arterial VCAM-1 expression through NADPH oxidase-derived superoxide (O2-). Carotid arteries of DOCA-salt or sham-operated rats were transduced ex vivo with extracellular superoxide dismutase (EC-SOD), dominant negative HA-tagged N17Rac1 that inhibits Rac1, the small GTPase component of NADPH oxidase, or beta-galactosidase (beta-gal) reporter gene (5x10(10) plaque formation units [pfu]/mL), and the effect of transgene expression on O2- and VCAM-1 levels was assayed 24 hours afterward. The arterial activity of NADPH oxidase but not xanthine oxidase was significantly higher in DOCA-salt than in sham rats, which was abolished by the selective ETA receptor antagonist ABT-627 (3x10(-8) mol/L), NADPH oxidase inhibitor apocynin (10(-4) mol/L), or dominant negative Rac1 gene transfer. The levels of O2- and VCAM-1 were significantly increased in arteries of DOCA-salt rats, an effect that was ameliorated after EC-SOD or dominant negative Rac1 but not beta-gal reporter gene transfer. ABT-627 and apocynin also significantly reduced elevated VCAM-1 levels in ET-1-treated arteries of normal rats and arteries of DOCA-salt rats. The results of this study indicate that ET-1 stimulates arterial VCAM-1 expression by producing O2- from an ETA receptor/NADPH oxidase pathway in low-renin mineralocorticoid hypertension.
...
PMID:Endothelin-1 stimulates arterial VCAM-1 expression via NADPH oxidase-derived superoxide in mineralocorticoid hypertension. 1451 26

Diabetes is associated with increased risk for complications following coronary bypass grafting (CABG) surgery. Augmented superoxide (*O2*) production plays an important role in diabetic complications by causing vascular dysfunction. The potent vasoconstrictor endothelin-1 (ET-1) is also elevated in diabetes and following CABG; however, the effect of ET-1 on *O2* generation and/or vascular dysfunction in bypass conduits remain unknown. Accordingly, this study investigated basal and ET-1-stimulated *O2* production in bypass conduits and determined the effect of *O2* on conduit reactivity. Saphenous vein specimens were obtained from nondiabetic (n = 24) and diabetic (n = 24) patients undergoing CABG. Dihydroethidium staining and NAD(P)H oxidase activity assays (5380 +/- 940 versus 16,362 +/- 2550 relative light units/microg) demonstrated increased basal *O2* levels in the diabetes group (p < 0.05). Plasma ET-1 levels were associated with elevated basal *O2* levels, and treatment of conduits with exogenous ET-1 further increased *O2* production and augmented vasoconstriction. Furthermore, vascular relaxation was impaired in the diabetic group (75 versus 40%), which was restored by *O2* scavenger superoxide dismutase. These findings suggest that ET-1 causes bypass conduits dysfunction via stimulation of *O2* production in diabetes. Novel therapies that attenuate *O2* generation in bypass conduits may improve acute and late outcome of CABG in diabetic patients.
...
PMID:Vascular dysfunction of venous bypass conduits is mediated by reactive oxygen species in diabetes: role of endothelin-1. 1560 82


1 2 3 4 5 6 7 8 9 Next >>

---