scholarly journals Neutrophils from p40phox−/− mice exhibit severe defects in NADPH oxidase regulation and oxidant-dependent bacterial killing

2006 ◽  
Vol 203 (8) ◽  
pp. 1927-1937 ◽  
Author(s):  
Chris D. Ellson ◽  
Keith Davidson ◽  
G. John Ferguson ◽  
Rod O'Connor ◽  
Len R. Stephens ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Critical Role ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Phagocytic Cells ◽  
Bacterial Killing ◽  
Catalytic Core ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Factor Α

The generation of reactive oxygen species (ROS) by the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex plays a critical role in the antimicrobial functions of the phagocytic cells of the immune system. The catalytic core of this oxidase consists of a complex between gp91phox, p22phox, p47phox, p67phox, p40phox, and rac-2. Mutations in each of the phox components, except p40phox, have been described in cases of chronic granulomatous disease (CGD), defining their essential role in oxidase function. We sought to establish the role of p40phox by investigating the NADPH oxidase responses of neutrophils isolated from p40phox−/− mice. In the absence of p40phox, the expression of p67phox is reduced by ∼55% and oxidase responses to tumor necrosis factor α/fibrinogen, immunoglobulin G latex beads, Staphylococcus aureus, formyl-methionyl-leucyl-phenylalanine, and zymosan were reduced by ∼97, 85, 84, 75, and 30%, respectively. The defect in ROS production by p40phox−/− neutrophils in response to S. aureus translated into a severe, CGD-like defect in the killing of this organism both in vitro and in vivo, defining p40phox as an essential component in bacterial killing.

scholarly journals Differential activation of RAGE by HMGB1 modulates neutrophil-associated NADPH oxidase activity and bacterial killing

2012 ◽  
Vol 302 (1) ◽  
pp. C249-C256 ◽  
Author(s):  
Jean-Marc Tadié ◽  
Hong-Beom Bae ◽  
Sami Banerjee ◽  
Jaroslaw W. Zmijewski ◽  
Edward Abraham
Keyword(s):  
Nadph Oxidase ◽  
Intraperitoneal Injection ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
High Mobility ◽  
Bacterial Killing ◽  
E Coli ◽  
Glycation End Products ◽  
Nadph Oxidase Activation

The receptor for advanced glycation end products (RAGE) plays an important role in host defense against bacterial infection. In the present experiments, we investigated the mechanisms by which RAGE contributes to the ability of neutrophils to eradicate bacteria. Wild-type ( RAGE+/+) neutrophils demonstrated significantly greater ability to kill Eschericia coli compared with RAGE−/−neutrophils. After intraperitoneal injection of E. coli , increased numbers of bacteria were found in the peritoneal fluid from RAGE−/−as compared with RAGE+/+mice. Exposure of neutrophils to the protypical RAGE ligand AGE resulted in activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and enhanced killing of E. coli , and intraperitoneal injection of AGE enhanced bacterial clearance during peritonitis. However, incubation of neutrophils with high mobility group box 1 protein (HMGB1), which also binds to RAGE, diminished E. coli -induced activation of NADPH oxidase in neutrophils and bacterial killing both in vitro and in vivo. Deletion of the COOH-terminal tail of HMGB1, a region necessary for binding to RAGE, abrogated the ability of HMGB1 to inhibit bacterial killing. Incubation of neutrophils with HMGB1 diminished bacterial or AGE-dependent activation of NADPH oxidase. The increase in phosphorylation of the p40phoxsubunit of NADPH oxidase that occurred after culture of neutrophils with E. coli was inhibited by exposure of the cells to HMGB1. These results showing that HMGB1, through RAGE-dependent mechanisms, diminishes bacterial killing by neutrophils as well as NADPH oxidase activation provide a novel mechanism by which HMGB1 can potentiate sepsis-associated organ dysfunction and mortality.

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.

Cadmium Chloride Induces Memory Deficits and Hippocampal Damage by Activating the JNK/p66Shc/NADPH Oxidase Axis

2020 ◽  
Vol 39 (5) ◽  
pp. 477-490
Author(s):  
Attalla Farag El-kott ◽  
Ali S. Alshehri ◽  
Heba S. Khalifa ◽  
Abd-El-karim M. Abd-Lateif ◽  
Mohammad Ali Alshehri ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Cadmium Chloride ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Male Rats ◽  
Hippocampal Damage ◽  
Vitro Experiment ◽  
In Vitro Experiment ◽  
In Vivo Experiment

This study investigated whether the mechanism underlying the neurotoxic effects of cadmium chloride (CdCl2) in rats involves p66Shc. This study comprised an initial in vivo experiment followed by an in vitro experiment. For the in vivo experiment, male rats were orally administered saline (vehicle) or CdCl2 (0.05 mg/kg) for 30 days. Thereafter, spatial and retention memory of rats were tested and their hippocampi were used for biochemical and molecular analyses. For the in vitro experiment, control or p66Shc-deficient hippocampal cells were treated with CdCl2 (25 µM) in the presence or absence of SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. Cadmium chloride impaired the spatial learning and retention memory of rats; depleted levels of glutathione and manganese superoxide dismutase; increased reactive oxygen species (ROS), tumor necrosis factor α, and interleukin 6; and induced nuclear factor kappa B activation. Cadmium chloride also decreased the number of pyramidal cells in the CA1 region and induced severe damage to the mitochondria and endoplasmic reticulum of cells in the hippocampi of rats. Moreover, CdCl2 increased the total unphosphorylated p66Shc, phosphorylated (Ser36) p66Shc, phosphorylated JNK, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, cytochrome c, and cleaved caspase-3. A dose–response increase in cell death, ROS, DNA damage, p66Shc, and NADPH oxidase was also observed in cultured hippocampal cells treated with CdCl2. Of note, all of these biochemical changes were attenuated by silencing p66Shc or inhibiting JNK with SP600125. In conclusion, CdCl2 induces hippocampal ROS generation and apoptosis by promoting the JNK-mediated activation of p66Shc.

scholarly journals Dextromethorphan Reduces Oxidative Stress and Inhibits Uremic Artery Calcification

2021 ◽  
Vol 22 (22) ◽  
pp. 12277
Author(s):  
En-Shao Liu ◽  
Nai-Ching Chen ◽  
Tzu-Ming Jao ◽  
Chien-Liang Chen
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Vascular Calcification ◽  
Wistar Rats ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Oxidase Inhibitor ◽  
In Vivo Studies ◽  
Ros Production

Medial vascular calcification has emerged as a key factor contributing to cardiovascular mortality in patients with chronic kidney disease (CKD). Vascular smooth muscle cells (VSMCs) with osteogenic transdifferentiation play a role in vascular calcification. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors reduce reactive oxygen species (ROS) production and calcified-medium–induced calcification of VSMCs. This study investigates the effects of dextromethorphan (DXM), an NADPH oxidase inhibitor, on vascular calcification. We used in vitro and in vivo studies to evaluate the effect of DXM on artery changes in the presence of hyperphosphatemia. The anti-vascular calcification effect of DXM was tested in adenine-fed Wistar rats. High-phosphate medium induced ROS production and calcification of VSMCs. DXM significantly attenuated the increase in ROS production, the decrease in ATP, and mitochondria membrane potential during the calcified-medium–induced VSMC calcification process (p < 0.05). The protective effect of DXM in calcified-medium–induced VSMC calcification was not further increased by NADPH oxidase inhibitors, indicating that NADPH oxidase mediates the effect of DXM. Furthermore, DXM decreased aortic calcification in Wistar rats with CKD. Our results suggest that treatment with DXM can attenuate vascular oxidative stress and ameliorate vascular calcification.

scholarly journals Active involvement of catalase during hemolytic crises of favism

Blood ◽  
1996 ◽  
Vol 88 (3) ◽  
pp. 1084-1088 ◽  
Author(s):  
GF Gaetani ◽  
M Rolfo ◽  
S Arena ◽  
R Mangerini ◽  
GF Meloni ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Past History ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Human Erythrocytes ◽  
Active Involvement ◽  
Fava Beans ◽  
Minimal Reduction ◽  
Reduced Nicotinamide Adenine Dinucleotide

Abstract The endemic occurrence of favism in certain Mediterranean regions provided an investigative opportunity for testing in vivo the validity of claims as to the role of catalase in protecting human erythrocytes against peroxidative injury. Reduced activity of catalase was found in the erythrocytes of six boys who were deficient in erythrocytic glucose- 6-phosphate dehydrogenase (G6PD) and who were studied while suffering hemolysis after ingesting fava beans. Activity of catalase was further reduced when their red blood cells were incubated with aminotriazole. In contrast, minimal reduction of catalase activity was found, both with and without incubation with aminotriazole, in erythrocytes of a G6PD-deficient boy who had ingested fava beans 7 days earlier and in erythrocytes of seven G6PD-deficient men with a past history of favism. These results confirmed earlier studies in vitro indicating that catalase is a major disposer of hydrogen peroxide in human erythrocytes and, like the glutathione peroxidase/reductase pathway, is dependent on the availability of reduced nicotinamide adenine dinucleotide phosphate (NADPH). The effect of divicine on purified catalase and on the catalase of intact G6PD-deficient erythrocytes was similar to the previously demonstrated effect on catalase of a known system for generating hydrogen peroxide. This effect of divicine strengthens earlier arguments that divicine is the toxic peroxidative component of fava beans.

scholarly journals A novel pathway spatiotemporally activates Rac1 and redox signaling in response to fluid shear stress

2013 ◽  
Vol 201 (6) ◽  
pp. 863-873 ◽  
Author(s):  
Yunhao Liu ◽  
Caitlin Collins ◽  
William B. Kiosses ◽  
Ann M. Murray ◽  
Monika Joshi ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Molecular Mechanisms ◽  
Fluid Shear Stress ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Redox Signaling ◽  
Hemodynamic Forces ◽  
Rac1 Gtpase ◽  
Embryonic Organ

Hemodynamic forces regulate embryonic organ development, hematopoiesis, vascular remodeling, and atherogenesis. The mechanosensory stimulus of blood flow initiates a complex network of intracellular pathways, including activation of Rac1 GTPase, establishment of endothelial cell (EC) polarity, and redox signaling. The activity of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase can be modulated by the GTP/GDP state of Rac1; however, the molecular mechanisms of Rac1 activation by flow are poorly understood. Here, we identify a novel polarity complex that directs localized Rac1 activation required for downstream reactive oxygen species (ROS) production. Vav2 is required for Rac1 GTP loading, whereas, surprisingly, Tiam1 functions as an adaptor in a VE-cadherin–p67phox–Par3 polarity complex that directs localized activation of Rac1. Furthermore, loss of Tiam1 led to the disruption of redox signaling both in vitro and in vivo. Our results describe a novel molecular cascade that regulates redox signaling by the coordinated regulation of Rac1 and by linking components of the polarity complex to the NADPH oxidase.

scholarly journals Digestive vacuole of Plasmodium falciparum released during erythrocyte rupture dually activates complement and coagulation

Blood ◽  
2012 ◽  
Vol 119 (18) ◽  
pp. 4301-4310 ◽  
Author(s):  
Prasad Dasari ◽  
Sophia D. Heber ◽  
Maike Beisele ◽  
Michael Torzewski ◽  
Kurt Reifenberg ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Inflammatory Responses ◽  
Alternative Pathway ◽  
Critical Role ◽  
Plasmodium Falciparum Malaria ◽  
Digestive Vacuole ◽  
Phagocytic Cells ◽  
Nociceptive Responses

Abstract Severe Plasmodium falciparum malaria evolves through the interplay among capillary sequestration of parasitized erythrocytes, deregulated inflammatory responses, and hemostasis dysfunction. After rupture, each parasitized erythrocyte releases not only infective merozoites, but also the digestive vacuole (DV), a membrane-bounded organelle containing the malaria pigment hemozoin. In the present study, we report that the intact organelle, but not isolated hemozoin, dually activates the alternative complement and the intrinsic clotting pathway. Procoagulant activity is destroyed by phospholipase C treatment, indicating a critical role of phospholipid head groups exposed at the DV surface. Intravenous injection of DVs caused alternative pathway complement consumption and provoked apathy and reduced nociceptive responses in rats. Ultrasonication destroyed complement-activating and procoagulant properties in vitro and rendered the DVs biologically inactive in vivo. Low-molecular-weight dextran sulfate blocked activation of both complement and coagulation and protected animals from the harmful effects of DV infusion. We surmise that in chronic malaria, complement activation by and opsonization of the DV may serve a useful function in directing hemozoin to phagocytic cells for safe disposal. However, when the waste disposal system of the host is overburdened, DVs may transform into a trigger of pathology and therefore represent a potential therapeutic target in severe malaria.

scholarly journals Role of Nox2 and p22phox in Persistent Postoperative Hypertension in Aldosterone-Producing Adenoma Patients after Adrenalectomy

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaojing Geng ◽  
Li Yan ◽  
Jun Dong ◽  
Ying Liang ◽  
Yajuan Deng ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Secondary Hypertension ◽  
Zona Glomerulosa ◽  
Catalytic Core ◽  
Plasma Aldosterone Concentration ◽  
Unilateral Adrenalectomy ◽  
Protein Levels ◽  
Aldosterone Producing Adenoma

Adrenal aldosterone-producing adenoma (APA), producing the salt-retaining hormone aldosterone, commonly causes secondary hypertension, which often persists after unilateral adrenalectomy. Although persistent hypertension was correlated with residual hormone aldosterone, thein vivomechanism remains unclear. NADPH oxidase is the critical cause of aldosterone synthesisin vitro. Nox2 and p22phox comprise the NADPH oxidase catalytic core, serving to initiate a reactive oxygen species (ROS) cascade that may participate in the pathology. mRNAs of seven NADPH oxidase isoforms in APA were evaluated by RT-PCR and Q-PCR and their proteins by immunohistochemistry and Western blotting. NADPH oxidase activity was also detected. Nox2 and p22phox were especially abundant in APA. Particularly higher Nox2 and p22phox gene and protein levels were seen in APA than controls. Significant correlations betweenNox2mRNA andaldosterone synthase (CYP11B2)mRNA (R=0.66,P<0.01) and Nox2 protein and baseline plasma aldosterone concentration (PAC) (R=0.503,P<0.01) were detected in APA; however, none were found betweenp22phoxmRNA,CYP11B2mRNA,p22phoxprotein, and baseline PAC. Importantly, we found that Nox2 localized specifically in hyperplastic zona glomerulosa cells. In conclusion, our results highlight that Nox2 and p22phox may be directly involved in pathological aldosterone production and zona glomerulosa cell proliferation after APA resection.

Angiotensin II increases the expression of the transcription factor ETS-1 in mesangial cells

2008 ◽  
Vol 294 (5) ◽  
pp. F1094-F1100 ◽  
Author(s):  
Damien D. Pearse ◽  
Run-Xia Tian ◽  
Jessica Nigro ◽  
Julian B. Iorgulescu ◽  
Leopold Puzis ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Angiotensin Ii ◽  
Nadph Oxidase ◽  
Mesangial Cells ◽  
Critical Role ◽  
Ang Ii ◽  
Specific Sequence ◽  
Cox 2

Maladaptive activation of the renin-angiotensin system (RAS) has been shown to play a critical role in the pathogenesis of chronic kidney disease. Reactive oxygen species (ROS) are critical signals for many of the nonhemodynamic effects of angiotensin II (ANG II). We have demonstrated that ANG II increases mesangial and cortical cyclooxygenase-2 (COX-2) expression and activity via NADPH oxidase-derived ROS. The transcription factor ETS-1 (E26 transformation-specific sequence) has been identified as a critical regulator of growth-related responses and inflammation. The present studies were designed to determine: 1) whether ANG II induces ETS-1 expression in vitro in cultured rat mesangial cells and in vivo in rats infused with ANG II; and 2) whether ROS and COX-2 are mediators of ETS-1 induction in response to ANG II. Mesangial cells stimulated with ANG II (10−7 M) exhibited a significant increase in ETS-1 expression that was prevented by the angiotensin type 1 receptor blocker candesartan. NADPH oxidase inhibition with dyphenilene iodinium or apocynin also prevented ETS-1 induction, establishing the role of ROS as mediators of ETS-1 expression in response to ANG II. COX-2 inhibition prevented ETS-1 expression in response to ANG II, suggesting that COX-2 is required for ETS-1 induction. By utilizing short interfering RNAs against ETS-1, we have also determined that ETS-1 is required to induce the production of fibronectin in response to ANG II. Furthermore, rats infused with ANG II manifested increased glomerular expression of ETS-1. These studies unveil novel pathways that may play an important role in the pathogenesis of renal injury when RAS is activated.

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