scholarly journals Nox2-derived oxidative stress results in inefficacy of antibiotics against post-influenza S. aureus pneumonia

2016 ◽  
Vol 213 (9) ◽  
pp. 1851-1864 ◽  
Author(s):  
Keer Sun ◽  
Vijaya Kumar Yajjala ◽  
Christopher Bauer ◽  
Geoffrey A. Talmon ◽  
Karl J. Fischer ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Influenza Infection ◽  
Treatment Strategies ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Inflammatory Cells ◽  
Oxidase Inhibitor ◽  
Lung Damage ◽  
Surrounding Tissue ◽  
Staphylococcus Aureus Pneumonia

Clinical post-influenza Staphylococcus aureus pneumonia is characterized by extensive lung inflammation associated with severe morbidity and mortality even after appropriate antibiotic treatment. In this study, we show that antibiotics rescue nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (Nox2)–deficient mice but fail to fully protect WT animals from influenza and S. aureus coinfection. Further experiments indicate that the inefficacy of antibiotics against coinfection is attributable to oxidative stress–associated inflammatory lung injury. However, Nox2-induced lung damage during coinfection was not associated with aggravated inflammatory cytokine response or cell infiltration but rather caused by reduced survival of myeloid cells. Specifically, oxidative stress increased necrotic death of inflammatory cells, thereby resulting in lethal damage to surrounding tissue. Collectively, our results demonstrate that influenza infection disrupts the delicate balance between Nox2-dependent antibacterial immunity and inflammation. This disruption leads to not only increased susceptibility to S. aureus infection, but also extensive lung damage. Importantly, we show that combination treatment of antibiotic and NADPH oxidase inhibitor significantly improved animal survival from coinfection. These findings suggest that treatment strategies that target both bacteria and oxidative stress will significantly benefit patients with influenza-complicated S. aureus pneumonia.

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 Impaired Insulin Secretion by Diphenyleneiodium Associated with Perturbation of Cytosolic Ca2+ Dynamics in Pancreatic β-Cells

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5391-5400 ◽  
Author(s):  
Hirofumi Imoto ◽  
Nobuhiro Sasaki ◽  
Masanori Iwase ◽  
Udai Nakamura ◽  
Miwako Oku ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Nadph Oxidase ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Mitochondrial Respiratory Chain ◽  
Membrane Depolarization ◽  
Oxidase Inhibitor ◽  
Channel Blockers ◽  
Β Cells ◽  
Impaired Insulin Secretion ◽  
Impaired Insulin

Pancreatic islets express the superoxide-producing nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system, but its role remains unknown. To address this, we studied the mechanisms of impaired insulin secretion induced by diphenyleneiodium (DPI), an NADPH oxidase inhibitor. We investigated the effects of DPI on glucose- and nonfuel-stimulated insulin secretion, islet glucose metabolism, and intracellular Ca2+ concentration ([Ca2+]i) dynamics in rat islets and β-cell line RINm5F cells. DPI did not affect insulin secretion at 3.3 mm glucose but totally suppressed insulin secretion stimulated by 16.7 mm glucose (percentage of control, 9.2 ± 1.2%; P &lt;0.001). DPI also inhibited insulin release by high K+-induced membrane depolarization (percentage of control, 36.0 ± 5.3%; P &lt;0.01) and protein kinase C activation (percentage of control, 30.2 ± 10.6% in the presence of extracellular Ca2+, P &lt;0.01; percentage of control, 42.0 ± 4.7% in the absence of extracellular Ca2+, P &lt;0.01). However, DPI had no effect on mastoparan-induced insulin secretion at 3.3 and 16.7 mm glucose under Ca2+-free conditions. DPI significantly suppressed islet glucose oxidation and ATP content through its known inhibitory action on complex I in the mitochondrial respiratory chain. On the other hand, DPI altered [Ca2+]i dynamics in response to high glucose and membrane depolarization, and DPI per se dose-dependently increased [Ca2+]i. The DPI-induced [Ca2+]i rise was associated with a transient increase in insulin secretion and was attenuated by removal of extracellular Ca2+, by L-type voltage-dependent Ca2+ channel blockers, by mitochondrial inhibitors, or by addition of 0.1 or 1.0 μm H2O2 exogenously. Our results showed that DPI impairment of insulin secretion involved altered Ca2+ signaling, suggesting that NADPH oxidase may modulate Ca2+ signaling in β-cells.

Abstract 107: Apocynin Attenuates Isoproterenol-induced Myocardial Injury: Implications For Targeting Nadph Oxidase In Myocardial Fibrogenesis

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Yu Chen ◽  
Jingang Cui ◽  
Qinbo Yang ◽  
Chenglin Jia ◽  
Minqi Xiong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Myocardial Fibrosis ◽  
Myocardial Injury ◽  
Oxidase Inhibitor ◽  
Ros Generation ◽  
Dependent Manner ◽  
Expression Of Genes ◽  
Therapeutic Development ◽  
Myocardial Injuries

Myocardial fibrosis results from cardiac injuries caused by various pathophysiological mechanisms including myocardial infarction, leading to destruction of myocardial architecture and progressive cardiac dysfunction. Oxidative stress is likely involved in myocardial ischemic injury and the subsequent tissue remodeling mediated by myocardial fibrogenesis. Our current study aimed to evaluate the implication of NADPH oxidase in overproduction of reactive oxygen species and its contribution to the pathogenesis of myocardial fibrogenesis after ischemic injuries. The effects of Apocynin, a selective NADPH oxidase inhibitor, were evaluated in the mouse model of isoproterenol-induced myocardial injury by histopathological approaches and whole-genome gene expression profiling. The results demonstrated that Apocynin was able to inhibit the development of ISO-induced myocardial necrotic lesions and fibrogenesis in a dose-dependent manner. Moreover, the preventive effects of Apocynin on myocardial injuries were associated with suppressed expression of genes implicated in inflammation responses and extracellular matrix, which were remarkably upregulated by isoproterenol administration. In summary, o ur study provides proof-of-concept for the involvement of NADPH oxidase-mediated ROS generation in myocardial ischemic injuries and fibrogenesis, which will benefit the mechanism-based therapeutic development targeting NADPH oxidase and oxidative stress in treating myocardial fibrosis and related disorders.

scholarly journals NADPH Oxidase as a Therapeutic Target for Oxalate Induced Injury in Kidneys

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Sunil Joshi ◽  
Ammon B. Peck ◽  
Saeed R. Khan
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Tissue Injury ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Renal Tissue ◽  
Oxygen Species ◽  
Gene Expressions

A major role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes is to catalyze the production of superoxides and other reactive oxygen species (ROS). These ROS, in turn, play a key role as messengers in cell signal transduction and cell cycling, but when they are produced in excess they can lead to oxidative stress (OS). Oxidative stress in the kidneys is now considered a major cause of renal injury and inflammation, giving rise to a variety of pathological disorders. In this review, we discuss the putative role of oxalate in producing oxidative stress via the production of reactive oxygen species by isoforms of NADPH oxidases expressed in different cellular locations of the kidneys. Most renal cells produce ROS, and recent data indicate a direct correlation between upregulated gene expressions of NADPH oxidase, ROS, and inflammation. Renal tissue expression of multiple NADPH oxidase isoforms most likely will impact the future use of different antioxidants and NADPH oxidase inhibitors to minimize OS and renal tissue injury in hyperoxaluria-induced kidney stone disease.

The NADPH oxidase inhibitor apocynin induces nitric oxide synthesis via oxidative stress

2008 ◽  
Vol 228 (3) ◽  
pp. 277-285 ◽  
Author(s):  
Chiara Riganti ◽  
Costanzo Costamagna ◽  
Sophie Doublier ◽  
Erica Miraglia ◽  
Manuela Polimeni ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Nadph Oxidase ◽  
Oxidase Inhibitor ◽  
Nitric Oxide Synthesis ◽  
Nadph Oxidase Inhibitor

Overexpression of the Superoxide Anion and NADPH Oxidase Isoforms 1 and 4 (NOX1 and NOX4) in Allergic Nasal Mucosa

2009 ◽  
Vol 23 (4) ◽  
pp. 370-376 ◽  
Author(s):  
Joon Hwan Moon ◽  
Tae Hoon Kim ◽  
Heung Man Lee ◽  
Seung Hoon Lee ◽  
Whan Choe ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Allergic Rhinitis ◽  
Nadph Oxidase ◽  
Nasal Mucosa ◽  
Vascular Endothelium ◽  
Superoxide Anion ◽  
Nasal Polyps ◽  
Inflammatory Cells ◽  
Submucosal Glands ◽  
Cellular Source

Background The purpose of this study was to investigate the expression and distribution of superoxide anion, NADPH oxidase (NOX)1, and NOX4 in healthy, allergic nasal mucosa and nasal polyps to evaluate the possible influence of oxidative stress on the development of allergic rhinitis and nasal polyps. Methods The expression and distribution of superoxide anion, NOX1 and NOX4 were evaluated in healthy and allergic nasal mucosa and nasal polyps, using dihydroethidium fluorescence, semiquantitative reverse transcriptase-polymerase chain reaction, immunohistochemistry, and Western blot. Results NOX1 and NOX4 were localized mainly in the epithelial layer, submucosal glands, vascular endothelium, and inflammatory cells in healthy and allergic nasal mucosa and nasal polyps. The cellular source that generated superoxide anion is also localized in the epithelial cells, submucosal glands, vascular endothelium, and inflammatory cells, demonstrating the similar sites of expression of NOX1 and NOX4 in healthy and allergic nasal mucosa and nasal polyps. NOX1 and NOX4 mRNA and proteins and superoxide anions had increased levels of expression in allergic nasal mucosa and nasal polyps compared with healthy nasal mucosa. Conclusions These results indicate that NOX1 and NOX4 may play an important role in reactive oxygen species production, contributing to the oxidative stress in allergic rhinitis and nasal polyp tissues.

scholarly journals Xanthine Oxidase Inhibitor, Allopurinol, Prevented Oxidative Stress, Fibrosis, and Myocardial Damage in Isoproterenol Induced Aged Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Md. Abu Taher Sagor ◽  
Nabila Tabassum ◽  
Md. Abdullah Potol ◽  
Md. Ashraful Alam
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Inflammatory Cells ◽  
Oxidase Inhibitor ◽  
Oxidative Stress Markers ◽  
Aged Rats ◽  
Sample Collection ◽  
Xanthine Oxidase Inhibitor ◽  
Glutathione Concentration ◽  
Stress Markers

We evaluated the preventive effect of allopurinol on isoproterenol (ISO) induced myocardial infarction in aged rats. Twelve- to fourteen-month-old male Long Evans rats were divided into three groups: control, ISO, and ISO + allopurinol. At the end of the study, all rats were sacrificed for blood and organ sample collection to evaluate biochemical parameters and oxidative stress markers analyses. Histopathological examinations were also conducted to assess inflammatory cell infiltration and fibrosis in heart and kidneys. Our investigation revealed that the levels of oxidative stress markers were significantly increased while the level of cellular antioxidants, catalase activity, and glutathione concentration in ISO induced rats decreased. Treatment with allopurinol to ISO induced rats prevented the elevated activities of AST, ALT, and ALP enzymes, and the levels of lipid peroxidation products and increased reduced glutathione concentration. ISO induced rats also showed massive inflammatory cells infiltration and fibrosis in heart and kidneys. Furthermore, allopurinol treatment prevented the inflammatory cells infiltration and fibrosis in ISO induced rats. In conclusion, the results of our study suggest that allopurinol treatment is capable of protecting heart of ISO induced myocardial infarction in rats probably by preventing oxidative stress, inflammation, and fibrosis.

scholarly journals The Post-Ischemic Increase in GluA2 Ser880 Phosphorylation Involves NADPH Oxidase

2018 ◽  
Vol 4 (1) ◽  
pp. 170-181
Author(s):  
Darrell A. Jackson ◽  
Fanny Astruc-Diaz ◽  
Nicole M. Byrnes ◽  
Phillip H. Beske
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Hippocampal Slices ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Glucose Deprivation ◽  
Subunit Composition ◽  
Stress Signaling ◽  
Scaffolding Proteins ◽  
Nadph Oxidase Activity

Most 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl) propanoic acid receptors (AMPARs) expressed on adult hippocampal pyramidal neurons contain the edited form of GluA2 (Q607R) and are thus impermeable to Ca2+/Zn2+ entry.  Following ischemic injury, these receptors undergo a subunit composition change, switching from a GluA2-containing Ca2+/Zn2+-impermeable AMPAR to a GluA2-lacking Ca2+/Zn2+-permeable AMPAR. Recent studies indicate that an oxidative stress signaling pathway is responsible for the I/R-induced changes in AMPAR subunit composition.  Studies suggest that nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase), a superoxide generator, is the source that initiates the oxidative stress-signaling cascade during post-ischemic reperfusion. The objective of the present study was to determine if suppression of NADPH oxidase activity prevents the increase in phosphorylation and subsequent internalization of the GluA2 AMPAR subunit during reperfusion of post-ischemic hippocampal slices. In this study, we demonstrated that exposure of adult rat hippocampal slices to oxygen glucose deprivation/reperfusion (OGD/R) results in an increase in Ser880 phosphorylation of the GluA2 subunit.  The increase in Ser880 phosphorylation resulted in the dissociation of GluA2 from the scaffolding proteins Glutamate receptor-interacting protein 1 (GRIP1) and AMPAR binding protein (ABP), thus enabling the association of GluA2 with protein interacting with C kinase 1 (PICK1). OGD/R also resulted in an increase in the association of activated protein kinase C ? (PKC?) with PICK1. We have found that pharmacological inhibition of NADPH oxidase with apocynin diminishes the OGD/R-induced increase in activated PKC? association with PICK1 and subsequent Ser880 phosphorylation of GluA2. Suppression of NADPH oxidase activity also blunted OGD/R-induced decreased association of GluA2 with the scaffolding proteins GRIP1 and ABP.  Protein phosphatase 2A (PP2A), which regulates PKC? activity by dephosphorylating the kinase, was inactivated by OGD/R-induced increase in tyrosine phosphorylation of the phosphatase (Y307). Inhibition of NADPH oxidase activity ameliorated OGD/R-induced PP2A phosphorylation and inactivation. Our findings are consistent with a model of OGD/R-induced Ser880 phosphorylation of GluA2 that implicates NADPH oxidase mediated inactivation of PP2A and sustained PKC? phosphorylation of GluA2.

scholarly journals The Antioxidant 3H-1,2-Dithiole-3-Thione Potentiates Advanced Glycation End-Product-Induced Oxidative Stress in SH-SY5Y Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Robert Pazdro ◽  
John R. Burgess
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Antioxidant Defenses ◽  
Chemical Induction ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
Ros Formation ◽  
Endogenous Antioxidant ◽  
Neurite Degeneration

Oxidative stress is implicated as a major factor in the development of diabetes complications and is caused in part by advanced glycation end products (AGEs). AGEs ligate to the receptor for AGEs (RAGE), promoting protein kinase C (PKC)-dependent activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and superoxide radical generation. While scavenging antioxidants are protective against AGEs, it is unknown if induction of endogenous antioxidant defenses has the same effect. In this study, we confirmed that the compound 3H-1,2-dithiole-3-thione (D3T) increases reduced-state glutathione (GSH) concentrations and NADPH:quinone oxidoreductase 1 (NQO1) activity in SH-SY5Y cells and provides protection against H2O2. Surprisingly, D3T potentiated oxidative damage caused by AGEs. In comparison to vehicle controls, D3T caused greater AGE-induced cytotoxicity and depletion of intracellular GSH levels while offering no protection against neurite degeneration or protein carbonylation. D3T potentiated AGE-induced reactive oxygen species (ROS) formation, an effect abrogated by inhibitors of PKC and NADPH oxidase. This study suggests that chemical induction of endogenous antioxidant defenses requires further examination in models of diabetes.

Role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in upregulation of intermediate-conductance Ca[superscript 2+] -activated K[superscript +] channels (K[subscript Ca]3.1) associated with atherosclerosis

2010 ◽  
Author(s):  
◽  
Hope Kara Anne Gole
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Nadph Oxidase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Phenotypic Modulation ◽  
Channel Activity ◽  
Coronary Smooth Muscle ◽  
Expression And Activity

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] A key risk factor for the development of atherosclerosis is familial hypercholesterolemia (FH), a genetic disease characterized by elevated levels of low density lipoprotein (LDL). Studies have shown that oxidative stress and vascular smooth muscle cell (VSMC) phenotypic modulation play critical roles in the development and stability of atherosclerotic plaques. The key source of reactive oxygen species (ROS) contributing to oxidative stress in the vasculature is the enzymatic complex nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Upregulation of intermediateconductance Ca[superscript 2 +]-activated K[superscript +] channels (K[subscript Ca]3.1) and modification of NADPH oxidase activity have been shown to mediate phenotypic modulation of coronary smooth muscle cells (CSMC). It remains unclear, however, whether K[subscript Ca]3.1 expression and activity are altered in atherosclerotic coronary smooth muscle of individuals with FH, and whether NADPH oxidase plays a role in atherosclerosis through regulation of K[subscript Ca]3.1 channels. Our objective was thus twofold, 1) to determine whether K[subscript Ca]3.1 expression and activity are increased in CSMCs isolated from FH swine, and 2) to determine if NADPH oxidase plays a role in growth factor-induced upregulation of K[subscript Ca]3.1. Right coronary artery (RCA) sections from 2 year old FH swine showed a [approximate sign]15 fold increase in artery stenosis accompanied by significantly elevated triglyceride and cholesterol values. In the media of the diseased FH coronaries, there was a trend for increased K[subscript Ca]3.1mRNA expression and K[subscript Ca]3.1 protein expression was elevated [approximate sign]20% compared to control coronaries. In addition, K[subscript Ca]3.1 channel activity increased almost 2- fold in coronary artery cells isolated from FH swine compared to control animals. In cultured CSMCs, basic fibroblast growth factor (bFGF) increased superoxide (O[subscript 2] [superscript .-]) production which was inhibited by treatment with the NADPH oxidase inhibitor apocynin (Apo). Treatment with bFGF increased K[subscript Ca]3.1 mRNA levels [aproximate sign]2.5 fold in both right coronary artery (RCA) sections and CSMCs, while addition of Apo prevented the increase. Furthermore, inhibition of NADPH oxidase abolished the bFGF-induced increase in coronary smooth muscle K[subscript Ca]3.1 protein expression and CSMC K[subscript Ca]3.1 channel activity. Treatment with bFGF significantly increased activator protein-1 (AP-1) promoter activity which was inhibited by addition of Apo. RCA and CSMC express all four cardiovascular Nox isoforms (Nox1, Nox2, Nox4, Nox5) with Nox4 being the predominant isoform. Treatment with bFGF decreased Nox1, Nox2, and Nox4 CSMC message, while treatment with Apo increased the mRNA expression of all four isoforms. Knock down of Nox2 and Nox4 did not affect the K[subscript Ca]3.1 message response to bFGF or Apo. Consistent with our earlier findings of increased medial K[subscript Ca]3.1 expression in FH coronaries; whole vessel K[subscript Ca]3.1 mRNA expression was increased in FH coronary smooth muscle and Nox2 rather than Nox4 was the predominant Nox isoform. Our findings demonstrate that K[subscript Ca]3.1 is upregulated in coronary smooth muscle of FH swine and support previous research indicating K[subscript Ca]3.1 plays a key role in the development and progression of atherosclerosis. Our findings also provide novel evidence that NADPH oxidase contributes to VSMC phenotypic modulation associated with atherosclerosis through AP-1 transcriptional upregulation of K[subscript Ca]3.1.

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