scholarly journals CYP450 Mediates Reactive Oxygen Species Production in a Mouse Model of β-Thalassemia through an Increase in 20-HETE Activity

2021 ◽  
Vol 22 (3) ◽  
pp. 1106
Author(s):  
Rayan Bou-Fakhredin ◽  
Batoul Dia ◽  
Hilda E. Ghadieh ◽  
Stefano Rivella ◽  
Maria Domenica Cappellini ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Mouse Model ◽  
Cell Injury ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
Species Production ◽  
Different Sources ◽  
Dependent Pathway

Oxidative damage by reactive oxygen species (ROS) is one of the main contributors to cell injury and tissue damage in thalassemia patients. Recent studies suggest that ROS generation in non-transfusion-dependent (NTDT) patients occurs as a result of iron overload. Among the different sources of ROS, the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes and cytochrome P450 (CYP450) have been proposed to be major contributors for oxidative stress in several diseases. However, the sources of ROS in patients with NTDT remain poorly understood. In this study, Hbbth3/+ mice, a mouse model for β-thalassemia, were used. These mice exhibit an unchanged or decreased expression of the major NOX isoforms, NOX1, NOX2 and NOX4, when compared to their C57BL/6 control littermates. However, a significant increase in the protein synthesis of CYP4A and CYP4F was observed in the Hbbth3/+ mice when compared to the C57BL/6 control mice. These changes were paralleled by an increased production of 20-hydroxyeicosatetraenoic acid (20-HETE), a CYP4A and CYP4F metabolite. Furthermore, these changes corroborate with onset of ROS production concomitant with liver injury. To our knowledge, this is the first report indicating that CYP450 4A and 4F-induced 20-HETE production mediates reactive oxygen species overgeneration in Hbbth3/+ mice through an NADPH-dependent pathway.

Abstract 19967: Differential Roles of the NADPH-Oxidase 1 and 2 in Platelet Activation and Thrombosis

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Michael K Delaney ◽  
Kyungho Kim ◽  
Brian Estevez ◽  
Aleksandra Stojanovic-Terpo ◽  
Bo Shen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Platelet Activation ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
General Role ◽  
Glycoprotein Vi ◽  
Activation Pathways

Objective: Reactive oxygen species (ROS) generated from activated platelets is known to regulate platelet activation. However, it remains unclear whether and how different isoforms of nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidases (NOXs) play roles in different platelet activation pathways. Here we investigated the role of NOX1 and NOX2 in different platelet activation pathways using NOX1 and NOX2 knockout mice. Approach and Results: NOX1-/- platelets showed selective defects in G protein coupled receptor (GPCR)-mediated platelet activation induced by thrombin, protease-activated receptor 4 agonist peptide (PAR4AP) and thromboxane A2 analog U46619, but was not affected in platelet activation induced by collagen-related peptide (CRP), a glycoprotein VI (GPVI) agonist. In contrast, NOX2-/- platelets showed potent inhibition of CRP-induced platelet activation, and also showed partial inhibition of thrombin-induced platelet aggregation and secretion. Consistently, production of reactive oxygen species (ROS) was inhibited in NOX1-/- platelets stimulated with thrombin, but not CRP, whereas NOX2-/- platelets showed reduced ROS generation induced by CRP or thrombin. Interestingly, laser-induced arterial thrombosis was impaired in NOX2-/- mice, and in thrombocytopenic mice transfused with NOX2-/- platelets, suggesting an important role for NOX2-dependent platelet ROS production in the laser-induced injury model of thrombosis. Conclusions: NOX1 and NOX2 play differential roles in different platelet activation pathways: NOX1 mediates GPCR-mediated ROS production and platelet activation, whereas NOX2 plays a general role in GPVI- and GPCR-induced ROS production and platelet activation in vitro , and in laser-induced thrombosis in vivo .

scholarly journals Novel Approach to Reactive Oxygen Species in Nontransfusion-Dependent Thalassemia

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Paul I. Tyan ◽  
Amr H. Radwan ◽  
Assaad Eid ◽  
Anthony G. Haddad ◽  
David Wehbe ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Iron Overload ◽  
Cell Injury ◽  
Clinical Manifestations ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
Ineffective Erythropoiesis ◽  
Chronic Anemia ◽  
Globin Chains

The term Nontransfusion dependent thalassaemia (NTDT) was suggested to describe patients who had clinical manifestations that are too severe to be termed minor yet too mild to be termed major. Those patients are not entirely dependent on transfusions for survival. If left untreated, three main factors are responsible for the clinical sequelae of NTDT: ineffective erythropoiesis, chronic hemolytic anemia, and iron overload. Reactive oxygen species (ROS) generation in NTDT patients is caused by 2 major mechanisms. The first one is chronic hypoxia resulting from chronic anemia and ineffective erythropoiesis leading to mitochondrial damage and the second is iron overload also due to chronic anemia and tissue hypoxia leading to increase intestinal iron absorption in thalassemic patients. Oxidative damage by reactive oxygen species (generated by free globin chains and labile plasma iron) is believed to be one of the main contributors to cell injury, tissue damage, and hypercoagulability in patients with thalassemia. Independently increased ROS has been linked to a myriad of pathological outcomes such as leg ulcers, decreased wound healing, pulmonary hypertension, silent brain infarcts, and increased thrombosis to count a few. Interestingly many of those complications overlap with those found in NTDT patients.

scholarly journals Impact of CD14 on Reactive Oxygen Species Production from Human Leukocytes Primed byEscherichia coliLipopolysaccharides

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Dmitry S. Kabanov ◽  
Olga Yu. Vwedenskaya ◽  
Marina A. Fokina ◽  
Elena M. Morozova ◽  
Sergey V. Grachev ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Polymorphonuclear Neutrophils ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Human Pmns ◽  
Species Production ◽  
The Impact ◽  
Priming Activity

Lipopolysaccharides (LPS) from Gram-negative bacteria prime human polymorphonuclear neutrophils (PMNs) via multicomponent receptor cluster including CD14 and MD-2·TLR4 for the enhanced release of reactive oxygen species (ROS) were triggered by bacterial derived peptideN-formyl-methionyl-leucyl-phenylalanine (fMLP). In this study, we investigated the impact of CD14 on LPS-induced priming of human PMNs for fMLP-triggered ROS generation (respiratory or oxidative) burst. Monoclonal antibodies against human CD14 (mAbs) as well as isotype-matched IgG2a did not influence significantly fMLP-triggered ROS production from LPS-unprimed PMNs. Anti-CD14 mAbs (clone UCHM-1) attenuated LPS-induced priming of PMNs as it had been mirrored by fMLP-triggered decrease of ROS production. Similar priming activity of S-LPS or Re-LPS fromEscherichia colifor fMLP-triggered ROS release from PMNs was found. Obtained results suggest that glycosylphosphatidylinositol-anchored CD14 is the key player in LPS-induced PMN priming for fMLP-triggered ROS production. We believe that blockade of CD14 on the cell surface and clinical use of anti-CD14 mAbs or their Fab fragments may diminish the production of ROS and improve outcomes during cardiovascular diseases manifested by LPS-induced inflammation.

Abstract 54: Differential Regulation of NADPH-oxidases 1 and 2 and a Common Syk/PLC/Calcium-dependent ROS Signaling Pathway Mediating Platelet Activation

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Zheng Xu
Keyword(s):  
Reactive Oxygen Species ◽  
Platelet Aggregation ◽  
Signaling Pathway ◽  
Platelet Activation ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Differential Regulation ◽  
Ros Generation ◽  
Oxygen Species ◽  
Activation Pathways

Objective: Reactive oxygen species (ROS) generated from activated platelets is known to regulate platelet activation. This study investigates how different isoforms of nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) oxidases (NOXs) mediates different platelet activation pathways. Approach and Results: ROS generation in different platelet activation pathways are mediated differentially by NOX1 and NOX2. NOX1 -/y platelets showed no defects in platelet aggregation and secretion induced by glycoprotein (GP) VI agonists, collagen-related peptide (CRP), but were partially defective in platelet aggregation and secretion induced by low doses of agonists of G protein coupled receptor (GPCR), thrombin, protease-activated receptor 4 agonist peptide (PAR4AP) and thromboxane A2 analog U46619. In contrast, NOX2 -/- platelets showed significantly defective platelet aggregation and secretion induced by CRP, and also showed partial inhibition of thrombin-induced platelet aggregation and secretion. Consistently, production of reactive oxygen species (ROS) was inhibited in NOX1 -/- platelets stimulated with thrombin, but not CRP, whereas NOX2 -/- platelets were defective ROS generation induced by CRP or thrombin. These differential effects of NOX1 and NOX2 is likely due to upstream differential regulation of these different enzymes, as thrombin-stimulated NOX1-/y platelets and CRP-stimulated NOX2-/- platelets similarly showed defective activation of tyrosine kinase Syk, its downstream target phospholipase Cγ (PLCγ) and calcium mobilization, which is mediated by PLC. Furthermore, mitogen-activated protein kinase pathways, which is another important platelet activation pathway was not significantly affected in either NOX1-/y or NOX2-/- platelets. Finally, NOX-/- platelets is defective in mediating arteriolar thrombosis in vivo, although minimally affected tail bleeding time. Conclusions: NOX1 and NOX2 play differential roles in different platelet activation pathways. The differential roles of these enzyme are due to differential upstream regulation. Both NOX isoforms mediates platelet activation via a common ROS-dependent activation Src-PLC-calcium signaling pathway.

scholarly journals Wear Particles Promote Reactive Oxygen Species-Mediated Inflammation via the Nicotinamide Adenine Dinucleotide Phosphate Oxidase Pathway in Macrophages Surrounding Loosened Implants

2015 ◽  
Vol 35 (5) ◽  
pp. 1857-1867 ◽  
Author(s):  
Weishen Chen ◽  
Ziqing Li ◽  
Ying Guo ◽  
Yuhuan Zhou ◽  
Ziji Zhang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Nicotinamide Adenine ◽  
Ros Generation ◽  
Wear Particles ◽  
Oxygen Species ◽  
Prosthesis Loosening ◽  
Ti Particles

Background/Aims: Prosthesis loosening is closely associated with chronic inflammatory cytokine secretion by macrophages, which are activated by wear particles or inflammatory stimulants such as lipopolysaccharide (LPS). Reactive oxygen species (ROS) are critical regulators of inflammation, but their enzymatic sources in response to wear particles and their effects on peri-implant LPS-tolerance remain unclear. Methods: Three ROS-related enzymes—nicotinamide adenine dinucleotide phosphate oxidase (NOX)-1 and -2 and catalase—were investigated in interface membrane tissues and in titanium (Ti) particle-stimulated macrophages in vitro. The generation of ROS and downstream inflammatory effects were measured with or without pre-incubation with apocynin, an NOX inhibitor. Results: Pre-exposure to Ti particles attenuated NF-κB activation in LPS-stimulated macrophages, indicating that wear particles suppress immune response, which may lead to chronic inflammation. NOX-1 and -2 were highly expressed in aseptically loosened interface membranes and in macrophages stimulated with Ti particles; the particles induced a moderate amount of ROS generation, NF-κB activation, and TNF-a secretion in macrophages, and these effects were suppressed by apocynin. Conclusion: Wear particles induce ROS generation through the NOX signaling pathway, resulting in persistent inflammation and delayed loosening. Thus, the suppression of NOX activity may be a useful strategy for preventing prosthesis loosening.

scholarly journals The impact of reactive oxygen species in the development of cardiometabolic disorders: a review

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Roland Akhigbe ◽  
Ayodeji Ajayi
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Acid Oxidation ◽  
Ros Generation ◽  
Metabolic Memory ◽  
Oxygen Species ◽  
Cardiometabolic Disorders ◽  
The Impact

AbstractOxidative stress, an alteration in the balance between reactive oxygen species (ROS) generation and antioxidant buffering capacity, has been implicated in the pathogenesis of cardiometabolic disorders (CMD). At physiological levels, ROS functions as signalling mediators, regulates various physiological functions such as the growth, proliferation, and migration endothelial cells (EC) and smooth muscle cells (SMC); formation and development of new blood vessels; EC and SMC regulated death; vascular tone; host defence; and genomic stability. However, at excessive levels, it causes a deviation in the redox state, mediates the development of CMD. Multiple mechanisms account for the rise in the production of free radicals in the heart. These include mitochondrial dysfunction and uncoupling, increased fatty acid oxidation, exaggerated activity of nicotinamide adenine dinucleotide phosphate oxidase (NOX), reduced antioxidant capacity, and cardiac metabolic memory. The purpose of this study is to discuss the link between oxidative stress and the aetiopathogenesis of CMD and highlight associated mechanisms. Oxidative stress plays a vital role in the development of obesity and dyslipidaemia, insulin resistance and diabetes, hypertension via various mechanisms associated with ROS-led inflammatory response and endothelial dysfunction.

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