PubMed Central (PMC3 - NLM DTD)
Archive of life sciences journal literature at the U.S. National Institutes of Health (NIH), developed and managed by NIH's National Center for Biotechnology Information (NCBI) in the National Library of Medicine (NLM).
Antioxidants & Redox Signaling
Mostrando recursos 1 - 20 de 517
Reactive Oxygen Species in Inflammation and Tissue Injury - Mittal, Manish; Siddiqui, Mohammad Rizwan; Tran, Khiem; Reddy, Sekhar P.; Malik, Asrar B.
Reactive oxygen species (ROS) are key signaling molecules that play an important role in the progression of inflammatory disorders. An enhanced ROS generation by polymorphonuclear neutrophils (PMNs) at the site of inflammation causes endothelial dysfunction and tissue injury. The vascular endothelium plays an important role in passage of macromolecules and inflammatory cells from the blood to tissue. Under the inflammatory conditions, oxidative stress produced by PMNs leads to the opening of inter-endothelial junctions and promotes the migration of inflammatory cells across the endothelial barrier. The migrated inflammatory cells not only help in the clearance of pathogens and foreign particles but...
Redox Modulation of HMGB1-Related Signaling - Janko, Christina; Filipović, Milos; Munoz, Luis E.; Schorn, Christine; Schett, Georg; Ivanović-Burmazović, Ivana; Herrmann, Martin
Significance: In the cells' nuclei, high-mobility group box protein 1 (HMGB1) is a nonhistone chromatin-binding protein involved in the regulation of transcription. Extracellularly, HMGB1 acts as a danger molecule with properties of a proinflammatory cytokine. It can be actively secreted from myeloid cells or passively leak from any type of injured, necrotic cell. Increased serum levels of active HMGB1 are often found in pathogenic inflammatory conditions and correlate with worse prognoses in cancer, sepsis, and autoimmunity. By damaging cells, superoxide and peroxynitrite promote leakage of HMGB1. Recent Advances: The activity of HMGB1 strongly depends on its redox state: Inflammatory-active HMGB1...
A Glutathione-Dependent Detoxification System Is Required for Formaldehyde Resistance and Optimal Survival of Neisseria meningitidis in Biofilms - Chen, Nathan H.; Couñago, Rafael M.; Djoko, Karrera Y.; Jennings, Michael P.; Apicella, Michael A.; Kobe, Bostjan; McEwan, Alastair G.
Aim: The glutathione-dependent AdhC-EstD formaldehyde detoxification system is found in eukaryotes and prokaryotes. It is established that it confers protection against formaldehyde that is produced from environmental sources or methanol metabolism. Thus, its presence in the human host-adapted bacterial pathogen Neisseria meningitidis is intriguing. This work defined the biological function of this system in the meningococcus using phenotypic analyses of mutants linked to biochemical and structural characterization of purified enzymes. Results: We demonstrated that mutants in the adhC and/or estD were sensitive to killing by formaldehyde. Inactivation of adhC and/or estD also led to a loss of viability in biofilm...
Selenium Inhibits Renal Oxidation and Inflammation But Not Acute Kidney Injury in an Animal Model of Rhabdomyolysis - Shanu, Anu; Groebler, Ludwig; Kim, Hyun Bo; Wood, Sarah; Weekley, Claire M.; Aitken, Jade B.; Harris, Hugh H.; Witting, Paul K.
Acute kidney injury (AKI) is a manifestation of rhabdomyolysis (RM). Extracellular myoglobin accumulating in the kidney after RM promotes oxidative damage, which is implicated in AKI. Aim: To test whether selenium (Se) supplementation diminishes AKI and improves renal function. Results: Dietary selenite increased Se in the renal cortex, as demonstrated by X-ray fluorescence microscopy. Experimental RM-stimulated AKI as judged by increased urinary protein/creatinine, clusterin, and kidney injury molecule-1 (KIM-1), decreased creatinine clearance (CCr), increased plasma urea, and damage to renal tubules. Concentrations of cholesterylester (hydro)peroxides and F2-isoprostanes increased in plasma and renal tissues after RM, while aortic and renal cyclic...
Lipid Peroxidation Product 4-Hydroxy-2-Nonenal Promotes Seeding-Capable Oligomer Formation and Cell-to-Cell Transfer of α-Synuclein - Bae, Eun-Jin; Ho, Dong-Hwan; Park, Eunbi; Jung, Jin Woo; Cho, Kyungcho; Hong, Ji Hye; Lee, He-Jin; Kim, Kwang Pyo; Lee, Seung-Jae
Aims: Abnormal accumulation of α-synuclein aggregates is one of the key pathological features of many neurodegenerative movement disorders and dementias. These pathological aggregates propagate into larger brain regions as the disease progresses, with the associated clinical symptoms becoming increasingly severe and complex. However, the factors that induce α-synuclein aggregation and spreading of the aggregates remain elusive. Herein, we have evaluated the effects of the major lipid peroxidation byproduct 4-hydroxy-2-nonenal (HNE) on α-synuclein oligomerization and cell-to-cell transmission of this protein. Results: Incubation with HNE promoted the oligomerization of recombinant human α-synuclein via adduct formation at the lysine and histidine residues. HNE-induced...
Is Trichloroacetic Acid an Insufficient Sample Quencher of Redox Reactions? - Curbo, Sophie; Reiser, Kathrin; Rundlöf, Anna-Klara; Karlsson, Anna; Lundberg, Mathias
The global protein thiol pool has been reported to play a major role in the defense against oxidative stress as a redox buffer similar to glutathione. The present study uses a novel method to visualize cellular changes of the global protein thiol pool in response to induced oxidative stress. Unexpectedly, the results showed an uneven distribution of protein thiols in resting cells with no apparent change in their level or distribution in response to diamide as has been reported previously. Further analysis revealed that thiol pool oxidation is artificially high due to insufficient activity of the widely used sample quencher...
Is Inflammation a Mitochondrial Dysfunction-Dependent Event in Fibromyalgia? - Cordero, Mario D.; Díaz-Parrado, Eduardo; Carrión, Angel M.; Alfonsi, Simona; Sánchez-Alcazar, José Antonio; Bullón, Pedro; Battino, Maurizio; de Miguel, Manuel
Fibromyalgia (FM) is a complex disorder that affects up to 5% of the general population worldwide. Both mitochondrial dysfunction and inflammation have been implicated in the pathophysiology of FM. We have investigated the possible relationship between mitochondrial dysfunction, oxidative stress, and inflammation in FM. We studied 30 women diagnosed with FM and 20 healthy women. Blood mononuclear cells (BMCs) from FM patients showed reduced level of coenzyme Q10 (CoQ10) and mtDNA contents and high level of mitochondrial reactive oxygen species (ROS) and serum tumor necrosis factor (TNF)-alpha and transcript levels. A significant negative correlation between CoQ10 and TNF-alpha levels (r=−0.588;...
Nox Family NADPH Oxidases in Mechano-Transduction: Mechanisms and Consequences - Brandes, Ralf P.; Weissmann, Norbert; Schröder, Katrin
Significance: The majority of cells in a multi-cellular organism are continuously exposed to ever-changing physical forces. Mechano-transduction links these events to appropriate reactions of the cells involving stimulation of signaling cascades, reorganization of the cytoskeleton and alteration of gene expression. Recent Advances: Mechano-transduction alters the cellular redox balance and the formation of reactive oxygen species (ROS). Nicotine amide adenine dinucleotide reduced form (NADPH) oxidases of the Nox family are prominent ROS generators and thus, contribute to this stress-induced ROS formation. Critical Issues: Different types and patterns of mechano-stress lead to Nox-dependent ROS formation and Nox-mediated ROS formation contributes to cellular...
Are Reactive Oxygen Species Always Detrimental to Pathogens? - Paiva, Claudia N.; Bozza, Marcelo T.
Reactive oxygen species (ROS) are deadly weapons used by phagocytes and other cell types, such as lung epithelial cells, against pathogens. ROS can kill pathogens directly by causing oxidative damage to biocompounds or indirectly by stimulating pathogen elimination by various nonoxidative mechanisms, including pattern recognition receptors signaling, autophagy, neutrophil extracellular trap formation, and T-lymphocyte responses. Thus, one should expect that the inhibition of ROS production promote infection. Increasing evidences support that in certain particular infections, antioxidants decrease and prooxidants increase pathogen burden. In this study, we review the classic infections that are controlled by ROS and the cases in which...
Eat-Me: Autophagy, Phagocytosis, and Reactive Oxygen Species Signaling - Vernon, Philip J.; Tang, Daolin
Significance: Phagocytosis is required for the clearance of dying cells. The subsequent regulation of inflammatory responses by phagocytic cells is mediated by both innate and adaptive immune responses. Autophagy, an evolutionarily ancient process of lysosomal self-digestion of organelles, protein aggregates, apoptotic corpses, and cytosolic pathogens, has only recently become appreciated for its dynamic relationship with phagocytosis, including newly discovered autophagic-phagocytosis “hybrid” processes such as microtubule-associated protein 1 light chain 3-associated phagocytosis (LAP). Recent Advances: Signal transduction by reactive oxygen species (ROS) plays a critical role in the modulation of autophagy, phagocytosis, and LAP, and serves as both a link and...
Hypothalamic Apelin/Reactive Oxygen Species Signaling Controls Hepatic Glucose Metabolism in the Onset of Diabetes - Drougard, Anne; Duparc, Thibaut; Brenachot, Xavier; Carneiro, Lionel; Gouazé, Alexandra; Fournel, Audren; Geurts, Lucie; Cadoudal, Thomas; Prats, Anne-Catherine; Pénicaud, Luc; Vieau, Didier; Lesage, Jean; Leloup, Corinne; Benani, Alexandre; Cani, Patrice D.; Valet, Philippe; Knauf, Claude
Aims: We have previously demonstrated that central apelin is implicated in the control of peripheral glycemia, and its action depends on nutritional (fast versus fed) and physiological (normal versus diabetic) states. An intracerebroventricular (icv) injection of a high dose of apelin, similar to that observed in obese/diabetic mice, increase fasted glycemia, suggesting (i) that apelin contributes to the establishment of a diabetic state, and (ii) the existence of a hypothalamic to liver axis. Using pharmacological, genetic, and nutritional approaches, we aim at unraveling this system of regulation by identifying the hypothalamic molecular actors that trigger the apelin effect on liver...
Glutathione Peroxidase 7 Utilizes Hydrogen Peroxide Generated by Ero1α to Promote Oxidative Protein Folding - Wang, Lei; Zhang, Lihui; Niu, Yingbo; Sitia, Roberto; Wang, Chih-chen
Aims: Ero1 flavoproteins catalyze oxidative folding in the endoplasmic reticulum (ER), consuming oxygen and generating hydrogen peroxide (H2O2). The ER-localized glutathione peroxidase 7 (GPx7) shows protein disulfide isomerase (PDI)-dependent peroxidase activity in vitro. Our work aims at identifying the physiological role of GPx7 in the Ero1α/PDI oxidative folding pathway and at dissecting the reaction mechanisms of GPx7. Results: Our data show that GPx7 can utilize Ero1α-produced H2O2 to accelerate oxidative folding of substrates both in vitro and in vivo. H2O2 oxidizes Cys57 of GPx7 to sulfenic acid, which can be resolved by Cys86 to form an intramolecular disulfide bond. Both...
Redox Control of Cardiac Excitability - Aggarwal, Nitin T.; Makielski, Jonathan C.
Reactive oxygen species (ROS) have been associated with various human diseases, and considerable attention has been paid to investigate their physiological effects. Various ROS are synthesized in the mitochondria and accumulate in the cytoplasm if the cellular antioxidant defense mechanism fails. The critical balance of this ROS synthesis and antioxidant defense systems is termed the redox system of the cell. Various cardiovascular diseases have also been affected by redox to different degrees. ROS have been indicated as both detrimental and protective, via different cellular pathways, for cardiac myocyte functions, electrophysiology, and pharmacology. Mostly, the ROS functions depend on the type...