GSH transport in mitochondria: defense against TNF-induced oxidative stress and alcohol-induced defect

1997 ◽  
Vol 273 (1) ◽  
pp. G7-G17 ◽  
Author(s):  
J. C. Fernandez-Checa ◽  
N. Kaplowitz ◽  
C. Garcia-Ruiz ◽  
A. Colell ◽  
M. Miranda ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Plasma Membrane ◽  
Molecular Oxygen ◽  
Respiratory Chain ◽  
Superoxide Anion ◽  
Complex Iii ◽  
Contributory Factor ◽  
Xenopus Laevis Oocytes ◽  
Mitochondrial Matrix

Mitochondria generate reactive oxygen species (ROS) as byproducts of molecular oxygen consumption in the electron transport chain. Most cellular oxygen is consumed in the cytochrome-c oxidase complex of the respiratory chain, which does not generate reactive species. The ubiquinone pool of complex III of respiration is the major site within the respiratory chain that generates superoxide anion as a result of a single electron transfer to molecular oxygen. Superoxide anion and hydrogen peroxide, derived from the former by superoxide dismutase, are precursor of hydroxyl radical through the participation of transition metals. Glutathione (GSH) in mitochondria is the only defense available to metabolize hydrogen peroxide. A small fraction of the total cellular GSH pool is sequestered in mitochondria by the action of a carrier that transports GSH from the cytosol to the mitochondrial matrix. Mitochondria are not only one of the main cellular sources of ROS, they also are a key target of ROS. Mitochondria are subcellular targets of cytokines, especially tumor necrosis factor (TNF); depletion of GSH in this organelle renders the cell more susceptible to oxidative stress originating in mitochondria. Ceramide generated during TNF signaling leads to increased production of ROS in mitochondria. Chronic ethanol-fed hepatocytes are selectively depleted of GSH in mitochondria due to a defective operation of the carrier responsible for transport of GSH from the cytosol into the mitochondrial matrix. Under these conditions, limitation of the mitochondrial GSH pool represents a critical contributory factor that sensitizes alcoholic hepatocytes to the prooxidant effects of cytokines and prooxidants generated by oxidative metabolism of ethanol. S-adenosyl-L-methionine prevents development of the ethanol-induced defect. The mitochondrial GSH carrier has been functionally expressed in Xenopus laevis oocytes microinjected with mRNA from rat liver. This critical carrier displays functional characteristics distinct from other plasma membrane GSH carriers, such as its ATP dependency, inhibitor specificity, and the size class of mRNA that encode the corresponding carrier, suggesting that the mitochondrial carrier of GSH is a gene product distinct from the plasma membrane transporters.

Mitochondrial respiratory chain-dependent generation of superoxide anion and its release into the intermembrane space

2001 ◽  
Vol 353 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Derick HAN ◽  
Everett WILLIAMS ◽  
Enrique CADENAS
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Respiratory Chain ◽  
Superoxide Anion ◽  
Complex Iii ◽  
Spin Adduct ◽  
Intermembrane Space ◽  
Epr Signal ◽  
Mitochondrial Respiratory

It has been generally accepted that superoxide anion generated by the mitochondrial respiratory transport chain are vectorially released into the mitochondrial matrix, where they are converted to hydrogen peroxide through the catalytic action of Mn-superoxide dismutase. Release of superoxide anion into the intermembrane space is a controversial topic, partly unresolved by the reaction of superoxide anion with cytochrome c, which faces the intermembrane space and is present in this compartment at a high concentration. This study was aimed at assessing the topological site(s) of release of superoxide anion during respiratory chain activity. To address this issue, mitoplasts were prepared from isolated mitochondria by digitonin treatment to remove portions of the outer membrane along with portions of cytochrome c. EPR analysis in conjunction with spin traps of antimycin-supplemented mitoplasts revealed the formation of a spin adduct of superoxide anion. The EPR signal was (i) abrogated by superoxide dismutase, (ii) decreased competitively by exogenous ferricytochrome c and (iii) broadened by the membrane-impermeable spin-broadening agent chromium trioxalate. These results confirm the production and release of superoxide anion towards the cytosolic side of the inner mitochondrial membrane. In addition, co-treatment of mitoplasts with myxothiazol and antimycin A, resulting in an inhibition of the oxidation of ubiquinol to ubisemiquinone, abolished the EPR signal, thus suggesting that ubisemiquinone autoxidation at the outer site of the complex-III ubiquinone pool is a pathway for superoxide anion formation and subsequent release into the intermembrane space. The generation of superoxide anion towards the intermembrane space requires consideration of the mitochondrial steady-state values for superoxide anion and hydrogen peroxide, the decay pathways of these oxidants in this compartment and the implications of these processes for cytosolic events.

scholarly journals Potential of Mitochondria-Targeted Antioxidants to Prevent Oxidative Stress in Pancreatic β-cells

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Lydie Plecitá-Hlavatá ◽  
Hana Engstová ◽  
Jan Ježek ◽  
Blanka Holendová ◽  
Jan Tauber ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pancreatic Islets ◽  
Targeted Delivery ◽  
Complex I ◽  
Chain Complex ◽  
Redox Signaling ◽  
Complex Iii ◽  
Mitochondrial Matrix ◽  
Isolated Pancreatic Islets ◽  
Superoxide Formation

Pancreatic β-cells are vulnerable to oxidative stress due to their low content of redox buffers, such as glutathione, but possess a rich content of thioredoxin, peroxiredoxin, and other proteins capable of redox relay, transferring redox signaling. Consequently, it may be predicted that cytosolic antioxidants could interfere with the cytosolic redox signaling and should not be recommended for any potential therapy. In contrast, mitochondrial matrix-targeted antioxidants could prevent the primary oxidative stress arising from the primary superoxide sources within the mitochondrial matrix, such as at the flavin (IF) and ubiquinone (IQ) sites of superoxide formation within respiratory chain complex I and the outer ubiquinone site (IIIQ) of complex III. Therefore, using time-resolved confocal fluorescence monitoring with MitoSOX Red, we investigated various effects of mitochondria-targeted antioxidants in model pancreatic β-cells (insulinoma INS-1E cells) and pancreatic islets. Both SkQ1 (a mitochondria-targeted plastoquinone) and a suppressor of complex III site Q electron leak (S3QEL) prevented superoxide production released to the mitochondrial matrix in INS-1E cells with stimulatory glucose, where SkQ1 also exhibited an antioxidant role for UCP2-silenced cells. SkQ1 acted similarly at nonstimulatory glucose but not in UCP2-silenced cells. Thus, UCP2 can facilitate the antioxidant mechanism based on SkQ1+ fatty acid anion- pairing. The elevated superoxide formation induced by antimycin A was largely prevented by S3QEL, and that induced by rotenone was decreased by SkQ1 and S3QEL and slightly by S1QEL, acting at complex I site Q. Similar results were obtained with the MitoB probe, for the LC-MS-based assessment of the 4 hr accumulation of reactive oxygen species within the mitochondrial matrix but for isolated pancreatic islets. For 2 hr INS-1E incubations, some samples were influenced by the cell death during the experiment. Due to the frequent dependency of antioxidant effects on metabolic modes, we suggest a potential use of mitochondria-targeted antioxidants for the treatment of prediabetic states after cautious nutrition-controlled tests. Their targeted delivery might eventually attenuate the vicious spiral leading to type 2 diabetes.

scholarly journals Resistance to the Nitric Oxide/Cyclic Guanosine 5′-Monophosphate/Protein Kinase G Pathway in Vascular Smooth Muscle Cells from the Obese Zucker Rat, a Classical Animal Model of Insulin Resistance: Role of Oxidative Stress

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1480-1489 ◽  
Author(s):  
I. Russo ◽  
P. Del Mese ◽  
G. Doronzo ◽  
L. Mattiello ◽  
M. Viretto ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Hydrogen Peroxide ◽  
Smooth Muscle ◽  
Superoxide Anion ◽  
Zucker Rats ◽  
No Donor ◽  
Vasp Phosphorylation ◽  
Donor Ability

Some in vivo and ex vivo studies demonstrated a resistance to the vasodilating effects of nitric oxide (NO) in insulin-resistant states and, in particular, obese Zucker rats (OZR). To evaluate the biochemical basis of this phenomenon, we aimed to identify defects of the NO/cGMP/cGMP-dependent protein kinase (PKG) pathway in cultured vascular smooth muscle cells (VSMCs) from OZR and lean Zucker rats (LZR) by measuring: 1) NO donor ability to increase cGMP in the absence and presence of inhibitors of soluble guanylate cyclase (sGC) and phosphodiesterases (PDEs); 2) NO and cGMP ability to induce, via PKG, vasodilator-stimulated phosphoprotein (VASP) phosphorylation at serine 239 and PDE5 activity; 3) protein expression of sGC, PKG, total VASP, and PDE5; 4) superoxide anion concentrations and ability of antioxidants (superoxide dismutase+catalase and amifostine) to influence the NO/cGMP/PKG pathway activation; and 5) hydrogen peroxide influence on PDE5 activity and VASP phosphorylation. VSMCs from OZR vs. LZR showed: 1) baseline cGMP concentrations higher, at least in part owing to reduced catabolism by PDEs; 2) impairment of NO donor ability to increase cGMP, even in the presence of PDE inhibitors, suggesting a defect in the NO-induced sGC activation; 3) reduction of NO and cGMP ability to activate PKG, indicated by the impaired ability to phosphorylate VASP at serine 239 and to increase PDE5 activity via PKG; 4) similar baseline protein expression of sGC, PKG, total VASP, and PDE5; and 5) higher levels of superoxide anion. Antioxidants partially prevented the defects of the NO/cGMP/PKG pathway observed in VSMCs from OZR, which were reproduced by hydrogen peroxide in VSMCs from LZR, suggesting the pivotal role of oxidative stress.

scholarly journals Silymarin versus Silibinin: Differential Antioxidant and Neuroprotective Effects against H2O2-induced Oxidative Stress in PC12 Cells

2016 ◽  
Vol 11 (5) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Hui-Hui Jiang ◽  
Fa-Shun Yan ◽  
Liang Shen ◽  
Hong-Fang Ji
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Pc12 Cells ◽  
Superoxide Anion ◽  
Active Component ◽  
Antioxidant Activities ◽  
Neuroprotective Effect ◽  
Neuroprotective Effects ◽  
Future Studies ◽  
Pheochromocytoma Pc12

The present study assessed comparatively the antioxidant activities of silymarin and its major active component silibinin and their neuroprotective effects against hydrogen peroxide (H2O2)-induced oxidative stress in rat pheochromocytoma PC12 cells. It was found that despite newly prepared silymarin and silibinin solution possessing comparable superoxide anion (O2.–)-scavenging activities, with time the activity of silymarin lowered slightly, but that of silibinin decreased dramatically. Both silymarin and silibinin suppressed H2O2-induced oxidative stress and apoptosis, and the neuroprotective effect of silymarin was overall relatively stronger than that of silibinin. The findings provided clues for future studies on therapeutic potentials of the whole silymarin or purified silibinin for neurodegenerative diseases.

scholarly journals Oxidative stress induced by NOX2 contributes to neuropathic pain via plasma membrane translocation of PKCε in rat dorsal root ganglion neurons

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jing Xu ◽  
Shinan Wu ◽  
Junfei Wang ◽  
Jianmei Wang ◽  
Yi Yan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Neuropathic Pain ◽  
Plasma Membrane ◽  
Dorsal Root Ganglion ◽  
Dorsal Root ◽  
Mechanical Allodynia ◽  
Membrane Translocation ◽  
Drg Neurons ◽  
Ganglion Neurons

Abstract Background Nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2)-induced oxidative stress, including the production of reactive oxygen species (ROS) and hydrogen peroxide, plays a pivotal role in neuropathic pain. Although the activation and plasma membrane translocation of protein kinase C (PKC) isoforms in dorsal root ganglion (DRG) neurons have been implicated in multiple pain models, the interactions between NOX2-induced oxidative stress and PKC remain unknown. Methods A spared nerve injury (SNI) model was established in adult male rats. Pharmacologic intervention and AAV-shRNA were applied locally to DRGs. Pain behavior was evaluated by Von Frey tests. Western blotting and immunohistochemistry were performed to examine the underlying mechanisms. The excitability of DRG neurons was recorded by whole-cell patch clamping. Results SNI induced persistent NOX2 upregulation in DRGs for up to 2 weeks and increased the excitability of DRG neurons, and these effects were suppressed by local application of gp91-tat (a NOX2-blocking peptide) or NOX2-shRNA to DRGs. Of note, the SNI-induced upregulated expression of PKCε but not PKC was decreased by gp91-tat in DRGs. Mechanical allodynia and DRG excitability were increased by ψεRACK (a PKCε activator) and reduced by εV1-2 (a PKCε-specific inhibitor). Importantly, εV1-2 failed to inhibit SNI-induced NOX2 upregulation. Moreover, the SNI-induced increase in PKCε protein expression in both the plasma membrane and cytosol in DRGs was attenuated by gp91-tat pretreatment, and the enhanced translocation of PKCε was recapitulated by H2O2 administration. SNI-induced upregulation of PKCε was blunted by phenyl-N-tert-butylnitrone (PBN, an ROS scavenger) and the hydrogen peroxide catalyst catalase. Furthermore, εV1-2 attenuated the mechanical allodynia induced by H2O2 Conclusions NOX2-induced oxidative stress promotes the sensitization of DRGs and persistent pain by increasing the plasma membrane translocation of PKCε.

scholarly journals Oxidant-impaired intracellular Ca2+ signaling in pancreatic acinar cells: role of the plasma membrane Ca2+-ATPase

2007 ◽  
Vol 293 (3) ◽  
pp. C938-C950 ◽  
Author(s):  
Jason I. E. Bruce ◽  
Austin C. Elliott
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Cell Injury ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Dependent Manner ◽  
Atpase Inhibitors

Pancreatitis is an inflammatory disease of pancreatic acinar cells whereby intracellular calcium concentration ([Ca2+]i) signaling and enzyme secretion are impaired. Increased oxidative stress has been suggested to mediate the associated cell injury. The present study tested the effects of the oxidant, hydrogen peroxide, on [Ca2+]i signaling in rat pancreatic acinar cells by simultaneously imaging fura-2, to measure [Ca2+]i, and dichlorofluorescein, to measure oxidative stress. Millimolar concentrations of hydrogen peroxide increased cellular oxidative stress and irreversibly increased [Ca2+]i, which was sensitive to antioxidants and removal of external Ca2+, and ultimately led to cell lysis. Responses were also abolished by pretreatment with (sarco)endoplasmic reticulum Ca2+-ATPase inhibitors, unless cells were prestimulated with cholecystokinin to promote mitochondrial Ca2+ uptake. This suggests that hydrogen peroxide promotes Ca2+ release from the endoplasmic reticulum and the mitochondria and that it promotes Ca2+ influx. Lower concentrations of hydrogen peroxide (10–100 μM) increased [Ca2+]i and altered cholecystokinin-evoked [Ca2+]i oscillations with marked heterogeneity, the severity of which was directly related to oxidative stress, suggesting differences in cellular antioxidant capacity. These changes in [Ca2+]i also upregulated the activity of the plasma membrane Ca2+-ATPase in a Ca2+-dependent manner, whereas higher concentrations (0.1–1 mM) inactivated the plasma membrane Ca2+-ATPase. This may be important in facilitating “Ca2+ overload,” resulting in cell injury associated with pancreatitis.

scholarly journals Insights into the respiratory chain and oxidative stress

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Véronique Larosa ◽  
Claire Remacle
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Signal Transduction ◽  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Oxygen Species ◽  
Hydroperoxyl Radical ◽  
Photosynthetic Organisms ◽  
The Common ◽  
And Oxidative Stress

Reactive oxygen species (ROS) are highly reactive reduced oxygen molecules that result from aerobic metabolism. The common forms are the superoxide anion (O2∙−) and hydrogen peroxide (H2O2) and their derived forms, hydroxyl radical (HO∙) and hydroperoxyl radical (HOO∙). Their production sites in mitochondria are reviewed. Even though being highly toxic products, ROS seem important in transducing information from dysfunctional mitochondria. Evidences of signal transduction mediated by ROS in mitochondrial deficiency contexts are then presented in different organisms such as yeast, mammals or photosynthetic organisms.

scholarly journals Oxidative stress in moss Bryum caespiticium (Bryaceae) under the influence of high temperature and light intensity in a technogenically transformed environment

2021 ◽  
Vol 12 (4) ◽  
pp. 710-717
Author(s):  
O. L. Baik ◽  
N. Y. Kyyak ◽  
O. M. Humeniuk ◽  
V. V. Humeniuk
Keyword(s):  
Oxidative Stress ◽  
Thermal Stability ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Antioxidant Enzymes ◽  
High Temperatures ◽  
Superoxide Anion ◽  
Anion Radical ◽  
Extreme Temperatures ◽  
Thermal Stability Of

Mosses are pioneer plants in post-technogenic areas. Therefore, the question of adaptive reactions of mosses from these habitats represents a scientific interest. The research is devoted to the study of adaptive changes in the metabolism of the dominant moss species Bryum caespiticium Hedw., collected in the devastated territories of the Novoyavorivsk State Mining and Chemical Enterprise (SMCE) “Sirka (Sulfur)” exposed to hyperthermia and insolation, which cause oxidative stress in plants. The influence of these stressors on the activity and thermal stability of antioxidant enzymes, hydrogen peroxide content, anion radical generation and accumulation of prooxidant components in moss shoots was studied. The activity and thermal stability of peroxidase and superoxide dismutase (SOD) were analysed forB. caespiticium moss from different locations of northern exposure at the sulfur mining dump No 1 in summer and autumn. We established the dependence of the activity of antioxidant enzymes of moss on the intensity of light and temperature on the experimental plots of the dump No 1. In summer, the highest activity and thermal stability rates of peroxidase and SOD were observed. Under the conditions of the experiment in shoots of В. caespiticium from the northern peak of the dump under the influence of 2 hours temperature action (+ 42 ºС) the most significant increase in peroxidase activity was found by 1.78 times and SOD by 1.89 times, as well as increase in its thermal stability by 1.35–1.42 times, respectively. The increase in peroxidase and SOD activity, as well as the increase in their thermal stability caused by hyperthermia were negated by pre-processing with a protein biosynthesis inhibitor cyclohexamide, which may indicate the participation of the protein-synthesizing system in this process. The effect of increasing the thermal stability of enzymes can be considered as a mechanism of adaptation of the protein-synthesizing system to the action of high temperatures. Increase in the activity and thermal stability of antioxidant enzymes is caused primarily by changes in the expression of stress protein genes, which control the synthesis of specific adaptogens and protectors. The obtained results indicate that the extreme conditions of the anthropogenically transformed environment contribute to the development of forms with the highest potential abilities. The mechanism of action of high temperatures is associated with the development of oxidative stress, which is manifested in the intensification of lipid peroxidation and the generation of superoxide anion radical. It was found that temperature stress and high insolation caused an increased generation of superoxide anion radical as the main inducers of protective reactions in the samples of B. caespiticium from the experimental transect of the sulfur mining heap. It is known that the synthesis of Н2О2 occurs under stress and is a signal to start a number of molecular, biochemical and physiological processes of cells, including adaptation of plants to extreme temperatures. It is shown that high temperatures initiate the generation of hydrogen peroxide. Increased reactive oxygen species (ROS) formation, including Н2О2, under the action of extreme temperatures, can cause the activation of signaling systems. Therefore, the increase in the content of Н2О2 as a signaling mediator is a component of the antioxidant protection system. It is determined that adaptive restructuring of the metabolism of the moss В. caespiticium is associated with the accumulation of signaling prooxidant components (diene and triene conjugates and dienketones). The increase in primary lipid peroxidation products, detected by us, under the action of hyperthermia may indicate the intensification of free radical oxidation under adverse climatic conditions in the area of the sulfur production dump, which leads to the intensification of lipid peroxidation processes. The accumulation of radical and molecular lipid peroxidation products are signals for the activation of protective systems, activators of gene expression and processes that lead to increased resistance of plants.

scholarly journals Efficacy of a Low Dose of Estrogen on Antioxidant Defenses and Heart Rate Variability

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Cristina Campos ◽  
Karina Rabello Casali ◽  
Dhãniel Baraldi ◽  
Adriana Conzatti ◽  
Alex Sander da Rosa Araújo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Superoxide Anion ◽  
Low Dose ◽  
Estrogen Therapy ◽  
Antioxidant Defenses ◽  
High Dose ◽  
Hemodynamic Assessment

This study tested whether a low dose (40% less than the pharmacological dose of 17-βestradiol) would be as effective as the pharmacological dose to improve cardiovascular parameters and decrease cardiac oxidative stress. Female Wistar rats (n=9/group) were divided in three groups: (1) ovariectomized (Ovx), (2) ovariectomized animals treated for 21 days with low dose (LE; 0.2 mg), and (3) high dose (HE; 0.5 mg) 17-βestradiol subcutaneously. Hemodynamic assessment and spectral analysis for evaluation of autonomic nervous system regulation were performed. Myocardial superoxide dismutase (SOD) and catalase (CAT) activities, redox ratio (GSH/GSSG), total radical-trapping antioxidant potential (TRAP), hydrogen peroxide, and superoxide anion concentrations were measured. HE and LE groups exhibited an improvement in hemodynamic function and heart rate variability. These changes were associated with an increase in the TRAP, GSH/GSSG, SOD, and CAT. A decrease in hydrogen peroxide and superoxide anion was also observed in the treated estrogen groups as compared to the Ovx group. Our results indicate that a low dose of estrogen is just as effective as a high dose into promoting cardiovascular function and reducing oxidative stress, thereby supporting the approach of using low dose of estrogen in clinical settings to minimize the risks associated with estrogen therapy.

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