scholarly journals Role of glutathione and catalase in H2O2detoxification in LPS-activated hepatic endothelial and Kupffer cells

1997 ◽  
Vol 273 (6) ◽  
pp. G1304-G1311 ◽  
Author(s):  
Zoltán Spolarics ◽  
Jun-Xi Wu
Keyword(s):  
Endothelial Cells ◽  
Kupffer Cells ◽  
Reductase Activity ◽  
Reducing Power ◽  
Glutathione Reductase Activity ◽  
Dichlorofluorescein Diacetate ◽  
Proportional Increase ◽  
And Control ◽  
Fluorescence Plate Reader

The present study investigated the effect of lipopolysaccharide (LPS; from Escherichia coli, 2 mg/kg body wt ip) on selected aspects of the antioxidant status in Kupffer and sinusoidal endothelial cells. Cells were isolated 18 h after the injection of saline or LPS. In fresh suspension cultures, cellular reduced glutathione (GSH) and H2O2were determined by monochlorobimane, and 2′,7′-dichlorofluorescein diacetate, respectively, using a fluorescence plate reader. LPS injection increased GSH content two- to threefold in Kupffer cells compared with cells from control rats. Cellular GSH content was higher in endothelial than Kupffer cells. However, LPS did not increase GSH content in endothelial cells. Addition of H2O2(40–200 μM) to Kupffer or endothelial cells caused a transient decrease in GSH, which was more pronounced in cells from control rats (∼45% drop) than in LPS-exposed cells (∼25% drop). Depleted GSH levels were accompanied by a proportional increase in cellular H2O2. After inhibition of catalase by 3-amino-1,2,4-triazole, the presence of 0.2 mM H2O2depleted GSH content by 75% and 40% in Kupffer cells from saline- or LPS-injected rats, respectively. The same treatments caused a similar 50% decrease in both activated and control endothelial cells. LPS decreased catalase activity by 45% in Kupffer cells, whereas it had no effect on catalase in endothelial cells. Glutathione reductase activity was not altered by LPS in either cell type. These data show that in activated Kupffer cells the elevated level of cellular glutathione plays an augmented role in the protection against reactive oxygen species, whereas the contribution of catalase to H2O2detoxification is attenuated. In LPS-stimulated endothelial and Kupffer cells, the efficient maintenance of GSH is consistent with upregulated production of reducing power through the hexose phosphate shunt observed previously.

scholarly journals The Preventive Effects of Asparagus officinalis Extract on Sodium Selenite-Induced Cataractogenesis in Experimental Animal Models

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Momammad Azadbakht ◽  
Mohammad Asghari ◽  
Kiumars Nowroozpoor Dailami ◽  
Ali Davoodi ◽  
Amirhossein Ahmadi
Keyword(s):  
Sodium Selenite ◽  
Reductase Activity ◽  
Control Plant ◽  
Asparagus Officinalis ◽  
Safe Alternative ◽  
Hydroalcoholic Extract ◽  
Plant Groups ◽  
Malondialdehyde Content ◽  
Glutathione Reductase Activity ◽  
And Control

Background and Objectives. Cataract is the leading cause of blindness worldwide. Although surgery is now considered the most successful cure, the development of alternative treatments is needed due to postsurgical complications. Oxidative stress in the lens is considered to be the most crucial factor in the formation of cataracts. Therefore, the effects of the hydroalcoholic extract of Asparagus officinalis L, a traditional antioxidative plant, on cataract formation of sodium selenite were evaluated. Materials and Methods. Neonatal rats received a single dose of sodium selenite as an intraperitoneal injection (30 μmol/kg) on day 10 postnatal to induce cataract. Animals were then posttreated with various oral solutions of A. officinalis extract at 200 mg/kg or 400 mg/kg once daily on days 10–16 postnatal. Cataract was evaluated by slit-lamp, and lens opacification was analyzed in each group 24 hours after the last treatment at day seven postadministration of the extracts or vehicle. The total protein concentration of lenses, glutathione reductase activity as the glutathione antioxidant capacity, and malondialdehyde content as a marker of lipid peroxidation were further assessed in removed rat lenses on day 30 postnatal. Results. All lenses in the healthy and control plant groups were clear. Sodium selenite significantly increased cataract grade (2.8 ± 0.2) when compared to the healthy group p = 0.001 . However, cataract grades were decreased considerably as 1.9 ± 0.72 and 1.5 ± 0.85 in groups that received 200 mg/kg and 400 mg/kg oral extract of A. officinalis, respectively. A. officinalis extract also restored all abnormalities of biochemical markers induced by sodium selenite. Conclusion. Our data suggest that A. officinalis could be a promising candidate as a safe alternative treatment in cataracts upon further clinical trials. This effect is probably associated with the antioxidant activity of A. officinalis.

Neutrophils Clearance by Endothelial Cells Regulates Homeostasis and Coagulation.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3782-3782
Author(s):  
Wen Li ◽  
Shuchuan Liu ◽  
Yueyue Fu ◽  
Jinxiao Hou ◽  
Xiushuai Dong ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Kupffer Cells ◽  
Milk Fat ◽  
Conflicts Of Interest ◽  
Umbilical Vein ◽  
Large Fraction ◽  
Background Level ◽  
Procoagulant Activity ◽  
Phagocytic Cells

Abstract Abstract 3782 Neutrophils, also called polymorphonuclear leukocytes (PMN's) have a half-life of only 6 hours in the blood. Inflammation can further shorten the circulating life-time. A large fraction of the bone marrow capacity is committed to ongoing production of these short-lived cells but the manner of their clearance from the circulation is less well understood. We have previously demonstrated that PMN's are cleared by liver macrophages. However, the details of PMN adhesion-induced PMN clearance in the liver are unknown. The aim of this study is to evaluate a pathway of PMNs clearance by endothelial cells, which are not ordinarily considered phagocytes. Lactadherin is a glycoprotein of milk fat globules and is also secreted by stimulated macrophages. Lactadherin binds phosphatidylserine on apoptotic cells via tandem lectin-homology domains with homology to factor VIII and binds αvβ3 and αvβ5 integrins on phagocytic cells via an RGD sequence in an epithelial growth factor domain. Lactadherin aids in engulfment of senescent lymphocytes by splenic macrophages and mediates an anti-inflammatory response. We utilized lactadherin as a probe to detect phosphatidylserine exposure on aging PMN's and evaluated the lactadherin-dependent engulfment of these PMN's by endothelial cells. Cultured human PMNs from healthy donors, with 95% purity, were 40% and 96% PS-exposure positive at 9 and 24 h, respectively. They displayed a parallel increase in procoagulant supporting, activity related to the PS exposure. Coculture of the aging PMNs and human umbilical vein endothelial cells resulted in phagocytosis of the PMN's, observed by confocal microscopy and electron microscopy. Exogenous lactadherin increased phagocytosis by 3–5 fold during 120 minutes of observation. An anti-lactadherin RGD antibody and an anti-lactadherin C2 domain antibody inhibited phagocytosis to approx 1/2 the background level suggesting that lactadherin secreted by PMN's or neutrophils contributes to the base level of phagocytosis. Clearance of the senescent neutrophils by endothelial cells decreased procoagulant activity >70% and blockade of neutrophil PS with lactadherin reduced procoagulant activity by > 90% indicating the potential role of neutrophil uptake in limiting prothrombotic activity. In a rat model of neutrophil homeostasis we injected low dose lipopolysaccharide (LPS) and gadolinium chloride intravenously to increase the number circulating PMN's and block clearance by Kupffer cells. This allowed observation of PMN adhesion and sequestration in the liver. The number of PMNs peaked at 9 h and decreased to the normal range at 24 h after blockade of Kupffer cells. Blocking the endothelial P-selectin significantly delayed PMN's removal in the liver. Injection of lactadherin promoted the PMNs accumlation and removal. The current results suggest that ECs contribute to maintaining the homeostasis of PMNs in the circulation and a possible role of lactadherin in the EC-mediated clearance. Our results also indicate that lactadherin-mediated clearance may limit procoagulant or prothrombotic activity of senescent PMN's. Disclosures: No relevant conflicts of interest to declare.

Expression of P-Selectin on Hepatic Endothelia and Platelets Promoting Neutrophil Removal by Liver Macrophages

Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 520-528
Author(s):  
Jialan Shi ◽  
Yoshihiro Kokubo ◽  
Kenjiro Wake
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
Kupffer Cells ◽  
Polymorphonuclear Leukocyte ◽  
Low Molecular Weight Heparin ◽  
Acute Inflammation ◽  
Combined Treatment ◽  
Gadolinium Chloride ◽  
Low Molecular Weight

The role of P-selectin on polymorphonuclear leukocyte (PMN) adhesion-induced PMN elimination in the liver is unclear. Our objectives were to show the expression and distribution of P-selectin in rat liver, as well as to evaluate the changes in the modulation of the expression of P-selectin and its role in the accumulation and sequestration of PMNs. The intravenous administration of endotoxin markedly increased the expression of P-selectin on the venous and sinusoidal endothelial cells, as well as on the platelets trapped in the liver. Its expression peaked at 6 hours postinjection and was associated with a rapid increase in the aggregation and elimination of PMNs in the hepatic sinusoids. Combined treatment with an antibody to P-selectin or with low molecular weight heparin, a P-selectin antagonist, blocked the P-selectin, significantly reduced the arrest of PMNs, and delayed their removal in the liver. Pretreatment with gadolinium chloride inhibited phagocytosis of PMNs by the Kupffer cells, decreased the expression of P-selectin, and limited the hepatic accumulation of PMNs. Thus, P-selectin played a role in accumulation and elimination of PMNs from the liver. Results also suggest that activated Kupffer cells can modulate the expression of P-selectin in the liver and influence the homeostasis of PMNs in the circulation during acute inflammation.

scholarly journals Changes in antioxidant status of heart muscle tissue in experimental diabetes in rabbits.

2002 ◽  
Vol 49 (2) ◽  
pp. 529-535 ◽  
Author(s):  
Anna Gumieniczek ◽  
Hanna Hopkała ◽  
Zbigniew Wójtowicz ◽  
Justyna Nikołajuk
Keyword(s):  
Oxidative Stress ◽  
Defense Mechanisms ◽  
Reductase Activity ◽  
Control Level ◽  
Heart Tissue ◽  
Control Groups ◽  
Time Intervals ◽  
Glutathione Reductase Activity ◽  
And Control ◽  
Sulfhydryl Compounds

The present study was designed to evaluate the oxidative stress-related parameters in alloxan-induced diabetes in rabbits. After 3, 6, 12 and 24 weeks of hyperglycaemia the enzymatic and non-enzymatic factors were measured in heart tissue of diabetic and control groups. Superoxide dismutase and glutathione peroxidase activities and the contents of total sulfhydryl compounds significantly increased at all time intervals. Catalase activity increased initially (after 3 and 6 weeks), decreased after 12 weeks and increased again at the 24th week of the experiment. Glutathione reductase activity increased initially (at 3rd week), decreased below control level after 6 and 12 weeks, then increased again. Ascorbic acid concentration decreased after 3 and 6 weeks, and increased at the 12th and 24th weeks. The level of lipid peroxidation products was reduced after 3, 6 and 12 weeks of the experiment. After 24 weeks it was significantly elevated. These data suggest that hyperglycaemia induces oxidative stress in the heart but the defense mechanisms in the heart tissue are fairly efficacious against oxidative injury.

The role of heat shock proteins 27 and 70 in redox-dependent regulation of apoptosis in Jurkat tumor cells

2016 ◽  
Vol 62 (6) ◽  
pp. 670-673 ◽  
Author(s):  
O.L. Nosareva ◽  
N.V. Ryazantseva ◽  
E.A. Stepovaya ◽  
E.V. Shakhristova ◽  
E.A. Stepanova ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Cell Apoptosis ◽  
Intact Cell ◽  
Reductase Activity ◽  
Cellular Level ◽  
Jurkat Cells ◽  
Glutathione Reductase Activity ◽  
Shock Proteins

Heat shock proteins Hsp) act as molecular chaperones, protecting enzymes and other proteins against reactive oxygen species. The objective of the study was to investigate the role of Hsp27 in maintaining the balance of the glutathione system and Hsp70 concentrations as well as in implementing Jurkat tumor cell apoptosis. Addition of the Hsp27 inhibitor KRIBB3 (5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl)-isoxazol) to Jurkat cells resulted in glutathione redox imbalance (increased GSSG and increased glutathione reductase activity), a decrease in Hsp70 concentrations, and also increased cell apoptosis as compared with to the intact cell culture. The proposed selective regulation of chaperone activity is a promising direction in regulating apoptosis at the cellular level.

scholarly journals Overexpression of the alpha-type protein kinase (PK) C in LLC-PK1 cells does not lead to a proportional increase in the induction of two 12-O-tetradecanoylphorbol-13-acetate-inducible genes.

1991 ◽  
Vol 2 (6) ◽  
pp. 491-502 ◽  
Author(s):  
M Wartmann ◽  
D A Jans ◽  
P J Parker ◽  
Y Nagamine ◽  
B A Hemmings ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Phorbol Esters ◽  
Fold Increase ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Proportional Increase ◽  
Inducible Genes ◽  
And Control ◽  
Alpha Type

Phorbol esters, by activating protein kinase C (PKC), induce the expression of the urokinase-type plasminogen activator (uPA) gene and the proto-oncogene c-fos in LLC-PK1 (PK1) porcine kidney epithelial cells. To investigate the role of PKC in the regulation of these two 12-O-tetradecanoylphorbol-13-acetate (TPA)-inducible genes, the alpha-type PKC, the predominant subtype present in the PK1 cells, was overexpressed in this cell line. Two clonal PK1 derivatives overexpressing the alpha PKC 15- and 20-fold, respectively, were established. Compared with the parental and control cells, only a modest but substantially sustained (2- to 3-fold) increase in the accumulation of uPA as well as c-fos mRNAs were observed by TPA in these cells. These results indicate that the extent of induction of these genes mediated by TPA was not proportional to the amounts of alpha-type PKC stably overexpressed in these cells, suggesting that factor(s) downstream of the activation of the alpha PKC appear to be rate limiting for the induction of both TPA-inducible genes in PK1 cells.

Oxidative stress inhibits bradykinin-stimulated 45Ca2+ flux in pulmonary vascular endothelial cells

1991 ◽  
Vol 260 (2) ◽  
pp. H549-H556
Author(s):  
S. J. Elliott ◽  
W. P. Schilling
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Reductase Activity ◽  
Oxidant Stress ◽  
K Channel ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Prolonged Incubation ◽  
Glutathione Reductase Activity ◽  
Tetrabutylammonium Chloride

The effects of oxidant stress and altered glutathione reductase activity on agonist-induced flux of Ca2+ were studied in cultured calf pulmonary artery endothelial cells using radioisotopic 45Ca2+. Bradykinin-stimulated uptake of 45Ca2+ was determined after cells were incubated with the membrane-permeant oxidant t-butylhydroperoxide (0.4 mM) for various durations. t-Butylhydroperoxide increased uptake of 45Ca2+ under basal conditions and significantly decreased bradykinin-stimulated uptake in a time-dependent manner through incubation periods of 2 h. Preincubation of cells with 1,3-bis(chloroethyl)-1-nitrosourea markedly reduced bradykinin-stimulated uptake in cells subsequently treated with t-butylhydroperoxide. Bradykinin-stimulated efflux of 45Ca2+ and 86Rb+ was examined in control and oxidant-stressed endothelial cells. t-Butylhydroperoxide initially decreased bradykinin-stimulated efflux of 45Ca2+ but had no effect on 86Rb+ efflux. After more prolonged incubation with the oxidant, stimulated 45Ca2+ efflux was further inhibited, and basal efflux of 86Rb+ was increased to a rate similar to that observed with bradykinin stimulation. Elevated basal 86Rb+ efflux was blocked by tetrabutylammonium chloride, a selective inhibitor of Ca2(+)-dependent K+ channels in endothelial cells. These findings, together with our previously described results using fura-2, suggest that oxidant stress initially inhibits bradykinin-stimulated Ca2+ influx and later inhibits stimulated Ca2+ efflux. Finally, cytosolic free Ca2+ concentration becomes persistently elevated and is associated with elevated basal efflux of K+ via the Ca2(+)-dependent K+ channel.

BCNU-induced protection from hyperbaric hyperoxia: role of glutathione metabolism

1988 ◽  
Vol 65 (6) ◽  
pp. 2531-2536 ◽  
Author(s):  
S. G. Jenkinson ◽  
J. M. Jordan ◽  
R. A. Lawrence
Keyword(s):  
Reductase Activity ◽  
Glutathione Metabolism ◽  
Hyperbaric Hyperoxia ◽  
Oxidation Reduction ◽  
Reduction Cycle ◽  
Hepatic Glutathione ◽  
Glutathione Oxidation ◽  
Glutathione Reductase Activity ◽  
Hyperbaric O2

To explore the role of the glutathione oxidation-reduction cycle in altering the sensitivity of rats to the effects of hyperbaric hyperoxia, we administered N,N-bis(2-chloroethyl)-N-nitrosourea (BCNU) to decrease tissue glutathione reductase activity. We then exposed these animals and their matched vehicle-treated controls to 100% O2 at 4 ATA. Animals that received BCNU and were immediately exposed to hyperbaric O2 showed enhanced toxicity by seizing earlier in the exposure than controls. Animals that received BCNU 18 h before the hyperbaric O2 exposure were paradoxically protected from the effects of the exposure with a prolongation of their time to initial seizure and a marked increase in their survival time during the exposure. Tissue glutathione concentrations were also measured in the various groups and the hyperbaric O2 exposure produced marked decreases in hepatic glutathione levels in all control animals. In animals treated with BCNU 18 h before exposure, hepatic glutathione concentrations also decreased, but the concentrations had significantly increased during the 18-h waiting period, allowing these animals to maintain hepatic levels in the normal range even during their hyperbaric exposures. We conclude that treatment of rats with BCNU 18 h before exposure to hyperbaric hyperoxia results in enhanced protection of the animals during the exposure.

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