Plumbagin Modulates Leukemia Cell Redox Status

The chemopreventive effects of dietaryn-3 PUFA in various pathologies has so far remained controversial, and we were interested in studying their potential influence on cell redox status. DHA (22:6n-3), a typical highly unsaturatedn-3 PUFA, was used at 30µmol/l in a model of human fibroblast cell culture. A dose–response effect, roughly linear, was checked for DHA between 0 and 60µmol/l, and was accompanied by a large increase in intracellular GSH content. A time course study of this effect shows that, after a short fall, as soon as 4h after the beginning of the experiment, the large increase in the GSH content was associated with elevated catalytic activities of γ-glutamyl-cysteinyl ligase, glutathione reductase and glutathioneS-transferase. This coordinated response is characteristic of an antioxidant response and was confirmed by the induction of expression of mRNA for γ-glutamyl-cysteinyl ligase, glutathione reductase and haem-oxygenase. This large increase in the GSH content contributes to decreasing the reactive oxygen species level, as assessed by the decreased accumulation of dichlorofluorescein inside cells. To our knowledge, this is the first report on a specific and potent effect of DHA for decreasing the oxidative stress of human fibroblasts.

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HYDROGEN PEROXIDE INDUCES APOPTOSIS IN HUMAN HEPATOMA CELLS AND ALTERS CELL REDOX STATUS

Cell Biology International ◽

10.1006/cbir.1999.0438 ◽

2000 ◽

Vol 24 (1) ◽

pp. 9-23 ◽

Cited By ~ 53

Author(s):

J Li

Keyword(s):

Hydrogen Peroxide ◽

Redox Status ◽

Hepatoma Cells ◽

Human Hepatoma ◽

Human Hepatoma Cells ◽

Cell Redox Status

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Blood cell redox status and fatty acids

Prostaglandins Leukotrienes and Essential Fatty Acids ◽

10.1016/0952-3278(95)90015-2 ◽

1995 ◽

Vol 52 (2-3) ◽

pp. 159-161 ◽

Cited By ~ 5

Author(s):

M. Lagarde ◽

E. Véricel ◽

B. Chabannes ◽

A.F. Prigent

Keyword(s):

Fatty Acids ◽

Blood Cell ◽

Redox Status ◽

Cell Redox Status

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Assaying Chlamydia pneumoniae persistence in monocyte-derived macrophages identifies schisandrin lignans as phenotypic switchers

10.1101/708487 ◽

2019 ◽

Author(s):

Eveliina Taavitsainen ◽

Maarit Kortesoja ◽

Leena Hanski

Keyword(s):

Chlamydia Pneumoniae ◽

Redox Status ◽

Productive Infection ◽

Respiratory Pathogen ◽

Steady Increase ◽

Intracellular Bacteria ◽

Success Factor ◽

Antibacterial Drug ◽

Copy Numbers ◽

Cell Redox Status

AbstractAntibiotic-tolerant persister bacteria involve frequent treatment failures, relapsing infections and the need for extended antibiotic treatment. Taking persisters into account in susceptibility assays is thus an essential success factor in antibacterial drug discovery. The virulence of the obligate intracellular bacterium Chlamydia pneumoniae is tightly linked to its propensity for persistence, but current susceptibility screening on this gram-negative respiratory pathogen relies on permissive epithelial cells. To establish an improved antichlamydial susceptibility assay allowing the analysis of both actively growing and persister bacteria, we studied C. pneumoniae clinical isolate CV-6 infection kinetics in THP-1 macrophages by qPCR and quantitative culture. Indicated by the steady increase of chlamydial genome copy numbers and infectious progeny as well as the failure of azithromycin to eradicate the intracellular forms of the bacterium, the macrophages were found to harbor a subpopulation of persister C. pneumoniae cells. The potential of the assay for the discovery of anti-persister molecules against intracellular bacteria was demonstrated by the identification of the differential effects of two dibenzocyclooctadiene lignans on C. pneumoniae infection. While schisandrin reverted C. pneumoniae persistence and promoted productive infection, schisandrin C was superior to azithromycin in eradicating the C. pneumoniae infection. The phenotypic switch was associated with the suppression of cellular glutathione pools, implying that targeting glutathione homeostasis may provide a novel means for intracellular bacteria resuscitation. In conclusion, these data highlight the value of macrophages over permissive cell lines in anti-persister agent discovery on intracellular bacteria and targeting host cell redox status to fight persistent infections.

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Role of Melatonin in Plant Tolerance to Soil Stressors: Salinity, pH and Heavy Metals

Molecules ◽

10.3390/molecules25225359 ◽

2020 ◽

Vol 25 (22) ◽

pp. 5359

Author(s):

Mohamed Moustafa-Farag ◽

Amr Elkelish ◽

Mohamed Dafea ◽

Mumtaz Khan ◽

Marino B. Arnao ◽

...

Keyword(s):

Heavy Metals ◽

Redox Status ◽

Free Radical Scavenger ◽

Radical Scavenger ◽

Plant Tolerance ◽

Biochemical Processes ◽

Chemical Pollutants ◽

General Metabolism ◽

Cell Redox Status

Melatonin (MT) is a pleiotropic molecule with diverse and numerous actions both in plants and animals. In plants, MT acts as an excellent promotor of tolerance against abiotic stress situations such as drought, cold, heat, salinity, and chemical pollutants. In all these situations, MT has a stimulating effect on plants, fomenting many changes in biochemical processes and stress-related gene expression. Melatonin plays vital roles as an antioxidant and can work as a free radical scavenger to protect plants from oxidative stress by stabilization cell redox status; however, MT can alleviate the toxic oxygen and nitrogen species. Beyond this, MT stimulates the antioxidant enzymes and augments antioxidants, as well as activates the ascorbate–glutathione (AsA–GSH) cycle to scavenge excess reactive oxygen species (ROS). In this review, we examine the recent data on the capacity of MT to alleviate the effects of common abiotic soil stressors, such as salinity, alkalinity, acidity, and the presence of heavy metals, reinforcing the general metabolism of plants and counteracting harmful agents. An exhaustive analysis of the latest advances in this regard is presented, and possible future applications of MT are discussed.

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Salicylic Acid Binding Proteins (SABPs): The Hidden Forefront of Salicylic Acid Signalling

International Journal of Molecular Sciences ◽

10.3390/ijms20184377 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4377 ◽

Cited By ~ 11

Author(s):

Igor Pokotylo ◽

Volodymyr Kravets ◽

Eric Ruelland

Keyword(s):

Salicylic Acid ◽

Binding Proteins ◽

Redox Status ◽

Signal Transduction Pathways ◽

Main Role ◽

Induced Responses ◽

Transcriptional Responses ◽

Plant Life ◽

Molecular Machinery ◽

Cell Redox Status

Salicylic acid (SA) is a phytohormone that plays important roles in many aspects of plant life, notably in plant defenses against pathogens. Key mechanisms of SA signal transduction pathways have now been uncovered. Even though details are still missing, we understand how SA production is regulated and which molecular machinery is implicated in the control of downstream transcriptional responses. The NPR1 pathway has been described to play the main role in SA transduction. However, the mode of SA perception is unclear. NPR1 protein has been shown to bind SA. Nevertheless, NPR1 action requires upstream regulatory events (such as a change in cell redox status). Besides, a number of SA-induced responses are independent from NPR1. This shows that there is more than one way for plants to perceive SA. Indeed, multiple SA-binding proteins of contrasting structures and functions have now been identified. Yet, all of these proteins can be considered as candidate SA receptors and might have a role in multinodal (decentralized) SA input. This phenomenon is unprecedented for other plant hormones and is a point of discussion of this review.

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679 The positive and negative effects of TNF on cardiac contraction are mediated by AA and are controlled by the cell redox status

European Journal of Heart Failure Supplements ◽

10.1016/s1567-4215(03)90424-3 ◽

2003 ◽

Vol 2 (1) ◽

pp. 139-140

Author(s):

M CAILLERET ◽

A AMADOU ◽

A NAWROCKI ◽

F ROCARIES ◽

M BESTBELPOMME ◽

...

Keyword(s):

Redox Status ◽

Cardiac Contraction ◽

Negative Effects ◽

Cell Redox Status

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A Novel Approach for In Vivo Measurement of Red Cell Redox Status

Blood ◽

10.1182/blood.v116.21.2036.2036 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2036-2036 ◽

Cited By ~ 1

Author(s):

Xiuling Xu ◽

Katharina von Loehneysen ◽

Deborah Noack ◽

Andrew Vu ◽

Jeff S. Friedman

Keyword(s):

Fluorescence Emission ◽

Redox Status ◽

Red Cells ◽

Cysteine Residues ◽

Excitation Wavelength ◽

Red Cell ◽

Reducing Conditions ◽

Cell Redox Status

Abstract Abstract 2036 Maintenance of a reducing redox balance is a critical physiologic function of red cell metabolic machinery. Perturbation of this balance, whether inherited or acquired, is found in a variety of red cell pathologies. Methods for evaluation of red cell redox status include direct approaches such as determining glutathione (GSH, GSSG) levels, and indirect approaches such as measuring fluorescence of oxidation sensitive dyes. Here we describe an alternative method for evaluation of red cell redox status that can be used in vivo and in real-time assays. Engineered variants of GFP possessing two solvent accessible cysteine residues function as molecular redox sensors with distinct fluorescence characteristics. Excitation spectrum shifts upon the oxidation of cysteine residues forming a disulfide. A higher ratio of fluorescence when comparing excitation at 405nm versus 488nm indicates rising levels of oxidized GFP and a shift in cellular redox status. To validate redox GFPs in erythroid cells, we first performed in vitro assays with MEL cells over-expressing several related GFP sensors (ro-GFPs), selecting the brightest molecule (roGFP2) for further study. The sensor function of roGFP2 in MEL cells was verified by stimulation with exogenous oxidant (1mM H202) or reductant (10 mM DTT) as shown in the figure below. In order to create a physiologic in vivo model for study of red cell redox status, transgenic mice expressing roGFP2 specifically in the erythroid lineage were generated. roGFP2 expressing red cells demonstrate the expected shift in fluorescence upon exposure to H202 or t-butyl peroxide in a short-term assay. In vivo, we have measured red cell lifespan (using biotin-labeling) in roGFP2 transgenic animals to follow redox status of red cells as a function of cell age. Expression of roGFP2 has no effect on red cell survival. Interestingly, when comparing old red cells (age > 50days) with younger cells (age < 50days), a shift in GFP fluorescence ratio indicating that a higher fraction of the sensor is oxidized in the aged cells was observed. This observation is consistent with the hypothesis that metabolic changes, in particular a decline in ability to reduce oxidative damage, contribute to red cell senescence. We are generating several murine strains with defined red cell defects also expressing roGFP2 in order to assess the role of changes in intra-erythrocyte redox status in a range of pathologic conditions. In vitro and in vivo assays using roGFP2 transgenic cells/mice are in process to determine the potential utility of this system as a screen for hematoxicity of drugs and other compounds. Figure 1 Evaluation of roGFP2 function in MEL cells. The Y-axis shows fluorescence emission as a function of excitation wavelength (X-axis)—showing a shift when cells are exposed to oxidizing or reducing conditions. Figure 1. Evaluation of roGFP2 function in MEL cells. The Y-axis shows fluorescence emission as a function of excitation wavelength (X-axis)—showing a shift when cells are exposed to oxidizing or reducing conditions. Disclosures: No relevant conflicts of interest to declare.

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