scholarly journals Glutathione Metabolism in Plants under Stress: Beyond Reactive Oxygen Species Detoxification

Metabolites ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 641
Author(s):  
Sonia Dorion ◽  
Jasmine C. Ouellet ◽  
Jean Rivoal
Keyword(s):  
Reactive Oxygen Species ◽  
Current Knowledge ◽  
Reactive Oxygen ◽  
Covalent Modification ◽  
Regulatory Function ◽  
Glutathione Metabolism ◽  
Oxygen Species ◽  
Post Translational Modification ◽  
Stress Regulation ◽  
Recent Developments

Glutathione is an essential metabolite for plant life best known for its role in the control of reactive oxygen species (ROS). Glutathione is also involved in the detoxification of methylglyoxal (MG) which, much like ROS, is produced at low levels by aerobic metabolism under normal conditions. While several physiological processes depend on ROS and MG, a variety of stresses can dramatically increase their concentration leading to potentially deleterious effects. In this review, we examine the structure and the stress regulation of the pathways involved in glutathione synthesis and degradation. We provide a synthesis of the current knowledge on the glutathione-dependent glyoxalase pathway responsible for MG detoxification. We present recent developments on the organization of the glyoxalase pathway in which alternative splicing generate a number of isoforms targeted to various subcellular compartments. Stress regulation of enzymes involved in MG detoxification occurs at multiple levels. A growing number of studies show that oxidative stress promotes the covalent modification of proteins by glutathione. This post-translational modification is called S-glutathionylation. It affects the function of several target proteins and is relevant to stress adaptation. We address this regulatory function in an analysis of the enzymes and pathways targeted by S-glutathionylation.

Cell signalling by oxidized lipids and the role of reactive oxygen species in the endothelium

2005 ◽  
Vol 33 (6) ◽  
pp. 1385-1389 ◽  
Author(s):  
J.W. Zmijewski ◽  
A. Landar ◽  
N. Watanabe ◽  
D.A. Dickinson ◽  
N. Noguchi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Lipid Oxidation ◽  
Protein Function ◽  
Cell Signalling ◽  
Reactive Oxygen ◽  
Oxidation Products ◽  
Oxidized Lipids ◽  
Oxygen Species ◽  
Post Translational Modification ◽  
Lipid Oxidation Products

The controlled formation of ROS (reactive oxygen species) and RNS (reactive nitrogen species) is now known to be critical in cellular redox signalling. As with the more familiar phosphorylation-dependent signal transduction pathways, control of protein function is mediated by the post-translational modification at specific amino acid residues, notably thiols. Two important classes of oxidant-derived signalling molecules are the lipid oxidation products, including those with electrophilic reactive centres, and decomposition products such as lysoPC (lysophosphatidylcholine). The mechanisms can be direct in the case of electrophiles, as they can modify signalling proteins by post-translational modification of thiols. In the case of lysoPC, it appears that secondary generation of ROS/RNS, dependent on intracellular calcium fluxes, can cause the secondary induction of H2O2 in the cell. In either case, the intracellular source of ROS/RNS has not been defined. In this respect, the mitochondrion is particularly interesting since it is now becoming apparent that the formation of superoxide from the respiratory chain can play an important role in cell signalling, and oxidized lipids can stimulate ROS formation from an undefined source. In this short overview, we describe recent experiments that suggest that the cell signalling mediated by lipid oxidation products involves their interaction with mitochondria. The implications of these results for our understanding of adaptation and the response to stress in cardiovascular disease are discussed.

scholarly journals Triptolide suppresses IDH1-mutated malignancy via Nrf2-driven glutathione metabolism

2020 ◽  
Vol 117 (18) ◽  
pp. 9964-9972 ◽  
Author(s):  
Di Yu ◽  
Yang Liu ◽  
Yiqiang Zhou ◽  
Victor Ruiz-Rodado ◽  
Mioara Larion ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
De Novo ◽  
Synthetic Lethality ◽  
Reactive Oxygen ◽  
Metabolic Reprogramming ◽  
Glutathione Metabolism ◽  
Oxygen Species ◽  
Genetic Abnormality

Isocitrate dehydrogenase (IDH) mutation is a common genetic abnormality in human malignancies characterized by remarkable metabolic reprogramming. Our present study demonstrated that IDH1-mutated cells showed elevated levels of reactive oxygen species and higher demands on Nrf2-guided glutathione de novo synthesis. Our findings showed that triptolide, a diterpenoid epoxide from Tripterygium wilfordii, served as a potent Nrf2 inhibitor, which exhibited selective cytotoxicity to patient-derived IDH1-mutated glioma cells in vitro and in vivo. Mechanistically, triptolide compromised the expression of GCLC, GCLM, and SLC7A11, which disrupted glutathione metabolism and established synthetic lethality with reactive oxygen species derived from IDH1 mutant neomorphic activity. Our findings highlight triptolide as a valuable therapeutic approach for IDH1-mutated malignancies by targeting the Nrf2-driven glutathione synthesis pathway.

scholarly journals Signaling Toward Reactive Oxygen Species-Scavenging Enzymes in Plants

2021 ◽  
Vol 11 ◽  
Author(s):  
Petr Dvořák ◽  
Yuliya Krasylenko ◽  
Adam Zeiner ◽  
Jozef Šamaj ◽  
Tomáš Takáč
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Enzymes ◽  
Environmental Conditions ◽  
Antioxidant Defense ◽  
Current Knowledge ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Negative Consequences ◽  
Ros Scavenging ◽  
Enzymatic Antioxidant

Reactive oxygen species (ROS) are signaling molecules essential for plant responses to abiotic and biotic stimuli as well as for multiple developmental processes. They are produced as byproducts of aerobic metabolism and are affected by adverse environmental conditions. The ROS content is controlled on the side of their production but also by scavenging machinery. Antioxidant enzymes represent a major ROS-scavenging force and are crucial for stress tolerance in plants. Enzymatic antioxidant defense occurs as a series of redox reactions for ROS elimination. Therefore, the deregulation of the antioxidant machinery may lead to the overaccumulation of ROS in plants, with negative consequences both in terms of plant development and resistance to environmental challenges. The transcriptional activation of antioxidant enzymes accompanies the long-term exposure of plants to unfavorable environmental conditions. Fast ROS production requires the immediate mobilization of the antioxidant defense system, which may occur via retrograde signaling, redox-based modifications, and the phosphorylation of ROS detoxifying enzymes. This review aimed to summarize the current knowledge on signaling processes regulating the enzymatic antioxidant capacity of plants.

scholarly journals  Metals as a cause of oxidative stress in fish: a review

2011 ◽  
Vol 56 (No. 11) ◽  
pp. 537-546 ◽  
Author(s):  
M. Sevcikova ◽  
H. Modra ◽  
A. Slaninova ◽  
Z. Svobodova
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Oxidative Damage ◽  
Metal Binding ◽  
Special Functions ◽  
Current Knowledge ◽  
Reactive Oxygen ◽  
Enzyme Inactivation ◽  
Oxygen Species ◽  
Antioxidant Defences

This review summarizes the current knowledge on the contribution of metals to the development of oxidative stress in fish. Metals are important inducers of oxidative stress in aquatic organisms, promoting formation of reactive oxygen species through two mechanisms. Redox active metals generate reactive oxygen species through redox cycling, while metals without redox potential impair antioxidant defences, especially that of thiol-containing antioxidants and enzymes. Elevated levels of reactive oxygen species lead to oxidative damage including lipid peroxidation, protein and DNA oxidation, and enzyme inactivation. Antioxidant defences include the enzyme system and low molecular weight antioxidants. Metal-binding proteins, such as ferritin, ceruloplasmin and metallothioneins, have special functions in the detoxification of toxic metals and also play a role in the metabolism and homeostasis of essential metals. Recent studies of metallothioneins as biomarkers indicate that quantitative analysis of mRNA expression of metallothionein genes can be appropriate in cases with elevated levels of metals and no evidence of oxidative damage in fish tissue. Components of the antioxidant defence are used as biochemical markers of oxidative stress. These markers may be manifested differently in the field than in results found in laboratory studies. A complex approach should be taken in field studies of metal contamination of the aquatic environment.  

scholarly journals Antioxidants: Positive or Negative Actors?

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 124 ◽  
Author(s):  
Bahare Salehi ◽  
Miquel Martorell ◽  
Jack Arbiser ◽  
Antoni Sureda ◽  
Natália Martins ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Current Knowledge ◽  
Disease Onset ◽  
Reactive Oxygen ◽  
Population Based ◽  
Reactive Species ◽  
Oxygen Species ◽  
A Cell ◽  
Nuanced Understanding ◽  
Definition Of

The term “antioxidant” is one of the most confusing definitions in biological/medical sciences. In chemistry, “antioxidant” is simply conceived “a compound that removes reactive species, mainly those oxygen-derived”, while in a cell context, the conceptual definition of an antioxidant is poorly understood. Indeed, non-clinically recommended antioxidants are often consumed in large amounts by the global population, based on the belief that cancer, inflammation and degenerative diseases are triggered by high oxygen levels (or reactive oxygen species) and that through blocking reactive species production, organic unbalances/disorders can be prevented and/or even treated. The popularity of these chemicals arises in part from the widespread public mistrust of allopathic medicine. In fact, reactive oxygen species play a dual role in dealing with different disorders, since they may contribute to disease onset and/or progression but may also play a key role in disease prevention. Further, the ability of the most commonly used supplements, such as vitamins C, E, selenium, and herbal supplements to decrease pathologic reactive oxygen species is not clearly established. Hence, the present review aims to provide a nuanced understanding of where current knowledge is and where it should go.

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