Thiol redox control via thioredoxin and glutaredoxin systems

2005 ◽  
Vol 33 (6) ◽  
pp. 1375-1377 ◽  
Author(s):  
A. Holmgren ◽  
C. Johansson ◽  
C. Berndt ◽  
M.E. Lönn ◽  
C. Hudemann ◽  
...  

The Trx (thioredoxin) and Grx (glutaredoxin) systems control cellular redox potential, keeping a reducing thiol-rich intracellular state, which on generation of reactive oxygen species signals through thiol redox control mechanisms. Here, we give a brief overview of the human Trx and Grx systems. The main part focuses on our current knowledge about mitochondrial Grx2, which facilitates mitochondrial redox homoeostasis during oxidative stress-induced apoptosis.

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Meng-Hsuan Cheng ◽  
Hung-Ling Huang ◽  
Yen-You Lin ◽  
Kuan-Hao Tsui ◽  
Pei-Chin Chen ◽  
...  

Lung cancer is the leading cause of cancer deaths in the world, with a five-year survival rate of less than 30%. Clinically effective chemotherapeutic treatments at the initial stage may eventually face the dilemma of no drug being effective due to drug resistance; therefore, finding new effective drugs for lung cancer treatment is a necessary and important issue. Compounds capable of further increasing the oxidative stress of cancer cells are considered to have anticancer potential because they possessed the ability to induce apoptosis. This study mainly investigated the effects of BA6 (heteronemin), the marine sponge sesterterpene, on lung cancer cell apoptosis, via modulation of mitochondrial reactive oxygen species (mtROS) and oxidative phosphorylation (OXPHOS). BA6 has cellular cytotoxic activities against a variety of cancer cell lines, but it has no effect on nontumor cells. The BA6-treated lung cancer cells show a significant increase in both cellular ROS and mtROS, which in turn caused the loss of mitochondrial membrane potential (MMP). The increase of oxidative stress in lung cancer cells treated with BA6 was accompanied by a decrease in the expression of antioxidant enzymes Cu/Zn SOD, MnSOD, and catalase. In addition, OXPHOS performed in the mitochondria and glycolysis in the cytoplasm were inhibited, which subsequently reduced downstream ATP production. Pretreatment with mitochondria-targeted antioxidant MitoTEMPO reduced BA6-induced apoptosis through the mitochondria-dependent apoptotic pathway, which was accompanied by increased cell viability, decreased mtROS, enhanced MMP, and suppressed expression of cleaved caspase-3 and caspase-9 proteins. In conclusion, the results of this study clarify the mechanism of BA6-induced apoptosis in lung cancer cells via the mitochondrial apoptotic pathway, suggesting that it is a potentially innovative alternative to the treatment of human lung cancer.


2013 ◽  
Vol 288 (38) ◽  
pp. 27456-27468 ◽  
Author(s):  
Jun Lu ◽  
Suman K. Vodnala ◽  
Anna-Lena Gustavsson ◽  
Tomas N. Gustafsson ◽  
Birger Sjöberg ◽  
...  

Trypanosoma brucei is the causing agent of African trypanosomiasis. These parasites possess a unique thiol redox system required for DNA synthesis and defense against oxidative stress. It includes trypanothione and trypanothione reductase (TryR) instead of the thioredoxin and glutaredoxin systems of mammalian hosts. Here, we show that the benzisothiazolone compound ebsulfur (EbS), a sulfur analogue of ebselen, is a potent inhibitor of T. brucei growth with a favorable selectivity index over mammalian cells. EbS inhibited the TryR activity and decreased non-protein thiol levels in cultured parasites. The inhibition of TryR by EbS was irreversible and NADPH-dependent. EbS formed a complex with TryR and caused oxidation and inactivation of the enzyme. EbS was more toxic for T. brucei than for Trypanosoma cruzi, probably due to lower levels of TryR and trypanothione in T. brucei. Furthermore, inhibition of TryR produced high intracellular reactive oxygen species. Hydrogen peroxide, known to be constitutively high in T. brucei, enhanced the EbS inhibition of TryR. The elevation of reactive oxygen species production in parasites caused by EbS induced a programmed cell death. Soluble EbS analogues were synthesized and cured T. brucei brucei infection in mice when used together with nifurtimox. Altogether, EbS and EbS analogues disrupt the trypanothione system, hampering the defense against oxidative stress. Thus, EbS is a promising lead for development of drugs against African trypanosomiasis.


Author(s):  
Nosratola D. Vaziri

Reactive oxygen species (ROS) are produced at low levels physiologically and their production conveys signals and has specific functions. Control mechanisms ensure that this does not cause damage. ROS are highly reactive and cytotoxic and are also deliberately produced by inflammatory cells (granulocytes, macrophages) to kill pathogens. If these chemicals are released inappropriately or excessively, or if control mechanisms are under-functioning, bystander or unintended tissue damage may be caused. The concept of oxidative stress is based on the idea that in certain states, commonly inflammatory states, release of oxygen radicals may be excessive, or control mechanisms weakened, so that tissue damage occurs. In CKD, both overproduction and diminished control may apply. No effective therapies acting via these pathways have been established so far though there remain some candidates.


2011 ◽  
Vol 56 (No. 11) ◽  
pp. 537-546 ◽  
Author(s):  
M. Sevcikova ◽  
H. Modra ◽  
A. Slaninova ◽  
Z. Svobodova

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.  


2000 ◽  
Vol 279 (6) ◽  
pp. L1005-L1028 ◽  
Author(s):  
Victor J. Thannickal ◽  
Barry L. Fanburg

Reactive oxygen species (ROS) are generated as by-products of cellular metabolism, primarily in the mitochondria. When cellular production of ROS overwhelms its antioxidant capacity, damage to cellular macromolecules such as lipids, protein, and DNA may ensue. Such a state of “oxidative stress” is thought to contribute to the pathogenesis of a number of human diseases including those of the lung. Recent studies have also implicated ROS that are generated by specialized plasma membrane oxidases in normal physiological signaling by growth factors and cytokines. In this review, we examine the evidence for ligand-induced generation of ROS, its cellular sources, and the signaling pathways that are activated. Emerging concepts on the mechanisms of signal transduction by ROS that involve alterations in cellular redox state and oxidative modifications of proteins are also discussed.


2015 ◽  
Vol 96 (6) ◽  
pp. 1176-1191 ◽  
Author(s):  
Brandán Pedre ◽  
Inge Van Molle ◽  
Almudena F. Villadangos ◽  
Khadija Wahni ◽  
Didier Vertommen ◽  
...  

2021 ◽  
Vol 12 (6) ◽  
pp. 7342-7355

The present study focuses on exploring the antilithiatic potential of Didymocarpus pedicellata, which is valuable in managing renal disorders. Urolithiasis is an idiopathic disorder with a high recurrence and an incidence rate and is of major concern worldwide due to partial and unsatisfactory relief. Calcium oxalate crystals in contact with renal epithelial cells (HK2), causing reactive oxygen species overproduction, oxidative stress, apoptosis resulting in crystal adhesion and internalization. Crystals were modulated by cotreatment with ethanolic extract of D. pedicellata. Cell toxicity assay was assessed using flow cytometry. Cell-crystal interaction, adhesion, and internalization were visualized through Scanning electron microscopy (SEM) analysis and hematoxylin-eosin staining. The lithogenic induction caused impairment of renal function due to oxidative stress, measured by ROS levels. Cell death assays were detected by dual staining methods. Fluorimeter evaluation pointed to active caspase 3 mediated cell death (apoptotic) in oxalate injured cells was attenuated by Didymocarpus pedicellata extract. Alterations in cell adhesion were observed by immunocytochemistry. The current study revealed that the Didymocarpus pedicellata was endowed with antiurolithiatic activity as it displayed increased viability, reduced oxidative stress due to lowered production of intracellular reactive oxygen species (ROS), and decreased apoptosis when oxalate injured HK2 cells were cotreated with the extract.


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