scholarly journals Peroxiredoxins play a major role in protecting Trypanosoma cruzi against macrophage- and endogenously-derived peroxynitrite

2008 ◽  
Vol 410 (2) ◽  
pp. 359-368 ◽  
Author(s):  
Lucía Piacenza ◽  
Gonzalo Peluffo ◽  
María Noel Alvarez ◽  
John M. Kelly ◽  
Shane R. Wilkinson ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Trypanosoma Cruzi ◽  
Fluorescence Probe ◽  
Reactive Oxygen ◽  
Cysteine Residue ◽  
Protective Effects ◽  
Nitrogen Species ◽  
Intact Cells ◽  
Tryparedoxin Peroxidase

There is increasing evidence that Trypanosoma cruzi antioxidant enzymes play a key immune evasion role by protecting the parasite against macrophage-derived reactive oxygen and nitrogen species. Using T. cruzi transformed to overexpress the peroxiredoxins TcCPX (T. cruzi cytosolic tryparedoxin peroxidase) and TcMPX (T. cruzi mitochondrial tryparedoxin peroxidase), we found that both cell lines readily detoxify cytotoxic and diffusible reactive oxygen and nitrogen species generated in vitro or released by activated macrophages. Parasites transformed to overexpress TcAPX (T. cruzi ascorbate-dependent haemoperoxidase) were also more resistant to H2O2 challenge, but unlike TcMPX and TcCPX overexpressing lines, the TcAPX overexpressing parasites were not resistant to peroxynitrite. Whereas isolated tryparedoxin peroxidases react rapidly (k=7.2×105 M−1·s−1) and reduce peroxynitrite to nitrite, our results demonstrate that both TcMPX and TcCPX peroxiredoxins also efficiently decompose exogenous- and endogenously-generated peroxynitrite in intact cells. The degree of protection provided by TcCPX against peroxynitrite challenge results in higher parasite proliferation rates, and is demonstrated by inhibition of intracellular redox-sensitive fluorescence probe oxidation, protein 3-nitrotyrosine and protein–DMPO (5,5-dimethylpyrroline-N-oxide) adduct formation. Additionally, peroxynitrite-mediated over-oxidation of the peroxidatic cysteine residue of peroxiredoxins was greatly decreased in TcCPX overexpressing cells. The protective effects generated by TcCPX and TcMPX after oxidant challenge were lost by mutation of the peroxidatic cysteine residue in both enzymes. We also observed that there is less peroxynitrite-dependent 3-nitrotyrosine formation in infective metacyclic trypomastigotes than in non-infective epimastigotes. Together with recent reports of up-regulation of antioxidant enzymes during metacyclogenesis, our results identify components of the antioxidant enzyme network of T. cruzi as virulence factors of emerging importance.

Anti-toxicant Properties of Saffron and Relevance to Protection from Toxins and Drugs

2020 ◽  
Vol 16 (3) ◽  
pp. 265-283
Author(s):  
Kyriaki Hatziagapiou ◽  
George I. Lambrou
Keyword(s):  
Redox Reactions ◽  
Case Reports ◽  
Meta Analysis ◽  
Reactive Oxygen ◽  
Crocus Sativus ◽  
Protective Effects ◽  
Nitrogen Species ◽  
Eligibility Criteria ◽  
Crocus Sativus L

Background: Reactive oxygen species and reactive nitrogen species, which are collectively called reactive oxygen nitrogen species, are inevitable by-products of cellular metabolic redox reactions, such as oxidative phosphorylation in the mitochondrial respiratory chain, phagocytosis, reactions of biotransformation of exogenous and endogenous substrata in endoplasmic reticulum, eicosanoid synthesis, and redox reactions in the presence of metal with variable valence. Among medicinal plants there is a growing interest in Crocus sativus L. It is a perennial, stemless herb, belonging to Iridaceae family, cultivated in various countries such as Greece, Italy, Spain, Israel, Morocco, Turkey, Iran, India, China, Egypt and Mexico. Objective: The present study aims to address the anti-toxicant role of Crocus sativus L. in the cases of toxin and drug toxification. Materials and Methods: An electronic literature search was conducted by the two authors from 1993 to August 2017. Original articles and systematic reviews (with or without meta-analysis), as well as case reports were selected. Titles and abstracts of papers were screened by a third reviewer to determine whether they met the eligibility criteria, and full texts of the selected articles were retrieved. Results: The authors focused on literature concerning the role of Crocus Sativus L. as an anti-toxicant agent. Literature review showed that Saffron is a potent anti-toxicant agent with a plethora of applications ranging from anti-oxidant properties, to chemotherapy protective effects. Conclusion: Literature findings represented in current review herald promising results for using Crocus Sativus L. and/or its active constituents as anti-toxicant, chemotherapy-induced protection and toxin protection.

scholarly journals Sweet Pepper (Capsicum annuum L.) Fruits Contain an Atypical Peroxisomal Catalase That Is Modulated by Reactive Oxygen and Nitrogen Species

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 374 ◽  
Author(s):  
Marta Rodríguez-Ruiz ◽  
Salvador González-Gordo ◽  
Amanda Cañas ◽  
María Jesús Campos ◽  
Alberto Paradela ◽  
...  
Keyword(s):  
Capsicum Annuum ◽  
Fruit Ripening ◽  
Reactive Oxygen ◽  
Bovine Liver ◽  
Sweet Pepper ◽  
Cysteine Residue ◽  
Nitrogen Species ◽  
Capsicum Annuum L ◽  
Native Molecular Mass ◽  
Pepper Fruit

During the ripening of sweet pepper (Capsicum annuum L.) fruits, in a genetically controlled scenario, enormous metabolic changes occur that affect the physiology of most cell compartments. Peroxisomal catalase gene expression decreases after pepper fruit ripening, while the enzyme is also susceptible to undergo post-translational modifications (nitration, S-nitrosation, and oxidation) promoted by reactive oxygen and nitrogen species (ROS/RNS). Unlike most plant catalases, the pepper fruit enzyme acts as a homodimer, with an atypical native molecular mass of 125 to 135 kDa and an isoelectric point of 7.4, which is higher than that of most plant catalases. These data suggest that ROS/RNS could be essential to modulate the role of catalase in maintaining basic cellular peroxisomal functions during pepper fruit ripening when nitro-oxidative stress occurs. Using catalase from bovine liver as a model and biotin-switch labeling, in-gel trypsin digestion, and nanoliquid chromatography coupled with mass spectrometry, it was found that Cys377 from the bovine enzyme could potentially undergo S-nitrosation. To our knowledge, this is the first report of a cysteine residue from catalase that can be post-translationally modified by S-nitrosation, which makes it especially important to find the target points where the enzyme can be modulated under either physiological or adverse conditions.

scholarly journals Cold Plasma-Treated Ringer’s Saline: A Weapon to Target Osteosarcoma

Cancers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 227 ◽  
Author(s):  
Miguel Mateu-Sanz ◽  
Juan Tornín ◽  
Bénédicte Brulin ◽  
Anna Khlyustova ◽  
Maria-Pau Ginebra ◽  
...  
Keyword(s):  
Culture Media ◽  
Reactive Oxygen ◽  
Plasma Jets ◽  
Atmospheric Plasma ◽  
Nitrogen Species ◽  
Organotypic Cultures ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Cold Plasmas

Osteosarcoma (OS) is the main primary bone cancer, presenting poor prognosis and difficult treatment. An innovative therapy may be found in cold plasmas, which show anti-cancer effects related to the generation of reactive oxygen and nitrogen species in liquids. In vitro models are based on the effects of plasma-treated culture media on cell cultures. However, effects of plasma-activated saline solutions with clinical application have not yet been explored in OS. The aim of this study is to obtain mechanistic insights on the action of plasma-activated Ringer’s saline (PAR) for OS therapy in cell and organotypic cultures. To that aim, cold atmospheric plasma jets were used to obtain PAR, which produced cytotoxic effects in human OS cells (SaOS-2, MG-63, and U2-OS), related to the increasing concentration of reactive oxygen and nitrogen species generated. Proof of selectivity was found in the sustained viability of hBM-MSCs with the same treatments. Organotypic cultures of murine OS confirmed the time-dependent cytotoxicity observed in 2D. Histological analysis showed a decrease in proliferating cells (lower Ki-67 expression). It is shown that the selectivity of PAR is highly dependent on the concentrations of reactive species, being the differential intracellular reactive oxygen species increase and DNA damage between OS cells and hBM-MSCs key mediators for cell apoptosis.

scholarly journals Transposon Mutagenesis Screen of Klebsiella pneumoniae Identifies Multiple Genes Important for Resisting Antimicrobial Activities of Neutrophils in Mice

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Michelle K. Paczosa ◽  
Rebecca J. Silver ◽  
Anne L. McCabe ◽  
Albert K. Tai ◽  
Colin H. McLeish ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Bacterial Pathogen ◽  
Reactive Oxygen ◽  
Antimicrobial Activities ◽  
Virulence Determinants ◽  
Nitrogen Species ◽  
Content Type ◽  
Transposon Insertion ◽  
Tract Infections

ABSTRACT Klebsiella pneumoniae is a Gram-negative bacterial pathogen that causes a range of infections, including pneumonias, urinary tract infections, and septicemia, in otherwise healthy and immunocompromised patients. K. pneumoniae has become an increasing concern due to the rise and spread of antibiotic-resistant and hypervirulent strains. However, its virulence determinants remain understudied. To identify novel K. pneumoniae virulence factors needed to cause pneumonia, a high-throughput screen was performed with an arrayed library of over 13,000 K. pneumoniae transposon insertion mutants in the lungs of wild-type (WT) and neutropenic mice using transposon sequencing (Tn-seq). Insertions in 166 genes resulted in K. pneumoniae mutants that were significantly less fit in the lungs of WT mice than in those of neutropenic mice. Of these, mutants with insertions in 51 genes still had significant defects in neutropenic mice, while mutants with insertions in 52 genes recovered significantly. In vitro screens using a minilibrary of K. pneumoniae transposon mutants identified putative functions for a subset of these genes, including in capsule content and resistance to reactive oxygen and nitrogen species. Lung infections in mice confirmed roles in K. pneumoniae virulence for the ΔdedA, ΔdsbC, ΔgntR, Δwzm-wzt, ΔyaaA, and ΔycgE mutants, all of which were defective in either capsule content or growth in reactive oxygen or nitrogen species. The fitness of the ΔdedA, ΔdsbC, ΔgntR, ΔyaaA, and ΔycgE mutants was higher in neutropenic mouse lungs, indicating that these genes encode proteins that protect K. pneumoniae against neutrophil-related effector functions.

Antioxidant enzymes regulation in plants in reference to reactive oxygen species (ROS) and reactive nitrogen species (RNS)

Plant Gene ◽  
2019 ◽  
Vol 19 ◽  
pp. 100182 ◽  
Author(s):  
Dhriti Kapoor ◽  
Simranjeet Singh ◽  
Vijay Kumar ◽  
Romina Romero ◽  
Ram Prasad ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Antioxidant Enzymes ◽  
Reactive Nitrogen Species ◽  
Reactive Oxygen ◽  
Reactive Nitrogen ◽  
Oxygen Species ◽  
Nitrogen Species

scholarly journals In vitro scavenging capacity of annatto seed extracts against reactive oxygen and nitrogen species

2011 ◽  
Vol 127 (2) ◽  
pp. 419-426 ◽  
Author(s):  
Renan Campos Chisté ◽  
Adriana Zerlotti Mercadante ◽  
Ana Gomes ◽  
Eduarda Fernandes ◽  
José Luís Fontes da Costa Lima ◽  
...  
Keyword(s):  
Reactive Oxygen ◽  
Nitrogen Species ◽  
Scavenging Capacity ◽  
Seed Extracts
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