In Vitro Evaluation of Hepg2 Cell Proliferation Altered by Reactive Oxygen and Nitrogen Species

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.

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In Vitro Evaluation of the Effects of Intraocular Lens Material on Lens Epithelial Cell Proliferation, Migration, and Transformation

Current Eye Research ◽

10.3109/02713683.2016.1156133 ◽

2016 ◽

Vol 42 (1) ◽

pp. 72-78 ◽

Cited By ~ 5

Author(s):

Gui-Qin Wang ◽

Ya-Long Dang ◽

Qi Huang ◽

Victor Chi-Pang Woo ◽

Kwok-Fai So ◽

...

Keyword(s):

Cell Proliferation ◽

Epithelial Cell ◽

Intraocular Lens ◽

Lens Epithelial Cell ◽

Epithelial Cell Proliferation ◽

In Vitro Evaluation ◽

Lens Material

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

Biochemical Journal ◽

10.1042/bj20071138 ◽

2008 ◽

Vol 410 (2) ◽

pp. 359-368 ◽

Cited By ~ 88

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.

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Concurrent Production of Reactive Oxygen and Nitrogen Species by Airway Epithelial Cells In Vitro

Free Radical Biology and Medicine ◽

10.1016/s0891-5849(97)00375-4 ◽

1998 ◽

Vol 24 (5) ◽

pp. 863-868 ◽

Cited By ~ 80

Author(s):

Lori G Rochelle ◽

Bernard M Fischer ◽

Kenneth B Adler

Keyword(s):

Epithelial Cells ◽

Reactive Oxygen ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Nitrogen Species

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

Infection and Immunity ◽

10.1128/iai.00034-20 ◽

2020 ◽

Vol 88 (4) ◽

Cited By ~ 5

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.

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