A novel method of analyzing environmental chemical mutagens in human cell systems

2000 ◽  
Vol 42 (7-8) ◽  
pp. 133-138 ◽  
Author(s):  
S. Takahashi ◽  
X. J. Chi ◽  
J. Nomura ◽  
S. Sugaya ◽  
K. Kita ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Mutagenic Activity ◽  
Peripheral Blood Lymphocytes ◽  
Environmental Chemical ◽  
Cell Systems ◽  
Low Concentrations ◽  
Cultured Human Cells ◽  
Novel Method ◽  
Mutation Assay ◽  
Ethylhexyl Phthalate

Estimation of levels of plasminogen activator (PA)-like protease activity in peripheral blood lymphocytes was demonstrated to be a rapid and sensitive method for screening chemicals with mutagenic activity in mammalian cells. The combination of the PA induction test and K-ras codon 12 mutation assay was suitable for screening the mutagenic chemicals at very low concentrations. Using these methods, the mutagenicity of chlorpropham (CIPC) and di(2-ethylhexyl)phthalate (DEHP) was demonstrated in cultured human cells.

scholarly journals Acanthamoeba-Campylobacter Coculture as a Novel Method for Enrichment of Campylobacter Species

2007 ◽  
Vol 73 (21) ◽  
pp. 6864-6869 ◽  
Author(s):  
Diana Axelsson-Olsson ◽  
Patrik Ellstr�m ◽  
Jonas Waldenstr�m ◽  
Paul D. Haemig ◽  
Lars Brudin ◽  
...  
Keyword(s):  
Culture Medium ◽  
Bacterial Species ◽  
Oxygen Quenching ◽  
Free Living ◽  
Promising Tool ◽  
Low Concentrations ◽  
Novel Method ◽  
Selective Antibiotics ◽  
Different Sources ◽  
Bacterial Concentrations

ABSTRACT In this study, we present a novel method to isolate and enrich low concentrations of Campylobacter pathogens. This method, Acanthamoeba-Campylobacter coculture (ACC), is based on the intracellular survival and multiplication of Campylobacter species in the free-living protozoan Acanthamoeba polyphaga. Four of the Campylobacter species relevant to humans and livestock, Campylobacter jejuni, C. coli, C. lari, and C. hyointestinalis, were effectively enriched by the coculture method, with growth rates comparable to those observed in other Campylobacter enrichment media. Studying six strains of C. jejuni isolated from different sources, we found that all of the strains could be enriched from an inoculum of fewer than 10 bacteria. The sensitivity of the ACC method was not negatively affected by the use of Campylobacter-selective antibiotics in the culture medium, but these were effective in suppressing the growth of seven different bacterial species added at a concentration of 104 CFU/ml of each species as deliberate contamination. The ACC method has advantages over other enrichment methods as it is not dependent on a microaerobic milieu and does not require the use of blood or other oxygen-quenching agents. Our study found the ACC method to be a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.

scholarly journals A putative antiviral role of plant cytidine deaminases

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 622
Author(s):  
Susana Martín ◽  
José M. Cuevas ◽  
Ana Grande-Pérez ◽  
Santiago F. Elena
Keyword(s):  
Mammalian Cells ◽  
Mutagenic Activity ◽  
Population Diversity ◽  
Viral Fitness ◽  
Cauliflower Mosaic Virus ◽  
Cytidine Deaminases ◽  
Viral Genomes ◽  
Mutational Spectra ◽  
Antiviral Mechanism

Background: A mechanism of innate antiviral immunity operating against viruses infecting mammalian cells has been described during the last decade.  Host cytidine deaminases (e.g., APOBEC3 proteins) edit viral genomes, giving rise to hypermutated nonfunctional viruses; consequently, viral fitness is reduced through lethal mutagenesis.  By contrast, sub-lethal hypermutagenesis may contribute to virus evolvability by increasing population diversity.  To prevent genome editing, some viruses have evolved proteins that mediate APOBEC3 degradation.  The model plant Arabidopsis thaliana genome encodes nine cytidine deaminases (AtCDAs), raising the question of whether deamination is an antiviral mechanism in plants as well. Methods: Here we tested the effects of expression of AtCDAs on the pararetrovirus Cauliflower mosaic virus (CaMV). Two different experiments were carried out. First, we transiently overexpressed each one of the nine A. thaliana AtCDA genes in Nicotiana bigelovii plants infected with CaMV, and characterized the resulting mutational spectra, comparing them with those generated under normal conditions.  Secondly, we created A. thaliana transgenic plants expressing an artificial microRNA designed to knock-out the expression of up to six AtCDA genes.  This and control plants were then infected with CaMV.  Virus accumulation and mutational spectra where characterized in both types of plants. Results:  We have shown that the A. thaliana AtCDA1 gene product exerts a mutagenic activity, significantly increasing the number of G to A mutations in vivo, with a concomitant reduction in the amount of CaMV genomes accumulated.  Furthermore, the magnitude of this mutagenic effect on CaMV accumulation is positively correlated with the level of AtCDA1 mRNA expression in the plant. Conclusions: Our results suggest that deamination of viral genomes may also work as an antiviral mechanism in plants.

Detection of acrolein and crotonaldehyde DNA adducts in cultured human cells and canine peripheral blood lymphocytes by 32P-postlabeling and nucleotide chromatography

1991 ◽  
Vol 12 (8) ◽  
pp. 1483-1490 ◽  
Author(s):  
Vincent L. Wilson ◽  
Peter G. Foiles ◽  
Fung-Lung Chung ◽  
Andrew C. Povey ◽  
Anthony A. Frank ◽  
...  
Keyword(s):  
Dna Adducts ◽  
Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
Human Cells ◽  
Blood Lymphocytes ◽  
Cultured Human Cells

scholarly journals Manganese-induced Trafficking and Turnover of the cis-Golgi Glycoprotein GPP130

2010 ◽  
Vol 21 (7) ◽  
pp. 1282-1292 ◽  
Author(s):  
Somshuvra Mukhopadhyay ◽  
Collin Bachert ◽  
Donald R. Smith ◽  
Adam D. Linstedt
Keyword(s):  
Mammalian Cells ◽  
Essential Element ◽  
Multivesicular Bodies ◽  
Low Concentrations ◽  
Early Endosomes ◽  
Rapid Changes ◽  
Golgi Protein ◽  
Elevated Exposure ◽  
Dependent Pathway ◽  
Mn Concentrations

Manganese is an essential element that is also neurotoxic at elevated exposure. However, mechanisms regulating Mn homeostasis in mammalian cells are largely unknown. Because increases in cytosolic Mn induce rapid changes in the localization of proteins involved in regulating intracellular Mn concentrations in yeast, we were intrigued to discover that low concentrations of extracellular Mn induced rapid redistribution of the mammalian cis-Golgi glycoprotein Golgi phosphoprotein of 130 kDa (GPP130) to multivesicular bodies. GPP130 was subsequently degraded in lysosomes. The Mn-induced trafficking of GPP130 occurred from the Golgi via a Rab-7–dependent pathway and did not require its transit through the plasma membrane or early endosomes. Although the cytoplasmic domain of GPP130 was dispensable for its ability to respond to Mn, its lumenal stem domain was required and it had to be targeted to the cis-Golgi for the Mn response to occur. Remarkably, the stem domain was sufficient to confer Mn sensitivity to another cis-Golgi protein. Our results identify the stem domain of GPP130 as a novel Mn sensor in the Golgi lumen of mammalian cells.

The Potential Use of Liquid Oxidizer in PEM Cells

2006 ◽  
Author(s):  
Paul Erickson ◽  
David Grupp
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Catalytic Activity ◽  
Fuel Cell ◽  
Liquid Phase ◽  
Concentration Polarization ◽  
Pem Fuel Cell ◽  
Cell Systems ◽  
Novel Method ◽  
Potential Use

A novel method of using a liquid phase oxidizer in fuel cell applications has been discovered by researchers at UC Davis. This paper outlines potential implications for improving heat transfer and catalytic activity with this method. Experimental data have been collected and the results show that the proposed method of using liquid phase oxidizer does indeed allow operation of PEM fuel cell systems. Data indicate an improvement in overvoltage at low current but also clearly indicate a severely limited concentration polarization region with non-regenerated fluid. The preliminary data indicate the physical feasibility of the method but also show that more research and development is required.

scholarly journals QSAR Analysis for the Inhibition of the Mutagenic Activity by Anthocyanin Derivatives

2020 ◽  
Vol 5 (4) ◽  
pp. 69-82
Author(s):  
Nicolas Alejandro Szewczuk ◽  
Pablo Román Duchowicz ◽  
Alicia Beatriz Pomilio
Keyword(s):  
Cytochrome P450 ◽  
Mammalian Cells ◽  
Mutagenic Activity ◽  
3D Qsar ◽  
Cytochrome P450 3A4 ◽  
Linear Regression Models ◽  
Qsar Analysis ◽  
Proposed Model ◽  
Qsar Models ◽  
Cellular Dna

Flavonoid compounds modulate the cytochrome P450 3A4 enzyme activity and inhibit the mutagenic activity of mammalian cells, preventing carcinogen activation and cellular DNA damage. In this work, the quantitative structure-activity relationships (QSAR) theory is applied to predict the cytochrome P450 3A4 inhibition constant by anthocyanin derivatives. Different freely available software calculates 102,260 non-conformational molecular descriptors. A training set of 12 compounds is used to calibrate the best univariable linear regression models, while a test set of 4 compounds is used to explore their predictive capability. The present results are compared with previously reported ones by using 3D-QSAR, thus demonstrating that the proposed topological QSAR models achieve acceptable statistical quality. The proposed model provides a prospective QSAR guide for the search of new anthocyanin derivatives possessing high or low predicted mutagenicity.

scholarly journals Interactions between neutral endopeptidase (EC 3.4.24.11) and the substance P (NK1) receptor expressed in mammalian cells

1994 ◽  
Vol 299 (3) ◽  
pp. 683-693 ◽  
Author(s):  
A Okamoto ◽  
M Lovett ◽  
D G Payan ◽  
N W Bunnett
Keyword(s):  
Substance P ◽  
Epithelial Cells ◽  
Mammalian Cells ◽  
Neutral Endopeptidase ◽  
Nk1 Receptor ◽  
Endopeptidase 24.11 ◽  
Low Concentrations ◽  
Substance P Receptor ◽  
Maximal Binding ◽  
Fold Excess

Interactions between neutral endopeptidase-24.11 (NEP) and the substance P receptor (SPR; NK1) were investigated by examining substance P (SP) degradation, SP binding and SP-induced Ca2+ mobilization in epithelial cells transfected with cDNA encoding the rat SPR and rat NEP. Expression of NEP accelerated the degradation of SP by intact epithelial cells and by membrane preparations, and degradation was reduced by the NEP inhibitor thiorphan. In cells expressing SPR alone, specific 125I-SP binding after 20 min incubation at 37 degrees C was 92.2 +/- 3.1% of maximal binding and was unaffected by thiorphan. Coexpression of NEP in the same cells as the SPR markedly reduced SP binding to 13.9 +/- 0.5% of maximal, and binding was increased to 82.7 +/- 2.4% of maximal with thiorphan. Coexpression of NEP in the same cells as the SPR also reduced to undetectable the increase in intracellular Ca2+ in response to low concentrations of SP (0.3 and 0.5 nM), and significantly reduced the response to higher concentrations (1 and 3 nM). The Ca2+ response was restored to control values by inhibition of NEP with thiorphan. In contrast, SP binding and SP-induced Ca2+ mobilization were only slightly reduced when cells expressing SPR alone were mixed with a 3- to 24-fold excess of cells expressing NEP alone. Therefore, in this system, NEP markedly down-regulates SP binding and SP-induced Ca2+ mobilization only when coexpressed in the same cells as the SPR.

scholarly journals Effect of sodium butyrate on lymphocyte activation

1976 ◽  
Vol 144 (6) ◽  
pp. 1674-1678 ◽  
Author(s):  
D Kyner ◽  
P Zabos ◽  
J Christman ◽  
G Acs
Keyword(s):  
Tissue Culture ◽  
Dna Synthesis ◽  
Sodium Butyrate ◽  
Cell Morphology ◽  
Mammalian Cells ◽  
Lymphocyte Activation ◽  
Extended Period ◽  
Present Evidence ◽  
Growth Of A Variety ◽  
Low Concentrations

Butyrate, in relatively low concentrations, has been shown to induce synthesis of enzymes, cause changes in cell morphology, and inhibit growth of a variety of mammalian cells in tissue culture (reviewed in [1]). In this communication, we report our observations on the effect of butyrate on lymphocyte activation. Butyrate completely and reversibly inhibits mitogen-induced blast formation. We present evidence that it does not interfere with the binding of mitogens, that it does not inhibit a number of the early reactions involved in activation, and that it does not affect ongoing DNA synthesis for an extended period of time. However, butyrate rapidly inhibits any increase in the rate of DNA synthesis.

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