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1

Effects of silver nanoparticles of different sizes on cytotoxicity and oxygen metabolism disorders in both reproductive and respiratory system cells

Zapór L.

Archives of Environmental Protection

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2016

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Vol. 42, no. 4

32--47

EN

Silver nanoparticles (AgNPs) are widely used in numerous industries and areas of daily life, mainly as antimicrobial agents. The particles size is very important, but still not suffi ciently recognized parameter infl uencing the toxicity of nanosilver. The aim of this study was to investigate the cytotoxic effects of AgNPs with different particle size (~ 10, 40 and 100 nm). The study was conducted on both reproductive and pulmonary cells (CHO-9, 15P-1 and RAW264.7). We tested the effects of AgNPs on cell viability, cell membrane integrity, mitochondrial metabolic activity, lipid peroxidation, total oxidative and antioxidative status of cells and oxidative DNA damage. All kinds of AgNPs showed strong cytotoxic activity at low concentrations (2÷13 μg/ml), and caused an overproduction of reactive oxygen species (ROS) at concentrations lower than cytotoxic ones. The ROS being formed in the cells induced oxidative damage of DNA in alkaline comet assay. The most toxic was AgNPs<10 nm. The results indicate that the silver nanoparticles, especially less than 10 nm, may be harmful to the organisms. Therefore, risk should be considered when using nanosilver preparations and provide appropriate protective measures when they are applied.

PL

Nanocząstki srebra (AgNPs), ze względu na silne właściwości bakteriobójcze, mają szerokie zastosowanie w wielu dziedzinach przemysłu, biomedycynie i produktach konsumenckich. Rozmiar cząstek jest istotnym, ale wciąż niewystarczająco zbadanym parametrem wpływającym na toksyczność nanosrebra. W pracy oceniono toksyczne działanie różnej wielkości cząstek srebra (~ 10, 40 i 100 nm) na komórki układu rozrodczego i oddechowego (CHO-9, 15P-1 i RAW264.7). Badano wpływ AgNPs na przeżywalność komórek, przepuszczalność błon komórkowych i aktywność metaboliczną komórek, zaburzenia metabolizmu tlenowego oraz odległe skutki działania w postaci uszkodzeń materiału genetycznego (DNA). Wszystkie badane AgNPs wykazywały silne działanie cytotoksyczne, w zakresie niskich stężeń (2÷13 μg/ml) oraz powodowały powstawanie stresu oksydacyjnego w komórkach w stężeniach niższych niż cytotoksyczne. Powstające w komórkach reaktywne formy tlenu powodowały oksydacyjne uszkodzenia DNA wykrywane w teście kometowym. Najsilniejsze działanie wykazywały cząstki o wielkości < 10 nm. Otrzymane wyniki wskazują, że nanocząstki srebra, zwłaszcza poniżej 10 nm, mogą stanowić zagrożenie dla organizmów. Dlatego też należy rozważyć ryzyko stosowania preparatów z nanosrebrem i zapewnić środki zapobiegające ich niekontrolowanemu uwalnianiu.

2

Nie tylko BRCA - geny umiarkowanego ryzyka w raku piersi

Pamuła-Piłat J., Tęcza K.

Laboratorium - Przegląd Ogólnopolski

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2015

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nr 7-8

26--33

PL

Ryzyko rozwoju procesu nowotworowego może być modulowane przez mutacje genetyczne bądź polimorfizmy wysokiej, umiarkowanej i niskiej penetracji. Choroba nowotworowa zatem niezmiernie rzadko jest efektem wystąpienia pojedynczej zmiany genetycznej, jest raczej rezultatem nagromadzenia określonych wariantów genów oraz ich wzajemną współzależnością.

EN

The risk of developing cancer is modulated by mutations or/and polymorphisms of low, intermediate or high penetrance. Therefore the cancer itself is very rarely caused by single genetic modification. Rather, it is a result of cumulation of several variants and is strongly depended on their mutual cooperation.

3

Wykorzystanie spektrometrii mas do analizy modyfikacji nukleotydów i adduktów DNA

Hanus J., Jelonek K., Pietrowska M.

Wiadomości Chemiczne

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2011

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[Z] 65, 3-4

191-205

EN

Chemically modified nucleotides, which are not normally present in genetic material, are called DN A adducts. This type of DN A modifications (damage) is directly related to processes of mutagenesis and carcinogenesis. Elevated levels of DN A adducts present in genetic material reflect exposure of humans to carcinogenic factors and are markers of increased risk of cancer [1]. For this reason different methods useful for quantitative and qualitative analyses of DN A adducts are used in the field of cancer prevention and research (Tab. 1). Enzymatically-catalyzed methylation of cytosine, observed mostly in so called CpG islands, is a frequent endogenous modification of genetic material. Such a DN A methylation is a key factor involved in regulation of gene expression, and methylation status of oncogenes and tumor supressor genes is an important biomarker of carcinogenesis. As such, analytical methods for assessment of DN A methylation are of great importance for molecular diagnostics of cancer. During the last decade significant progress has been made in methods available for quantitative, qualitative and structural analyses of biological molecules. Among intensively developed tools for bioanalyses are methods of mass spectrometry. Spectrometers that are based on two methods of ionization, namely electrospray ionization (ESI ) [30] and matrix-assisted laser desorption-ionization (MALDI ) [48], are particularly suitable for analyses of biological macromolecules: proteins and nucleic acids. Currently available mass spectrometers, together with microscale methods for sample preparation and separation, significantly increased sensitivity and accessible mass range of analyses. New generation of “user-friendly” instruments is developed to bring the techniques directly into the workplaces of biological and clinical investigators. This review demonstrates representative examples of mass spectrometry techniques used for qualitative analyses of nucleotide modifications and adducts present in genetic material of humans. In this field several methods base on spectrometers with electrospray ionization. Generated ions are separated according to their mass-to-charge ratio in an analyzer by electric fields; among different ion analyzers frequently used in this methods are single or triple quadrupole and ion traps (Fig. 1). Among other methods available for assessment of DN A adducts is so called Accelerator Mass Spectrometry (Fig. 2) [41]. The most frequently applied method for the assessment of DN A methylation is based on methylation-specific PCR reaction. Products of such PCR reactions are analyzed using MALDI mass spectrometry [54] (Fig. 3). In summary, new powerful methods of mass spectrometry that made available qualitative analyses of damage and modifications of human genetic material found their important place in modern biological and medical laboratories.

4

5',8-cyklo-2'-deoksyadenozyna. Podwójne uszkodzenie w obrębie pojedynczego nukleozydu/nukleotydu

Karwowski B.T.

Wiadomości Chemiczne

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2010

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[Z] 64, 11-12

1013-1052

EN

Free radicals can react with different biomolecules present in the cells such as lipids, sugars or nucleic acid peptides. These free radicals initiate reactions with DNA or RNA molecules and then can lead to changes in the genome sequence. These mutations are most probably responsible for a number of different diseases (involving a change in the genome sequence) or, at least, can accompany them. Reactive oxygen species and more specifically - hydroxyl radical can react with DNA molecules and lead to changes in their structures. Formation of radicals at C5' and C8 atoms of 2'-deoxyadenosine leads, through intramolecular cyclisation, to 5',8-cyclo-2'-deoxyadenosine (cdA) derivatives. Frequency of DNA damage occurrence surges with an increase of an ionizing radiation dose. Different repair systems are however present in cellular machinery: BER, which exploits glycosylase and NER - a more complex process involving the removal of damaged oligonucleotides. The later is the basic mechanism for removal the 5',6-cyclo-2'-deoxynucleosides and 5',8-cyclo-2'-deoxynucleosides like cdA. Their defective activity may be responsible for many types of diseases, such as Parkinson, Alzheimer, chronic hepatitis, HCV, atopic dermatitis and different types of cancer. The mechanistic, structural and biochemical studies presented in this work produce quite clear answer as to the approximate range level of the (5'R)-cdA and (5'S)-cdA accumulation in the genome after the lesion period. Using quantum chemistry methods (DFT) paths of the cyclisation reaction have been determined. From the structural analysis point of view, it has been demonstrated that the covalent bond between C(5') and C(8) in nucleoside induces an unusual West conformation of the furanose ring. Based on the NMR data analysis it can be postulated that the rigid and fixed structure of cdA can strongly influence the global geometry of oligonucleosides. Moreover, using the quantum mechanic study of double strand DNA it has been demonstrated that the presence of (5'S)-cdA provokes a "domino effect" extending towards the 5'-end of the strand with this lesion. No domino effect is observed for the 3'-end. The obtained biological results indicate that the presence of (5'S)-cdA in the complementary strand to the strand under repair on the 5'-end side is the critical factor for the inhibition of the BER process of DNA.

5

Specific for DNA damages GFP microbial biosensor as a tool for genotoxic action assessment of environmental pollution

Matejczyk M.

Budownictwo i Inżynieria Środowiska

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2010

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Vol. 1, no. 4

319-326

EN

In the presented paper, autofluorescent reporter of Escherichia coli K-12 recA::gfpmut2 strain, which contained a plasmid-borne transcriptional fusion between DNA-damage inducible recA promoter involved in the SOS regulon response and fast folding GFP variant reporter gene-gfpmut2, have been used. GFP-based bacterial biosensors allowed the detection of bacterial cells response to selected tested genotoxic compounds such as mitomycin C (MMC), actinomycin D, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and formaldehyde (CH2O). Experiment indicated that E. coli K-12 recA::gfpmut2 biosensor strain is more specific and sensitive for especially two genotoxins: actinomycin D and MNNG and with very low response to other agents. So it was concluded that for formaldehyde and MMC E. coli K-12 recA::gfpmut2 genetic system is disqualified for genotoxicity screening.

6

Samoobrona komórkowa receptor czynnika wzrostowego pobudza naprawę DNA uszkodzonego przez promieniowanie X

Grądzka I., Sochanowicz B., Szumiel I.

Postępy Techniki Jądrowej

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2007

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z. 2

2-8

7

Dlaczego komórki różnią się promieniowrażliwością?

Szumiel I.

Postępy Techniki Jądrowej

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2007

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z. 4

18-24