Systemic oxidoreductive balance in patients without clinical manifestation of atherosclerosis

Introduction. Oxidative stress plays an important role in atherosclerosis, but numerous clinical trials have not confirmed a favourable effect of antioxidant supplementation. We aimed to determine the oxidative stress parameters in patients without clinical manifestation of vascular disease. Material and methods. Forty-eight patients were divided into two groups in relation to the presence or absence of clinically silent signs of atherosclerosis (ankle-brachial index < 0.9, intima-media thickness ≥ 0.9 mm, the presence of carotid atherosclerotic plaques, silent ischaemia in a treadmill stress test or focal myocardial contractility found in echocardiography). Plasma concentrations of: retinol, ascorbic acid, alpha-tocopherol and uric acid, as well as the products of oxidative DNA damage repair: 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodG) in blood leucocytes and urine, and 8-oxo-7,8-dihydroguanine (8-oxo-Gua) in urine. Results. Patients with signs of subclinical atherosclerosis had lower blood concentration of alpha- tocopherol, and a non-significantly greater urine concentration of 8-oxoGua. Women had significantly greater blood concentration of ascorbic acid and alpha-tocopherol, as well as lower level of retinol and uric acid. They also had greater leucocyte concentration of 8-oxodG. Plasma concentration of alpha-tocopherol 30.34 μM distinguished patients with and without signs of subclinical atherosclerosis. Conclusions. Oxidative stress has clinical importance in the early stages of atherosclerosis and may be helpful in predicting its subclinical stage. Women had higher level of antioxidant defence, which explains their natural protection against early atherosclerosis development. Further studies are needed to determine the usefulness of tocopherol determination as a biomarker for atherosclerosis risk evaluation

Ślady gospodarki roślinno-zwierzęcej ludności kultury łużyckich pól popielnicowych z osady w Rudzie, gmina Grudziądz, północna Polska

Site 3–6 in Ruda, Grudziądz district, is situated in southern part of the Grudziądz Basin, just at the foot of the brink of Vistula Valley, on the flat, vast headland, sloping towards the river. The Motorway Investigations Team at the Institute of Archaeology Nicolas Copernic University, during their research in years 2000–2002, found some evidence of settlement that had existed there in the later Bronze Age and the early Iron Age. The site of the Lusatian Urnfield Culture included remains of homesteads composed of dwellings of different purpose as well as pits of various functions. Archaeological material from the site is represented by abundant set of ceramic dishes fragments, dishes and ornaments of bronze and first found in Chełmno Land metallurgical clay casting moulds as well as tools of stone and flint. Numerous and diverse set of collected plants, cereals, weeds and carbonised remains of various timber species have been discovered in number of pits. Pieces of domestic and wild animal bones and mollusc shells represent are also known from the site. The use of animals and plants is represented by biogenic materials discovered in cultural layers. Soil samples, analysed with regard to phosphorus content, present diverse values of that element in pits. Archaeological finds together botanical and zoological evidence provide a unique opportunity for interpretation of economy, spatial settlement organisation and farming characteristic for the Lusatian Urnfield Culture communities

Oxidation products of 5-methyl cytosine are decreased in senescent cells and tissues of progeroid mice

5-Hydroxymethylcytosine and 5-formylcytosine are stable DNA base modifications generated from 5-methylcytosine by the ten-eleven translocation protein family that function as epigenetic markers. 5-Hydroxymethyluracil may also be generated from thymine by ten-eleven translocation enzymes. Here, we asked if these epigenetic changes accumulate in senescent cells, since they are thought to be inversely correlated with proliferation. Testing this in ERCC1-XPF-deficient cells and mice also enabled discovery if these DNA base changes are repaired by nucleotide excision repair. Epigenetic marks were measured in proliferating, quiescent and senescent wild-type (WT) and Ercc1−/− primary mouse embryonic fibroblasts. The pattern of epigenetic marks depended more on the proliferation status of the cells than their DNA repair capacity. The cytosine modifications were all decreased in senescent cells compared to quiescent or proliferating cells, whereas 5-(hydroxymethyl)-2′-deoxyuridine was increased. In vivo, both 5-(hydroxymethyl)-2′-deoxyuridine and 5-(hydroxymethyl)-2′-deoxycytidine were significantly increased in liver tissues of aged WT mice compared to young adult WT mice. Livers of Ercc1-deficient mice with premature senescence and aging had reduced level of 5-(hydroxymethyl)- 2′-deoxycytidine and 5-formyl-2′-deoxycytidine compared to aged-matched WT controls. Taken together, we demonstrate for the first time, that 5-(hydroxymethyl)-2′-deoxycytidine is significantly reduced in senescent cells and tissue, potentially yielding a novel marker of senescence

Polystyrene nanoparticles: the mechanism of their genotoxicity in human peripheral blood mononuclear cells

Plastic nanoparticles are widely spread in the biosphere, but health risk associated with their effect on the human organism has not yet been assessed. The purpose of this study was to determine the genotoxic potential of non-functionalized polystyrene nanoparticles (PS-NPs) of different diameters of 29, 44, and 72nm in human peripheral blood mononuclear cells (PBMCs) (in vitro). To select non-cytotoxic concentrations of tested PS-NPs, we analyzed metabolic activity of PBMCs incubated with these particles in concentrations ranging from 0.001 to 1000 ug/mL. Then, PS-NPs were used in concentrations from 0.0001 to 100 ug/mL and incubated with tested cells for 24 h. Physico-chemical properties of PS-NPs in media and suspension were analyzed using dynamic light scattering (DLS), atomic force microscopy (AFM), scanning electron microscopy (SEM) and zeta potential. For the first time, we investigated the mechanism of genotoxic action of PS-NPs based on detection of single/double DNA strand-breaks and 8-oxo-2'-deoxyguanosine (8-oxodG) formation, as well as determination of oxidative modification of purines and pyrimidines and repair efficiency of DNA damage. Obtained results have shown that PS-NPs caused a decrease in PBMCs metabolic activity, increased single/double-strand break formation, oxidized purines and pyrimidines and increased 8oxodG levels. The resulting damage was completely repaired in the case of the largest PS-NPs. It was also found that extent of genotoxic changes in PBMCs depended on the size of tested particles and their f-potential value.Narodowe Centrum Nauki (NCN), Preludium 20 nr 2021/41/N/NZ7/0204

Targeted DNA oxidation by LSD1–SMAD2/3 primes TGF-β1/ EMT genes for activation or repression

Abstract The epithelial-to-mesenchymal transition (EMT) is a complex transcriptional program induced by transforming growth factor β1 (TGF-β1). Histone lysine-specific demethylase 1 (LSD1) has been recognized as a key mediator of EMT in cancer cells, but the precise mechanism that underlies the activation and repression of EMT genes still remains elusive. Here, we characterized the early events induced by TGF-β1 during EMT initiation and establishment. TGF-β1 triggered, 30–90 min post-treatment, a nuclear oxidative wave throughout the genome, documented by confocal microscopy and mass spectrometry, mediated by LSD1. LSD1 was recruited with phosphorylated SMAD2/3 to the promoters of prototypic genes activated and repressed by TGF-β1. After 90 min, phospho-SMAD2/3 downregulation reduced the complex and LSD1 was then recruited with the newly synthesized SNAI1 and repressors, NCoR1 and HDAC3, to the promoters of TGF-β1-repressed genes such as the Wnt soluble inhibitor factor 1 gene (WIF1), a change that induced a late oxidative burst. However, TGF-β1 early (90 min) repression of transcription also required synchronous signaling by reactive oxygen species and the stress-activated kinase c-Jun N-terminal kinase. These data elucidate the early events elicited by TGF-β1 and the priming role of DNA oxidation that marks TGF-β1-induced and -repressed genes involved in the EMT

N6-methyladenosine regulates the stability of RNA:DNA hybrids in human cells

© 2019, The Author(s), under exclusive licence to Springer Nature America, Inc. R-loops are nucleic acid structures formed by an RNA:DNA hybrid and unpaired single-stranded DNA that represent a source of genomic instability in mammalian cells1–4. Here we show that N6-methyladenosine (m6A) modification, contributing to different aspects of messenger RNA metabolism5,6, is detectable on the majority of RNA:DNA hybrids in human pluripotent stem cells. We demonstrate that m6A-containing R-loops accumulate during G2/M and are depleted at G0/G1 phases of the cell cycle, and that the m6A reader promoting mRNA degradation, YTHDF2 (ref. 7), interacts with R-loop-enriched loci in dividing cells. Consequently, YTHDF2 knockout leads to increased R-loop levels, cell growth retardation and accumulation of γH2AX, a marker for DNA double-strand breaks, in mammalian cells. Our results suggest that m6A regulates accumulation of R-loops, implying a role for this modification in safeguarding genomic stability

Exploring the crop epigenome: a comparison of DNA methylation profiling techniques

Epigenetic modifications play a vital role in the preservation of genome integrity and in the regulation of gene expression. DNA methylation, one of the key mechanisms of epigenetic control, impacts growth, development, stress response and adaptability of all organisms, including plants. The detection of DNA methylation marks is crucial for understanding the mechanisms underlying these processes and for developing strategies to improve productivity and stress resistance of crop plants. There are different methods for detecting plant DNA methylation, such as bisulfite sequencing, methylation-sensitive amplified polymorphism, genome-wide DNA methylation analysis, methylated DNA immunoprecipitation sequencing, reduced representation bisulfite sequencing, MS and immuno-based techniques. These profiling approaches vary in many aspects, including DNA input, resolution, genomic region coverage, and bioinformatics analysis. Selecting an appropriate methylation screening approach requires an understanding of all these techniques. This review provides an overview of DNA methylation profiling methods in crop plants, along with comparisons of the efficacy of these techniques between model and crop plants. The strengths and limitations of each methodological approach are outlined, and the importance of considering both technical and biological factors are highlighted. Additionally, methods for modulating DNA methylation in model and crop species are presented. Overall, this review will assist scientists in making informed decisions when selecting an appropriate DNA methylation profiling method