Mutagenesis最新文献

The objective of this longitudinal study was to jointly assess DNA damage, apoptosis, inflammatory marker levels and white blood cell (WBC) counts in physicians occupationally exposed to inhalation anesthetics during specializations. Thus, we aimed to identify a possible cause-effect relationship between occupational exposure to waste anesthetic gases (WAGs), which were measured, and genotoxic, cytotoxic and immunotoxic effects. Nineteen medical residents were evaluated at four time points: before entering medical residency (baseline) and at the beginning, middle and end of medical residency. Peripheral blood mononuclear cells (PBMCs) were investigated for DNA damage, which was detected via the comet assay, and for apoptosis, which was detected via an annexin marker (flow cytometry). High-sensitivity C-reactive protein and serum inflammatory cytokines were evaluated via flow cytometry, and total and differential WBCs were counted. In addition, the concentrations of the WAGs measured in the workplace during the study were evaluated via an infrared spectrophotometer. The WAG concentrations were far higher than the internationally recommended values. Compared with those at previous time points, we observed increased DNA damage (p = 0.008) and apoptosis (p = 0.001) in PBMCs from the middle to the end of medical residency. Significant increases (p < 0.05) in the IL-8, IL-10, IL-12p70, IL-17A, IL-18 and IL-23 levels throughout medical residency were detected. There was no effect on the WBC count (p < 0.05), and all the means were within the reference range values. Occupational exposure to high levels of WAGs induces DNA damage, apoptosis, and changes in serum inflammatory marker levels, but not in leukocyte counts, in physicians who work in surgical theaters lacking an adequate scavenging system during medical residency.

In the comet assay, DNA damage is assessed by differences in DNA migration from gel-embedded nucleoids. Even a small difference in DNA migration between exposure groups can be statistically significant, but may invite speculation about the biological significance of such slight increases in DNA migration. A small difference can be defined as a net difference of 1-2% Tail DNA, but background levels of DNA migration typically vary already more than 1-2% Tail DNA between studies. Here we have used studies on ionizing radiation to assess lowest detectable differences in DNA migration; variation in exposure-effect relationships; variation in central tendencies of DNA migration; unsystematic (residual) variation; and the actual number of lesions detectable with the comet assay. A total of 51 studies on ionizing radiation exposure in mammalian cells have been systematically reviewed, including results from ring-trial studies where the same batch of irradiated cells has been analyzed in different laboratories. Ring-trial studies have shown that unsystematic variation is approximately 4% Tail DNA in studies on ionizing radiation. Studies on ionizing radiation in cell cultures have shown statistically significant effects when the net increase of DNA migration is 0.3-3.1% Tail DNA. Among those experiments, the ones with optimal assay conditions to detect low levels of DNA damage show statistically significant effects with doses of around 0.30 Gy, which corresponds to approximately 350 lesions per diploid cell. However, it has also been shown that the same dose of ionizing radiation can give rise to different levels of DNA migration (i.e. 0.7-7.8% Tail DNA per Gy) in different studies.. In summary, the results show that even a small statistically significant difference in DNA migration has biological significance within the same experiment, but comparisons of DNA migration values between studies have limited biological implications.

DNA damage is a common event in cells, resulting from both internal and external factors. The maintenance of genomic integrity is vital for cellular function and physiological processes. The inadequate repair of DNA damage results in the genomic instability, which has been associated with the development and progression of various human diseases. Accumulation of DNA damage can lead to multiple diseases, such as neurodegenerative disorders, cancers, immune deficiencies, infertility and aging. This comprehensive review delves the impact of alterations in DNA damage response genes (DDR) and tries to elucidate how and to what extent the same traits modulate diverse major human diseases, such as cancer, neurodegenerative diseases, and immunological disorders. DDR is apparently the trait connecting important complex disorders in humans. However, the pathogenesis of the above disorders and diseases are different and leading to the divergent consequences. It is important to discover the switch(es) that direct further the pathogenic process either to proliferative, or degenerative diseases. Our understanding the influence of DNA damage on diverse human disorders may enable a development of the strategies to prevent, diagnose, and treat these diseases. In our article, we analysed publicly available GWAS summary statistics from the NHGRI-EBI GWAS Catalog and identified 12,009 single nucleotide polymorphisms (SNPs) associated with cancer. Among these, 119 SNPs were found in DDR pathways, exhibiting significant p-values. Additionally, we identified 44 SNPs linked to various cancer types and neurodegenerative diseases (NDDs), including four located in DDR-related genes: ATM, CUX2, and WNT3. Furthermore, 402 SNPs were associated with both cancer and immunological disorders, with two found in DDR gene RAD51B. This highlights the versatility of the DDR pathway in multifactorial diseases. However, the specific mechanisms that regulate DDR to initiate distinct pathogenic processes remain to be elucidated.

We investigated the impact of cigarette smoking, daily exposure to tar and nicotine, and the duration of smoking on genetic instability (chromosomal damage - micronuclei, MN, nuclear buds - gene amplification) as well as on disturbances in mitosis (resulting in binucleated cells). Furthermore, we analyzed markers of cytotoxic effects (such as the formation of condensed chromatin, pyknotic, karyolytic, and karyorrhectic cells) and the mitotic activity of the oral mucosa. These parameters were monitored in groups of old (postmenopausal) and young (premenopausal) smoking and non-smoking women (n= 25/group). We found no differences of the MN frequencies in the non-smoking groups and only a moderate (not significant) increase of MN in both groups of smokers. However, we observed a clear increase of markers of genomic instability in both smoking groups. Furthermore, the mitotic activity of cells in the mucosa and of anomalies caused by acute cytotoxicty was higher in both smoking groups. Nicotine uptake was associated with pronounced acute toxic effects and increased the cell division rate. Chromosomal damage (MN) was higher in individuals which consumed high amounts of tar (this effect was not significant) and caused moderate acute toxicity. Our findings indicate (i) that age and hormonal status have no strong impact on the genotoxic and cytotoxic effects in smoking women, (ii) consumption of up to 30 cigarettes/day does not cause chromosomal damage in buccal cells, however positive results were found in earlier studies in heavy smokers, (iii) smoking increased markers which reflect genetic instability and the division rate of oral mucosa cells. These effects may play a role in neoplastic transformation of cells in the upper respiratory tract in smokers. The duration of smoking was associated with a slight (not significant) increase of the mitotic activity and of chromosomal damage and with moderate acute cytotoxicity.

The fetal brain is susceptible to programming effects during pregnancy, potentially leading to long-term consequences for offspring's cognitive health. Fructose intake is thought to adversely affect fetal brain development, whereas physical exercise before and during pregnancy may be protective. Therefore, this study aimed to assess biochemical and genotoxic changes in maternal hippocampi and behavioral, genotoxic, and biochemical alterations in offspring hippocampi. Seventy female mice were exposed to fructose (20%/L) and/or voluntary physical exercise (VPE) pre-pregnancy for eight weeks, and then mated and exposure was continued until weaning. Offspring were evaluated at 60 days old using behavioral test, genotoxic and biochemical markers. Fructose induced long-term memory impairment in male offspring, which was alleviated by VPE. VPE mitigated DNA damage from maternal fructose consumption in both maternal and offspring hippocampi in female offspring, VPE increased levels of APE-1, NRF2, and CREB proteins, whereas in males, OGG1 levels upregulate. Fructose consumption led to oxidative stress and antioxidant defense alterations in offspring, while VPE mitigated these effects. Telomere shortening was observed in male offspring from mothers who consumed fructose during pregnancy. Our findings suggest that exposure to fructose during (pre)pregnancy and lactation has adverse effects on offspring's hippocampi later in life, and VPE has a protective effect. Overall, the study underscores the significance of maternal dietary and physical habits on long term offspring health, with an emphasis on implications for adult cognitive function.

Nucleotide excision repair (NER) is crucial for repairing bulky lesions and crosslinks in DNA caused by exogenous and endogenous genotoxins. The number of studies that have considered DNA repair as a biomarker is limited, and therefore one of the primary objectives of the European COST Action hCOMET (CA15132) was to assemble and analyze a pooled database of studies with data on NER activity. The database comprised 738 individuals, gathered from 5 laboratories that ran population studies using the comet-based in vitro DNA repair assay. NER activity data in peripheral blood mononuclear cells (PBMCs) were normalized and correlated with various host-related factors, including sex, age, body mass index (BMI), and smoking habits. This multifaceted analysis uncovered significantly higher NER activity in female participants compared to males (1.08 ± 0.74 vs. 0.92 ± 0.71; P = 0.002). Higher NER activity was seen in older subjects (> 30 years), and the effect of age was most pronounced in the oldest females, particularly those over 70 years (P = 0.001). Females with a normal BMI (< 25 kg/m2) exhibited the highest levels of NER, whereas the lowest NER was observed in overweight males (BMI ≥ 25 kg/m2). No independent effect of smoking was found. After stratification by sex and BMI, higher NER was observed in smoking males (P = 0.017). The biological implication of higher or lower repair capacity remains unclear; the inclusion of DNA repair as a biomarker in molecular epidemiological trials should elucidate the link between health and disease status.

The COVID-19 pandemic has led to the emergence of acute and chronic post-COVID syndromes, which present diverse clinical manifestations. The underlying pathophysiology of these conditions is not yet fully understood, but genetic instability has been proposed as a potential contributing factor. This study aimed to explore the differential impact of physical and psychological health factors on genetic instability in individuals with acute and chronic post-COVID syndromes. In this study, three groups of subjects were analyzed: a control group, an acute post-COVID group, and a chronic post-COVID group, with a total of 231 participants. The participants were assessed using a questionnaire for long-COVID-19COVID, and female participants reported more symptoms than male participants in areas related to fatigue, memory, mental health, and well-being during the chronic phase. Genetic instability was assessed using the comet assay, and participants' physical and psychological profiles were evaluated. The overall results showed no significant differences in DNA damage, as measured by the comet assay, among the three groups, suggesting that genetic instability, as assessed by this method, may not be a primary driver of the distinct clinical presentations observed in post-COVID syndromes. However, when gender was considered, male participants in the acute long COVID group exhibited higher levels of genetic instability compared to females. Multiple linear regression analysis revealed that gender, age, and waist circumference were significant predictors of DNA damage. Among females in the acute group, sexual health, and eye-related symptoms significantly influenced the increase in DNA damage. These findings indicate the need for further investigation on the gender-specific differences in genetic instability and their potential implications for the pathophysiology of post-COVID syndromes. Exploring alternative markers of genetic instability and the interplay between genetic, inflammatory, and cellular processes could provide valuable insights for the management of these debilitating post-viral sequelae.

An ethanol extract of Piper auritum leaves (PAEE) inhibits the mutagenic effect of three food-borne aromatic amines (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP); 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx); 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx)) in the TA98 Salmonella typhimurium strain. Preincubation with MeIQx demonstrated in mutagenesis experiments that inhibition of Cytochrome P450 (CYP), as well as direct interaction between component(s) of the plant extract with mutagens, might account for the antimutagenic observed effect. Gas chromatography/mass spectrometry analysis revealed that safrole (50.7%), α-copaene (7.7%), caryophyllene (7.2%), β-pinene (4.2%), γ-terpinene (4.1%), and pentadecane (4.1%) as the main components (PAEE). Piper extract and safrole were able to inhibit the rat liver microsomal CYP1A1 activity that participates in the amines metabolism, leading to the formation of the ultimate mutagenic/ molecules. According to this, safrole and PAEE-inhibited MeIQx mutagenicity but not that of the direct mutagen 2-nitrofluorene. No mutagenicity of plant extract or safrole was detected. This study shows that PAEE and its main component safrole are associated with the inhibition of heterocyclic amines activation due in part to the inhibition of CYP1A subfamily activity.

River water in Kosovo is exposed to various discharges from industrial and agricultural activities as well as to urban wastewater. Rivers Sitnica and Drenica are among the most affected ones and water samples drawn from these rivers show the presence of various toxic substances. Genotoxic effects are seen in fish living in these rivers indicating a cytotoxic and mutagenic potential of the river water. Aiming at substantiating these observations, we assessed the cyto- and genotoxic effects of water samples collected at different locations from the Drenica and Sitnica rivers. Samples drawn from Lake Badovc served for comparison. To address seasonal effects, samples were collected at different seasons/time points during the period of summer 2016-spring 2018. The water samples were analyzed employing primary rat hepatocytes as a reliable in vitro cell model for the assessment of cytotoxic effects (mitotic arrest and cell death) and DNA damage/genotoxicity (micronucleus assay and Comet assay). The results do not account for significant effects associated with specific locations but demonstrate seasonal differences of the genotoxic potential of the water samples collected along both rivers, which are accompanied by a limited cytotoxic potential. Our data provide substantial support to earlier observations and strongly warrant the need for continuous chemical as well as biological monitoring of the river water in Kosovo, focusing on improved toxicant profiling of the river water and investigations addressing the observed seasonal variations.