Nuclear Abnormalities Research Articles

Hepatic graft-versus-host disease: what we know, when to biopsy, and how to diagnose

Graft-versus-host disease (GVHD) is one of the serious complications that may develop after hematopoietic cell transplantation (HCT), for hematologic malignancies, solid organ transplantation, and other hematologic disorders. GVHD develops due to T lymphocytes present in the graft attacking the host antigens, which results in tissue damage. A significant number of HCT patients develop acute or chronic GVHD, which may affect multiple organs including the liver. The diagnosis of hepatic GVHD (hGVHD) is challenging as many other conditions in HCT patients may lead to liver dysfunction. Particularly challenging among the various conditions that give rise to liver dysfunction is differentiating sinusoidal obstruction syndromeand drug-induced liver injury (DILI) from hGVHD on clinical grounds and laboratory tests. Despite the minimal risks involved in performing a liver biopsy, the information gleaned from the histopathologic changes may help in the management of these very complex patients. There is a spectrum of histologic features found in hGVHD, and most involve histopathologic changes affecting the interlobular bile ducts. These include nuclear and cytoplasmic abnormalities including dysmorphic bile ducts, apoptosis, and cholangiocyte necrosis, among others. The hepatitic form of hGVHD typically shows severe acute hepatitis. With chronic hGVHD, there is progressive bile duct loss and eventually fibrosis. Accurate diagnosis of hGVHD is paramount so that timely treatment and management can be initiated. Techniques to prevent and lower the risk of GVHD from developing have recently evolved. If a diagnosis of acute GVHD is made, the first-line of treatment is steroids. Recurrence is common and steroid resistance or dependency is not unusual in this setting. Second-line therapies differ amonginstitutions and have not been uniformly established. The development of GVHD, particularly hGVHD, is associated with increased morbidity and mortality.

Micronuclei and nuclear buds in amniotic tissue of rats treated with cyclophosphamide.

Fetal development can be altered by DNA damage caused by maternal exposure to chemical, physical, or biological agents during gestation. One method of assessing genotoxicity is to detect micronuclei (MNs) and/or nuclear abnormalities. This can be performed in vivo and requires only frequently dividing tissues, such as amniotic tissue (AT), which is in contact with the fetal environment and is composed of very thin layers of cells. This study evaluated the presence of MNs, nucleoplasmic bridges, and nuclear buds (NBs) in the fetal AT following maternal exposure to cyclophosphamide (CP) during pregnancy. Pregnant Wistar rats were divided into a negative control group and an experimental group that was orally administered CP (10mg/kg). Daily blood smears were obtained from pregnant rats on days 14-19 of gestation. The rats were dissected, and fetal ATs were obtained on the 19th day of gestation. The MN and NB frequencies in AT cells were analyzed using a fluorescence microscope (100×). Micronucleated erythrocytes in the peripheral blood of the control rats were also assessed. Micronucleated polychromatic erythrocyte frequencies were significantly higher than those in the controls. Polychromatic erythrocyte frequencies were lower in CP-treated rats than in controls at 48-120h. Fetuses in the CP-treated group also showed a significant increase in MNs and NBs in AT cells. In conclusion, AT could be used for analyzing MNs and NBs in rats following maternal exposure to a genotoxic agent and as a viable alternative for analyzing the integrity of fetal DNA during gestation.

Micronucleus testing and nuclear abnormalities in freshwater organisms exposed acutely and chronically to titanium dioxide nanoparticles

Freshwater invertebrates are widely accepted models for ecotoxicological testing due to their global distribution, high abundance, high reproduction rates, short life cycles, rapid adaptation to laboratory conditions and high sensitivity to contaminants, including metal-based nanoparticles. Crusher invertebrates play a key role in the food chain of plant detritus in low-order forest rivers, transferring carbon and energy from the material to higher trophic. These disposers are very sensitive to water quality. Therefore, in this study, the objective was to investigate the responses of these shredder invertebrates to various metal-based nano particles in a sublethal exposure through water and food. The objectives of this work were centered on: evaluating the toxicity of titanium dioxide nanoparticles, erbium-doped titanium dioxide, and cobalt ferrites in aquatic fungi; check through antioxidant enzymes such as catalase, glutathione s-transferase and glutathione peroxidase, oxidative stress at the cellular level; test potential toxic effects at higher trophic levels using detritivorous invertebrates.

Research on the anti-ageing mechanism of Prunella vulgaris L.

Prunella vulgaris L. (P. vulgaris) has long been considered to have antipyretic, analgesic and anti-inflammatory effects, lowering blood lipids and pressure. Many studies show that in addition to the traditional telomere attrition, DNA damage and epigenetic changes, immunosenescence is also a new possibility to explore the mechanism of ageing. Therefore, this herb may have potential anti-ageing effects. Typically, there are a series of markers that identify senescent cells, such as superoxide dismutase (SOD)2, an inhibitor of CDK4 (p16INK4A), tumor necrosis factor (TNF)-α, immune cells number, proliferation, and nuclear abnormalities. These changes rarely present in young tissues, while greatly increasing in response to ageing. Firstly, the ageing model of the Institute of Cancer Research (ICR) mouse was established by d-galactose subcutaneous injection. Then, SOD2, p16INK4A and TNF-α were detected by quantitative Real-time PCR (qPCR), Western Blot (WB) and Enzyme-Linked Immunosorbent Assay (ELISA). Simultaneously, senescent cells in livers were stained by hematoxylin and eosin (HE). The viability of splenocytes was detected by Cell Counting Kit-8(CCK-8). The difference in specific immune cells (NK cells, B lymphocytes and T lymphocytes) was detected by flow cytometry. Both low (100 mg/kg) and high (300 mg/kg) concentrations of P. vulgaris treated ageing ICR mice show anti-ageing alterations, such as p16INK4A decreased approximately 1/2 and SOD2 tripled in livers, TNF-α decreased from 1 to 0.6 in plasma, and T cells increased from 0.09 to 0.19%. Compared with the ageing group, the spleen cells in the Prunella-treated group had stronger proliferation ability. Thus, P. vulgaris could have an anti-ageing effect. This is the first study to demonstrate the anti-ageing effect of P. vulgaris. It may also be capable of preventing a variety of age-related diseases.

Damage on DNA and hematological parameters of two bat species due to heavy metal exposure in a nickel-mining area in central Brazil.

Exposure to heavy metals in mining zones is a significant threat, which can affect ecosystem services and contribute to the decline of wild bat populations. The present study investigated the impacts caused by mining on two bat species in central Brazil, the nectarivorous Glossophaga soricina and the frugivorous Carollia perspicillata. The bats were collected from a nickel-mining zone (treatment) and a protected area (control). The leukocyte profile of each species was compiled and genotoxicity (comet assay) and mutagenicity (micronucleus test) were determined using the appropriate procedures. Glossophaga soricina presented significantly higher frequencies of eosinophils and monocytes in the mining zone in comparison with the protected area, whereas C. perspicillata presented higher frequencies of lymphocytes in the mining zone, but significantly lower frequencies of monocytes. Concomitantly, G. soricina also presented a higher frequency of DNA damage, although no variation was found in this parameter in C. perspicillata when comparing environments. We also found no significant differences between populations in terms of the frequency of micronuclei and other nuclear abnormalities. Overall, the results of the study indicate that bats are susceptible to immunological disorders and DNA damage in mining zones, with the nectarivorous G. soricina appearing to be relatively more susceptible and thus a potentially effective bioindicator of the impact of contamination in these environments.

Mutagenicity, hepatotoxicity, and neurotoxicity of glyphosate and fipronil commercial formulations in Amazon turtles neonates (Podocnemis expansa)

Pesticides are considered one of the main causes of the population decline of reptiles worldwide, with freshwater turtles being particularly susceptible to aquatic contamination. In this context, we investigated the potential mutagenic, hepatotoxic, and neurotoxic effects in neonates of Podocnemis expansa exposed to substrate contaminated with different concentrations of glyphosate and/or fipronil during embryonic development. Eggs collected from the natural environment were artificially incubated in sand moistened with pure water, water added with glyphosate Atar 48® at concentrations of 65 and 6500 μg/L (groups G1 and G2, respectively), water added with fipronil Regent® 800WG at 4 and 400 μg/L (groups F1 and F2, respectively) and, water added with the combination of 65 μg/L glyphosate and 4 μg/L fipronil or with 6500 μg/L glyphosate and 400 μg/L fipronil (groups GF1 and GF2, respectively). For mutagenicity analysis, we evaluated the frequency of micronuclei (MN) and other erythrocyte nuclear abnormalities (ENAs), while for evaluation of hepatotoxicity and neurotoxicity, livers and encephalon were analyzed for histopathological alterations. Exposure to pesticides, alone or in combination, increased the frequency of erythrocyte nuclear abnormalities, particularly blebbed nuclei, moved nuclei, and notched nuclei. Individuals exposed to fipronil exhibited congestion and inflammatory infiltrate in their liver tissue, while, in the encephalon, congestion, and necrosis were present. Our study confirms that the incubation of eggs in substrate polluted with glyphosate and fipronil causes histopathological damage and mutagenic alteration in P. expansa, highlighting the importance of using different biomarkers to evaluate the ecotoxicological effects of these pesticides, especially in oviparous animals.

Cytotoxicity and Genotoxicity Evaluation of Zanthoxylum rhoifolium Lam and In Silico Studies of Its Alkaloids.

The alkaloids isolated from Zanthoxylum rhoifolium have demonstrated great pharmacological potential; however, the toxic profiles of these extracts and fractions are still not well elucidated. This study evaluated the toxicity of the ethanol extract (EEZR) and neutral (FNZR) and alkaloid (FAZR) fractions. Chemical characterization was performed by chromatographic methods: thin-layer chromatography (TLC) and high-performance liquid chromatography coupled with diode array detection (HPLC-DAD). The cytotoxicity of the samples was evaluated in human hepatocellular carcinoma (HepG2) cells using the cell viability method (MTT) and mutagenicity by the Allium cepa assay (ACA). Alkaloids isolated from the species were selected for toxicity prediction using preADMET and PROTOX. The molecular docking of the topoisomerase II protein (TOPOII) was used to investigate the mechanism of cell damage. In the EEZR, FNZR, and FAZR, the presence of alkaloids was detected in TCL and HPLC-DAD analyses. These samples showed a 50% inhibitory concentration (IC50) greater than 400 μg/mL in HepG2 cells. In ACA, time- and concentration-dependent changes were observed, with a significant reduction in the mitotic index and an increase in chromosomal aberrations for all samples. Nuclear sprouts and a micronucleus of the positive control (PC) were observed at 10 µg/mL and in the FAZR at 30 µg/mL; a chromosomal bridge in FNZR was observed at 105 µg/mL, CP at a concentration of 40 µg/mL, and nuclear bud and mitotic abnormalities in the EEZR were observed at 170 µg/mL. The alkaloids with a benzophenanthridine were selected for the in silico study, as structural alterations demonstrated certain toxic effects. Molecular docking with topo II demonstrated that all alkaloids bind to the protein. In summary, the fractionation of Z. rhoifolium did not interfere with toxicity; it seems that alkaloids with a benzophenanthridine nucleus may be involved in this toxicity.

Multi-omic analysis of mandibuloacral dysplasia type A patient iPSC-derived MSC senescence reveals miR-311 as a novel biomarker for MSC senescence.

Mandibuloacral dysplasia type A (MADA) is a rare genetic progeroid syndrome associated with lamin A/C (LMNA) mutations. Pathogenic mutations of LMNA result in nuclear structural abnormalities, mesenchymal tissue damage and progeria phenotypes. However, it remains elusive how LMNA mutations cause mesenchymal-derived cell senescence and disease development. Here, we established an in vitro senescence model using induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs) from MADA patients with homozygous LMNA p.R527C mutation. When expanded to passage 13 in vitro, R527C iMSCs exhibited marked senescence and attenuation of stemness potential, accompanied by immunophenotypic changes. Transcriptome and proteome analysis revealed that cell cycle, DNA replication, cell adhesion and inflammation might play important roles in senescence. In-depth evaluation of changes in extracellular vesicle (EV) derived iMSCs during senescence revealed that R527C iMSC-EVs could promote surrounding cell senescence by carrying pro-senescence microRNAs (miRNAs), including a novel miRNA called miR-311, which can serve as a new indicator for detecting chronic and acute mesenchymal stem cell (MSC) senescence and play a role in promoting senescence. Overall, this study advanced our understanding of the impact of LMNA mutations on MSC senescence and provided novel insights into MADA therapy as well as the link between chronic inflammation and aging development.

Cytotoxicity and genotoxicity of tributyltin in the early embryonic chick, Gallus gallus domesticus.

Tributyltin (TBT) is used in many commercial applications, including pesticides and antifouling paints, due to its biocidal properties. We examined the cytotoxicity and genotoxicity of TBT in the early chick embryo (Gallus gallus domesticus). Chick embryos (11 days) were treated with various doses of TBT to measure LD50 values for 24, 48, and 72h exposures, which were determined to be 110, 54, and 18μg/egg, respectively. The embryos were exposed to sub-lethal doses of TBT for evaluation of cytotoxicity and genotoxicity. An increase in the incidence of micronuclei (MN) was observed but it was not statistically significant. Induction of other nuclear abnormalities (ONA) after 72h TBT exposure was significant. A significant increase in comet assay tail DNA content was also detected in TBT-exposed embryos. Cytotoxicity was also evidenced by alteration in the polychromatic erythrocytes (PCE) to normochromatic erythrocytes (NCE) ratio and by an increase in the erythroblast population in treated organisms. The cytotoxicity and genotoxicity of TBT may have long-term complications in later stages of the life cycle.

Single and Mixture Cytogenetic Effects Evaluation of Atrazine and Glyphosate Herbicides at Environmentally Relevant Concentrations on Allium cepa Root Meristem Cells

The mixture of pesticides is employed to obtain other mechanisms of action on target organisms. The herbicides atrazine and glyphosate are used worldwide to control weeds in agricultural crops, and their indiscriminate use results in their constant presence in the environment. In this sense, this study aimed to evaluate the cytotoxic potential, the presence of chromosomal aberrations and nuclear abnormalities, and the frequency of micronuclei of active ingredients and commercial formulations of the herbicides atrazine (AT = 2 and 25 μg L-1) and glyphosate (GF = 65 and 160 μg L-1) isolated and in mixture (MIX = 2 + 65 and 25 + 160 μg L-1). Allium cepa root meristem cells were used as the test organism to evaluate environmentally relevant concentrations. Treatments containing the herbicides inhibited the mitotic index (ATAI2: 9.40 ± 1.36; GFAI65: 8.58 ± 1.10; MIXAI2+65: 6.99 ± 0.57; GFAI160: 9.77 ± 1.08; ATCOM25: 7.40 ± 1.38; GFCOM160: 8.26 ± 0.79) and showed chromosomal aberrations and nuclear abnormalities (ATAI2: 0.85 ± 0.17; ATCOM2: 0.97 ± 0.18; GFCOM65: 1.00 ± 0.18; MIXCOM2+65: 1.09 ± 0.25; ATAI25: 0.82 ± 0.17; GFAI160: 0.87 ± 0.23; MIXAI25+160: 0.95 ± 0.19; ATCOM25: 0.67 ± 0.19; MIXCOM25+160: 0.80 ± 0.25), indicating the cytotoxic/genotoxic potential of these herbicides. Mutagenic effects were seen in the mixture of the active ingredients of the herbicides at the lowest concentration tested (MIXAI2+65: 0.70 ± 0.57). These results indicate that the isolated herbicides and their mixture directly affect the genetic material. Therefore, we suggest reviewing the acceptable limits of these herbicides in the environment, emphasizing the importance and care required for properly handling these products to minimize environmental and human health risks.

Toxicological manifestations in gills, liver, kidney and muscles of Channa punctatus exposed to mercuric chloride

Aquatic regimes are exposed to a variety of pollutants that are mainly released by anthropogenic activities. Mercuric chloride (HgCl2) pose serious hazards to freshwater fish resource for its toxicity and long persistence. It is also a threat to humans who consume fish as a food resource. This study aimed to determine the consequences of acute exposure to HgCl2 in the freshwater food fish Channa punctatus (Bloch, 1973). The acute study of 96 hours was composed of three groups (in triplicates), having ten fish in each group which includes group I (control), group II (0.112 mg/l of HgCl2) and group III (0.224 mg/l of HgCl2). Results showed induction in reactive oxygen species (ROS) level in erythrocytes of group III (22159 ± 258.036). The biomarkers of oxidative stress, glutathione reduced (GSH) and lipid peroxidase (LPO) showed significant (p < 0.05) decrement and increment in their activity, respectively, in gills, liver, kidney and muscle tissues of the fish treated with HgCl2. Further, micronuclei (MN) and nuclear abnormalities (NAs) were formed in the erythrocytes of the fish of groups II and III, revealing DNA damage, hence showing genotoxicity. Histopathological studies in sample tissues of HgCl2 treated group demonstrated irreversible tissue injuries and anomalies. Thus, the findings from the study demonstrate that biological stress is induced in fish because of acute exposure to HgCl2, leading to health impairment

Genotoxicity and genomic instability in oral epithelial cells of agricultural workers exposed to pesticides using micronucleus and comet assay in Nineveh, Iraq

In agriculture, pesticides are used to preserve plants, but they might be dangerous for farmers and the environment. The present study aimed to use the comet assay and the micronucleus (MN) test to assess the genotoxic effects on lymphocytes and buccal exfoliation in pesticide-exposed male agricultural workers. The samples were collected from 102 workers having exposure to pesticides (Roundup SL, Weed waster, and paraquat 20% SL) and 100 control individuals (without pesticide exposure) from different Mosul, Iraq, neighbourhoods. With the help of the comet assay and the MN test, exfoliated buccal cells from the individuals were analyzed for DNA damage. Each individual's lymphocytes and epithelial baseline cells had their comet tail length assessed, along with any other nuclear abnormalities such as nuclear buds, karyolysis, karyorrhexis, and binucleate cells. The results showed that the frequency of MN considerably rose in the exposed group, and that group also revealed nuclear anomalies linked to cytotoxic or genotoxic effects. There were significant disparities in the amount of DNA damage between recently exposed employees and controls and recently exposed and followed-up cases. In comparison to controls, there was a considerable increase in the and frequency of cells that migrated in exposed workers. However, it was shown that confounding factors, such as age and the varying length of pesticide exposure, substantially impacted DNA damage. Educational programs for agricultural workers are critical to limit the use of chemicals in agriculture, given the evidence of a genetic risk associated with exposure brought on by the extensive use of pesticides.

Assessment of imidacloprid induced genotoxicity in Pethia conchonius (Rosy barb), a common freshwater fish of India

Imidacloprid is one of the highly efficient, globally used neonicotinoid groups of insecticides. The indiscriminate use of imidacloprid is contaminating large water bodies affecting not only the target organisms but also non-target organisms including fish. The present study aimed to assess the extent of nuclear DNA damage by imidacloprid in Pethia conchonius a freshwater fish in India using comet and micronucleus assays. The LC50 value of imidacloprid was estimated to be 227.33 mg L−1. Based on the LC50-96 h value, three sub-lethal concentrations of imidacloprid, SLC I −18.94 mg L−1, SLC II −28.41 mg L−1 and SLC III −56.83 mg L−1 were used to detect its genotoxic effect at DNA and cellular level. The imidacloprid exposed fishes exhibited higher DNA damage and nuclear abnormalities (p < 0.05) than the control. The %head DNA, %tail DNA, tail length and the frequency of micronuclei with other nuclear abnormalities like blebbed and notched nuclei were significantly higher than the control in a time and concentration-dependent manner. The DNA damage parameters such as %head DNA (29.107 ± 1.843), %tail DNA (70.893 ± 1.843), tail length (361.431 ± 8.455) micronucleus (1.300 ± 0.019), notched (0.844 ± 0.011) and blebbed (0.811 ± 0.011) nuclei were found to be highest for SLC III (56.83 mg L−1) at 96 h. The findings indicate that IMI is highly genotoxic in fish and other vertebrates leading to mutagenic/clastogenic effects. The study will be helpful in optimization of the imidacloprid use.

Exposure to pyrogallol impacts the hemato-biochemical endpoints in catfish (Clarias gariepinus)

Pyrogallol is widely used in several industrial applications and can subsequently contaminate aquatic ecosystems. Here, we report for the first time the presence of pyrogallol in wastewater in Egypt. Currently, there is a complete lack of toxicity and carcinogenicity data for pyrogallol exposure in fish. To address this gap, both acute and sub-acute toxicity experiments were conducted to determine the toxicity of pyrogallol in catfish (Clarias gariepinus). Behavioral and morphological endpoints were evaluated, in addition to blood hematological endpoints, biochemical indices, electrolyte balance, and the erythron profile (poikilocytosis and nuclear abnormalities). In the acute toxicity assay, it was determined that the 96 h median-lethal concentration (96 h-LC50) of pyrogallol for catfish was 40 mg/L. In sub-acute toxicity experiment, fish divided into four groups; Group 1 was the control group. Group 2 was exposed to 1 mg/L of pyrogallol, Group 3 was exposed to 5 mg/L of pyrogallol, and Group 4 was exposed to 10 mg/L of pyrogallol. Fish showed morphological changes such as erosion of the dorsal and caudal fins, skin ulcers, and discoloration following exposure to pyrogallol for 96 h. Exposure to 1, 5, or 10 mg/L pyrogallol caused a significant decrease in hematological indices, including red blood cells (RBCs), hemoglobin, hematocrit, white blood cells (WBC), thrombocytes, and large and small lymphocytes in a dose-dependent manner. Several biochemical parameters (creatinine, uric acid, liver enzymes, lactate dehydrogenase, and glucose) were altered in a concentration dependent manner with short term exposures to pyrogallol. Pyrogallol exposure also caused a significant concentration-dependent rise in the percentage of poikilocytosis and nuclear abnormalities of RBCs in catfish.In conclusion, our data suggest that pyrogallol should be considered further in environmental risk assessments of aquatic species.

Anticancer effects of phytol against Sarcoma (S-180) and Human Leukemic (HL-60) cancer cells.

Phytol (Pyt), a diterpenoid, possesses many important bioactivities. This study evaluates the anticancer effects of Pyt on sarcoma 180 (S-180) and human leukemia (HL-60) cell lines. For this purpose, cells were treated with Pyt (4.72, 7.08, or 14.16 μM) and a cell viability assay was performed. Additionally, the alkaline comet assay and micronucleus test with cytokinesis were also performed using doxorubicin (6 μM) and hydrogen peroxide (10 mM) as positive controls and stressors, respectively. Results revealed that Pyt significantly reduced the viability and rate of division in S-180 and HL-60 cells with IC50 values of 18.98 ± 3.79 and 1.17 ± 0.34 μM, respectively. Pyt at 14.16 μM exerted aneugenic and/or clastogenic effects in S-180 and HL-60 cells, where the number of micronuclei and other nuclear abnormalities (e.g., nucleoplasmic bridges and nuclear buds) were frequently observed. Moreover, Pyt at all concentrations induced apoptosis and showed necrosis at 14.16 μM, suggesting its anticancer effects on the tested cancer cell lines. Taken together, Pyt showed promising anticancer effects, possibly through inducing apoptosis and necrosis mechanisms, and it exerted aneugenic and/or clastogenic effects on the S-180 and HL-60 cell lines.

Modulation of phytotoxic and cytogenetic effects of cadmium by humic acid: Findings from a short-term plant-based bioassay.

The study of the modulation of the toxicity of heavy metals by coexisting chemicals in the environment is vital for realistic ecological risk assessment. Our study was aimed at determining possible toxicity modulations of Cd by humic acid (HA) using the Allium cepa test system. A. cepa bulbs were exposed to Cd (1 and 5 mg/L) and HA (10 mg/L) individually or in mixtures. The root lengths of the bulbs and cytogenetic endpoints in root meristematic cells, including the mitotic index (MI), nuclear abnormalities (NAs), and chromosomal abnormalities (CAs), were determined. The results revealed that the MIs of A. cepa co-exposed to HA and Cd were significantly recovered by >15% compared with those of A. cepa subjected to Cd-only treatments, and this response was more sensitive than the phytotoxic response (root length). Furthermore, the burden of NAs was significantly decreased in the co-exposed bulbs by >20% compared with bulbs with Cd-only treatments. The frequencies of CAs were also reduced in the bulbs co-exposed to HA and 1 and 5 mg/L Cd by >15 and >25%, respectively, compared with bulbs receiving Cd-only treatments. Therefore, our findings indicated that HA plays a significant protective role in Cd toxicity in A. cepa.

Metal bioaccumulation and genotoxicity in Oreochromis niloticus reared in farming pools influenced by mining activities in Napo, in the Ecuadorian Amazonia

Mining areas may suffer long-term metal contamination and represent harmful remnants of former mining activities. In the northern Amazon of Ecuador, former mining waste pits are used in Oreochromis niloticus (Nile tilapia) fish farming. Given the high consumption of this species by the local population, we aimed to estimate human consumption risks by determining Cd, Cu, Cr, Pb, and Zn tissue bioaccumulation (liver, gills, and muscle) and genotoxicity (micronucleus essay) in tilapia cultivated in one former mining waste pit (S3) and compare the findings to tilapias reared in two non-mining areas (S1 and S2); 15 fish total. Tissue metal content was not significantly higher in S3 than in non-mining areas. Cu and Cd were higher in the gills of tilapias from S1 compared to the other study sites. Higher Cd and Zn were detected in the liver of tilapias from S1 compared to the other sampling sites. Cu was higher in the liver of fish from S1 and S2, and Cr, in the gills of fish from S1. The highest frequency of nuclear abnormalities was observed in fish from S3, indicating chronic exposure to metals at this sampling site. The consumption of fish reared at the three sampling sites results in a 200-fold higher Pb and Cd ingestion than their maximum tolerable intake thresholds. Calculated estimated weekly intakes (EWI), hazard quotients (THQ), and Carcinogenic Slope Factors (CSFing) denote potential human health risks, indicating the need for continuous monitoring in this area to ensure food safety not only in areas affected by mining, but in general farms in the region.

Oxidative stress, genotoxic effects, and other damages caused by chronic exposure to silver nanoparticles (Ag NPs) and zinc oxide nanoparticles (ZnO NPs), and their mixtures in zebrafish (Danio rerio)

This study assessed the oxidative stress impacts of Ag NPs and ZnO NPs and their mixtures in zebrafish (Danio rerio). Zebrafish were exposed to sublethal concentrations of each NP and a mixture for 28 days followed by a 28-day recovery period (without NP exposure) and measurements made on hepatic levels of antioxidant enzymes (CAT, SOD, and GPx), MDA levels, expression of the genes for the Hsp70 and Hsp90, and MT, blood biochemical parameters (total protein, globulin, albumin, AST, ALT, ALP, and LDH), and genotoxicity in erythrocytes (via measurement of micronuclei (MN) and nuclear (NA) abnormalities). There was a tendency for an increase in the variation in the responses of antioxidant defense systems and there were higher MDA levels with increasing exposure concentration of Ag NPs and with increasing exposure time. Total protein, globulin, and albumin decreased during the exposure period, especially on the days of 28. Moreover, levels of AST and LDH increased significantly in the NPs co-exposure treatments, while levels of ALT and ALP significantly decreased. The highest expression levels for these genes occurred on day 14 and in the NPs co-exposure treatments. For exposure to both NPs individually and as a mixture, the frequency of MN and other NA were significantly increased (p < 0.05). During the recovery periods, most of the effects seen were reduced, most notably in the individual NPs treatments. The overall results suggest that the toxic effects of Ag NPs and ZnO NPs in combination significantly increase their toxicity in zebrafish.

Identification of epigenetic modulators as determinants of nuclear size and shape.

The shape and size of the human cell nucleus is highly variable among cell types and tissues. Changes in nuclear morphology are associated with disease, including cancer, as well as with premature and normal aging. Despite the very fundamental nature of nuclear morphology, the cellular factors that determine nuclear shape and size are not well understood. To identify regulators of nuclear architecture in a systematic and unbiased fashion, we performed a high-throughput imaging-based siRNA screen targeting 867 nuclear proteins including chromatin-associated proteins, epigenetic regulators, and nuclear envelope components. Using multiple morphometric parameters, and eliminating cell cycle effectors, we identified a set of novel determinants of nuclear size and shape. Interestingly, most identified factors altered nuclear morphology without affecting the levels of lamin proteins, which are known prominent regulators of nuclear shape. In contrast, a major group of nuclear shape regulators were modifiers of repressive heterochromatin. Biochemical and molecular analysis uncovered a direct physical interaction of histone H3 with lamin A mediated via combinatorial histone modifications. Furthermore, disease-causing lamin A mutations that result in disruption of nuclear shape inhibited lamin A-histone H3 interactions. Oncogenic histone H3.3 mutants defective for H3K27 methylation resulted in nuclear morphology abnormalities. Altogether, our results represent a systematic exploration of cellular factors involved in determining nuclear morphology and they identify the interaction of lamin A with histone H3 as an important contributor to nuclear morphology in human cells.

Combined use of biomarkers to assess the impact of untreated wastewater from the Danube River, Serbia.

In this study a battery of bioassays, both in vivo (metals and metalloids concentrations, erythrocyte morphometry, comet assay, micronucleus assay, and histopathological analyses) on vimba bream Vimba vimba (L., 1758) and white bream Blicca bjoerkna (L., 1758), and in vitro (treatment of HepG2 cells with native water samples) was applied to assess the harmful potential of untreated wastewater. Faecal indicator bacteria were quantified to assess the microbiological water quality. Vimba bream had significantly higher Fe concentrations in both liver and muscle, while white bream had higher Ca and Cu concentrations in liver. Vimba bream had a significantly higher level of DNA damage in both liver and blood cells, in comparison to white bream. Low levels of micronucleus and nuclear abnormalities were observed in both species. Erythrocytes morphometry did not show significant interspecific differences. Histopathological analyses revealed a similar response of the studied species, with a significantly higher presence of ceroid pigments in the liver of vimba bream. Treatment of HepG2 cells revealed the high genotoxic potential of water downstream of the discharge point. The results of this study clearly demonstrate the importance of effect-based monitoring, in order to enforce more efficient management of natural resources and implementation of wastewater treatment systems.