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1.
J Hazard Mater ; 421: 126688, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34315634

RESUMO

Improper disposal of copper mining wastes can threaten the ecosystem and human health due to the high levels of potentially toxic elements released into the environment. The objective of this study was to determine the properties of Cu mining wastes generated in the eastern Amazon and their potential risks to environment and human health. Samples of forest soil and artisanal/industrial Cu mining wastes were collected and subjected to characterization of properties and pseudo-total concentrations of Al, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, and Zn, in addition to chemical fractionation of Cu. The pH ranged from near neutrality to alkaline. Pseudo-total concentrations of Cu were high in all wastes, mainly in the artisanal rock waste, with 19,034 mg kg-1, of which 61% is concentrated in the most reactive fractions. Pollution indices indicated that the wastes are highly contaminated by Cu and moderately contaminated by Cr and Ni. However, only the artisanal rock waste is associated with environmental risk. Non-carcinogenic and carcinogenic human health risks were detected, especially from exposure to Cr in the artisanal rock waste. Prevention actions and monitoring of the artisanal mining area are necessary to avoid impacts to the local population.


Assuntos
Metais Pesados , Poluentes do Solo , Cobre/toxicidade , Ecossistema , Monitoramento Ambiental , Humanos , Resíduos Industriais/análise , Metais Pesados/análise , Mineração , Medição de Risco , Poluentes do Solo/análise
2.
Environ Pollut ; 292(Pt A): 118296, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34627961

RESUMO

Cellular transport of metal nanoparticles (NPs) is critical in determining their potential toxicity, but the transformation of metal ions released from the internalized NPs is largely unknown. Cu-based NPs are the only metallic-based NPs that are reported to induce higher toxicity compared with their corresponding ions, likely due to their unique cellular turnover. In the present study, we developed a novel gold core to differentiate the particulate and ionic Cu in the Cu2O microparticles (MPs), and the kinetics of bioaccumulation, exocytosis, and cytotoxicity of Au@Cu2O MPs to zebrafish embryonic cells were subsequently studied. We demonstrated that the internalized MPs were rapidly dissolved to Cu ions, which then undergo lysosome-mediated exocytosis. The uptake rate of smaller MPs (130 nm) was lower than that of larger ones (200 nm), but smaller MPs were dissolved much quickly in cells and therefore activated the exocytosis more quickly. The rapid release of Cu ions resulted in an immediate toxic action of Cu2O MPs, while the cell deaths mainly occurred by necrosis. During this process, the buffering ability of glutathione greatly alleviated the Cu toxicity. Therefore, although the turnover of intracellular Cu at a sublethal exposure level was hundred times faster than the basal values, labile Cu(I) concentration increased by only 2 times at most. Overall, this work provided new insights into the toxicity of copper NPs, suggesting that tolerance to Cu-based NPs depended on their ability to discharge the released Cu ions.


Assuntos
Nanopartículas Metálicas , Peixe-Zebra , Animais , Cobre/toxicidade , Íons , Nanopartículas Metálicas/toxicidade , Metais
3.
Environ Pollut ; 292(Pt B): 118413, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34751154

RESUMO

Various modern products have metallic nanoparticles (MNPs) embedded to enhance products performance. Technological advances enable nowadays even multiple hybrid nanoparticles. Consequently, the future co-release of multiple MNPs will inevitably result in the presence of MNP mixtures in the environment. An important question is if the responses of mixtures of MNPs can be dealt with in a similar way as with the responses of biota to mixtures of metal salts. Moreover, natural organic matter (NOM) is an important parameter affecting the behavior and effect of MNPs. Herein, we determined the joint toxicity and accumulation of copper nanoparticles (CuNPs) and zinc oxide nanoparticles (ZnONPs) in Daphnia magna in the absence and presence of Suwannee River natural organic matter (SR-NOM), compared to the joint toxicity and accumulation of corresponding metal salts. The results of toxicity testing showed that the joint toxicity of CuNPs + ZnONPs was greater than the single toxicity of CuNPs or ZnONPs. The joint toxic action of CuNPs + ZnONPs was additive or more-than-additive for D. magna. A similar pattern was found in the toxicity of the mixtures of Cu- and Zn-salts from the literature data. The presence of SR-NOM had no significant impact on the joint toxicity of CuNPs + ZnONPs. The calculated component-specific contribution to overall toxicity indicated that SR-NOM increased the relative contribution of dissolved ions released from the MNPs to the toxicity of the binary mixtures at high-effect concentrations of individual MNPs. Moreover, dissolved Zn-ions released from the ZnONPs were found to dominate the joint toxicity of CuNPs + ZnONPs in the presence of SR-NOM. Furthermore, the results of the accumulation experiment displayed that the presence of SR-NOM significantly enhanced the accumulation of either CuNPs or ZnONPs in D. magna exposed to the MNP mixtures.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Poluentes Químicos da Água , Óxido de Zinco , Animais , Cobre/toxicidade , Daphnia , Íons , Nanopartículas Metálicas/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade
4.
Chemosphere ; 287(Pt 3): 132252, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34555583

RESUMO

The presence of engineered nanoparticles (ENPs) in soil gradually increases, among others due to the nano-agrochemicals application. So far, the co-existence of different ENPs in soil is poorly examined. Here, the metal extractability and toxicity of soils spiked (300 mg kg-1) singly and jointly with Zn- and Cu-based ENPs or metal salts were tested. The samples were aged for 1 and 90 days. The predicting available metal component of ENPs concentrations were determined by different methods including soil pore water collection and batch extractions with H2O, CaCl2 or DTPA. Survival and reproduction of Folsomia candida were also evaluated. The combined effect of ENPs on the extractability of metals was mainly found with DTPA characterized by the highest leaching capacity among the used extractants. In fresh soil, the mixtures of ENPs differentiated only DTPA-extractable Cu level, while aging resulted in changes in both Zn and Cu concentrations leached by CaCl2 or DTPA. However, the character of the combined effect was an ENPs- and soil type-dependent, whereas the mixtures of metal salts mostly provided higher Zn and Cu recovery than the individual compounds. The pattern of co-toxicity of metal-oxide ENPs was also time-dependent: the antagonistic and synergistic effect was observed in the samples after 1 and 90 days, respectively. However, the toxicity was weakly related with extractable concentrations in both single and joint treatment of metal compounds. The distinct joint effect patterns of ENPs imply the need for more in-depth investigation of mechanisms of activity of ENPs mixtures in soil.


Assuntos
Artrópodes , Nanopartículas Metálicas , Nanopartículas , Poluentes do Solo , Animais , Cobre/toxicidade , Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Zinco
5.
Chemosphere ; 287(Pt 1): 131883, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34818820

RESUMO

Ecological risk assessments of chemicals are frequently based on laboratory toxicity data from a small number of model species that may be reared in labs for years or decades. These populations can undergo many processes in the lab including artificial selection, founder effect, and genetic drift, and may not adequately represent their wild counterparts, potentially undermining the goal of protecting natural populations. Here we measure variation in lethality to copper chloride among strains of an emerging model species in toxicology, Caenorhabditis elegans. We tested four wild strains from Chile, Germany, Kenya, and Madeira (Portugal) against several versions of the standard laboratory N2 strain from Bristol, UK used in molecular biology. The four wild strains were more sensitive than any of the N2 strains tested with copper. We also found that the standard N2 strain cultured in the laboratory for >1 year was less sensitive than a recently cultured N2 strain as well as a cataloged ancestral version of the N2 strain. These results suggest that toxicologists should be cognizant of performing toxicity testing with long-held animal cultures, and should perhaps use multiple strains as well as renew cultures periodically in the laboratory. This study also shows that multi-strain toxicity testing with nematodes is highly achievable and useful for understanding variation in intra- and interspecific chemical sensitivity.


Assuntos
Caenorhabditis elegans , Nematoides , Animais , Caenorhabditis elegans/genética , Cobre/toxicidade , Laboratórios , Testes de Toxicidade
6.
Chemosphere ; 287(Pt 2): 132166, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826900

RESUMO

Nanomaterials are the sixth most emerging contaminants that are entering into aquatic habitat posing a risk to the inhabiting organisms. Nanoparticles of copper ferrite have been extensively used in biomedical applications. However, very limited studies are available on the cytotoxicity evaluation of copper ferrite nanoparticles (CuFe2O4NPs) on different cell lines. The current work investigates on the cytotoxicity, oxidative stress and morphological variations triggered by CuFe2O4NPs in Channel catfish ovary (CCO) cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT), neutral red uptake (NRU), lipid peroxidation (LPO), catalase (CAT), reduced glutathione (GSH), glutathione sulfotransferase (GST) and glutathione peroxidase (GPX) assays after 24 h of treatment. Dose dependent decline in cell survival was noticed in MTT and NRU assays. A significant increase in LPO, GST and GPX was observed in CCO cells exposed to CuFe2O4NPs after 24 h of treatment. However, the CAT and GSH levels in CCO cells exposed to CuFe2O4NPs decreased significantly after 24 h. The CCO cells exposed to 10 µg/mL concentration of CuFe2O4NPs for 24 h showed remarkable changes in their morphology. Further, the study also describes the detailed mechanism of toxicity of CuFe2O4NPs in other model cell lines to probe the risk of inhabiting organisms.


Assuntos
Ictaluridae , Nanopartículas , Animais , Cobre/toxicidade , Feminino , Compostos Férricos , Ovário , Estresse Oxidativo
7.
J Hazard Mater ; 422: 126899, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34418838

RESUMO

Copper (Cu), a hazardous heavy metal, can lead to toxic effects on host physiology. Recently, specific mitochondria-localized miRNAs (mitomiRs) were shown to modulate mitochondrial function, but the underlying mechanisms remain undefined. Here, we identified mitomiR-1285 as an important molecule regulating mitochondrial dysfunction and mitophagy in jejunal epithelial cells under Cu exposure. Mitochondrial dysfunction and mitophagy were the important mechanisms of Cu-induced pathological damage in jejunal epithelial cells, which were accompanied by significant increase of mitomiR-1285 in vivo and in vitro. Knockdown of mitomiR-1285 significantly attenuated Cu-induced mitochondrial respiratory dysfunction, ATP deficiency, mitochondrial membrane potential reduction, mitochondrial reactive oxygen species accumulation, and mitophagy. Subsequently, bioinformatics analysis and luciferase reporter assay demonstrated that IDH2 was a direct target of mitomiR-1285. RNA interference of IDH2 dramatically reversed the effect that mitomiR-1285 knockdown relieved mitochondrial dysfunction and mitophagy induced by Cu, and the opposite effect was shown by overexpression of IDH2. Therefore, our results suggested that mitomiR-1285 aggravated Cu-induced mitochondrial dysfunction and mitophagy via suppressing IDH2 expression. These findings identified the important mechanistic connection between mitomiRs and mitochondrial metabolism under Cu exposure, providing a new insight into Cu toxicology.


Assuntos
MicroRNAs , Mitofagia , Animais , Cobre/toxicidade , Células Epiteliais , Mitocôndrias , Mitofagia/genética , Suínos
8.
Chemosphere ; 286(Pt 2): 131698, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34365176

RESUMO

Metal oxide nanoparticles have been extensively studied for their toxicological impacts. However, accurate tracing/quantification of the nanomaterials and their biological responses are difficult to measure at low concentrations. To overcome the challenge, we developed a dual-labelling technique of CuO nanoparticles with a stable isotope of 65Cu, and with rhodamine dye. In vivo experiments on C. elegans were performed using natural feeding of Rhodamine B isothiocyanate-(3 aminopropyl) triethoxysilane functionalized 65CuO nanoprobes (RBITC-APTES@65CuO) (size = 7.41 ± 1 nm) within the range of Predicted Environmental Concentration (PEC) of CuO nanoparticles in soil and sediments. Fluorescence emission (570 nm) was detected in the lumen of the intestine and the pharynx of C. elegans with no impact of nanoparticle exposure on the brood size and life span of worms. The ingested fluorescent labelled RBITC-APTES@65CuO nanoprobes did not enter the reproductive system and were distributed in the alimentary canal of C. elegans. Strong fluorescent signals from the ingested RBITC-APTES@65CuO nanoprobes were achieved even after 24 h of exposure demonstrating the high stability of these nanoprobes in vivo. The net accumulation measured of 65Cu in C. elegans after background subtraction was 0.001 µg mg-1 (3.52 %), 0.005 µg mg-1 (1.76 %) and 0.024 µg mg-1 (1.69 %) for an exposure concentration of 0.0284 µg mg-1, 0.284 µg mg-1, and 1.42 µg mg-1 of 65Cu, respectively. Using C. elegans as a model organism, we demonstrated that RBITC-APTES tagged 65CuO nanoparticles acted as novel nanoprobes for measuring the uptake, accumulation, and biodistribution through quantification and imaging the nanoprobes at a very low exposure concentration (65CuO concentration: 0.033 µg mg-1).


Assuntos
Nanopartículas Metálicas , Nanopartículas , Animais , Caenorhabditis elegans , Cobre/toxicidade , Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Distribuição Tecidual
9.
Chemosphere ; 286(Pt 3): 131930, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426290

RESUMO

A toxicokinetic-toxicodynamic model was constructed to delineate the exposure-response causality. The model could be used: to predict metal accumulation considering the influence of water chemistry and biotic ligand characteristics; to simulate the dynamics of subcellular partitioning considering metabolism, detoxification, and elimination; and to predict chronic toxicity as represented by biomarker responses from the concentration of metals in the fraction of potentially toxic metal. The model was calibrated with data generated from an experiment in which the Zebra mussel Dreissena polymorpha was exposed to Cu at nominal concentrations of 25 and 50 µg/L and with varied Na+ concentrations in water up to 4.0 mmol/L for 24 days. Data used in the calibration included physicochemical conditions of the exposure environment, Cu concentrations in subcellular fractions, and oxidative stress-induced responses, i.e. glutathione-S-transferase activity and lipid peroxidation. The model explained the dynamics of subcellular Cu partitioning and the effect mechanism reasonably well. With a low affinity constant for Na + binding to Cu2+ uptake sites, Na + had limited influence on Cu2+ uptake at low Na+ concentrations in water. Copper was taken up into the metabolically available pool (MAP) at a largely higher rate than into the cellular debris. Similar Cu concentrations were found in these two fractions at low exposure levels, which could be attributed to sequestration pathways (metabolism, detoxification, and elimination) in the MAP. However, such sequestration was inefficient as shown by similar Cu concentrations in detoxified fractions with increasing exposure level accompanied by the increasing Cu concentration in the MAP.


Assuntos
Dreissena , Poluentes Químicos da Água , Animais , Cobre/toxicidade , Ligantes , Metais , Poluentes Químicos da Água/toxicidade
10.
Chemosphere ; 287(Pt 1): 132019, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34450372

RESUMO

The coexistence of antibiotics and heavy metals may result in complex ecotoxicological effects on living organisms. In this work, the combined toxic effects of norfloxacin (NOR) and copper (Cu) on Caenorhabditis elegans (C. elegans) were investigated due to the highly possible co-pollution tendency. The results indicated that locomotion behaviors (frequency of head thrash and body bend) of C. elegans were more sensitive as the exposure time of NOR or Cu prolonged. Meanwhile, the physiological indexes (locomotion behaviors, body length) of C. elegans were more sensitive to the combined pollution that with lower Cu dosage (0.0125 µM), in prolonged exposure experiments. In addition, the toxic effects of NOR-Cu on physiological indexes of C. elegans seemed to be alleviated during prolonged exposure when Cu was 1.25 µM. Similarly, the ROS production and apoptosis level almost unchanged with the addition of NOR compared with Cu (1.25 µM) exposure groups, but both significantly higher than the control groups. Furthermore, compared with Cu (0.0125 µM and 1.25 µM) exposure experiments, the addition of NOR had resulted in the genetic expression decrease of hsp-16.1, hsp-16.2, hsp-16.48, and the oxidative stress in C. elegans seems to be alleviated. However, the significantly decreased of ape-1 and sod-3 expression indicated the disruption of ROS defense mechanism. The irregular change in ace-1 and ace-2 gene expressions in NOR-Cu (0.0125 µM) would result in the locomotion behaviors disorders of C. elegans, and this also explains why C. elegans are more sensitive to the combination of NOR and lower concentration of Cu.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Cobre/toxicidade , Norfloxacino/toxicidade , Estresse Oxidativo
11.
Sci Total Environ ; 803: 150001, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34492493

RESUMO

Copper oxide nanoparticles (CuO-NPs) have been increasingly released in aquatic ecosystems over the past decades as they are used in many applications. Cu toxicity to different organisms has already been highlighted in the literature, however toxicity mechanisms of the nanoparticulate form remain unclear. Here, we investigated the effect, transfer and localization of CuO-NPs compared to Cu salt on the aquatic plant Myriophyllum spicatum, an ecotoxicological model species with a pivotal role in freshwater ecosystems, to establish a clear mode of action. Plants were exposed to 0.5 mg/L Cu salt, 5 and 70 mg/L CuO-NPs during 96 h and 10 days. Several morphological and physiological endpoints were measured. Cu salt was found more toxic than CuO-NPs to plants based on all the measured endpoints despite a similar internal Cu concentration demonstrated via Cu mapping by micro particle-induced X-ray emission (µPIXE) coupled to Rutherford backscattering spectroscopy (RBS). Biomacromolecule composition investigated by FTIR converged between 70 mg/L CuO-NPs and Cu salt treatments after 10 days. This demonstrates that the difference of toxicity comes from a sudden massive Cu2+ addition from Cu salt similar to an acute exposure, versus a progressive leaching of Cu2+ from CuO-NPs representing a chronic exposure. Understanding NP toxicity mechanisms can help in the future conception of safer by design NPs and thus diminishing their impact on both the environment and humans.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Poluentes Químicos da Água , Cobre/análise , Cobre/toxicidade , Ecossistema , Humanos , Nanopartículas Metálicas/toxicidade , Óxidos , Análise Espectral , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Sci Total Environ ; 805: 150086, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34537705

RESUMO

Heavy metals driven co-selection of antibiotic resistance in soil and water bodies has been widely concerned, but the response of antibiotic resistance to co-existence of antibiotics and heavy metals in composting system is still unknown. Commonly used sulfamethoxazole and copper were individually and jointly added into four reactors to explore their effects on antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), heavy metal resistance genes (MRGs) and bacterial community structure. The abundance of total ARGs and MGEs were notably decreased by 68.64%-84.95% and 91.27-97.38%, respectively, after the composting. Individual addition of sulfamethoxazole, individual addition of copper, simultaneously addition of sulfamethoxazole and copper increased the abundance of ARGs and MGEs throughout the composting period. Co-exposure of sulfamethoxazole and copper elevated the total abundance of ARGs by 1.17-1.51 times by the end of the composting compared to individual addition of sulfamethoxazole or copper. Network analysis indicated that the shifts in potential host bacteria determined the ARGs variation. Additionally, MGEs and MRGs had significant effects on ARGs, revealing that horizontal gene transfer and heavy metals induced co-resistance could promote ARGs dissemination.


Assuntos
Compostagem , Metais Pesados , Animais , Antibacterianos/farmacologia , Cobre/toxicidade , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Esterco , Sulfametoxazol/farmacologia , Suínos
13.
Sci Total Environ ; 807(Pt 1): 150740, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-34619213

RESUMO

The brown food chain (based on decomposers) co-exists in streams with the green food chain (based on primary producers). The two trophic chains perform specific ecosystem functions which may be altered by the effect of contaminants. Copper is a common contaminant with recognized effects on several compartments of the two trophic chains. We applied it in two separate mesocosm experiments, in which we tested the effects of copper after contrasting patterns of contaminant exposure (constant vs hump-shaped). The constant input simulated a chronic contamination (average of 20 µg/L Cu), while the hump-shaped simulated the steady arrival of copper, the occurrence of a peak (reaching ca. 60 µg/L Cu), and its progressive decrease (down to 10-15 µg/L Cu). In the green trophic food chain, copper exposure decreased the total chlorophyll-a as well as the basal fluorescence and the photosynthetic yield. The treatment receiving hump-shaped inputs caused the highest mortality of the green food chain consumer, the snail Radix balthica. In the chronic copper exposure, mortality achieved a maximum of 80% by the end of the experiment but occurred later than that in the hump-shaped treatment. Effects on the brown food chain were not so pronounced; the microbial decomposition rate of leaflitter decreased nearly ca. 50% after 14 days of copper exposure. Effects on decomposition translated into the ingestion performance of detritivores, which decreased in the two copper treatments. Our results provide evidence that copper affected the two trophic food chains. The hump-shaped arrival included a peak of high concentration, which caused lethal effects on the consumers, but also a decreasing limb, which allowed a partial recovery of the algal photosynthetic variables. Our results suggest the need to consider the different compartments and functions performed within the stream trophic web when evaluating the effects of a contaminant in a river ecosystem.


Assuntos
Cadeia Alimentar , Rios , Clorofila A , Cobre/toxicidade , Ecossistema
14.
Sci Total Environ ; 806(Pt 3): 151302, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34743886

RESUMO

Copper (Cu) contamination threatens the stability of soil ecosystems. As important moderators of biochemical processes and soil remediation, the fungal community in contaminated soils has attracted much research interest. In this study, soil fungal diversity and community composition under long-term Cu contamination were investigated based on high-throughput sequencing. The co-occurrence networks were also constructed to display the co-occurrence patterns of the soil fungal community. The results showed that the richness and Chao1 index both significantly increased at 50 mg kg-1 Cu and then significantly decreased at 1600 and 3200 mg kg-1 Cu. Soil fungal diversity was significantly and positively correlated with plant dry weight. Specific tolerant taxa under different Cu contamination gradients were illustrated by linear discriminant analysis effect size (LEfSe). Soil Cu concentration and shoot dry weight were the strongest driving factors influencing fungal composition. The relative abundance of arbuscular mycorrhizal fungi increased first and then declined along with elevating Cu concentrations via FUNGuild analysis. The interactions among fungi were enhanced under light and moderate Cu contamination but weakened under heavy Cu contamination by random matrix theory (RMT)-based molecular ecological network analysis. Penicillium, identified as a keystone taxon in Cu-contaminated soils, had the function of removing heavy metals and detoxification, which might be vital to trigger the resistance of the fungal community to Cu contamination. The results may facilitate the identification of Cu pollution indicators and the development of in situ bioremediation technology for contaminated cultivated fields.


Assuntos
Micobioma , Micorrizas , Poluentes do Solo , Biodegradação Ambiental , Cobre/toxicidade , Ecossistema , Fungos , Micorrizas/química , Solo , Microbiologia do Solo , Poluentes do Solo/análise
15.
Ecotoxicol Environ Saf ; 229: 113039, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34922170

RESUMO

Nano-copper has been increasingly employed in various products. In previous studies, we showed that nano-copper caused damage in the rat testis, but it remains unclear whether the toxic reaction can affect the reproductive function. In this study, following 28 d of exposure to nano-copper at a dose of 44, 88, and 175 mg/kg/day, there was a decrease in sperm quality, fructose content, and the secretion of sex hormones. Nano-copper also increased the level of oxidative stress, sperm malformation rate, and induced abnormal structural changes in testicular tissue. Moreover, Nano-copper upregulated the expression of apoptosis-related protein Bax and autophagy-related protein Beclin, and downregulated the expression of Bcl2 and p62. Furthermore, nano-copper (175 mg/kg) downregulated the protein expression of AMPK, p-AKT, mTOR, p-mTOR, p-4E-BP1, p70S6K, and p-p70S6K, and upregulated the protein expression of p-AMPK. Therefore, nano-copper induced damage in testicular tissues and spermatogenesis is highly related to cell apoptosis and autophagy by regulating the Akt/mTOR signaling pathway. In summary, excess exposure to nano-copper may induce testicular apoptosis and autophagy through AKT/mTOR signaling pathways, and damage the reproductive system in adult males, which is associated with oxidative stress in the testes.


Assuntos
Cobre , Testículo , Animais , Apoptose , Autofagia , Cobre/toxicidade , Masculino , Ratos , Transdução de Sinais
16.
Ecotoxicol Environ Saf ; 229: 113088, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34923329

RESUMO

Copper-based nanoparticles (NPs) display a strong potential to replace copper salts (e.g., CuSO4) for application in agricultures as antimicrobial agents or nutritional amendments. Yet, their effects on crop quality are still not comprehensively understood. In this study, the Cu contents in soybeans grown in soils amended with Cu NPs and CuSO4 at 100-500 mg Cu/kg and the subsequent effects on the plant physiological markers were determined. The Cu NPs induced 29-89% at the flowering stage (on Day 40) and 100-165% at maturation stage (on Day 100) more Cu accumulation in soybeans than CuSO4. The presence of particle aggregates in the root cells with deformation upon the Cu NP exposure was observed by transmission electron microscopy. The Cu NPs at 100 and 200 mg/kg significantly improved the plant height and biomass, yet significantly inhibited at 500 mg/kg, compared to the control. In leaves chlorophyll-b was more sensitive than chlorophyll-a and carotenoids to the Cu NP effect. The Cu NPs significantly decreased the root nitrogen and phosphorus contents, while they significantly increased the leaf potassium content in comparison with control. Our results imply that cautious use of Cu NPs in agriculture is warranted due to relatively high uptake of Cu and altered nutrient quality in soybeans.


Assuntos
Cobre , Nanopartículas , Agricultura , Cobre/análise , Cobre/toxicidade , Nanopartículas/toxicidade , Raízes de Plantas/química , Solo , Soja
17.
J Environ Sci (China) ; 112: 376-387, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955220

RESUMO

Nanoparticles (NPs) are widely used for their special physical properties and released into the natural environment. When two types of NPs exist in the same environment, the presence of one type of NP may affect the properties of the other type of NP. This study investigated the toxic effects of multi-walled carbon nanotubes (MWCNTs) and copper oxide nanoparticles (CuO NPs) on Tetradesmus obliquus. Both NPs had toxic effects on algae, and the toxic effects of MWCNTs were significantly stronger than CuO NPs which the 96-hr median effective concentration to algae were 33.8 and 169.2 mg/L, respectively. Oxidative stress and cell membrane damage were the main reasons for the toxicity of NPs to algae, and they were concentration-dependent, and the existence of CuO NPs in some groups reduced cell membrane damage caused by MWCNTs which may because that CuO NPs formed heteroaggregation with MWCNTs, reducing the contact of nanoparticles with cell membranes, then reducing physical damage. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) results indicated cell damage, the heteroaggregation of MWCNTs-CuO NPs and obvious nanoparticles internalization. In some groups, the presence of CuO NPs significantly reduced reactive oxygen species (ROS) level induced by MWCNTs. However, for the highest concentration group, the ROS level was much higher than that of the two NPs alone treatment groups, which might be related to the high concentration of MWCNTs promoting the internalization of CuO NPs. MWCNTs and CuO NPs affected and interacted with each other, causing more complex toxic effects on aquatic organisms.


Assuntos
Clorófitas/efeitos dos fármacos , Cobre , Nanopartículas Metálicas , Nanotubos de Carbono , Cobre/toxicidade , Água Doce , Nanopartículas Metálicas/toxicidade , Nanotubos de Carbono/toxicidade , Óxidos , Espécies Reativas de Oxigênio , Poluentes Químicos da Água/toxicidade
18.
Aquat Toxicol ; 241: 106015, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34753109

RESUMO

A toxicokinetic-toxicodynamic model based on subcellular metal partitioning is presented for simulating chronic toxicity of copper (Cu) from the estimated concentration in the fraction of potentially toxic metal (PTM). As such, the model allows for considering the significance of different pathways of metal sequestration in predicting metal toxicity. In the metabolically available pool (MAP), excess metals above the metabolic requirements and the detoxification and elimination capacity form the PTM fraction. The reversibly and irreversibly detoxified fractions were distinguished in the biologically detoxified compartment, while responses of organisms were related to Cu accumulation in the PTM fraction. The model was calibrated using the data on Cu concentrations in subcellular fractions and physiological responses measured by the glutathione S-transferase activity and the lipid peroxidation level during 24-day exposure of the Zebra mussel to Cu at concentrations of 25 and 50 µg/L and varying Na+ concentrations up to 4.0 mmol/L. The model was capable of explaining dynamics in the subcellular Cu partitioning, e.g. the trade-off between elimination and detoxification as well as the dependence of net accumulation, elimination, detoxification, and metabolism on the exposure level. Increases in the net accumulation rate in the MAP contributed to increased concentrations of Cu in this fraction. Moreover, these results are indicative of ineffective detoxification at high exposure levels and spill-over effects of detoxification.


Assuntos
Dreissena , Poluentes Químicos da Água , Animais , Cobre/toxicidade , Metais , Toxicocinética , Poluentes Químicos da Água/toxicidade
19.
Ecotoxicol Environ Saf ; 227: 112876, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34634597

RESUMO

Olfactory epithelial cells are in direct contact with myriad environmental contaminants which may consequently disrupt their structure and function. Copper ions (Cu2+) and copper nanoparticles (CuNPs) are two types of olfactory neurotoxicants. However, their effects on the structure of olfactory epithelium are largely uninvestigated. The density of olfactory goblet cells in CuNP- and Cu2+ - exposed rainbow trout was assessed using light microscopy throughout time. In both copper (Cu) treatments, the number of goblet cells increased initially over the 24 h exposure and then recovered to normal throughout the 96 h exposure. These data suggested the 96 h exposure to Cu contaminants interfered with protective barrier provided by goblet cells. Nonetheless, lamellar and epithelial thickness of olfactory rosette did not change in the Cu-exposed fish. The gene transcript profile of olfactory mucosa studied by RNA-seq indicated Cu2+ and CuNPs differentially targeted the molecular composition of cell junctions. In the Cu2+ treatment, reduced mRNA abundances of tight junctions, adherens junction, desmosomes and hemidesmosomes, suggest that Cu2+-exposed olfactory mucosal cells had weak junctional complexes. In the CuNP treatment, on the other hand, the transcript abundances of cell junction compositions, except adherens junction, were upregulated. Transcripts associated with gap junctional channels were increased in both Cu treatments. The elevated transcript levels of gap junctions in both Cu treatments suggested that the demand for intercellular communication was increased in the Cu-exposed olfactory mucosa. Overall, our findings suggested that Cu2+ induced greater adverse effects on the molecular composition of olfactory cell junctions relative to CuNPs. Impairment of junctional complexes may disrupt the structural integrity of olfactory mucosa.


Assuntos
Nanopartículas , Oncorhynchus mykiss , Poluentes Químicos da Água , Animais , Cobre/toxicidade , Íons , Mucosa Olfatória/química , Poluentes Químicos da Água/análise
20.
Environ Sci Technol ; 55(21): 14772-14781, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34647741

RESUMO

The toxicity of Cu is related to its redox species, but the differential toxicity of Cu(II) and Cu(I) remains unknown. In the present study, we developed a novel protocol to simultaneously detect the biologically produced extracellular Cu(I) and internalized Cu(II) in a freshwater phytoplankton Chlamydomonas reinhardtii. The intracellular Cu(I) was further imaged using a fluorometric probe. Combining these pieces of evidence, we demonstrated that Cu(I) dominated the Cu toxicity in algal cells under Fe-deficient conditions. Our results showed that the labile Cu(I) content increased significantly in the low Fe quota cells. Intracellular biotransformation from Cu(II) to Cu(I) rather than the direct uptake of Cu(I) was responsible for the high Cu toxicity. The abnormal biotransformation from Cu(II) to Cu(I) under Fe deficiency was not resulted from the increase of overall Cu bioaccumulation but was likely due to the change of Cu(II) metabolism. High contents of Cu(II) were accumulated in the normal cells and the low Zn quota cells upon Cu exposure but did not induce cell death, further suggesting that Cu(I) dominated the Cu toxicity to the algae. This is the first study to simultaneously consider the effect of Cu(I) and Cu(II) during Cu exposure in phytoplankton. The results uncovered the underlying mechanisms of high Cu toxicity under Fe deficiency and highlighted the critical role of modulation of Cu metabolism in phytoplankton.


Assuntos
Chlamydomonas reinhardtii , Biotransformação , Cobre/toxicidade , Água Doce , Fitoplâncton
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