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1.
J Toxicol Sci ; 45(9): 539-548, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879253

RESUMO

We investigated the mechanism underlying intestinal cadmium (Cd) uptake based on the mediators (metal transporters) of essential elements, such as Fe, Zn, Cu, and Ca, under normal conditions in female rats. These elements interact with Cd uptake from the intestinal tract. Cd concentration at each site of the small intestine (duodenum, jejunum, and ileum) increased as Cd exposure increased. However, Cd concentration was the highest in the duodenum. The gene expression of ZIP14, DMT1, and ATP7A increased with increase in Cd concentration. Further, Cu concentration decreased as Cd concentration increased. In contrast, Fe concentration displayed a decreasing tendency with the increase in Cd concentration. The gene expression levels of ZIP14, DMT1, and ATP7A were positively correlated with Cd concentration. Immunohistochemical staining revealed the positive sites of ZIP14 and DMT1 scattered in the area adjacent to the goblet cells, resorbable epithelial cells, and lamina propria in the duodenum tissue, according to the increase in Cd concentration. Cd is induced to synthesize and bind to metallothionein (MT-I and -II) and accumulate in the intestinal tissues, mainly in the duodenum. Such findings suggest that Cd, a contaminant element, is taken up from the intestinal tract by multiple metal transporters such as Cu, Fe, and Zn, thereby involving in the intestinal Cd absorption.


Assuntos
Cádmio/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Absorção Intestinal/genética , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Animais , Proteínas de Transporte de Cátions/genética , Cobre , ATPases Transportadoras de Cobre/genética , ATPases Transportadoras de Cobre/metabolismo , Duodeno/metabolismo , Feminino , Expressão Gênica , Ferro , Metalotioneína/metabolismo , Ratos , Zinco
2.
Bull Environ Contam Toxicol ; 105(4): 559-564, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32974765

RESUMO

In this work, we propose to evaluate the effect of agriculture intensification under greenhouses on the biochemical and transcriptomic responses of the earthworms Eisenia andrei. This work was conducted on two sites in Téboulba and Sahline (Monastir governorate) and a control site in an experimental plot that is undergoing organic farming. For this purpose, the earthworms Eisenia andrei were exposed to the soils during 7 and 14 days. The physicochemical properties of the soils were analyzed. The biochemical biomarkers of metallothioneins (MTs) and malondialdehyde (MDA) accumulations were also assessed. Moreover, the gene expression level of the MTs was analyzed. The results of our study revealed a significant trace element accumulation accompanied by a high level of MDA and MT proteins. Moreover, a significant expression of the MT gene was observed in earthworms exposed to the soils from Sahline and Téboulba. Hence, this work reveals that intensive agriculture can affect the biological responses of earthworms and consequently, the soil's biofertility.


Assuntos
Agricultura , Biomarcadores Ambientais/fisiologia , Metais Pesados/metabolismo , Oligoquetos/efeitos dos fármacos , Poluentes do Solo/metabolismo , Solo/química , Agricultura/métodos , Animais , Expressão Gênica/efeitos dos fármacos , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Oligoquetos/genética , Oligoquetos/metabolismo , Tunísia
3.
Mar Environ Res ; 162: 105091, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32798697

RESUMO

Anthropogenic inputs of carbon dioxide in the atmosphere are driving ocean warming and acidification. The potential threat represented by these changes for marine species could be amplified in coastal areas, characterized by higher levels of pollutants. In addition, temperate organisms may exhibit a different seasonal tolerance to stressors influenced by fluctuations of environmental and physiological factors. In this study, Mediterranean mussels Mytilus galloprovincialis collected both in summer and winter were exposed to combinations of two temperatures (SST, seasonal surface temperature and SST+5 °C) and two levels of pH (8.20 and 7.40) in clean or cadmium contaminated seawater (20 µg/L Cd). mRNA levels of genes related to metal-induced stress response were investigated, including metallothionein mt-20, heat-shock protein hsp70, superoxide dismutase Cu/Zn-sod, catalase cat, glutathione peroxidase gpx1 and glutathione S-transferase gst-pi. To further elucidate if tissues with different physiological roles could exhibit different responsiveness, such analyses were carried out in digestive gland and in gills of exposed mussels. mt-20 mRNA increase after Cd-exposure was higher in the digestive gland than in the gills, with few modulations by temperature or pH only in the latter. Acidification, alone or in combination with other stressors, increased hsp70 mRNA, with seasonal- and tissue-specificities (higher in summer and in digestive gland). Among antioxidants, gpx1 mRNA was affected by Cd in both tissues and seasons, with further modulations due to pH and temperature variation tissue- and season-specific; in winter the combination of Cd, warming and acidification affected Cu/Zn-sod both in digestive gland and gills and cat only in gills, while weak seasonal variations were observed for gst-pi transcripts only in digestive gland. The overall results highlighted the importance of considering seasonality and responsiveness of different tissues to predict the effects of sudden changes in environmental parameters on responsiveness to and toxicity of chemicals in marine coastal organisms.


Assuntos
Mytilus , Poluentes Químicos da Água , Animais , Biomarcadores/metabolismo , Cádmio/toxicidade , Brânquias/química , Metalotioneína/metabolismo , Mytilus/genética , Mytilus/metabolismo , Oceanos e Mares , Estresse Oxidativo , Estações do Ano , Poluentes Químicos da Água/análise
4.
Ecotoxicol Environ Saf ; 202: 110917, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800252

RESUMO

Cadmium (Cd) is an extremely toxic environmental pollutant with high mobility in soils, which can contaminate groundwater, increasing its risk of entering the food chain. Yeast biosorption can be a low-cost and effective method for removing Cd from contaminated aqueous solutions. We transformed wild-type Saccharomyces cerevisiae (WT) with two versions of a Populus trichocarpa gene (PtMT2b) coding for a metallothionein: one with the original sequence (PtMT2b 'C') and the other with a mutated sequence, with an amino acid substitution (C3Y, named here: PtMT2b 'Y'). WT and both transformed yeasts were grown under Cd stress, in agar (0; 10; 20; 50 µM Cd) and liquid medium (0; 10; 20 µM Cd). Yeast growth was assessed visually and by spectrometry OD600. Cd removal from contaminated media and intracellular accumulation were also quantified. PtMT2b 'Y' was also inserted into mutant strains: fet3fet4, zrt1zrt2 and smf1, and grown under Fe-, Zn- and Mn-deficient media, respectively. Yeast strains had similar growth under 0 µM, but differed under 20 µM Cd, the order of tolerance was: WT < PtMT2b 'C' < PtMT2b 'Y', the latter presenting 37% higher growth than the strain with PtMT2b 'C'. It also extracted ~80% of the Cd in solution, and had higher intracellular Cd than WT. Mutant yeasts carrying PtMT2b 'Y' had slightly higher growth in Mn- and Fe-deficient media than their non-transgenic counterparts, suggesting the transgenic protein may chelate these metals. S. cerevisiae carrying the altered poplar gene offers potential for bioremediation of Cd from wastewaters or other contaminated liquids.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Metalotioneína/genética , Proteínas de Plantas/genética , Populus/genética , Saccharomyces cerevisiae/genética , Poluentes do Solo/metabolismo , Cádmio/toxicidade , Metalotioneína/metabolismo , Metais Pesados/análise , Populus/metabolismo , Saccharomyces cerevisiae/metabolismo , Solo
5.
Aquat Toxicol ; 226: 105555, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32645607

RESUMO

Fish strongly rely on olfaction as a variety of essential behaviors such as foraging and predator avoidance are mediated by the olfactory system. Cadmium (Cd) is known to impair olfaction and accumulate in the olfactory epithelium (OE) and bulb (OB) of fishes. In the present study, the acute toxicity of Cd on olfaction in zebrafish (Danio rerio) was characterized on the molecular and behavioral level. To this end, quantitative real-time PCR was performed in order to analyze the expression of selected genes in both the OE and OB. Moreover, the response of zebrafish to an alarm cue was investigated. Following 24 h of exposure to Cd, the expression of genes associated with olfactory sensory neurons was reduced in the OE. Furthermore, the antioxidant genes peroxiredoxin 1 (prdx1) and heme oxygenase 1 (hmox1), as well as the metallothionein 2 gene (mt2) were upregulated in the OE, whereas hmox1 and the stress-inducible heat shock protein 70 gene (hsp70) were upregulated in the OB upon exposure to Cd. Following stimulation with a conspecific skin extract, zebrafish displayed a considerable disruption of the antipredator behavior with increasing Cd concentration. Taken together, Cd impaired olfaction in zebrafish, thereby disrupting the antipredator response, which is crucial for the survival of individuals. Cellular stress followed by disruption of olfactory sensory neurons may have contributed to the observed behavioral deficits.


Assuntos
Comportamento Animal/efeitos dos fármacos , Cádmio/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Olfato/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Antioxidantes/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Metalotioneína/genética , Metalotioneína/metabolismo , Mucosa Olfatória/efeitos dos fármacos , Olfato/genética , Peixe-Zebra/genética , Peixe-Zebra/fisiologia
6.
Chemosphere ; 259: 127258, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32585458

RESUMO

This is the first study to investigate the reduction mechanism of Tl (III) to Tl(I) in the presence of plants, especially rice. Smaller plant density could effectively reduce the content of organic acids in the hydroponic system to keep the stability of Tl(III). As the plant density was reduced from 40 seedlings to 10 seedlings in 100 mL Tl(III) solution, the content of oxalate was declined to one-third of the original, and the ratio of Tl(III)/total Tl was increased from 39.6% to 81.0% in the first 2 h treatment. Then the differences in antioxidant capacity of rice exposed to the two Tl species were studied. The contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2˙-) of rice roots exposed to Tl(III) were all higher than those to Tl(I). Meanwhile, the catalase (CAT) activity was significantly depressed and peroxidase (POD) was increased by Tl(III), whereas superoxide dismutase (SOD) showed a rise in both Tl(I) and Tl(III) with no significant difference between them. The expression of metallothionein gene OsMT1a to Tl(I) was upregulated to 255.5 times of Tl(III) though OsMT2c was downregulated to 0.39 times of Tl(III). Overall, the different responses in metallothionein gene expression and antioxidative enzyme activation might result in more ROS accumulation to rice roots by Tl(III) treatment than those by Tl(I).


Assuntos
Metalotioneína/genética , Oryza/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Tálio/toxicidade , Antioxidantes/metabolismo , Catalase/metabolismo , Peróxido de Hidrogênio/metabolismo , Hidroponia , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Oryza/genética , Oryza/metabolismo , Peroxidase/metabolismo , Peroxidases/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
7.
Ecotoxicol Environ Saf ; 201: 110861, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32544748

RESUMO

Marine biota have been co-challenged with ocean warming and mercury (Hg) pollution over many generations because of human activities; however, the molecular mechanisms to explain their combined effects are not well understood. In this study, a marine planktonic copepod Pseudodiaptomus annandalei was acutely exposed to different temperature (22 and 25 °C) and Hg (0 and 118 µg/L) treatments in a 24-h cross-factored experiment. Hg accumulation and its subcellular fractions were determined in the copepods after exposure. The expression of the genes of superoxide dismutase (SOD), glutathione peroxidase (GPx), metallothionein1 (mt1), heat shock protein 70 (hsp70), hsp90, hexokinase (hk), and pyruvate kinase (pk) was also analyzed. Both the Hg treatment alone and the combined exposure of warmer temperature plus Hg pollution remarkably facilitated Hg bioaccumulation in the exposed copepods. Compared with the Hg treatment alone, the combined exposure increased total Hg accumulation and also the amount of Hg stored in the metal-sensitive fractions (MSF), suggesting elevated Hg toxicity in P. annandalei under a warmer environment, given that the MSF is directly related to metal toxicity. The warmer temperature significantly up-regulated the mRNA levels of mt1, hsp70, hsp90, and hk, indicating the copepods suffered from thermal stress. With exposure to Hg, the mRNA level of SOD increased strikingly but the transcript levels of hsp90, hk, and pk decreased significantly, indicating that Hg induced toxic events (e.g., oxidative damage and energy depletion). Particularly, in contrast to the Hg treatment alone, the combined exposure significantly down-regulated the mRNA levels of SOD and GPx but up-regulated the mRNA levels of mt1, hsp70, hsp90, hk, and pk. Collectively, the results of this study indicate that ocean warming will potentially boost Hg toxicity in the marine copepod P. annandalei, which is information that will increase the accuracy of the projections of marine ecosystem responses to the joint effects of climate change stressors and metal pollution on the future ocean.


Assuntos
Copépodes/efeitos dos fármacos , Temperatura Alta , Mercúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Copépodes/genética , Copépodes/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Hexoquinase/genética , Hexoquinase/metabolismo , Mercúrio/farmacocinética , Metalotioneína/genética , Metalotioneína/metabolismo , Piruvato Quinase/genética , Piruvato Quinase/metabolismo , RNA Mensageiro/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Regulação para Cima , Poluentes Químicos da Água/farmacocinética
8.
Bull Environ Contam Toxicol ; 105(1): 67-75, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32409854

RESUMO

Hydropower plants (HPPs) can affect the hydrological regime. However, biochemical responses of aquatic animals for the evaluation of this disturbing are not applied yet. The specimens of Unio tumidus were sampled in a reservoir (R) of a small HPP as well as downstream from the dam (DS). Biochemical indexes in the digestive gland and alkali labile phosphates (ALP) in the gonads were examined. The R-mollusks showed low cholinesterase, catalase and caspase-3 activities, and metallothionein concentration, but elevated levels of zinc and copper, oxidized glutathione and protein carbonyls. Concentrations of lactate, pyruvate and ALP, activity of superoxide dismutase and glutathione S-transferase, and lipid peroxidation level were similar in both groups. Integrated biomarker response (IBR/n) index (n = 13) was 2.17 and 0.29 in the R- and DS-groups correspondingly. We suggest that using integrative biological response based on the biochemical markers of bivalve mollusks can be a valid early warning step in assessing 'environmental flow' impact.


Assuntos
Monitoramento Ambiental , Centrais Elétricas , Unio/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Catalase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos , Metalotioneína/metabolismo , Moluscos/metabolismo , Rios , Ucrânia , Unio/metabolismo , Poluentes Químicos da Água/análise
9.
J Toxicol Sci ; 45(3): 117-129, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32147635

RESUMO

Silica nanoparticles (SiO2 NPs) are widely used in daily life and can enter organisms through several pathways, often causing unpredictable toxicity. Although SiO2 NPs are known to cause damage to the respiratory system, little is known about their oral toxicity, and their potential harm to the reproductive system is unclear. In this study, we used a Caenorhabditis elegans model to clarify SiO2 NPs oral toxicity in vivo and explore their effect on the reproductive system. We exposed C. elegans to 0.25, 0.5 and 1 mg /mL SiO2 NPs for 24 hr. Our results showed that SiO2 NPs exposure for 24 hr did not affect nematode survival rates, but did affect, to varying degrees, the reproduction, development, and movement of nematodes, with nematode fecundity being the most sensitive to SiO2 NPs toxicity. The NPs exposed group showed enhanced germ cell apoptosis and increased oxidative stress as seen through an increase in ROS and malondialdehyde (MDA), and decrease in reduced glutathione (GSH). N-acetyl-L-cysteine (NAC), an antioxidant, negated SiO2 NPs effect on germ cells and restored nematodes reproductive ability. We also found that SiO2 NPs could affect the expression of genes related to metal detoxification, oxidative stress, and apoptosis. The expression of metallothionein coding genes mtl-1 and mtl-2 changed most significantly among the tested genes. We demonstrated that SiO2 NPs could enhance germ cell apoptosis by inducing oxidative stress, providing a new area for studies of the mechanism of SiO2 NP toxicity.


Assuntos
Apoptose/efeitos dos fármacos , Caenorhabditis elegans/metabolismo , Células Germinativas/metabolismo , Células Germinativas/patologia , Nanopartículas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Dióxido de Silício/toxicidade , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Malondialdeído/metabolismo , Metalotioneína/genética , Metalotioneína/metabolismo , Estresse Oxidativo/efeitos dos fármacos
10.
PLoS One ; 15(3): e0230572, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32210477

RESUMO

Chromatin structure plays a decisive role in gene regulation through the actions of transcriptional activators, coactivators, and epigenetic machinery. These trans-acting factors contribute to gene expression through their interactions with chromatin structure. In yeast INO1 activation, transcriptional activators and coactivators have been defined through intense study but the mechanistic links within these trans-acting factors and their functional implications are not yet fully understood. In this study, we examined the crosstalk within transcriptional coactivators with regard to the implications of Snf2p acetylation during INO1 activation. Through various biochemical analysis, we demonstrated that both Snf2p and Ino80p chromatin remodelers accumulate at the INO1 promoter in the absence of Snf2p acetylation during induction. Furthermore, nucleosome density and histone acetylation patterns remained unaffected by Snf2p acetylation status. We also showed that cells experience increased sensitivity to copper toxicity when remodelers accumulate at the INO1 promoter due to the decreased CUP1 expression. Therefore, our data provide evidence for crosstalk within transcriptional co-activators during INO1 activation. In light of these findings, we propose a model in which acetylation-driven chromatin remodeler recycling allows for efficient regulation of genes that are dependent upon limited co-activators.


Assuntos
Adenosina Trifosfatases/metabolismo , Metalotioneína/metabolismo , Mio-Inositol-1-Fosfato Sintase/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Acetilação , Adenosina Trifosfatases/genética , Sobrevivência Celular/efeitos dos fármacos , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Cobre/metabolismo , Cobre/toxicidade , Histonas/metabolismo , Metalotioneína/genética , Mio-Inositol-1-Fosfato Sintase/metabolismo , Nucleossomos/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/genética , Ativação Transcricional
11.
Chemosphere ; 251: 126311, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32169710

RESUMO

The study provides cumulative data on the status of the two water bodies. The study designed revealed physicochemical properties (temperature, dissolved oxygen, pH, total dissolved solids and conductivity) to be in the desirable range, however, amongst the heavy metals excepting for Cd all were found to be higher than the permissible limits set by WHO and USEPA. It was observed that these elements cast their impact on bioindices (hepatosomatic index, condition factor, spleenosomatic index and kidney somatic index), renal marker enzyme (creatine kinase), hepatic marker enzymes (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase), histology of immune organs (liver, spleen, head-kidney and thymus) and level of serum immunoglobulin (IgM). Further, expression levels of Metallothionein (MT) and Glutathione peroxidase (GPX) genes in immune-related tissues (liver, spleen, head-kidney, thymus and blood) observed indicates metal pollution and abiotic stresses. These alterations are reliable indicators of the cellular and humoral immune response in Cyprinus carpio.


Assuntos
Carpas/fisiologia , Fatores Imunológicos/toxicidade , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Carpas/genética , Carpas/imunologia , Expressão Gênica , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Rim Cefálico/efeitos dos fármacos , Fatores Imunológicos/metabolismo , Rim/metabolismo , Lagos , Fígado/metabolismo , Metalotioneína/genética , Metalotioneína/metabolismo , Metais Pesados/análise , Tanques , Baço/efeitos dos fármacos , Poluentes Químicos da Água/análise , Áreas Alagadas
12.
Appl Environ Microbiol ; 86(9)2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32111593

RESUMO

Metallothionein (MT) genes are valuable genetic materials for developing metal bioremediation tools. Currently, a limited number of prokaryotic MTs have been experimentally identified, which necessitates the expansion of bacterial MT diversity. In this study, we conducted a metagenomics-guided analysis for the discovery of potential bacterial MT genes from the soil microbiome. More specifically, we combined resistance gene enrichment through diversity loss, metagenomic mining with a dedicated MT database, evolutionary trace analysis, DNA chemical synthesis, and functional genomic validation to identify novel MTs. Results showed that Cu stress induced a compositional change in the soil microbiome, with an enrichment of metal-resistant bacteria in soils with higher Cu concentrations. Shotgun metagenomic sequencing was performed to obtain the gene pool of environmental DNA (eDNA), which was subjected to a local BLAST search against an MT database for detecting putative MT genes. Evolutional trace analysis led to the identification of 27 potential MTs with conserved cysteine/histidine motifs different from those of known prokaryotic MTs. Following chemical synthesis of these 27 potential MT genes and heterologous expression in Escherichia coli, six of them were found to improve the hosts' growth substantially and enhanced the hosts' sorption of Cu, Cd, and Zn, among which MT5 led to a 13.7-fold increase in Cd accumulation. Furthermore, four of them restored Cu and/or Cd resistance in two metal-sensitive E. coli strains.IMPORTANCE The metagenomics-guided procedure developed here bypasses the difficulties encountered in classic PCR-based approaches and led to the discovery of novel MT genes, which may be useful in developing bioremediation tools. The procedure used here expands our knowledge on the diversity of bacterial MTs in the environment and may also be applicable to identify other functional genes from eDNA.


Assuntos
Bactérias/genética , Cádmio/efeitos adversos , Cobre/efeitos adversos , Farmacorresistência Bacteriana/genética , Metagenoma , Metalotioneína/genética , Microbiota/genética , Bactérias/efeitos dos fármacos , Genes Bacterianos , Metagenômica , Metalotioneína/metabolismo , Microbiota/efeitos dos fármacos , Microbiologia do Solo , Poluentes do Solo/efeitos adversos
13.
Ecotoxicol Environ Saf ; 195: 110477, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32200148

RESUMO

Bioindicator organisms are important tools in environmental monitoring studies. Understanding this, the overall goal of the present study was to evaluate the sensitivity and viability of the native fish species Banded tetra, (Astyanax aeneus; Günther, 1860), widely spread in the aquatic ecosystems of the Yucatan Peninsula in Mexico, as a bioindicator organism. In order to do this, we performed a bioassay at sublethal concentrations using copper (CuSO4) to experimentally evaluate and validate the relationship between the trace metals and oxidative stress biomarkers response [(catalase (CAT), lipoperoxidation content (LPO)], detoxification [(glutathione S-transferase (GST), metallothionein content (MT)] and neurotoxicity (AChE) in muscle of A. aeneus. Results showed changes in biomarkers after 96 h: Catalase activity (CAT) was significantly higher above 1.5 and 2 mg/L (154.35 and 172.50% increase, respectively); lipid peroxidation contents (TBARS), GST activity, and MT content were very similar to CAT activity at 1.5 and 2 mg/L of Cu. In terms of neurotoxicity, AChE activity was significantly inhibited at 0.1 mg/L (64%; p < 0.001) and 0.5 mg/L (44%; p < 0.001) of Cu. Based on the bioassay results, we performed a trace metal monitoring campaign in muscle of A. aeneus caught in 15 sites with different anthropogenic activities, during the summer of 2017, to establish a baseline of trace metals pollution in the state of Campeche. A. aeneus showed the highest trace metal accumulation in the following order: Al > Fe > Mn > Zn > Cu > Hg > Cr > Pb > Cd > V > As, while sites were arrange as follows: Xnoha lagoon > Palizada River > Candelaria River > Ululmal > Maravillas > López Mateos. PCA showed a cluster between biomarkers (GST, CAT, TBARS, and MT) and concentration of metals (Cd, Cu, Fe, Zn, Hg and Cr). Conversely, AChE inhibition was not related to a specific metal, but highest inhibitions (>50%) were present in those sites with intensive agricultural practices. These results determined that, based on its physiological response and trace metal bioaccumulation, Astyanax aeneus can be considered a good bioindicator for evaluating the presence of trace metals in tropical aquatic systems of the Yucatan Peninsula.


Assuntos
Caraciformes , Biomarcadores Ambientais , Metais/toxicidade , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/metabolismo , Animais , Monitoramento Biológico , Biomarcadores , Catalase/metabolismo , Caraciformes/metabolismo , Cobre/toxicidade , Ecossistema , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/metabolismo , Metais/análise , México , Músculos/efeitos dos fármacos , Músculos/enzimologia , Músculos/metabolismo , Estresse Oxidativo , Poluentes Químicos da Água/análise
14.
Ecotoxicol Environ Saf ; 193: 110365, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32114244

RESUMO

The biochemical responses of Bellamya aeruginosa as a dominant and widespread freshwater gastropod throughout China to waterborne cadmium (Cd) were investigated to explore the impacts of exposure concentration and duration in this potential sentinel species. After the 7 days' test of dosage-mortality relationship, gastropods were exposed for either 7 days at the LC50 (1.7 mg/L), the LC10 (0.7 mg/L) and 0.02 mg/L Cd, or 28 days at 0.02 mg/L Cd. A suite of biochemical indicators including metallothionein-like protein (MTLP), reduced glutathione (GSH), catalase (CAT), contents of tissue metal (Cd, Fe, Mn, Cu, Zn), and the compartments of these metals bound to MTLP were examined. The treatment of 0.02 mg/L Cd led to the increase of Cd bound to MTLP (Cd-MTLP) levels, the decrease of GSH content, and the upregulation of CAT activity, but no induction of MTLP, indicating that the intrinsic MTLP and GSH worked together for the detoxification of Cd at the low exposure. When the exposure concentration increased, GSH was depleted severely and synthesis of MTLP was triggered, leading to a strong and significant relationship between MTLP level and Cd accumulation. At the lethal concentrations (1.7 mg/L), both MTLP induction and CAT activity were inhibited while the proportion of Cd-MTLP to total Cd were increased, suggesting more intrinsic MTLP were utilized to sequester free Cd ions. Therefore, the content of Cd-MTLP in digestive glands of B. aeruginosa was recommended as a reliable biomarker for Cd contamination.


Assuntos
Cádmio/toxicidade , Gastrópodes/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Cádmio/farmacocinética , Catalase/metabolismo , Biomarcadores Ambientais , Água Doce , Gastrópodes/metabolismo , Glutationa/metabolismo , Metalotioneína/metabolismo , Metais/metabolismo , Poluentes Químicos da Água/farmacocinética
15.
Sci Rep ; 10(1): 2015, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32029749

RESUMO

Although metallothionein-3 (MT3), a brain-enriched form of metallothioneins, has been linked to Alzheimer's disease, little is known regarding the role of MT3 in glioma. As MT3 plays a role in autophagy in astrocytes, here, we investigated its role in irradiated glioma cells. Irradiation increased autophagy flux in GL261 glioma cells as evidenced by increased levels of LC3-II but decreased levels of p62 (SQSTM1). Indicating that autophagy plays a cytoprotective role in glioma cell survival following irradiation, measures inhibiting autophagy flux at various steps decreased their clonogenic survival of irradiated GL261 as well as SF295 and U251 glioma cells. Knockdown of MT3 with siRNA in irradiated glioma cells induced arrested autophagy, and decreased cell survival. At the same time, the accumulation of labile zinc in lysosomes was markedly attenuated by MT3 knockdown. Indicating that such zinc accumulation was important in autophagy flux, chelation of zinc with tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN), induced arrested autophagy in and reduced survival of GL261 cells following irradiation. Suggesting a possible mechanism for arrested autophagy, MT3 knockdown and zinc chelation were found to impair lysosomal acidification. Since autophagy flux plays a cytoprotective role in irradiated glioma cells, present results suggest that MT3 and zinc may be regarded as possible therapeutic targets to sensitize glioma cells to ionizing radiation therapy.


Assuntos
Autofagia/efeitos da radiação , Neoplasias Encefálicas/radioterapia , Glioma/radioterapia , Metalotioneína/metabolismo , Fótons/uso terapêutico , Animais , Autofagia/efeitos dos fármacos , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Quelantes/farmacologia , Etilenodiaminas/farmacologia , Técnicas de Silenciamento de Genes , Glioma/patologia , Humanos , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/efeitos da radiação , Metalotioneína/genética , Camundongos , RNA Interferente Pequeno/metabolismo , Tolerância a Radiação , Zinco/metabolismo
16.
Chemosphere ; 248: 125974, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32004885

RESUMO

Clam farming comprises an important part of China's economy. However, increasing pollution in the ocean caused by toxic metals has led to the bioaccumulation of toxic metals in marine animals, especially the bivalves such as clams, and the consequence of heavy metal-associated toxicity in these animals. Such toxicity can enhance the production of reactive oxygen species (ROS) within the tissues of the animals. In aquatic species, oxidative stress mechanisms have been studied by measuring the antioxidant and oxidative damage index in the tissues. The objectives of this study were to investigate the levels of different toxic metals and the extent of oxidative stress responses in the clam Sinonovacula constricta at different growth periods (from May to October) in an aquaculture farm in Wengyang, an important economic shellfish culture zone in Zhejiang Province, China. Water and sediment samples taken from the farm were subjected to Pb, Hg, Cd, Cr assays. Overall, the levels of these metals in the water and sediment could be considered as light pollution, though the levels of Hg in the water (0.266) and Cd in the sediment (0.813) could be considered as reaching moderate pollution. In addition, the levels of these metals, H2O2, MDA and GSH content, antioxidant enzyme (CAT, SOD, GPx) activities as well as the level of metallothioneins (MT) mRNA in the tissues of S. constricta were also analyzed. The levels of Pb, Hg, Cd, Cr increased with increasing culturing time, and a higher level of these metals was accumulated in the visceral mass than in the foot. The levels of MDA and GSH, as well as the level of SOD activity in the viscera and foot of S. constricta increased with increasing metal accumulation. However, CAT and GPX activities, H2O2 level and the expression of MT initially increased and then decreased. This suggested that S. constricta might have the ability to control oxidative damage by triggering antioxidant defense in coordination with the metal sequestering response. The results also implied that toxic metal pollution should be taken into account when selecting the site to be used as an aquaculture farm. In addition, the visceral mass should be considered to be a good tissue for measuring the level of metal pollutants.


Assuntos
Aquicultura , Bivalves/fisiologia , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Bivalves/metabolismo , China , Poluição Ambiental , Peróxido de Hidrogênio/metabolismo , Metalotioneína/metabolismo , Metais Pesados/análise , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Poluentes Químicos da Água/análise
17.
Chemosphere ; 249: 126157, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32062217

RESUMO

Waterborne metals may be hazardous to aquatic organisms and trigger stress responses. The present study aimed to assess the effect of exposure to 100 µg/L cadmium (Cd) or copper (Cu) for 48 h on juvenile Marsupenaeus japonicus, in terms of bioaccumulation and the whole body transcriptome. The results demonstrated that Cu accumulation in M. japonicas was much higher than that of Cd. Meanwhile, transcriptome analysis identified 1802 and 2670 differentially expressed genes (DEGs) after 48 h exposure to 100 µg/L Cd and Cu, respectively. Among them, 851 DEGs responded to both metals. Cd and Cu stress shared genes were related to the cytoskeleton, immunity, antioxidation, and detoxification. Metallothionein 1 (MT1) was specifically induced in the Cd-stress response, while glycometabolism, heat shock protein 90 (HSP90), metallothionein 2 (MT2), apoptosis, and iron transport-related genes were changed specifically in response to Cu stress. In addition, real-time PCR was used to verify the expression patterns of 28 randomly selected DEGs. The sequencing and real-time PCR results were consistent. Moreover, based on the number of significantly modulated genes and their expression levels, we deduced that Cu acts as a stronger stress inducer than Cd in M. japonicus. The identified Cd and Cu stress related genes and pathways will provide new insights into the common and different molecular mechanisms underlying Cd and Cu toxicity effects in M. japonicus.


Assuntos
Cádmio/toxicidade , Cobre/toxicidade , Penaeidae/fisiologia , Poluentes Químicos da Água/toxicidade , Adolescente , Animais , Antioxidantes , Perfilação da Expressão Gênica , Humanos , Metalotioneína/metabolismo , Metais , Penaeidae/genética , Transcriptoma
18.
Thorax ; 75(3): 253-261, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31915307

RESUMO

INTRODUCTION: Zinc is well known for its anti-inflammatory effects, including regulation of migration and activity of polymorphonuclear neutrophils (PMN). Zinc deficiency is associated with inflammatory diseases such as acute lung injury (ALI). As deregulated neutrophil recruitment and their hyper-activation are hallmarks of ALI, benefits of zinc supplementation on the development of lipopolysaccharides (LPS)-induced ALI were tested. METHODS: 64 C57Bl/6 mice, split into eight groups, were injected with 30 µg zinc 24 hours before exposure to aerosolised LPS for 4 hours. Zinc homoeostasis was characterised measuring serum and lung zinc concentrations as well as metallothionein-1 expression. Recruitment of neutrophils to alveolar, interstitial and intravascular space was assessed using flow cytometry. To determine the extent of lung damage, permeability and histological changes and the influx of protein into the bronchoalveolar lavage fluid were measured. Inflammatory status and PMN activity were evaluated via tumour necrosis factor α levels and formation of neutrophil extracellular traps. The effects of zinc supplementation prior to LPS stimulation on activation of primary human granulocytes and integrity of human lung cell monolayers were assessed as well. RESULTS: Injecting zinc 24 hours prior to LPS-induced ALI indeed significantly decreased the recruitment of neutrophils to the lungs and prevented their hyperactivity and thus lung damage was decreased. Results from in vitro investigations using human cells suggest the transferability of the finding to human disease, which remains to be tested in more detail. CONCLUSION: Zinc supplementation attenuated LPS-induced lung injury in a murine ALI model. Thus, the usage of zinc-based strategies should be considered to prevent detrimental consequences of respiratory infection and lung damage in risk groups.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/prevenção & controle , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/fisiologia , Zinco/farmacologia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/patologia , Animais , Líquido da Lavagem Broncoalveolar/química , Proteínas de Transporte de Cátions/genética , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quimiocina CXCL1/metabolismo , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos/genética , Homeostase , Humanos , Selectina L/metabolismo , Lipopolissacarídeos , Masculino , Metalotioneína/genética , Metalotioneína/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro , Receptores de Complemento 3b/metabolismo , Fator de Transcrição STAT3/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Zinco/metabolismo , Zinco/uso terapêutico
19.
Chemosphere ; 246: 125733, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31901659

RESUMO

Intake of toxic trace elements in drinking water can lead to adverse health effects. To remove toxic trace elements from water, we developed a novel biosorbent composed of cellulose and a fusion protein. The fusion protein was constructed from metallothionein (MT) and a carbohydrate-binding module (CBM), where CBM can bind to cellulose while MT can capture heavy metal ions in solution. In a batch experiment, the biosorbent had maximum biosorption capacities for Pb(II) and Zn(II) ions of 39.02 mg/g and 29.28 mg/g, respectively. Furthermore, the biosorbent could be used in a semi-continuous system and showed good regeneration and recyclability. Both cellulose and the MT-CBM are environmentally friendly and renewable materials, and this biosorbent has great potential for efficient removal of toxic trace elements from polluted water.


Assuntos
Chumbo/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Zinco/química , Adsorção , Celulose/química , Concentração de Íons de Hidrogênio , Íons , Cinética , Chumbo/análise , Metalotioneína/química , Metalotioneína/metabolismo , Metais Pesados/análise , Água , Poluentes Químicos da Água/análise , Poluição da Água , Zinco/análise
20.
Bull Environ Contam Toxicol ; 104(3): 315-320, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31960073

RESUMO

Microplastics have become a global concern in recent years. In this study, we studied (i) whether the presence of polyvinyl chloride (PVC) microparticles may affect cadmium (Cd) uptake in mussel (Mytilus edulis); and (ii) the biological effects of PVC microparticles exposure alone or in combination with Cd. Significant Cd uptake in digestive gland was observed following Cd exposure. However, PVC did not significantly increase Cd uptake compared with Cd alone treatment. In terms of biological impacts, significantly lower neutral red retention (NRR) time and elevated expression of Metallothionein isoform 20-IV (MT-20) were observed in mussels exposed to Cd alone, or combined with microplastics, yet there was no significant difference between them. catalase (CAT) expression only showed a significant increase in mussels exposed to Cd alone. This work provides an insight into the relationship on resulting biological impacts between these two contaminants.


Assuntos
Cádmio/metabolismo , Mytilus edulis/metabolismo , Cloreto de Polivinila/farmacologia , Animais , Catalase/metabolismo , Metalotioneína/metabolismo , Mytilus/metabolismo , Alimentos Marinhos , Poluentes Químicos da Água/metabolismo
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