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1.
Chemosphere ; 240: 124902, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563721

RESUMO

Eisenia fetida earthworm is an ecotoxicologically important test species to monitor various pollutants. However, there is a little knowledge about the effects of cadmium (Cd) on earthworms at the transcriptional level. Firstly, we exposed E. fetida to soils supplemented with different concentrations (10, 30, 60 mg/kg soil) of Cd. Moreover, we depicted the characterization of gene expressions with E. fetida using high-throughput profiling of gene expression. In addition, a comparison of the gene expression profiles between each Cd treatment group and the control group suggested that differential expressional genes (DEGs) mainly enriched in enzyme activity, metabolism, oxidative stress, regeneration and apoptosis pathways. 8 DEGs from these pathways had been selected randomly to confirm the data of RNA-seq. Among these DEGs, six genes (metallothionein-2, phytochelatin synthase 1a, CuZn superoxide dismutase, sex determining region Y-box 2, sex determining region Y-box 4b, TP53-regulated inhibitor of apoptosis 1-like) up-regulated and 2 genes (beta-1,4-endoglucanase, apoptosis-stimulating of p53 protein 2-like) down-regulated in response to Cd exposure. The alteration of them indicated that earthworms could reduce the toxicity and bioavailability of Cd in polluted soil ecosystems through different pathways. This work lays an important foundation for linking earthworm transcriptional level with the ecological risk of Cd in soil ecosystem.


Assuntos
Cádmio/toxicidade , Oligoquetos/fisiologia , Poluentes do Solo/toxicidade , Aminoaciltransferases , Animais , Disponibilidade Biológica , Cádmio/análise , Ecossistema , Perfilação da Expressão Gênica , Metalotioneína/genética , Metalotioneína/metabolismo , Oligoquetos/efeitos dos fármacos , Oligoquetos/genética , Estresse Oxidativo/efeitos dos fármacos , Solo , Poluentes do Solo/análise , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
2.
J Med Food ; 22(10): 1058-1066, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31560611

RESUMO

Previous studies have proven that polysaccharide obtained from the seeds of Plantago asiatica L. (PLCP) could induce maturation of murine dendritic cells, promote defecation, and possess antioxidant activity in vitro. However, the effect of PLCP on lipopolysaccharide (LPS)-induced liver injury in mice has been rarely reported. In this study, we investigated the anti-inflammatory effect of PLCP on LPS-induced liver injury. Mice were pretreated orally with different dose of PLCP for 3 weeks. On day 22, they were injected intraperitoneally with LPS and sacrificed 12 h later. The results showed that PLCP inhibited the excessive production of tumor necrosis factor-α, interleukin (IL)-6, IL-10, IL-2, and IL-1ß in mouse serum and liver. PLCP also improved glutathione peroxidase and total antioxidant capacity activities in mouse liver. In addition, PLCP inhibited nitric oxide, inducible nitric oxide synthase, and cyclooxygenase-2 expression, and increased metallothionein production in mouse liver. Consequently, PLCP may possess protective effects on inflammatory associated liver injury.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Plantago/química , Polissacarídeos/farmacologia , Sementes/química , Animais , Ciclo-Oxigenase 2/metabolismo , Interleucinas/sangue , Lipopolissacarídeos , Metalotioneína/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Compostos Fitoquímicos/farmacologia , Distribuição Aleatória , Fator de Necrose Tumoral alfa/sangue
3.
J Agric Food Chem ; 67(41): 11373-11379, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31539240

RESUMO

Cadmium bioremediation with metal-binding proteins is primarily conducted using metallothioneins (MTs). However, in the present study, we investigated a non-MT cadmium-binding protein from Lentinula edodes (LECBP) as a remediation tool for cadmium biosorption in Escherichia coli. The results indicated that the expression of LECBP significantly enhanced the cadmium biosorption capacity of transgenic E. coli. The secondary structure and conformation of LECBP were changed after binding with cadmium as evidenced by circular dichroism and fluorescence spectroscopy. The results of Fourier transform infrared spectroscopy indicated that carboxyl oxygen and amino nitrogen atoms were involved in the interaction between LECBP and cadmium. The results further demonstrated that glutamic acid and histidine residues are the potential binding sites. Our results have thus provided new insights into cadmium bioremediation in an aquatic environment.


Assuntos
Cádmio/metabolismo , Metalotioneína/metabolismo , Proteínas de Plantas/metabolismo , Cogumelos Shiitake/genética , Sítios de Ligação , Biodegradação Ambiental , Cádmio/química , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Metalotioneína/química , Metalotioneína/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Cogumelos Shiitake/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Sci Total Environ ; 692: 1029-1036, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539935

RESUMO

Marine mussels have been used widely as biomonitors of coastal contamination in many countries. Due to the restrain of their geographical distributions, it is often necessary to employ more than one species of mussels within a large-scale biomonitoring program. In the present study, we compared the differences of copper (Cu) bioaccumulation in three species of marine mussels (green mussel Perna viridis, blue mussel Mytilus edulis, and hard-shelled mussel Mytilus coruscus) widely distributing along the Chinese coastal waters, under identical Cu exposure conditions. Over the 21-days exposure to dissolved Cu, the green mussels and blue mussels exhibited comparable newly accumulated Cu concentrations, possibly due to their comparable Cu uptake rate constant ku (blue mussel, 0.573 L g-1 d-1; green mussel, 0.530 L g-1 d-1) and efflux rate constant ke (blue mussel, 0.053 d-1; green mussel, 0.065 d-1). In contrast, there was no net Cu accumulation in the hard-shell mussels, which may be accounted by the lower ku (0.394 L g-1 d-1) but higher ke (0.081 d-1) than the other two mussel species. Further subcellular distribution analyses showed that the cellular debris and metallothionein-like protein (MTLP) fraction were the key binding sites for Cu, and the MTLP fraction may act as a main contributor in Cu regulation and elimination in the blue mussels and hard-shell mussels. There was no strong evidence that the subcellular partitioning and dynamics of Cu in the mussels were responsible for the difference underlying the Cu accumulation in the three species of mussels. Our comparative study thereby suggested that it may be feasible to directly compare the Cu bioavailability in the green mussels and blue mussels based on their Cu biomonitoring data. Cu biomonitoring data from the hard-shell mussels may underestimate the actual Cu bioavailability of the sampling area given its much stronger regulation of Cu bioaccumulation as compared to the other two mussel species.


Assuntos
Bivalves/metabolismo , Cobre/metabolismo , Monitoramento Ambiental , Poluentes Químicos da Água/metabolismo , Animais , Cobre/análise , Metalotioneína/metabolismo , Poluentes Químicos da Água/análise
5.
Aquat Toxicol ; 215: 105284, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31479758

RESUMO

Metal pollution in the environment is a serious threat to the biological sustainability of coastal ecosystems. However, our current understanding of the biological effects of metals in these ecosystems is limited. Herein, we investigated the responses of the sea slug Onchidium reevesii to persistent sublethal Cd environmental stress. Dynamic expression was analyzed using various biomarkers. The full-length cDNA of O. reevesii metallothionein (MT) was cloned and consists of 1639 nucleotides encoding a 65 amino acid polypeptide. Phylogenetic analysis showed that Or-MT has conserved Cys residues typical of MTs, including a typical Cys-X-Cys motif, implying that it can function the same as the MT of other shellfish. Expression of Or-MT in response to Cd varied in different tissues, and was highest in gastropod tissues. Thus, regiotemporal expression of MT may be useful for assessing pollution in coastal areas. Cellular immunity (in the hemolymph) and enzyme activity (in the hepatopancreas) were investigated along with hemocyte viability, hemocyte phagocytosis, and superoxide dismutase (SOD) and aspartate aminotransferase (AST) activities. Hemocyte viability was elevated under continuous Cd exposure but hemocyte phagocytosis was decreased. SOD and AST activities in the hepatopancreas fluctuated considerably, and SOD activity was more sensitive. SOD activity was lowest at 4 h and highest at 12 h, while AST activity peaked at 2 h and was lowest at 48 h. Thus, changes in enzyme activity may reveal adaptation to stress. Furthermore, the response patterns of certain enzymes, cellular immunity, and MT expression in O. reevesii could serve as biomarkers of Cd pollution in aquatic environments.


Assuntos
Aspartato Aminotransferases/metabolismo , Biomarcadores/metabolismo , Cádmio/toxicidade , Gastrópodes/metabolismo , Hemócitos/metabolismo , Metalotioneína/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Sobrevivência Celular/efeitos dos fármacos , Exposição Ambiental , Gastrópodes/química , Gastrópodes/efeitos dos fármacos , Gastrópodes/genética , Hemócitos/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Filogenia , Homologia de Sequência de Aminoácidos , Poluentes Químicos da Água/toxicidade
6.
Environ Monit Assess ; 191(9): 555, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31401704

RESUMO

This work aims to diagnose the state of the northeastern coasts of Tunisia using P. articulatus species. Biological parameters, protein and metallothionein content, enzymatic activities, and metallic concentration were assessed at four stations during four seasons and analyzed by multiple regressions. The comparison of biological ratios showed minima at Sidi Daoued and maxima at Korbous where metallothioneins were maximal. The catalytic activity was low during summer and higher during cold periods contrary to acetylcholinesterase activity. Concerning glutathione S-transferase, its activity was important at Kelibia in autumn and at La Goulette and Sidi Daoued in warm seasons. The metallic concentrations were low at Korbous and maximal at Kelibia and Sidi Daoued stations. Kelibia seems to be the most polluted site followed by Sidi Daoued and La Goulette (industries, urbanization and fishing ports). The pollution seems to be reduced at Korbous station having more suitable conditions for the proliferation of monodonts.


Assuntos
Monitoramento Ambiental , Gastrópodes/fisiologia , Animais , Biomarcadores/metabolismo , Poluentes Ambientais , Poluição Ambiental/análise , Gastrópodes/metabolismo , Glutationa Transferase/metabolismo , Metalotioneína/metabolismo , Estações do Ano , Tunísia
7.
Sci Total Environ ; 694: 133470, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31398648

RESUMO

The complexity of seasonally and spatially variable environments, coupled with complex biological interactions, makes it difficult to pinpoint biological responses to specific environmental stressors, including chemical pollution. To disentangle causative factors and reveal biomarker responses, we applied biomarker-based multivariate approaches to 15 native populations of Mediterranean mussel Mytilus galloprovincialis in spring and autumn. In addition, we used a subset of these populations in transplant experiments between clean and polluted environments in nature and in lab mesocosms. The extent of biomarker responses in native populations is affected by season, and significantly lower variability across seasons was observed among mussels from clean than from polluted sites. Results of paired block designed transplant experiment demonstrated both regional and pollution effect, with mussels uniformly exhibiting higher responses on more impacted sites in each of the Adriatic regions. Biomarker status of mussels varied among Adriatic regions in dependence on the set of environmental variables, and between clean and polluted sites in dependence on measured concentrations of metals in mussels' tissue. Results of the mesocosm experiment revealed distinctive biomarker responses of two populations of different origin when exposed to common conditions. Multivariate description of biomarker activity and application of specific experiments allowed us to link environmental condition, exposure to pollution and seasonality to mussels' biomarker responses.


Assuntos
Monitoramento Ambiental , Mytilus/fisiologia , Animais , Biomarcadores/metabolismo , Metalotioneína/metabolismo , Estações do Ano , Poluentes Químicos da Água/análise
8.
Int J Mol Sci ; 20(16)2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31394742

RESUMO

Colorectal cancer (CRC) is a heterogeneous disease resulting from the combined influence of many genetic factors. This complexity has caused the molecular characterization of CRC to remain uncharacterized, with a lack of clear gene markers associated with CRC and the prognosis of this disease. Thus, highly sensitive tumor markers for the detection of CRC are the most essential determinants of survival. In this study, we examined the simultaneous downregulation of the mRNA levels of six metallothionein (MT) genes in CRC cell lines and public CRC datasets for the first time. In addition, we detected downregulation of these six MT mRNAs' levels in 30 pairs of tumor (T) and adjacent non-tumor (N) CRC specimens. In order to understand the potential prognostic relevance of these six MT genes and CRC, we presented a four-gene signature to evaluate the prognosis of CRC patients. Further discovery suggested that the four-gene signature (MT1F, MT1G, MT1L, and MT1X) predicted survival better than any combination of two-, three-, four-, five-, or six-gene models. In conclusion, this study is the first to report that simultaneous downregulation of six MT mRNAs' levels in CRC patients, and their aberrant expression together, accurately predicted CRC patients' outcomes.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Perfilação da Expressão Gênica , Metalotioneína/genética , Transcriptoma , Biomarcadores Tumorais , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Metalotioneína/metabolismo , Prognóstico , RNA Mensageiro/genética
9.
Environ Toxicol ; 34(12): 1303-1312, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31407482

RESUMO

Barium (Ba) is one of the environmental pollutant metals that incite deleterious effects on human health. The present study investigated the effects of exposure to different doses of barium chloride (BaCl2 ) on heart and lung of Wistar rats. Rats were exposed to BaCl2 at 150, 300, and 600 mg/L for seven consecutive days. Results indicated that exposure to Ba caused heart and lung damage evidenced by significant increase in plasma lactate dehydrogenase and creatine kinase activities, total cholesterol, triglyceride, and low-density lipoprotein-cholesterol levels, while high-density lipoprotein-cholesterol level decreased when compared with control. Moreover, BaCl2 significantly decreased superoxide dismutase, catalase, and acetylcholinesterase activities as well as glutathione level in heart and lung of the treated rats. Furthermore, the dose-dependent increase in cardiac and lung lipid peroxidation, advanced oxidative protein product and nitric oxide levels were accompanied by marked increase in metallothionein in the BaCl2 -treated rats. Administration of BaCl2 altered hematological parameters and significantly increased concentrations of interleukin-6 in the treated rats. Histology analysis showed significant alteration in the heart and lung tissues of Ba-treated rats. In conclusion, BaCl2 -induced heart and lung damages via disruption of antioxidant defense systems, and activation of inflammatory mediators and alteration in hematological parameters in rats.


Assuntos
Compostos de Bário/toxicidade , Cloretos/toxicidade , Poluentes Ambientais/toxicidade , Coração/efeitos dos fármacos , Lesão Pulmonar/patologia , Acetilcolinesterase/metabolismo , Animais , Antioxidantes/metabolismo , Creatina Quinase/sangue , Proteínas Ligadas por GPI/metabolismo , Glutationa/metabolismo , Interleucina-6/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Lesão Pulmonar/induzido quimicamente , Masculino , Metalotioneína/metabolismo , Miocárdio/metabolismo , Miocárdio/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo
10.
Mar Pollut Bull ; 146: 263-273, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426156

RESUMO

Metals are subject to internal subcellular compartmentalization, altering their bioavailability. Thus, subcellular metal assessments are crucial in biomonitoring efforts. Metal distribution in three subcellular fractions (insoluble - ISF, thermolabile - TLF and thermostable - TSF) were determined by ICP-MS in Steno bredanensis specimens from Southeastern Brazil. Associations between metals, metallothionein (MT) and reduced glutathione (GSH) were also investigated. Differential metal-detoxification mechanisms were observed. MT detoxification was mostly noted for As, Cd, and Pb, while Cu, Cr, Hg, Ni, Se and Ti displayed lower MT-associations. Fe, Zn and Se, on the other hand, were poorly associated to MT, and mostly present in the ISF, indicating low bioavailability. This is the first report on subcellular Sn and Ti distribution in cetaceans and the first in this species in Brazil. Potential protective roles of essential metals against toxic elements are postulated. This study indicates that important biochemical detoxification information is obtained through subcellular fraction analyses in marine mammals.


Assuntos
Golfinhos/metabolismo , Monitoramento Ambiental/métodos , Metalotioneína/metabolismo , Metais/metabolismo , Frações Subcelulares/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Brasil , Glutationa/metabolismo , Inativação Metabólica , Metais Pesados/análise , Estanho/metabolismo , Titânio/metabolismo
11.
Environ Sci Pollut Res Int ; 26(28): 28763-28774, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31376126

RESUMO

The genetic basis and biochemical aspects of heavy metal endurance abilities have been precisely studied in planktonic bacteria; however, in nature, bacteria mostly grows as surface-attached communities called biofilms. A hallmark trait of biofilm is increased resistance to heavy metals compared with the resistance of planktonic bacteria. A proposed mechanism that contributes to this increased resistance is the enhanced expression of metal-resistant genes. bmtA gene coding for metallothionein protein is one such metal-resistant gene found in many bacterial spp. In the present study, lead (Pb) remediation potential of a biofilm-forming marine bacterium Pseudomonas aeruginosa N6P6 was explored. Biofilm-forming marine bacterium P. aeruginosa N6P6 possess bmtA gene and shows resistance towards many heavy metals, i.e., Pb, Cd, Hg, Cr, and Zn. The expression of metallothionein encoding gene bmtA is significantly high in 48-h-old biofilm culture (11. 4 fold) followed by 24-h-old biofilm culture of P. aeruginosa N6P6 (4.7 fold) (P < 0.05). However, in the case of planktonically grown culture of P. aeruginosa N6P6, the highest expression of bmtA gene was observed in 24-h-old culture. The expression of bmtA also increased significantly with increase in Pb concentration up to 800 ppm. CSLM analysis indicated significant reduction in the raw integrated density of biofilm-associated lipids and polysaccharides (PS) of P. aeruginosa N6P6 biofilm grown in Pb (sub-lethal concentration)-amended medium (P < 0.05), whereas no significant reduction was observed in the raw integrated density of EPS-associated protein. The role of bmtA gene as Pb(II)-resistant determinant was characterized by overexpressing the bmtA gene derived from P. aeruginosa N6P6 in Escherichia coli BL21(DE3). ESI-MS and SDS-PAGE analyses validated the presence of 11.5-kDa MT protein isolated from Pb(II)-induced recombinant E. coli BL21(DE3) harboring bmtA gene.


Assuntos
Biodegradação Ambiental , Chumbo/metabolismo , Metalotioneína/metabolismo , Pseudomonas aeruginosa/fisiologia , Biofilmes , Escherichia coli/metabolismo , Metais Pesados , Plâncton , Polissacarídeos Bacterianos , Pseudomonas aeruginosa/metabolismo
12.
J Basic Microbiol ; 59(9): 879-889, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31339587

RESUMO

Metallothionein (MT) is a low-molecular-weight protein with a high metal binding capacity and plays a key role in organism adaptation to heavy metals. In this study, a metallothionein gene was successfully cloned and sequenced from Antarctic sea-ice yeast Rhodotorula mucilaginosa AN5. Nucleotide sequencing and analysis revealed that the gene had four exons interrupted by three introns. MTs complementary DNA (named as RmMT) had an open reading frame of 321 bp encoding a 106 amino acid protein with a predicted molecular weight of 10.3 kDa and pI of 8.49. The number of amino acids and distribution of cysteine residues indicated that RmMT was a novel family of fungal MTs. Quantitative real-time polymerase chain reaction analysis showed that RmMT expression was elevated under copper-induced stress. The RmMT gene was transferred into E. coli and the RmMT expressing bacteria showed improved tolerance to copper ion and increased accumulation of heavy metals, such as Cu2+ , Pb2+ , Zn2+ , Cd2+ , and Ag+ . Moreover, in vitro studies, purified recombinant RmMT demonstrated that it could be used as a good scavenger of superoxide anion, hydroxyl, and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals. In summary, these results demonstrate that RmMT plays a key role in the tolerance and bioaccumulation of heavy metals.


Assuntos
Camada de Gelo/microbiologia , Metalotioneína/genética , Metalotioneína/metabolismo , Metais Pesados/metabolismo , Rhodotorula/genética , Adaptação Fisiológica/genética , Regiões Antárticas , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Sequência de Bases , Clonagem Molecular , Cobre/metabolismo , Escherichia coli/genética , Escherichia coli/fisiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Expressão Gênica , Metalotioneína/isolamento & purificação , Fases de Leitura Aberta , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Rhodotorula/fisiologia
13.
Chemosphere ; 236: 124349, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31326753

RESUMO

Heavy metal Pb is a common toxic pollutant present in our environment adversely affecting health of the living organisms. Recent studies suggest positive correlation between heavy metal exposure and immune dysfunction and present work utilizes Drosophila to address this issue in relation to Pb exposure. In-vivo Pb toxicity was established by dietary intake where essential parameters like development and life span were found to be hampered and augmented upon metallothionein B (mtnB) downregulation hinting towards potential role of mtnB in Pb detoxification. Further response of Drosophila to B. subtilis bacterial infection was monitored by carrying out oral infections. Pb fed flies showed increased susceptibility to infection as compared to their controls. Since Drosophila hemocytes play dual role as immune cells, we checked for the total hemocyte count and found significant decrease in hemocyte numbers in Pb fed larvae. Both crystal cells and plasmatocytes, the two major hemocytes in third instar larval hemolymph were reduced. However we did not find any visible morphological changes in Giemsa stained hemocytes. Crystal cells are crucial for synthesis and release of phenoloxidase (PO), an enzyme required for melanin clot synthesis and deposition. PO activity assessed from total hemolymph protein isolates was found to be substantially decreased in Pb raised animals. Results were also confirmed by spot test and native gel activity assay of PO. Overall our results suggest immunotoxic effect of Pb through decrease in hemocyte count including crystal cell which in turn leads to decreased PO activity and increased susceptibility to B. subtilis.


Assuntos
Drosophila melanogaster/imunologia , Poluentes Ambientais/toxicidade , Infecções por Bactérias Gram-Positivas/induzido quimicamente , Hemócitos/citologia , Chumbo/toxicidade , Animais , Bacillus subtilis , Drosophila melanogaster/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Hemócitos/metabolismo , Hemolinfa/metabolismo , Larva/efeitos dos fármacos , Metalotioneína/metabolismo , Monofenol Mono-Oxigenase/metabolismo
14.
Aquat Toxicol ; 214: 105257, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31336221

RESUMO

The interactions between nanoparticles (NPs) and metals in aquatic environments may modify the bioavailability and toxicity of metals to organisms. In this study, we investigated the effects of titanium dioxide NPs (n-TiO2) on the bioconcentration, depuration, and neurotoxic effects of lead (Pb) in zebrafish larvae. Transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy showed that Pb2+ was adsorbed by n-TiO2 to form NP-Pb complexes in suspension, and these complexes were observed in larval tissues. The bioconcentration of Pb in larvae along with the depuration rates of Pb were higher in the presence of n-TiO2 compared to when n-TiO2 was absent. Exposure to Pb alone induced the expression of the biomarker metallothionein, downregulated neurodevelopment-related genes, and reduced swimming activity of larvae. However, the addition of n-TiO2 to the exposure solution alleviated these effects. The results suggest that n-TiO2 can act as a carrier of Pb to increase its bioconcentration; however, the formation of NP-Pb complexes likely reduces the amount of free Pb2+, thereby reducing toxicity to larvae.


Assuntos
Chumbo/toxicidade , Nanopartículas/toxicidade , Titânio/toxicidade , Peixe-Zebra/metabolismo , Adsorção , Animais , Comportamento Animal/efeitos dos fármacos , Disponibilidade Biológica , Larva/efeitos dos fármacos , Larva/genética , Larva/ultraestrutura , Locomoção/efeitos dos fármacos , Metalotioneína/metabolismo , Nanopartículas/ultraestrutura , Suspensões , Transcrição Genética/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/genética
15.
Chemosphere ; 235: 926-934, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31299706

RESUMO

We characterized the metal tolerance of recombinant strains harboring metallothionein from the freshwater crab Sinopotamon henanense (ShMT) in vivo and metal binding properties of ShMT purified in vitro. The recombinant strains harboring ShMT were exposed to 0.1 mM Cd2+, 0.3 mM Cu2+, 0.5 mM Pb2+, and 0.8 mM Zn2+. The growth curves and spot assays of recombinant strains and the contents of heavy metal ions were analysed in the media supplemented with above metal ions provided to recombinant E. coli synthesis. The structural characteristics of the Cd-, Cu-, Pb-, and Zn-ShMT were determined through ultraviolet spectroscopy (UV-vis), circular dichroism (CD), and isothermal titration calorimetry (ITC). The in vivo results showed that, compared to control strains, recombinant strains tolerated Cd2+, Cu2+, Pb2+, and Zn2+. Furthermore, the contents of Cd2+ and Pb2+ in media decreased substantially. In vitro and the Cd-ShMT had a higher degree of folding compactness in solution. 5,5'-Dithiobis-(2-nitrobenzoic) acid (DTNB) reaction and ITC results demonstrated that ShMT yielded Cd6-, Cu7-, and Pb6-ShMT. The binding stability order was Cu-ShMT > Cd-ShMT > Pb-ShMT > Zn-ShMT. Overall, ShMT is a canonical crustacean MT and is defined as a Cd-specific MT isoform that functions mainly in a detoxifying Cd2+ and Pb2+ and in regulating Zn2+ homeostasis in S. henanense. This research on the metal binding properties of ShMT provides a better understanding of the physiological function of ShMT reducing heavy metal bioavailability and by regulating essential trace metals.


Assuntos
Braquiúros/metabolismo , Metalotioneína/metabolismo , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Ácido Ditionitrobenzoico/química , Escherichia coli/genética , Escherichia coli/metabolismo , Água Doce , Regulação da Expressão Gênica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Alimentos Marinhos
16.
Chemosphere ; 236: 124224, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31306976

RESUMO

In this study, we investigated the metal handling capacity of non-tolerant and tolerant populations of Palaemon argentinus to cadmium (Cd), through evaluating of the main mechanisms of metal detoxification, metallothioneins (MT) and metal-rich granules (MRG), to probe that the presence of MRG in the second population is responsible of that condition. The tolerant population were exposed to 3.06 and 12.26 µg Cd·L-1, while the non-tolerant shrimp were exposed to 3.06 µg Cd·L-1. Each experiment involved the exposure during 3, 7, 10 and 15 days and, the depuration during 7, 14, 21 and 28 days, for which shrimp were transferred to clean water. The range values of MT concentrations for non-tolerant shrimp were: 12.24-23.91 µg g (w.w), while for tolerant shrimp were: 8.75-16.85 µg g (w.w); MRG levels were: 0.12-0.57 µg g (w.w) and 0.3-2.1 µg g (w.w), respectively. The results showed different strategies for Cd detoxification: the induction of MT was the main pathway in the non-tolerant population, while the formation of Cd-MRG was the main mechanism for tolerant shrimp. These differences could be related to the environmental history and the health status of each populations.


Assuntos
Cádmio/química , Poluentes Ambientais/química , Poluição Ambiental/efeitos adversos , Metalotioneína/metabolismo , Palaemonidae/química , Poluentes Químicos da Água/química , Animais
17.
Aquat Toxicol ; 214: 105255, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31325645

RESUMO

The heavy metal cadmium readily accumulates in organisms, causing damage. In this study, juvenile marine shrimp Marsupenaeus japonicus were exposed to cadmium (Cd2+; 5, 50 and 500 µg L-1). Cd accumulation and antioxidant-related indices were determined, and damage to biomolecules was assessed, after 24, 48 and 96 h. Cd bioaccumulation in M. japonicus increased with exposure time and concentration, which reached the highest value at 96 h. The data showed that 5, 50 and 500 µg L-1 Cd increased glutathione (GSH) content and the activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) in a Cd-dose-dependent manner, but 5 and 50 µg L-1 Cd had no effect on caspase-3 activity. The expression levels of SOD, GST, heat shock protein 70 (HSP70), metallothionein (MT), p53 and caspase-3 genes were rapidly increased after 50 and 500 µg L-1 Cd exposure, and remained at a significantly higher level than in the control after 96 h of exposure. After exposure to 5, 50 and 500 µg L-1 Cd, F-value (the ratio between double-stranded DNA and total DNA) remained high at 24 h, however, as the exposure time increased, the F-value decreased in a dose-dependent manner. An increase in malondialdehyde content was also observed following exposure to 50 and 500 µg L-1 Cd. Our data suggest that Cd induces oxidative stress, molecular damage and apoptosis in juvenile M. japonicus in a concentration- and time-dependent manner.


Assuntos
Cádmio/toxicidade , Crustáceos/fisiologia , Exposição Ambiental , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Caspase 3/genética , Caspase 3/metabolismo , Crustáceos/efeitos dos fármacos , Crustáceos/enzimologia , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Poluentes Químicos da Água/toxicidade
18.
Chemosphere ; 233: 579-589, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31195263

RESUMO

Complex interactions have been established between nanoparticles (NPs) and heavy metals in real environments. Herein we used zebrafish embryos to investigate the influence of titanium dioxide NPs (n-TiO2) on the uptake, bioconcentration, and depuration, and toxicity of Pb. The formation of n-TiO2-Pb complexes was confirmed in an exposure suspension. An increase in Pb bioconcentration was observed in zebrafish embryos upon co-exposure to n-TiO2 and Pb; moreover, n-TiO2-Pb complexes could be found in the embryos, indicating the bioavailability of NPs. However, there was no difference in the depuration rates of Pb in the presence of n-TiO2. Metallothionein (MT) content was significantly increased upon exposure to Pb alone, and the content significantly increased even further upon co-exposure. A downregulation in the expression levels of the neurodevelopment-related genes gfap, syn2α, and elavl3 was observed in the embryos, and we also noted a reduction in the swimming speed of and the total distance traveled by the larvae. To summarize, our results indicate that n-TiO2 can act as an effective carrier of Pb to enhance its uptake, bioavailability, and toxicity in zebrafish embryos.


Assuntos
Embrião não Mamífero/fisiologia , Chumbo/toxicidade , Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Animais , Disponibilidade Biológica , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Larva/metabolismo , Metalotioneína/metabolismo , Nanopartículas/toxicidade , Peixe-Zebra/metabolismo
19.
Ecotoxicol Environ Saf ; 181: 301-307, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202929

RESUMO

Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich, metal-binding proteins, which play important roles in metal homeostasis and heavy metal detoxification. In our previous study, a novel full length MT cDNA was successfully cloned from the freshwater crab (Sinopotamon henanense). In the present study, tandem repeats of two and three copies of the crab MT gene were integrated by overlap extension PCR (SOE-PCR) and expressed in Escherichia coli. The SUMO fusion expression system was adopted to increase the stability and solubility of the recombinant MT proteins. The recombinant proteins were purified and their metal-binding abilities were further analyzed by the ultraviolet absorption spectral scan. Furthermore, the metal tolerance and bioaccumulation of E. coli cells expressing oligomeric MTs were determined. Results showed that the recombinant plasmids pET28a-SUMO-2MT and pET28a-SUMO-3MT were successfully constructed. SDS-PAGE analysis showed that the SUMO-2MT and SUMO-3MT were expressed mainly in the soluble forms. Oligomeric MTs expression significantly enhanced Cu, Cd or Zn tolerance and accumulation in E. coli in the order: SUMO-3MT˃SUMO-2MT˃SUMO-MT˃control. Cells harboring pET28a-SUMO -3MT exhibited the highest Cu, Cd or Zn bioaccumulation at 5.8-fold, 3.1-fold or 6.7-fold higher than that of the control cells. Our research could lay a foundation for large-scale preparation of MTs and provide a scientific basis for bioremediation of heavy metal pollution by oligomeric MTs.


Assuntos
Escherichia coli/genética , Metalotioneína/genética , Metais Pesados/metabolismo , Animais , Braquiúros/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Metalotioneína/metabolismo , Metais Pesados/toxicidade , Proteínas Recombinantes de Fusão/metabolismo
20.
Sci Total Environ ; 685: 795-805, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31238283

RESUMO

This study investigates the combined effects of increased temperatures and copper on the early live stages of the Mediterranean mussel Mytilus galloprovincialis and the blue mussel Mytilus edulis as well as their hybrids. For this purpose, developmental abnormalities was measured after 48 h of exposure as well as a battery of oxidative stress markers such as, antioxidant enzyme activities, lipid peroxidation measured as malondialdehyde accumulation (MDA) and metallothionein contents (MT) and related gene expression pattern. Embryotoxicity and metal accumulation in tissues of mussel larvae exposed to a sublethal concentration of copper (10 µg/L) along with a slight temperature increase from 18 °C to22 °C were significantly increased after 48 h of exposure. Co-exposure to Cu and elevated temperatures significantly increased the antioxidant enzyme activities termed as, glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD) and being maintained at 22 °C only in pure M. galloprovincialis (PG) larvae and female galloprovincialis x male edulis hybrid larvae (HFG). A significant decrease in mRNA abundance of cat, sod, gst gene transcription levels was showed in the same species. Furthermore, metallothionein accumulation increased significantly in PG D-larvae exposed to copper at 22 °C. The same pattern was observed in term of gene expression of MTs cognates (mt-10 and mt-20). Significant increase of MDA levels in pure M. edulis (PE) larvae and their female M. edulis x male M. galloprovincialis hybrid larvae (HFE) combined with a low MTs content were observed. Overall, this study provides clues about the relatively higher resistance and resilience of M. galloprovincialis species compared to M. edulis species under environmental pollution and future climate change scenarios.


Assuntos
Cobre/toxicidade , Mytilus/fisiologia , Estresse Fisiológico/fisiologia , Temperatura Ambiente , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Catalase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismo
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