Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.141
Filtrar
1.
J UOEH ; 42(3): 275-279, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879192

RESUMO

The Japan Environment Health and Children's Study (JECS) is an ongoing cohort study designed to evaluate the impact of various environmental factors on children's health. In this study, more than 100,000 pregnant women were recruited in 15 regional centers throughout Japan. Within the University of Occupational and Environmental Health, the departments of Pediatrics, Obstetrics and Gynecology, Environmental Health, and the School of Health Sciences collaborate with the JECS University of Occupational and Environmental Health Subunit Center in advancing research in this study. Several original articles based on JECS and written by our unit members were published in recent years. The aim of this review is to summarize these studies by JECS and University of Occupational and Environmental Health Subunit Center based on the data from JECS. We introduce research articles covering the following categories; environmental health, occupational health, and maternal and child health. Studies found associations between concentrations of metals and maternal health, such as premature birth, placenta previa and placenta accrete, associations between metals and IgE, dietary differences among occupational groups, associations between work-related factors and dietary behaviors, associations between job changes and pregnancy/delivery, mental and physical stress among pregnant women and influence on work, associations between sleep and gestational diabetes, and associations between an ability to push up in the prone position and infant development. This review may promote the development of new research, such as collaborative research projects, including clinical and social medicine, epidemiological studies and laboratory investigations.


Assuntos
Saúde da Criança , Saúde Ambiental , Saúde do Trabalhador , Universidades , Estudos de Coortes , Diabetes Gestacional , Comportamento Alimentar , Feminino , Humanos , Imunoglobulina E , Japão , Metais/metabolismo , Placenta Acreta , Placenta Prévia , Gravidez , Nascimento Prematuro , Trabalho
2.
Nat Commun ; 11(1): 4557, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917908

RESUMO

Why metalloenzymes often show dramatic changes in their catalytic activity when subjected to chemically similar but non-native metal substitutions is a long-standing puzzle. Here, we report on the catalytic roles of metal ions in a model metalloenzyme system, human carbonic anhydrase II (CA II). Through a comparative study on the intermediate states of the zinc-bound native CA II and non-native metal-substituted CA IIs, we demonstrate that the characteristic metal ion coordination geometries (tetrahedral for Zn2+, tetrahedral to octahedral conversion for Co2+, octahedral for Ni2+, and trigonal bipyramidal for Cu2+) directly modulate the catalytic efficacy. In addition, we reveal that the metal ions have a long-range (~10 Å) electrostatic effect on restructuring water network in the active site. Our study provides evidence that the metal ions in metalloenzymes have a crucial impact on the catalytic mechanism beyond their primary chemical properties.


Assuntos
Anidrases Carbônicas/química , Íons/química , Metaloproteínas/química , Metais/química , Sítios de Ligação , Anidrase Carbônica II/química , Anidrase Carbônica II/metabolismo , Anidrases Carbônicas/metabolismo , Catálise , Domínio Catalítico , Cobalto/química , Cobre/química , Cristalografia por Raios X , Humanos , Íons/metabolismo , Cinética , Metaloproteínas/metabolismo , Metais/metabolismo , Modelos Moleculares , Níquel/química , Conformação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato , Zinco/química
3.
Nat Commun ; 11(1): 3969, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32769976

RESUMO

Mevalonate diphosphate decarboxylases (MDDs) catalyze the ATP-dependent-Mg2+-decarboxylation of mevalonate-5-diphosphate (MVAPP) to produce isopentenyl diphosphate (IPP), which is essential in both eukaryotes and prokaryotes for polyisoprenoid synthesis. The substrates, MVAPP and ATP, have been shown to bind sequentially to MDD. Here we report crystals in which the enzyme remains active, allowing the visualization of conformational changes in Enterococcus faecalis MDD that describe sequential steps in an induced fit enzymatic reaction. Initial binding of MVAPP modulates the ATP binding pocket with a large loop movement. Upon ATP binding, a phosphate binding loop bends over the active site to recognize ATP and bring the molecules to their catalytically favored configuration. Positioned substrates then can chelate two Mg2+ ions for the two steps of the reaction. Closure of the active site entrance brings a conserved lysine to trigger dissociative phosphoryl transfer of γ-phosphate from ATP to MVAPP, followed by the production of IPP.


Assuntos
Carboxiliases/metabolismo , Enterococcus faecalis/enzimologia , Sequência de Aminoácidos , Sítios de Ligação , Biocatálise , Carboxiliases/química , Sequência Conservada , Cristalografia por Raios X , Ligantes , Metais/metabolismo , Modelos Moleculares , Estrutura Secundária de Proteína , Especificidade por Substrato
4.
Chemosphere ; 260: 127553, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32653748

RESUMO

The impact of ionizing radiation on microorganisms such as microalgae is a topic of increasing importance for understanding the dynamics of aquatic ecosystems in response to environmental radiation, and for the development of efficient approaches for bioremediation of mining and nuclear power plants wastewaters. Currently, nothing is known about the effects of ionizing radiation on the microalgal cell wall, which represents the first line of defence against chemical and physical environmental stresses. Using various microscopy, spectroscopy and biochemical techniques we show that the unicellular alga Chlorella sorokiniana elicits a fast response to ionizing radiation. Within one day after irradiation with doses of 1-5 Gy, the fibrilar layer of the cell wall became thicker, the fraction of uronic acids was higher, and the capacity to remove the main reactive product of water radiolysis increased. In addition, the isolated cell wall fraction showed significant binding capacity for Cu2+, Mn2+, and Cr3+. The irradiation further increased the binding capacity for Cu2+, which appears to be mainly bound to glucosamine moieties within a chitosan-like polymer in the outer rigid layer of the wall. These results imply that the cell wall represents a dynamic structure that is involved in the protective response of microalgae to ionizing radiation. It appears that microalgae may exhibit a significant control of metal mobility in aquatic ecosystems via biosorption by the cell wall matrix.


Assuntos
Chlorella/metabolismo , Metais/metabolismo , Antioxidantes/metabolismo , Biodegradação Ambiental , Biomassa , Parede Celular/metabolismo , Chlorella/efeitos dos fármacos , Ecossistema , Microalgas/metabolismo , Radiação Ionizante , Águas Residuárias
5.
PLoS One ; 15(7): e0235508, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614917

RESUMO

This study examined the influence of bioaugmentation on metal concentrations (aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel and zinc) in anaerobically digested sewage sludge. To improve the digestion efficiency, bioaugmentation with a mixture of wild-living Archaea and Bacteria (MAB) from Yellowstone National Park, USA, was used. The total concentration of all metals was higher in the digestate than in the feedstock. During anaerobic digestion, the percent increase in the concentration of most of metals was slightly higher in the bioaugmented runs than in the un-augmented runs, but these differences were not statistically significant. However, the percent increase in cadmium and cobalt concentration was significantly higher in the bioaugmented runs than in the un-augmented runs. At MAB doses of 9 and 13% v/v, cadmium concentration in the digestate was 211 and 308% higher than in the feedstock, respectively, and cobalt concentration was 138 and 165%, respectively. Bioaugmentation increased over 4 times the percentage of Pseudomonas sp. in the biomass that are able to efficiently accumulate metals by both extracellular adsorption and intracellular uptake. Biogas production was not affected by the increased metal concentrations. In conclusion, bioaugmentation increased the concentration of metals in dry sludge, which means that it could potentially have negative effects on the environment.


Assuntos
Metais/metabolismo , Esgotos/química , Adsorção , Anaerobiose , Archaea/genética , Archaea/crescimento & desenvolvimento , Archaea/metabolismo , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Biomassa , Cádmio/análise , Cádmio/metabolismo , Cobalto/análise , Cobalto/metabolismo , Metais/química , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , Pseudomonas/metabolismo , Esgotos/microbiologia , Eliminação de Resíduos Líquidos
6.
Nat Commun ; 11(1): 2450, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415073

RESUMO

The exopolysaccharide galactosaminogalactan (GAG) is an important virulence factor of the fungal pathogen Aspergillus fumigatus. Deletion of a gene encoding a putative deacetylase, Agd3, leads to defects in GAG deacetylation, biofilm formation, and virulence. Here, we show that Agd3 deacetylates GAG in a metal-dependent manner, and is the founding member of carbohydrate esterase family CE18. The active site is formed by four catalytic motifs that are essential for activity. The structure of Agd3 includes an elongated substrate-binding cleft formed by a carbohydrate binding module (CBM) that is the founding member of CBM family 87. Agd3 homologues are encoded in previously unidentified putative bacterial exopolysaccharide biosynthetic operons and in other fungal genomes.


Assuntos
Amidoidrolases/química , Amidoidrolases/metabolismo , Aspergillus fumigatus/enzimologia , Aspergillus fumigatus/fisiologia , Biofilmes/crescimento & desenvolvimento , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Polissacarídeos/metabolismo , Acetilação , Sequência de Aminoácidos , Aspergillus fumigatus/genética , Domínio Catalítico , Sequência Conservada , Regulação Fúngica da Expressão Gênica , Glicosaminoglicanos/biossíntese , Metais/metabolismo , Domínios Proteicos , Homologia Estrutural de Proteína , Relação Estrutura-Atividade , Especificidade por Substrato , Fatores de Tempo
7.
Artigo em Inglês | MEDLINE | ID: mdl-32291614

RESUMO

The environmental exposure to As, Se, Hg, Pb, Cr and toxaphene was assessed for 11 freshwater fish species in irrigation channels, agricultural return flow drains, a drain collecting lagoon and sections of the Colorado River at the Mexicali valley in Baja California, México, during August 2015-April 2016. Arsenic (2.90 ng ml-1) and Se (1.41 ng ml-1) in water had the highest concentrations in the return flow drains (Hardy River and Xochimilco Lagoon, respectively). However, fish axial muscle tissue had the highest concentration of Se (8.3 µg g-1) and Hg (0.36 µg g-1) in Colorado River fresh water, while As (1.7 µg g-1) in Hardy River fish was highest. Selenium concentrations in all fishes and toxaphene in Cyprinus carpio and Ameiurus natalis are above the safe levels for human consumption (0.3 µg g-1 and 180 ng g-1 respectively). Toxaphene was detected in the fish axial tissue, having the highest concentrations in Poecilia latipinna (690 ng g-1) in the Colorado River. The low proportion of the 8-Cl toxaphene congeners in fish suggests degradation of this pollutant. Tilapia. sp. cf. zillii had the most genotoxic damage with 7.4 micronucleated erythrocytes per 10,000 erythrocytes in Xochimilco Lagoon and 2 in Hardy River. The genotoxicity in all the fish species studied was significantly correlated to the concentrations of As and Se in water.


Assuntos
Peixes/fisiologia , Metais/toxicidade , Toxafeno/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Monitoramento Ambiental , Metais/metabolismo , México , Rios , Toxafeno/metabolismo , Poluentes Químicos da Água/metabolismo
8.
Mar Pollut Bull ; 154: 111047, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32319892

RESUMO

We sought to determine mercury (Hg) and other trace metal concentrations in Adélie (Pygoscelis adeliae) and emperor penguin (Aptenodytes forsteri) breast feathers from the Ross Sea, Antarctica, and relate those concentrations to the trophic position and the habitats in which each of these species forage. Adélie penguin feathers from the southern Ross Sea colonies were higher in Hg than those sampled further north in the Ross Sea, potentially due to greater exposure to local sources, such as volcanism. Female Adélie penguins had lower feather total Hg concentrations than males. This may reflect female penguin's capacity to eliminate Hg through the egg development and laying process, or the larger and/or older prey items that male birds can consume, reflected by their higher trophic position. Emperor penguins have higher Hg concentrations than Adélie penguins which is also partially explained by Adélie penguins feeding at lower trophic levels than emperor penguins.


Assuntos
Poluentes Ambientais/metabolismo , Metais/metabolismo , Spheniscidae , Animais , Regiões Antárticas , Ecossistema , Plumas , Feminino , Masculino , Mercúrio
9.
Chemosphere ; 253: 126631, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32302917

RESUMO

We have previously demonstrated in a companion work that acclimation to 28 °C potentiated waterborne copper (Cu) toxic effects in Poecilia vivipara through oxidative stress-related processes. In the present study, we hypothesized that these results were related to kinetic metabolic adjustments in enzymes from aerobic and anaerobic pathways. To test this, P. vivipara was acclimated to two temperatures (22 °C or 28 °C) for three weeks and then exposed to Cu (control, 9 or 20 µg/L) for 96 h. The activity of enzymes from glycolysis (pyruvate kinase [PK] and lactate dehydrogenase [LDH]), Krebs cycle (citrate synthase [CS]) and the electron transport chain system (ETS) were assessed in gills, liver and muscle. Interactive effects were only seen for hepatic LDH activity, as both metal exposure and heat stress, combined or not, inhibited this enzyme, showing a suppression in anaerobic pathways. Conversely, a Cu main effect was present in the liver, expressed as an elevation in ETS activity, showing an enhancement in hepatic aerobic metabolism likely related with the very energy-demanding process of metal detoxification. Moreover, this study shows that P. vivipara has a remarkable ability to compensate heat stress in terms of energy metabolism, as we could not observe acclimation temperature effects for most of the cases. Nonetheless, a tissue-dependent effect of elevated temperature was observed, as we could observe an inhibition in muscular CS activity. Finally, it is concluded that kinetic adjustments in terms of the energy metabolism are not related with the temperature-dependent elevation of Cu toxicity in P. vivipara as we previously hypothesized.


Assuntos
Cobre/toxicidade , Metabolismo Energético/fisiologia , Poecilia/fisiologia , Temperatura , Poluentes Químicos da Água/toxicidade , Aclimatação/efeitos dos fármacos , Animais , Ciclo do Ácido Cítrico , Metabolismo Energético/efeitos dos fármacos , Fundulidae/metabolismo , Brânquias/metabolismo , Glicólise , L-Lactato Desidrogenase/metabolismo , Fígado/metabolismo , Metais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Poecilia/metabolismo , Piruvato Quinase/metabolismo
10.
Environ Monit Assess ; 192(5): 279, 2020 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-32279131

RESUMO

Correlation between metal concentrations in fish tissues and fish body size poses certain challenge when comparing concentration levels encountered at different locations or time periods by degrading performance of statistical tests due to variable age composition of fish sample pool. In order to overcome this, the concentrations of Hg, Cu, and Zn, measured in tissues of five fish species, were normalized to selected age group. Computed species-specific equations, based on empirically obtained exponential relationship, provided accurate estimates of the normalized concentrations under the conditions of substantial metal and fish age covariation. Obtained normalized and measured concentrations were then compared among sampling stations by means of commonly used analysis of variance (ANOVA) in combination with Tuckey's HSD test, where 11 out of 18 considered cases showed significant smoothing of the observed differences. The applied method worked well in the case of locally distributed coastal species populations where transformed data allowed clearer separation of spatial areas exhibiting different levels of pollution. At the same time, application of the method on pelagic fish species was less successful due to high mobility of specimens and mixed impact on the population originating from variable pollution levels at different areas of the entire migration region; therefore, attribution of a sample pool to a specific catchment area can cause a bias in assessment results.


Assuntos
Monitoramento Ambiental , Metais/metabolismo , Músculos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Cobre , Ecossistema , Peixes/metabolismo , Mercúrio , Zinco
11.
J Med Microbiol ; 69(6): 895-905, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32242794

RESUMO

Introduction. Pseudomonas aeruginosa grows in extracellular DNA (eDNA)-enriched biofilms and infection sites. eDNA is generally considered to be a structural biofilm polymer required for aggregation and biofilm maturation. In addition, eDNA can sequester divalent metal cations, acidify growth media and serve as a nutrient source.Aim. We wanted to determine the genome-wide influence on the transcriptome of planktonic P. aeruginosa PAO1 grown in the presence of eDNA.Methodology. RNA-seq analysis was performed to determine the genome-wide effects on gene expression of PAO1 grown with eDNA. Transcriptional lux fusions were used to confirm eDNA regulation and to validate phenotypes associated with growth in eDNA.Results. The transcriptome of eDNA-regulated genes included 89 induced and 76 repressed genes (FDR<0.05). A large number of eDNA-induced genes appear to be involved in utilizing DNA as a nutrient. Several eDNA-induced genes are also induced by acidic pH 5.5, and eDNA/acidic pH promoted an acid tolerance response in P. aeruginosa. The cyoABCDE terminal oxidase is induced by both eDNA and pH 5.5, and contributed to the acid tolerance phenotype. Quantitative metal analysis confirmed that DNA binds to diverse metals, which helps explain why many genes involved in a general uptake of metals were controlled by eDNA. Growth in the presence of eDNA also promoted intracellular bacterial survival and influenced virulence in the acute infection model of fruit flies.Conclusion. The diverse functions of the eDNA-regulated genes underscore the important role of this extracellular polymer in promoting antibiotic resistance, virulence, acid tolerance and nutrient utilization; phenotypes that contribute to long-term survival.


Assuntos
DNA Bacteriano/fisiologia , Regulação Bacteriana da Expressão Gênica , Homeostase , Metais/metabolismo , Nutrientes/metabolismo , Pseudomonas aeruginosa/genética , Animais , Drosophila/microbiologia , Concentração de Íons de Hidrogênio , Camundongos , Células RAW 264.7 , Análise de Sequência de RNA , Transcriptoma , Sistemas de Secreção Tipo III/fisiologia , Sistemas de Secreção Tipo VI/fisiologia , Virulência
12.
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
13.
J Vis Exp ; (157)2020 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-32202529

RESUMO

Trace metals such as iron and zinc are vital nutrients known to play key roles in prokaryotic processes including gene regulation, catalysis, and protein structure. Metal sequestration by hosts often leads to metal limitation for the bacterium. This limitation induces bacterial gene expression whose protein products allow bacteria to overcome their metal-limited environment. Characterization of such genes is challenging. Bacteria must be grown in meticulously prepared media that allows sufficient access to nutritional metals to permit bacterial growth while maintaining a metal profile conducive to achieving expression of the aforementioned genes. As such, a delicate balance must be established for the concentrations of these metals. Growing a nutritionally fastidious organism such as Neisseria gonorrhoeae, which has evolved to survive only in the human host, adds an additional level of complexity. Here, we describe the preparation of a defined metal-limited medium sufficient to allow gonococcal growth and the desired gene expression. This method allows the investigator to chelate iron and zinc from undesired sources while supplementing the media with defined sources of iron or zinc, whose preparation is also described. Finally, we outline three experiments that utilize this media to help characterize the protein products of metal-regulated gonococcal genes.


Assuntos
Regulação Bacteriana da Expressão Gênica , Metais/metabolismo , Metais/farmacologia , Neisseria gonorrhoeae/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Humanos , Ferro/metabolismo , Ligantes , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/metabolismo , Zinco/metabolismo
14.
Cell Mol Life Sci ; 77(17): 3293-3309, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32130428

RESUMO

Metallomics is a rapidly evolving field of bio-metal research that integrates techniques and perspectives from other "-omics" sciences (e.g. genomics, proteomics) and from research vocations further afield. Perhaps the most esoteric of this latter category has been the recent coupling of biomedicine with element and isotope geochemistry, commonly referred to as isotope metallomics. Over the course of less than two decades, isotope metallomics has produced numerous benchmark studies highlighting the use of stable metal isotope distribution in developing disease diagnostics-e.g. cancer, neurodegeneration, osteoporosis-as well as their utility in deciphering the underlying mechanisms of such diseases. These pioneering works indicate an enormous wealth of potential and provide a call to action for researchers to combine and leverage expertise and resources to create a clear and meaningful path forward. Doing so with efficacy and impact will require not only building on existing research, but also broadening collaborative networks, bolstering and deepening cross-disciplinary channels, and establishing unified and realizable objectives. The aim of this review is to briefly summarize the field and its underpinnings, provide a directory of the state of the art, outline the most encouraging paths forward, including their limitations, outlook and speculative upcoming breakthroughs, and finally to offer a vision of how to cultivate isotope metallomics for an impactful future.


Assuntos
Metais/metabolismo , Pesquisa Biomédica , Cromatografia por Troca Iônica , Humanos , Marcação por Isótopo , Espectrometria de Massas , Metais/análise , Neoplasias/metabolismo , Neoplasias/patologia , Osteoporose/metabolismo , Osteoporose/patologia
15.
Ecotoxicol Environ Saf ; 195: 110466, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32200145

RESUMO

Remediation of metal(loid) polluted soils is an important area of research nowadays. In particular, one remediation technique is much studied, phytomanagement. Phytomanagement combines amendment application and plant growth in order to reduce the risk posed by contaminants. Salicaceae plants showed tolerance towards metal(loid)s and the ability to accumulate high amounts of metal(loid)s in their tissue. Amendments are often applied to counterbalance the reduced soil fertility and high metal(loid) concentrations. Two amendments gathered attention over the last decades, biochar (product of biomass pyrolysis), which can be activated for better effects, and redmud (by-product of alumina production). Those two amendments showed ability to improve soil conditions and thus plant growth, although few studied their combined application. Moreover, since metal(loid)s are known to induce the overproduction of reactive oxygen species, it is important to measure the level of oxidative stress in the plant, to which plants respond using enzymatic and non-enzymatic systems. But no studies evaluate the response of Salicaceae plants to metal(loid) stress and amendment application at the biochemical level in a real soil condition. Therefore, a mesocosm study was set up to evaluate the effect of amending a mine soil with redmud combined to diverse biochars on the soil properties and Salix triandra growth, metal(loid) accumulation and stress marker levels. Results showed that all amendment combinations improved the soil fertility, reduced metal(loid) mobility and thus ameliorated Salix triandra growth, which accumulated metal(loid)s mainly in its roots. Moreover, among the different amendment combinations, Salix triandra plants still suffered from oxidative stress when grown on PG soil amended with redmud and chemical activated carbon, showing elevated levels of phenolic compounds and salicinoids and important antioxidant and enzymatic activities. Finally, one treatment showed levels of these stress markers similar or lower than the control, the combination of redmud with steam activated carbon. In conclusion, this treatment seemed a good solution in a phytomanagement strategy using Salix triandra, improving soil conditions and plant growth and reducing oxidative stress level in the plant roots.


Assuntos
Carvão Vegetal , Metaloides/metabolismo , Metais/metabolismo , Estresse Oxidativo , Salix/metabolismo , Poluentes do Solo/metabolismo , Óxido de Alumínio , Biodegradação Ambiental , Metaloides/toxicidade , Metais/toxicidade , Salix/efeitos dos fármacos , Salix/crescimento & desenvolvimento , Solo/química , Poluentes do Solo/toxicidade
16.
Ecotoxicol Environ Saf ; 195: 110449, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32220791

RESUMO

Environmental pollutants affect fish species differently because their routes of exposure make them more critical to a specific group regarding foraging habits or food preferences. However, the association between local problems and environmental conditions makes a particular species more suitable for use in monitoring programs. Thus, this study compared muscle accumulation of metals (Al, Ba, Cr, Cu, Fe, Mn, Ti and Zn) and toxicogenetic damage to three neotropical species from the Itapemirim River Basin (Brazil) with distinct foraging habits and feeding preferences: Geophagus brasiliensis (benthopelagic - omnivorous); Harttia sp. (benthic - detritivorous); and Leporinus copellandii (pelagic - omnivorous). There was seasonal influence on muscle metal concentrations: Ba and Mn concentrations in G. brasiliensis, Cr in Harttia sp. and Zn, Al and Fe in L. copellandii increased during the rainy season. G. brasiliensis was the most sensitive species, since it had a statistically higher prevalence of erythrocytic nuclear abnormalities, which was influenced by seasonality. This result might be an effect of its benthopelagic habits, which favors contact with a larger group of contaminants due to its interaction with both water column and sediment. The present study showed the differential sensitivity of fish species and that the combination of chemical analysis of pollutants with evaluation of toxicogenetic responses helps to choose the best species for field studies.


Assuntos
Peixes/metabolismo , Metais/metabolismo , Metais/toxicidade , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Brasil , Ciclídeos/metabolismo , Dano ao DNA , Monitoramento Ambiental , Comportamento Alimentar , Peixes/fisiologia , Músculos/metabolismo , Rios
17.
Chemistry ; 26(26): 5903-5910, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32142179

RESUMO

First-in-class CuII and AuIII metaled phosphorus dendrons were synthesized and showed significant antiproliferative activity against several aggressive breast cancer cell lines. The data suggest that the cytotoxicity increases with reducing length of the alkyl chains, whereas the replacement of CuII with AuIII considerably increases the antiproliferative activity of metaled phosphorus dendrons. Very interestingly, we found that the cell death pathway is related to the nature of the metal complexed by the plain dendrons. CuII metaled dendrons showed a potent caspase-independent cell death pathway, whereas AuIII metaled dendrons displayed a caspase-dependent apoptotic pathway. The complexation of plain dendrons with AuIII increased the cellular lethality versus dendrons with CuII and promoted the translocation of Bax into the mitochondria and the release of Cytochrome C (Cyto C).


Assuntos
Citocromos c/metabolismo , Dendrímeros/metabolismo , Metais/química , Mitocôndrias/química , Fósforo/química , Apoptose , Morte Celular , Citocromos c/química , Dendrímeros/química , Humanos , Células MCF-7 , Metais/metabolismo , Mitocôndrias/metabolismo , Estrutura Molecular , Fósforo/metabolismo
18.
Chemosphere ; 244: 125551, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050345

RESUMO

The distribution of Hg, Cd, Cu, and Zn in keratinized tissues, blood fractions, and excretory organs, and MTs in blood fractions and excretory organs was determined in captive, semicaptive, and wild Morelet's crocodiles and they were compared to select the most useful non-destructive tissues for the monitoring of metal exposure and to assess the potential of MTs as a biomarker. Our results indicate blood plasma, claws, and caudal scutes altogether are suitable tissues for xenobiotic metals exposure, with concentrations in blood plasma being an indicator of recent exposure, whereas concentrations in claws and caudal scutes are indicators of chronic exposure. Results in keratinized tissues suggest they are an important detoxification strategy in crocodiles, and claws presented the highest concentrations of metals in both captive (Hg = 0.44 ± 0.23 µg g-1, Cd = 11.10 ± 5.89 µg g-1, Cu = 45.98 ± 23.18 µg g-1, Zn = 124.75 ± 75.84 µg g-1) and wild populations (Hg = 1.31 ± 0.32 µg g-1, Cd = 26.47 ± 21.15 µg g-1, Cu = 191.75 ± 165.91 µg g-1, Zn = 265.81 ± 90.62 µg g-1). Thus, they are an appropriate tool for assessing metal exposure in populations where scutes clipping as a marking technique is not allowed, and their collection is less complicated than with other tissues. MTs are a suitable biomarker in blood plasma, whereas in erythrocytes detoxification processes might depend on hemoglobin, rather than MTs. Future studies should consider the implementation of these tools for the monitoring of wild populations.


Assuntos
Jacarés e Crocodilos/sangue , Monitoramento Ambiental/métodos , Metalotioneína/sangue , Metais/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Biomarcadores/sangue , Mercúrio/análise , Metais/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise
19.
Chemosphere ; 247: 125942, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32069721

RESUMO

We have evaluated the interactive toxicity of Cu(II) and Cd(II) in water with different hardness levels using adult zebrafish (Danio rerio). Zebrafish were exposed to Cd(II) (0.2-22 µM) or Cu(II) (0.1-8 µM) in single or binary exposures in very soft, moderately hard or very hard water. The whole body burdens of Cd(II) and Cu(II) reflect the net effect of biouptake and elimination, mortality was the indicator of toxicity, and whole body major ion content was measured to assess ion regulatory functions. Cu(II) was found to be more toxic than Cd(II) for zebrafish, and Cu(II) and Cd(II) exhibited a significant synergistic effect. The toxicity of metal ions increased upon decreasing the ionic strength of the exposure medium, probably due to elevated competition between metal ions with other cations in hard water and increased activity of Ca2+ pathways in soft water treatments. Whole body metal accumulation and the accumulation rate of both Cu and Cd increased as the metal ion concentration in the exposure medium increased. Nevertheless, neither parameter explained the observed synergistic effect on mortality. Finally, we observed a significant loss of whole body Na+ in fish which died during the metal exposure compared to surviving fish, irrespective of exposure conditions. Such an effect was not observed for other major cations (K+, Ca2+ and Mg2+). This observation suggests that, under the applied exposure conditions, survival was correlated to the capacity of the organism to maintain Na+ homeostasis.


Assuntos
Cádmio/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Cobre/toxicidade , Dureza , Íons/metabolismo , Metais/metabolismo , Sódio/metabolismo , Peixe-Zebra/metabolismo
20.
Adv Immunol ; 145: 187-241, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32081198

RESUMO

Metals are essential components in all forms of life required for the function of nearly half of all enzymes and are critically involved in virtually all fundamental biological processes. Especially, the transition metals iron (Fe), zinc (Zn), manganese (Mn), nickel (Ni), copper (Cu) and cobalt (Co) are crucial micronutrients known to play vital roles in metabolism as well due to their unique redox properties. Metals carry out three major functions within metalloproteins: to provide structural support, to serve as enzymatic cofactors, and to mediate electron transportation. Metal ions are also involved in the immune system from metal allergies to nutritional immunity. Within the past decade, much attention has been drawn to the roles of metal ions in the immune system, since increasing evidence has mounted to suggest that metals are critically implicated in regulating both the innate immune sensing of and the host defense against invading pathogens. The importance of ions in immunity is also evidenced by the identification of various immunodeficiencies in patients with mutations in ion channels and transporters. In addition, cancer immunotherapy has recently been conclusively demonstrated to be effective and important for future tumor treatment, although only a small percentage of cancer patients respond to immunotherapy because of inadequate immune activation. Importantly, metal ion-activated immunotherapy is becoming an effective and potential way in tumor therapy for better clinical application. Nevertheless, we are still in a primary stage of discovering the diverse immunological functions of ions and mechanistically understanding the roles of these ions in immune regulation. This review summarizes recent advances in the understanding of metal-controlled immunity. Particular emphasis is put on the mechanisms of innate immune stimulation and T cell activation by the essential metal ions like calcium (Ca2+), zinc (Zn2+), manganese (Mn2+), iron (Fe2+/Fe3+), and potassium (K+), followed by a few unessential metals, in order to draw a general diagram of metalloimmunology.


Assuntos
Imunidade Inata , Metais/metabolismo , Transdução de Sinais/imunologia , Animais , Cálcio/química , Cálcio/metabolismo , Cálcio/fisiologia , Enzimas , Humanos , Imunoterapia , Íons/química , Íons/metabolismo , Ferro/metabolismo , Ferro/fisiologia , Manganês/metabolismo , Manganês/fisiologia , Metais/química , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/imunologia , Potássio/química , Potássio/metabolismo , Potássio/fisiologia , Zinco/química , Zinco/deficiência , Zinco/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA