RESUMO
Heavy metals and metalloids in the environment are recognised as a threat to the health of organism. Terrestrial birds are ideal subjects for the examination of these pollutants because of their high mobility and high intra- and interspecific variation in trophic levels. We examined the contents of 6 trace metals (Cd, Pb, Cr, Sb and V) and metalloids (As) in the liver, kidney, muscle, and feathers of woodcocks (Scolopax rusticola) from Southern Italy by a validated ICP-MS method. Significant differences in trace elements were found in all the tissues examined (p < 0.05). The highest Sb and Cr levels were found in feathers samples with mean values of 0.019 mg/Kg and 0.085 mg/Kg, respectively. High Pb levels were found in muscle, with 23 % of the samples exceeding the limits set by the European Union. Cd was predominantly found in the kidney samples (0.76 mg/Kg). Vanadium was the less abundant trace metal, showing the highest concentrations in the liver (0.028 ± 0.011 mg/Kg). Higher As levels were found in muscle (0.02 ± 0.015 mg/Kg). No significant differences between sex and age classes (juveniles vs. adults) were found, nor were there correlations between morphometric parameters and trace metal/metalloid contents. Principal Component Analysis determined differences in metal accumulation between tissues. Feathers were confirmed as useful indicators of metal contamination. The results of this work confirmed that the accumulation of toxic elements in the tissues of woodcocks is primarily influenced by ecological traits such as feeding habits and migration status. Statistical analysis of the tissues would seem to exclude important accumulation phenomena of Pb. The high levels found in the muscle could be due to lead ammunition. This work provides the first data on the accumulation of As, Cr, Sb, and V in woodcocks tissue, providing a more comprehensive insight into the potential impact of these pollutants on birds.
Assuntos
Monitoramento Ambiental , Poluentes Ambientais , Metaloides , Metais Pesados , Animais , Itália , Poluentes Ambientais/metabolismo , Poluentes Ambientais/análise , Metaloides/análise , Metaloides/metabolismo , Metais Pesados/análise , Metais Pesados/metabolismo , Plumas/química , Oligoelementos/análise , Oligoelementos/metabolismo , Fígado/química , Fígado/metabolismo , Rim/química , Rim/metabolismo , Aves/metabolismoRESUMO
Arsenic is highly toxic and a significant threat to human health, but certain bacteria have developed defense mechanisms initiated by AsIII binding to AsIII-sensing proteins of the ArsR family. The transcriptional regulator AfArsR responds to AsIII and SbIII by coordinating the metalloids with three cysteines, located in a short sequence of the same monomer chain. Here, we characterize the binding of AsIII and HgII to a model peptide encompassing this fragment of the protein via solution equilibrium and spectroscopic/spectrometric techniques (pH potentiometry, UV, CD, NMR, PAC, EXAFS, and ESI-MS) combined with DFT calculations and MD simulations. Coordination of AsIII changes the peptide structure from a random-coil to a well-defined structure of the complex. A trigonal pyramidal AsS3 binding site is formed with almost exactly the same structure as observed in the crystal structure of the native protein, implying that the peptide possesses all of the features required to mimic the AsIII recognition and response selectivity of AfArsR. Contrary to this, binding of HgII to the peptide does not lead to a well-defined structure of the peptide, and the atoms near the metal binding site are displaced and reoriented in the HgII model. Our model study suggests that structural organization of the metal site by the inducer ion is a key element in the mechanism of the metalloid-selective recognition of this protein.
Assuntos
Arsênio , Arsênio/química , Arsênio/metabolismo , Sítios de Ligação , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Metaloides/química , Metaloides/metabolismo , Teoria da Densidade Funcional , Simulação de Dinâmica Molecular , Ligação ProteicaRESUMO
Arsenic (As) remediation is challenging due to the complex nature and the persistence of these metalloid compounds. While it may seem that differences between As forms influence have been extensively described, new findings challenge the previously accepted knowledge, particularly for woody plants. Therefore, this study focused on 2-year-old Tilia cordata Mill. seedlings early (0, 2, 4, 12, 24 h) and late (3, 7, 12, 18, 25, 33 days) responses during growth under: As(III), As(V) or dimethylarsinic acid (DMA) (0.3 mM). Time-dependent transformations of As forms, distribution in plants, and microbiological characteristics (actinobacteria, bacteria, fungi, enzyme activity) were investigated. The highest increase in total As content was observed in plants exposed to As(V) and As(III). Dynamic metalloid form changes in the solution and tree organs were indicated. The most phytotoxic was DMA. This form was the main factor limiting the growth and effective accumulation of As. Despite experimenting in hydroponics, microorganisms played an important role in As form transformations, suggesting the potential for microbial-assisted dendroremediation strategies. The study confirmed that trees can convert more toxic forms into less toxic ones (e.g. As(III) to phytochelatins - As(III)-(PC3)), whose presence in roots seedlings exposed to As(III) and As(V) has been identified. The formation of hydrophobic forms (e.g. dimethylarsinoyl lipid) in the roots of seedlings grown under As(V) was confirmed. It is the first discovery for trees, previously observed only in bacteria and algae. The dynamics of metalloid form changes indicated that T. cordata transforms As forms according to their needs, which may give tree species an advantage in phytoremediation techniques. It holds great promise for the potential of dendroremediation.
Assuntos
Arsênio , Biodegradação Ambiental , Plântula , Poluentes do Solo , Plântula/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Arsênio/metabolismo , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Árvores , Metaloides/metabolismoRESUMO
In the face of flourishing industrialization and global trade, heavy metal and metalloid contamination of the environment is a growing concern throughout the world. The widespread presence of highly toxic compounds of arsenic, antimony, and cadmium in nature poses a particular threat to human health. Prolonged exposure to these toxins has been associated with severe human diseases, including cancer, diabetes, and neurodegenerative disorders. These toxins are known to induce analogous cellular stresses, such as DNA damage, disturbance of redox homeostasis, and proteotoxicity. To overcome these threats and improve or devise treatment methods, it is crucial to understand the mechanisms of cellular detoxification in metal and metalloid stress. Membrane proteins are key cellular components involved in the uptake, vacuolar/lysosomal sequestration, and efflux of these compounds; thus, deciphering the multilevel regulation of these proteins is of the utmost importance. In this review, we summarize data on the mechanisms of arsenic, antimony, and cadmium detoxification in the context of membrane proteome. We used yeast Saccharomyces cerevisiae as a eukaryotic model to elucidate the complex mechanisms of the production, regulation, and degradation of selected membrane transporters under metal(loid)-induced stress conditions. Additionally, we present data on orthologues membrane proteins involved in metal(loid)-associated diseases in humans.
Assuntos
Metaloides , Saccharomyces cerevisiae , Estresse Fisiológico , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Metaloides/metabolismo , Metaloides/toxicidade , Humanos , Estresse Fisiológico/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Arsênio/toxicidade , Arsênio/metabolismo , Cádmio/toxicidade , Cádmio/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
Due to anthropogenic activities, environmental pollution of heavy metals/metalloids (HMs) has increased and received growing attention in recent decades. Plants growing in HM-contaminated soils have slower growth and development, resulting in lower agricultural yield. Exposure to HMs leads to the generation of free radicals (oxidative stress), which alters plant morpho-physiological and biochemical pathways at the cellular and tissue levels. Plants have evolved complex defense mechanisms to avoid or tolerate the toxic effects of HMs, including HMs absorption and accumulation in cell organelles, immobilization by forming complexes with organic chelates, extraction via numerous transporters, ion channels, signaling cascades, and transcription elements, among others. Nonetheless, these internal defensive mechanisms are insufficient to overcome HMs toxicity. Therefore, unveiling HMs adaptation and tolerance mechanisms is necessary for sustainable agriculture. Recent breakthroughs in cutting-edge approaches such as phytohormone and gasotransmitters application, nanotechnology, omics, and genetic engineering tools have identified molecular regulators linked to HMs tolerance, which may be applied to generate HMs-tolerant future plants. This review summarizes numerous systems that plants have adapted to resist HMs toxicity, such as physiological, biochemical, and molecular responses. Diverse adaptation strategies have also been comprehensively presented to advance plant resilience to HMs toxicity that could enable sustainable agricultural production.
Assuntos
Metaloides , Metais Pesados , Poluentes do Solo , Agricultura , Fenômenos Químicos , Metaloides/metabolismo , Metaloides/toxicidade , Metais Pesados/toxicidade , Plantas/metabolismo , Solo , Poluentes do Solo/toxicidadeRESUMO
INTRODUCTION: Nodulin-26-like intrinsic proteins (NIPs) are integral membrane proteins belonging to the aquaporin family, that facilitate the transport of neutral solutes across the bilayer. The OsNIP2;1 a member of NIP-III class of aquaporins is permeable to beneficial elements like silicon and hazardous arsenic. However, the atomistic cross-talk of these molecules traversing the OsNIP2;1 channel is not well understood. OBJECTIVE: Due to the lack of genomic variation but the availability of high confidence crystal structure, this study aims to highlight structural determinants of metalloid permeation through OsNIP2;1. METHODS: The molecular simulations, combined with site-directed mutagenesis were used to probe the role of specific residues in the metalloid transport activity of OsNIP2;1. RESULTS: We drew energetic landscape of OsNIP2;1, for silicic and arsenous acid transport. Potential Mean Force (PMF) construction illuminate three prominent energetic barriers for metalloid passage through the pore. One corresponds to the extracellular molecular entry in the channel, the second located on ar/R filter, and the third size constriction in the cytoplasmic half. Comparative PMF for silicic acid and arsenous acid elucidate a higher barrier for silicic acid at the cytoplasmic constrict resulting in longer residence time for silicon. Furthermore, our simulation studies explained the importance of conserved residues in loop-C and loop-D with a direct effect on pore dynamics and metalloid transport. Next we assessed contribution of predicted key residues for arsenic uptake, by functional complementation in yeast. With the aim of reducing arsenic uptake while maintaining beneficial elements uptake, we identified novel OsNIP2;1 mutants with substantial reduction in arsenic uptake in yeast. CONCLUSION: We provide a comprehensive assessment of pore lining residues of OsNIP2;1 with respect to metalloid uptake. The findings will expand mechanistic understanding of aquaporin's metalloid selectivity and facilitate variant interpretation to develop novel alleles with preference for beneficial metalloid species and reducing hazardous ones.
Assuntos
Aquaporinas , Arsênio , Arsenitos , Metaloides , Arsênio/metabolismo , Silício/metabolismo , Saccharomyces cerevisiae/metabolismo , Ácido Silícico/metabolismo , Aquaporinas/química , Aquaporinas/genética , Aquaporinas/metabolismo , Metaloides/metabolismoRESUMO
Metals and metalloids are used as weapons for predatory feeding by unicellular eukaryotes on prokaryotes. This review emphasizes the role of metal(loid) bioavailability over the course of Earth's history, coupled with eukaryogenesis and the evolution of the mitochondrion to trace the emergence and use of the metal(loid) prey-killing phagosome as a feeding strategy. Members of the genera Acanthamoeba and Dictyostelium use metals such as zinc (Zn) and copper (Cu), and possibly metalloids, to kill their bacterial prey after phagocytosis. We provide a potential timeline on when these capacities first evolved and how they correlate with perceived changes in metal(loid) bioavailability through Earth's history. The origin of phagotrophic eukaryotes must have postdated the Great Oxidation Event (GOE) in agreement with redox-dependent modification of metal(loid) bioavailability for phagotrophic poisoning. However, this predatory mechanism is predicted to have evolved much later - closer to the origin of the multicellular metazoans and the evolutionary development of the immune systems.
Assuntos
Dictyostelium , Metais , Fagocitose , Metais/metabolismo , Dictyostelium/metabolismo , Dictyostelium/fisiologia , Evolução Biológica , Acanthamoeba , Animais , Fagossomos/metabolismo , Zinco/metabolismo , Metaloides/metabolismo , Cobre/metabolismo , Disponibilidade Biológica , Mitocôndrias/metabolismoRESUMO
Aquaporins can facilitate the passive movement of water, small polar molecules, and some ions. Here, we examined solute selectivity for the barley Nodulin 26-like Intrinsic Protein (HvNIP2;1) embedded in liposomes and examined through stopped-flow light scattering spectrophotometry and Xenopus laevis oocyte swelling assays. We found that HvNIP2;1 permeates water, boric and germanic acids, sucrose, and lactose but not d-glucose or d-fructose. Other saccharides, such as neutral (d-mannose, d-galactose, d-xylose, d-mannoheptaose) and charged (N-acetyl d-glucosamine, d-glucosamine, d-glucuronic acid) aldoses, disaccharides (cellobiose, gentiobiose, trehalose), trisaccharide raffinose, and urea, glycerol, and acyclic polyols, were permeated to a much lower extent. We observed apparent permeation of hydrated KCl and MgSO4 ions, while CH3COONa and NaNO3 permeated at significantly lower rates. Our experiments with boric acid and sucrose revealed no apparent interaction between solutes when permeated together, and AgNO3 or H[AuCl4] blocked the permeation of all solutes. Docking of sucrose in HvNIP2;1 and spinach water-selective SoPIP2;1 aquaporins revealed the structural basis for sucrose permeation in HvNIP2;1 but not in SoPIP2;1, and defined key residues interacting with this permeant. In a biological context, sucrose transport could constitute a novel element of plant saccharide-transporting machinery. Phylogenomic analyses of 164 Viridiplantae and 2993 Archaean, bacterial, fungal, and Metazoan aquaporins rationalized solute poly-selectivity in NIP3 sub-clade entries and suggested that they diversified from other sub-clades to acquire a unique specificity of saccharide transporters. Solute specificity definition in NIP aquaporins could inspire developing plants for food production.
Assuntos
Aquaporinas , Hordeum , Metaloides , Água , Animais , Aquaporinas/metabolismo , Glucosamina , Hordeum/metabolismo , Metaloides/metabolismo , Sacarose , Água/metabolismoRESUMO
Heavy metals and metalloids (HMs) contamination in the environment has heightened recently due to increasing global concern for food safety and human livability. Zinc (Zn2+ ) is an important nutrient required for the normal development of plants. It is an essential cofactor for the vital enzymes involved in various biological mechanisms of plants. Interestingly, Zn2+ has an additional role in the detoxification of HMs in plants due to its unique biochemical-mediating role in several soil and plant processes. During any exposure to high levels of HMs, the application of Zn2+ would confer greater plant resilience by decreasing oxidative stress, maintaining uptake of nutrients, photosynthesis productivity and optimising osmolytes concentration. Zn2+ also has an important role in ameliorating HMs toxicity by regulating metal uptake through the expression of certain metal transporter genes, targeted chelation and translocation from roots to shoots. This review examined the vital roles of Zn2+ and nano Zn in plants and described their involvement in alleviating HMs toxicity in plants. Moving forward, a broad understanding of uptake, transport, signalling and tolerance mechanisms of Zn2+ /zinc and its nanoparticles in alleviating HMs toxicity of plants will be the first step towards a wider incorporation of Zn2+ into agricultural practices.
Assuntos
Metaloides , Metais Pesados , Humanos , Zinco/metabolismo , Metaloides/metabolismo , Metais Pesados/toxicidade , Metais Pesados/análise , Metais Pesados/metabolismo , Plantas/genética , SoloRESUMO
The constant, ever-increasing antibiotic resistance crisis leads to the announcement of "urgent, novel antibiotics needed" by the World Health Organization. Our previous works showed a promising synergistic antibacterial activity of silver nitrate with potassium tellurite out of thousands of other metal/metalloid-based antibacterial combinations. The silver-tellurite combined treatment not only is more effective than common antibiotics but also prevents bacterial recovery, decreases the risk of future resistance chance, and decreases the effective concentrations. We demonstrate that the silver-tellurite combination is effective against clinical isolates. Further, this study was conducted to address knowledge gaps in the available data on the antibacterial mechanism of both silver and tellurite, as well as to give insight into how the mixture provides synergism as a combination. Here, we defined the differentially expressed gene profile of Pseudomonas aeruginosa under silver, tellurite, and silver-tellurite combination stress using an RNA sequencing approach to examine the global transcriptional changes in the challenged cultures grown in simulated wound fluid. The study was complemented with metabolomics and biochemistry assays. Both metal ions mainly affected four cellular processes, including sulfur homeostasis, reactive oxygen species response, energy pathways, and the bacterial cell membrane (for silver). Using a Caenorhabditis elegans animal model we showed silver-tellurite has reduced toxicity over individual metal/metalloid salts and provides increased antioxidant properties to the host. This work demonstrates that the addition of tellurite would improve the efficacy of silver in biomedical applications. IMPORTANCE Metals and/or metalloids could represent antimicrobial alternatives for industrial and clinical applications (e.g., surface coatings, livestock, and topical infection control) because of their great properties, such as good stability and long half-life. Silver is the most common antimicrobial metal, but resistance prevalence is high, and it can be toxic to the host above a certain concentration. We found that a silver-tellurite composition has antibacterial synergistic effect and that the combination is beneficial to the host. So, the efficacy and application of silver could increase by adding tellurite in the recommended concentration(s). We used different methods to evaluate the mechanism for how this combination can be so incredibly synergistic, leading to efficacy against antibiotic- and silver-resistant isolates. Our two main findings are that (i) both silver and tellurite mostly target the same pathways and (ii) the coapplication of silver with tellurite tends not to target new pathways but targets the same pathways with an amplified change.
Assuntos
Anti-Infecciosos , Metaloides , Animais , Nitrato de Prata/farmacologia , Nitrato de Prata/metabolismo , Pseudomonas aeruginosa/metabolismo , Antibacterianos/química , Anti-Infecciosos/metabolismo , Metaloides/metabolismo , Testes de Sensibilidade MicrobianaRESUMO
Soil contamination with trace metals and metalloids can cause toxicity to plants and threaten food safety and human health. Plants have evolved sophisticated mechanisms to cope with excess trace metals and metalloids in soils, including chelation and vacuolar sequestration. Sulfur-containing compounds, such as glutathione and phytochelatins, play a crucial role in their detoxification, and sulfur uptake and assimilation are regulated in response to the stress of toxic trace metals and metalloids. This review focuses on the multi-level connections between sulfur homeostasis in plants and responses to such stresses, especially those imposed by arsenic and cadmium. We consider recent progress in understanding the regulation of biosynthesis of glutathione and phytochelatins and of the sensing mechanism of sulfur homeostasis for tolerance of trace metals and metalloids in plants. We also discuss the roles of glutathione and phytochelatins in controlling the accumulation and distribution of arsenic and cadmium in plants, and possible strategies for manipulating sulfur metabolism to limit their accumulation in food crops.
Assuntos
Arsênio , Metaloides , Humanos , Cádmio/metabolismo , Arsênio/metabolismo , Metaloides/metabolismo , Fitoquelatinas/metabolismo , Glutationa/metabolismo , Produtos Agrícolas/metabolismo , Enxofre/metabolismoRESUMO
Plants take up a wide range of trace metals/metalloids (hereinafter referred to as trace metals) from the soil, some of which are essential but become toxic at high concentrations (e.g., Cu, Zn, Ni, Co), while others are non-essential and toxic even at relatively low concentrations (e.g., As, Cd, Cr, Pb, and Hg). Soil contamination of trace metals is an increasing problem worldwide due to intensifying human activities. Trace metal contamination can cause toxicity and growth inhibition in plants, as well as accumulation in the edible parts to levels that threatens food safety and human health. Understanding the mechanisms of trace metal toxicity and how plants respond to trace metal stress is important for improving plant growth and food safety in contaminated soils. The accumulation of excess trace metals in plants can cause oxidative stress, genotoxicity, programmed cell death, and disturbance in multiple physiological processes. Plants have evolved various strategies to detoxify trace metals through cell-wall binding, complexation, vacuolar sequestration, efflux, and translocation. Multiple signal transduction pathways and regulatory responses are involved in plants challenged with trace metal stresses. In this review, we discuss the recent progress in understanding the molecular mechanisms involved in trace metal toxicity, detoxification, and regulation, as well as strategies to enhance plant resistance to trace metal stresses and reduce toxic metal accumulation in food crops.
Assuntos
Metaloides , Metais Pesados , Poluentes do Solo , Humanos , Metais Pesados/análise , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Metaloides/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Solo/química , Plantas/metabolismoRESUMO
Methylarsenite [MAs(III)] is a highly toxic arsenical produced by some microbes as an antibiotic. In this study, we demonstrate that a PadR family transcriptional regulator, PadRars , from Azospirillum halopraeferens strain Au 4 directly binds to the promoter region of the arsenic resistance (ars) operon (consisting of padRars , arsV, and arsW) and represses transcription of arsV and arsW genes involved in MAs(III) resistance. Quantitative reverse transcriptase PCR and transcriptional reporter assays showed that transcription of the ars operon is induced strongly by MAs(III) and less strongly by arsenite and antimonite. Electrophoretic mobility shift assays with recombinant PadRars showed that it represses transcription of the ars operon by binding to two inverted-repeat sequences within the ars promoter. PadRars has two conserved cysteine pairs, Cys56/57 and Cys133/134; mutation of the first pair to serine abolished the transcriptional response of the ars operon to trivalent metalloids, suggesting that Cys56/57 form a binding site for trivalent metalloids. Either C133S or C134S derivative responses to MAs(III) but not As(III) or Sb(III), suggesting that it is a third ligand to trivalent metalloids. PadRars represents a new type of repressor proteins regulating transcription of an ars operon involved in the resistance to trivalent metalloids, especially MAs(III).
Assuntos
Arsênio , Metaloides , Regulação Bacteriana da Expressão Gênica , Metaloides/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Óperon , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Arsênio/metabolismoRESUMO
Heavy metal/metalloids (HMs) are among the primary soil pollutants that limit crop production worldwide. Plants grown in HM contaminated soils exhibit reduced growth and development, resulting in a decrease in crop production. The exposure to HMs induces plant oxidative stress due to the formation of free radicals, which alter plant morphophysiological and biochemical mechanisms at cellular and tissue levels. When exposed to HM toxicity, plants evolve sophisticated physiological and cellular defense strategies, such as sequestration and transportation of metals, to ensure their survival. Plants also have developed efficient strategies by activating signaling pathways, which induce the expression of HM transporters. Plants either avoid the uptake of HMs from the soil or activate the detoxifying mechanism to tolerate HM stress, which involves the production of antioxidants (enzymatic and non-enzymatic) for the scavenging of reactive oxygen species. The metal-binding proteins including phytochelatins and metallothioneins also participate in metal detoxification. Furthermore, phytohormones and their signaling pathways also help to regulate cellular activities to counteract HM stress. The excessive levels of HMs in the soil can contribute to plant morpho-physiological, biochemical, and molecular alterations, which have a detrimental effect on the quality and productivity of crops. To maintain the commercial value of fruits and vegetables, various measures should be considered to remove HMs from the metal-polluted soils. Bioremediation is a promising approach that involves the use of tolerant microorganisms and plants to manage HMs pollution. The understanding of HM toxicity, signaling pathways, and tolerance mechanisms will facilitate the development of new crop varieties that help in improving phytoremediation.
Assuntos
Metaloides , Metais Pesados , Poluentes do Solo , Biodegradação Ambiental , Metaloides/metabolismo , Metais Pesados/análise , Plantas/metabolismo , Solo , Poluentes do Solo/análiseRESUMO
Metalloids in plants have diverse physiological effects. From being essential to beneficial to toxic, they have significant effects on many physiological processes, influencing crop yield and quality. Aquaporins are a group of membrane channels that have several physiological substrates along with water. Metalloids have emerged as one of their important substrates and they are found to have a substantial role in regulating plant metalloid homeostasis. The present review comprehensively details the multiple isoforms of aquaporins having specificity for metalloids and being responsible for their influx, distribution or efflux. In addition, it also highlights the usage of aquaporin-mediated transport as a selection marker in toxic screens and as tracer elements for closely related metalloids. Therefore, aquaporins, with their imperative contribution to the regulation of plant growth, development and physiological processes, need more research to unravel the metalloid trafficking mechanisms and their future applications.
Assuntos
Aquaporinas , Metaloides , Aquaporinas/metabolismo , Transporte Biológico , Metaloides/metabolismo , Proteínas de Plantas/metabolismo , Plantas/metabolismoRESUMO
Siderophores are small molecular weight iron scavengers that are mainly produced by bacteria, fungi, and plants. Recently, they have attracted increasing attention because of their potential role in environmental bioremediation. Although siderophores are generally considered to exhibit high specificity for iron, they have also been reported to bind to various metal and metalloid ions. This unique ability allows siderophores to solubilise and mobilise heavy metals and metalloids from soil, thereby facilitating their bioremediation. In addition, because of their redox nature, they can mediate the production of reactive oxygen species (ROS), and thus promote the biodegradation of organic contaminants. The aim of this review is to summarise the existing knowledge on the developed strategies of siderophore-assisted bioremediation of metals, metalloids, and organic contaminants. Additionally, this review also includes the biosynthesis and classification of microbial and plant siderophores.
Assuntos
Metaloides , Metais Pesados , Biodegradação Ambiental , Ferro/metabolismo , Metaloides/metabolismo , Metais Pesados/metabolismo , Sideróforos/metabolismoRESUMO
Metals and metalloids are integral to biological processes and play key roles in physiology and metabolism. Nonetheless, overexposure to some metals or lack of others can lead to serious health consequences. In this study, eight zebrafish facilities collaborated to generate a multielement analysis of their centralized recirculating water systems. We report a first set of average concentrations for 46 elements detected in zebrafish facilities. Our results help to establish an initial baseline for trouble-shooting purposes, and in general for safe ranges of metal concentrations in recirculating water systems, supporting reproducible scientific research outcomes with zebrafish.
Assuntos
Metaloides , Poluentes Químicos da Água , Animais , Metaloides/análise , Metaloides/metabolismo , Água , Poluentes Químicos da Água/análise , Peixe-Zebra/metabolismoRESUMO
With the introduction of tandem mass spectrometry to inductively coupled plasma mass spectrometry (ICPMS/MS), the potential for non-targeted elemental metabolomic analysis has been expanded to many non-metals of pivotal biological importance. Arsenic and selenium are trace elements that share chemical similarity with the non-metals phosphorus and sulfur, respectively, and this similarity can be exploited to gain more insight into the incompletely understood biological significance of these metalloids and the evolution of their biochemical pathways. As a proof of concept, we show the applicability of HPLC-ICPMS/MS for non-targeted and parallel speciation analysis of arsenic, selenium, phosphorus, and sulfur in mushrooms-metabolically diverse organisms. Incredibly contrasting levels of diversity were found in the metabolomic profiles of the four investigated elements among the various species along with sharp discrepancies among related elements (e.g. phosphorous vs. arsenic) in certain mushroom species. The present work shows that ICPMS/MS offers a new dimension in non-targeted metabolomic analysis and enables a unique comparative approach in investigating and tracking the biochemistry of related elements in moderately complex organisms.
Assuntos
Agaricales/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Metaloides/análise , Metais/análise , Espectrometria de Massas em Tandem/métodos , Metaloides/química , Metaloides/metabolismo , Metais/química , Metais/metabolismoRESUMO
BACKGROUND: Exposure to metals/metalloids, including essential and nonessential elements, has been associated to male reproductive health in animals. However, findings from human studies are inconsistent. OBJECTIVES: To investigate the impact of exposure to multiple metals/metalloids at environmental levels on the conventional human semen-quality parameters. MATERIALS AND METHODS: Men living in rural or industrial areas were recruited by personalized letters. No exclusion criteria were applied. Each man provided one semen sample and one blood sample. We analyzed the semen sample both to determine conventional sperm parameters (concentration, progressive motility and normal forms) and to quantify lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), nickel (Ni), vanadium (V) and selenium (Se) levels. The levels of these metals/metalloids were also quantified in venous blood and spermatozoa samples. Associations between the blood/seminal plasma metal/metalloid levels and semen quality parameters were assessed using confounder adjusted logistic regression models. Correlation and interactions between blood/seminal plasma and semen metal/metalloid levels were investigated using the Spearman's correlation. RESULTS: We found a positive association of seminal plasma cadmium level with lower Total count (OR = 4.48, 95%CI 0.25-80); whereas lead (OR = 4.51, 95%CI 0.86-23) and cadmium (OR = 3.45, 95%CI 0.77-16) seminal plasma levels had a positive association with progressive sperm motility. Overall, these associations remained suggestive after adjustment, though statistically unstable risks. Finally, we found weak interactions between beneficial effects of Se and detrimental ones only for Cd and Pb blood level on sperm concentration, total sperm count and progressive sperm motility. CONCLUSIONS: Our findings suggest that environmental exposure to Pb and Cd contributes to a decline in human semen quality, whereas Se can have beneficial effects. Measurements of metals/metalloids in the seminal fluid may be more predictable of semen quality than conventional blood measurements.
Assuntos
Exposição Ambiental , Metaloides/toxicidade , Metais/toxicidade , Sêmen/efeitos dos fármacos , Adulto , Arsênio/sangue , Líquidos Corporais , Cádmio/farmacologia , Estudos Transversais , Humanos , Masculino , Mercúrio , Metaloides/metabolismo , Metais/metabolismo , Níquel/farmacologia , Selênio , Análise do Sêmen , Contagem de Espermatozoides , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , VanádioRESUMO
The intensive shift on land cover by anthropogenic activities have led to changes in natural habitats and environmental contamination, which can ultimately impact and threat biodiversity and ecosystem services, such as pollination. The aim of this study was to evaluate the effect of native forest and human-modified land covers on the concentrations of chemical elements accumulated in the neotropical pollinator bee T. angustula. Eight landscapes, within an Ecological Corridor in the State of São Paulo, Brazil, with gradients of forest cover, spatial heterogeneity and varying land covers were used as sampling unities. Bees collected in traps or through actives searches had the concentration of 21 chemical elements determined by ICP-MS. Results show a beneficial effect of forested areas on the concentrations of some well-known toxic elements accumulated in bees, such as Hg, Cd, and Cr. Multivariate Redundancy Analysis (RDA) suggests road as the most important driver for the levels of Cr, Hg, Sb, Al, U, As, Pb and Pt and bare soil, pasture and urban areas as the landscape covers responsible for the concentrations of Zn, Cd, Mn, Mg, Ba and Sr in bees. The results reinforce the potential use of T. angustula bees as bioindicators of environmental quality and also show that these organisms are being directly affected by human land use, offering potential risks for the Neotropical ecosystem. Our study sheds light on how land covers (native forest and human-modified) can influence the levels of contaminants in insects within human-dominated landscapes. The generation of predictions of the levels of toxic metals and metalloids based on land use can both contribute to friendly farming planning as well as to support public policy development on the surrounding of protected areas and biodiversity conservation hotspots.