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The widespread application of nanoparticles (NPs) in recent times has caused concern because of their effects in biological systems. Although NPs can be produced naturally, industrially synthesized NPs affect the metabolism of a given organism because of their high reactivity. The biotransformation of NPs involves different processes, including aggregation/agglomeration, and reactions with biomolecules that will be reflected in their toxicity. Several analytical techniques, including inductively coupled plasma mass spectrometry (ICP-MS), have been used for characterizing and quantifying NPs in biological samples. In fact, in addition to providing information regarding the morphology and concentration of NPs, ICP-MS-based platforms, such as liquid chromatography/ICP-MS, single-particle ICP-MS, field-flow fractionation (asymmetrical flow field-flow fractionation)-ICP-MS, and laser ablation-ICP-MS, yield elemental information about molecules. Furthermore, such information together with speciation analysis enlarges our understanding of the interaction between NPs and biological organisms. This study reports the contribution of ICP-MS-based platforms as a tool for evaluating NPs in distinct biological samples by providing an additional understanding of the behavior of NPs and their toxicity in these organisms.
Assuntos
Espectrometria de Massas/métodos , Nanopartículas Metálicas/análise , Animais , Cromatografia Líquida , Fracionamento por Campo e Fluxo , Humanos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Plantas/química , Plantas/efeitos dos fármacos , Análise de Célula ÚnicaRESUMO
This work evaluates different generations of transgenic (cp4-EPSPS gene) and non-transgenic soybean plants through proteomics and metabolomics. For proteomics purpose, 24 differentially abundant protein spots were found through 2-D DIGE, being 4 belonging to transgenic plants. From this total, 19 were successfully identified, storage proteins as predominant class. Some identified proteins are involved in growing and cell division, and stress response, such as LEA and dehydrin. For metabolomics, 17 compounds were putatively annotated, mainly belonging to the secondary metabolism, such as flavonoids. From these analyzes, all generations and varieties of the soybean are prone to be differentiate by PLS-DA. According to our results, transgenic plants appear to be more stable than non-transgenic ones. In addition, the omics-based approaches allowed access some relations between those differential spot proteins and metabolites, mainly those storage proteins and flavonoid.
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Glycine max/fisiologia , Plantas Geneticamente Modificadas/fisiologia , Metabolômica , Plantas Geneticamente Modificadas/metabolismo , Proteômica , Sementes/metabolismo , Glycine max/genética , Glycine max/metabolismoRESUMO
PURPOSE: The SLC8A1 gene, which encodes the Na(+)/Ca(2+) exchanger, has a key role in calcium homeostasis. Our previous gene expression oligoarray data revealed SLC8A1 under expression in penile carcinoma. We investigated whether dysregulation of SLC8A1 expression is associated with apoptosis and cell proliferation in penile carcinoma via modulation of the calcium concentration. The underlying mechanisms of SLC8A1 under expression were also explored, focusing on copy number alteration and miRNA. MATERIALS AND METHODS: Transcript levels of the SLC8A1 gene and miR-223 were evaluated by quantitative polymerase chain reaction to compare penile carcinoma samples with normal glans tissue. SLC8A1 copy number was evaluated by microarray based comparative genomic hybridization. In normal and tumor samples we investigated caspase-3 and Ki-67 immunostaining as well as calcium distribution by laser ablation imaging inductively coupled plasma mass spectrometry. RESULTS: SLC8A1 under expression was detected in penile carcinoma samples (p = 0.001), confirming our previous data. It was not associated with gene copy number loss. In contrast, miR-223 over expression (p = 0.002) inversely correlated with its putative repressor SLC8A1 (r = -0.426, p = 0.015). SLC8A1 under expression was associated with decreased calcium distribution, high Ki-67 and low caspase-3 immunoexpression in penile carcinoma compared to normal tissue. CONCLUSIONS: Down-regulation of the SLC8A1 gene, most likely mediated by its regulator miR-223, can lead to decreased calcium in penile carcinoma and consequently to suppressed apoptosis and increased tumor cell proliferation. These data suggest that the miR-223-NCX1-calcium signaling axis may represent a potential therapeutic approach to penile carcinoma.
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Apoptose/fisiologia , Cálcio/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Neoplasias Penianas/genética , Neoplasias Penianas/metabolismo , Trocador de Sódio e Cálcio/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/patologia , Proliferação de Células , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Penianas/patologia , Adulto JovemRESUMO
The main goal of this work is to evaluate some differential protein species in transgenic (T) and nontransgenic (NT) Arabidopsis thaliana plants after their cultivation in the presence or absence of sodium selenite. The transgenic line was obtained through insertion of CaMV 35S controlling nptII gene. Comparative proteomics through 2D-DIGE is carried out in four different groups (NT × T; NT × Se-NT (where Se is selenium); Se-NT × Se-T, and T × Se-T). Although no differential proteins are achieved in the T × Se-T group, for the others, 68 differential proteins (by applying a regulation factor ≥1.5) are achieved, and 27 of them accurately characterized by ESI-MS/MS. These proteins are classified into metabolism, energy, signal transduction, disease/defense categories, and some of them are involved in the glycolysis pathway-Photosystems I and II and ROS combat. Additionally, laser ablation imaging is used for evaluating the Se and sulfur distribution in leaves of different groups, corroborating some results obtained and related to proteins involved in the glycolysis pathway. From these results, it is possible to conclude that the genetic modification also confers to the plant resistance to oxidative stress.
Assuntos
Arabidopsis/genética , Folhas de Planta/genética , Proteômica , Selenito de Sódio/administração & dosagem , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Eletroforese em Gel Bidimensional/métodos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lasers , Imagem Molecular/métodos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/biossíntese , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimentoRESUMO
Interactions between proteins and metal ions and their complexes are important in many areas of the life sciences, including physiology, medicine, and toxicology. Despite the involvement of essential elements in all major processes necessary for sustaining life, metalloproteomes remain ill-defined. This is not only owing to the complexity of metalloproteomes, but also to the non-covalent character of the complexes that most essential metals form, which complicates analysis. Similar issues may also be encountered for some toxic metals. The review discusses recently developed approaches and current challenges for the study of interactions involving entire (sub-)proteomes with such labile metal ions. In the second part, transition metals from the fourth and fifth periods are examined, most of which are xenobiotic and also tend to form more stable and/or inert complexes. A large research area in this respect concerns metallodrug-protein interactions. Particular attention is paid to separation approaches, as these need to be adapted to the reactivity of the metal under consideration.
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Proteoma , ÍonsRESUMO
This study investigated the effect of AgNPs and AgNO3, at concentrations equivalent, on the production of primary and secondary metabolites on transgenic soybean plants through an NMR-based metabolomics. The plants were cultivated in a germination chamber following three different treatments: T0 (addition of water), T1 (addition of AgNPs), and T2 (addition of AgNO3). Physiological characteristics, anatomical analyses through microscopic structures, and metabolic profile studies were carried out to establish the effect of abiotic stress on these parameters in soybean plants. Analysis of the 1H NMR spectra revealed the presence of amino acids, organic acids, sugars, and polyphenols. The metabolic profiles of plants with AgNP and AgNO3 were qualitatively similar to the metabolic profile of the control group, suggesting that the application of silver does not affect secondary metabolites. From the PCA, it was possible to differentiate the three treatments applied, mainly based on the content of fatty acids, pinitol, choline, and betaine.
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Glycine max , Espectroscopia de Ressonância Magnética , Metabolômica , Nanopartículas Metálicas , Plantas Geneticamente Modificadas , Prata , Glycine max/metabolismo , Glycine max/genética , Glycine max/química , Glycine max/efeitos dos fármacos , Glycine max/crescimento & desenvolvimento , Prata/metabolismo , Prata/química , Nanopartículas Metálicas/química , Espectroscopia de Ressonância Magnética/métodos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/química , Aminoácidos/metabolismo , Ácidos Graxos/metabolismo , Ácidos Graxos/químicaRESUMO
The imbalance in metal homeostasis can be associated with several human diseases, and exposure to increasing concentrations of metals promotes cell stress and toxicity. Therefore, understanding the cytotoxic effect of metal imbalance is important to unravel the biochemical mechanism of homeostasis and the action of potential protective proteins against metal toxicity. Several studies, including gene deletion in yeast, provide evidence indicating the possible indirect involvement of cochaperones from the Hsp40/DNAJA family in metal homeostasis, possibly through modulating the activity of Hsp 70.This work first investigated the effect of zinc and copper on the conformation and function of the human Hsp40 cochaperone DNAJA1, a zinc-binding protein. DNAJA1 was capable to complement the phenotype of a yeast strain deleted of the ydj1 gene, which was more sensitive to the presence of zinc and copper than the wild-type strain. To gain further insight about the role of the DNAJA family in metal binding, the recombinant human DNAJA1 protein was studied. Zinc removal from DNAJA1 affected both its stability and ability to act as a chaperone, i.e., to protect other proteins from aggregation. The reintroduction of zinc restored the native properties of DNAJA1 and, surprisingly, the addition of copper partially restored the native properties.
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Cobre , Saccharomyces cerevisiae , Humanos , Saccharomyces cerevisiae/metabolismo , Zinco/farmacologia , Proteínas de Choque Térmico HSP40/química , Chaperonas Moleculares/genética , Proteínas de Choque Térmico HSP70/metabolismoRESUMO
This work reports the evaluation of differentially expressed enzymes and proteins from transgenic and nontransgenic soybean seeds. Analysis of malondialdehyde, ascorbate peroxidase (EC 1.11.1.11), glutathione reductase (EC 1.6.4.2), and catalase (EC 1.11.1.6) revealed higher levels (29.8, 30.6, 71.4, and 35.3%, respectively) in transgenic seeds than in nontransgenic seeds. Separation of soybean seed proteins was done by two-dimensional polyacrylamide gel electrophoresis, and 192 proteins were identified by matrix-assisted laser desorption/ionization (MALDI) quadrupole time-of-flight (QTOF) mass spectrometry (MS) and electrospray ionization (ESI) QTOF MS. Additionally, the enzyme CP4 EPSPS, involved in the genetic modification, was identified by enzymatic digestions using either trypsin or chymotrypsin and ESI-QTOF MS/MS for identification. From the proteins identified, actin fragment, cytosolic glutamine synthetase, glycinin subunit G1, and glycine-rich RNA-binding protein were shown to be differentially expressed after analysis using the two-dimensional difference gel electrophoresis technique, and applying a regulator factor of 1.5 or greater.
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Glycine max/química , Glycine max/enzimologia , Plantas Geneticamente Modificadas/química , Proteômica , Sementes/química , Proteínas de Soja/genética , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Sementes/enzimologia , Sementes/genética , Sementes/metabolismo , Proteínas de Soja/química , Proteínas de Soja/metabolismo , Glycine max/genética , Glycine max/metabolismo , Espectrometria de Massas em Tandem , Eletroforese em Gel Diferencial BidimensionalRESUMO
Hydrocarbons may have a natural or anthropogenic origin and serve as a source of carbon and energy for microorganisms in Antarctic soils. Herein, 16S rRNA gene and shotgun sequencing were employed to characterize taxonomic diversity and genetic potential for hydrocarbon degradation of the microbiome from sediments of sites located in two Antarctic islands subjected to different temperatures, geochemical compositions, and levels of presumed anthropogenic impact, named: Crater Lake/Deception Island (pristine area), Whalers Bay and Fumarole Bay/Deception Island (anthropogenic-impacted area), and Hannah Point/Livingston Island (anthropogenic-impacted area). Hydrocarbon concentrations were measured for further correlation analyses with biological data. The majority of the hydrocarbon-degrading genes were affiliated to the most abundant bacterial groups of the microbiome: Proteobacteria and Actinobacteria. KEGG annotation revealed 125 catabolic genes related to aromatic hydrocarbon (styrene, toluene, ethylbenzene, xylene, naphthalene, and polycyclic hydrocarbons) and aliphatic (alkanes and cycloalkanes) pathways. Only aliphatic hydrocarbons, in low concentrations, were detected in all areas, thus not characterizing the areas under study as anthropogenically impacted or nonimpacted. The high richness and abundance of hydrocarbon-degrading genes suggest that the genetic potential of the microbiome from Antarctic sediments for hydrocarbon degradation is driven by natural hydrocarbon occurrence.
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Microbiota , Hidrocarbonetos Policíclicos Aromáticos , RNA Ribossômico 16S/genética , Regiões Antárticas , Hidrocarbonetos/metabolismo , Microbiota/genética , Microbiologia do Solo , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , Ilhas , Hidrocarbonetos Policíclicos Aromáticos/metabolismoRESUMO
We report a complete set of strategies for characterization and an accurate determination of gold in metallic nanoparticles. For this, gold nanorods (AuNR) were synthesized by using the surfactant hexadecyltrimethylammonium bromide (CTAB) as the stabilizer and shape-directing agent. The surfactant CTAB forms a bilayer structure around the nanoparticles and became a challenge for the development of the microwave-assisted decomposition of the AuNR colloid. The bilayer structure of CTAB prevents the Au3+ release for the acidic media during the decomposition procedure. To overcome this limitation, a combination of low sample volume consumption (only 200 µL), an acidic mixture of reverse aqua regia (1:3 v/v, HCl:HNO3), and sulfuric acid, and a microwave program was used. The gold quantification by ICP-MS and checked through the ICP OES, demonstrated that the seed-mediated growth method used for the AuNR synthesis has a high yield, presenting ca. 100% of gold content (ca. 100 mg L-1 of gold concentration) in the post-synthesis colloid (AuNR-total) as well as in the colloid after a washing step (AuNR-res). The microwave-assisted decomposition procedure also demonstrated to be efficient in the acidic decomposition of the gold-silver core-shell nanoparticle (Au@AgNR), which presents a high content of polyvinylpyrrolidone (PVP) (Mw ~55000 g mol-1) acting as a stabilizer, in addition to the matrix with CTAB. The results demonstrated an accurate recovery of ca. 100% of gold content for the Au@AgNR regarding the gold nanorod before the growth of the silver shell (AuNR_Core). The proposed microwave-assisted decomposition platform demonstrated to be an efficient, reliable, and robust characterization tool for the gold quantification in metallic nanoparticles, presenting no interference of the complex matrix with high organic content.
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BACKGROUND: The distribution of trace elements in tree rings although poorly known may be useful to better understand environmental changes, pollution trends, long-term droughts, forest dieback processes, and biology of trees. METHOD: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used for imaging micronutrients and potentially toxic elements distribution, allowing the investigation of trace elements at high spatial resolution within the tree rings. To ensure a more efficient determination of micronutrients and potentially toxic elements, LA-ICP-MS instrumental conditions were optimized and carbon, a major element in wood, is used as an internal standard during analysis to correct for random fluctuations. RESULTS: Spatial distributions maps of Ba, Cu, Fe, Mn, Ni, and Pb in growth layers of six tropical tree species were built-up using the LA-iMageS software, namely: Amburana cearensis (Fabaceae), Cedrela fissilis (Meliaceae), Hymenaea courbaril (Fabaceae), Maclura tinctoria (Moraceae), Parapiptadenia zehntneri (Fabaceae), Peltogyne paniculata (Fabaceae). A correlation between the trace element composition and different cell types (parenchyma, fiber, and vessel) was distinctly observed. It was observed a general pattern of Ba, Cu, Ni, Mn, and Pb accumulation mainly in the axial parenchyma and vessels. But the elemental composition of xylem cells is strongly species dependent. The multivariate analysis also points to a distinct accumulation of minerals between heartwood and sapwood in the same species. CONCLUSIONS: Imaging both essential and deleterious element distributions in the tree rings may improve visualization and can effectively contribute to understanding the lifetime metabolism of trees and evaluating the effects of environmental changes related to climatic seasonality, pollution, and future paleoclimate reconstructions.
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Terapia a Laser , Oligoelementos , Poluição Ambiental/análise , Poluição Ambiental/estatística & dados numéricos , Chumbo , Análise Espectral , Oligoelementos/análiseRESUMO
The study of metals in biological systems is an emerging scientific field, receiving great attention as a new frontier, because it brings together researchers from many areas, including biology, chemistry, geology, medicine, physics and pharmacy. New possibilities in terms of strategies and instrumentation (microwave-assisted extraction, laser ablation inductively coupled plasma mass spectrometry, Fourier transformed ion cyclotron resonance mass spectrometry and others) have greatly improved the sample preparation, identification, localization and quantification of metals in proteins, together forming the basis of metalloproteomics. Therefore, this area forms an important bridge between researchers from different backgrounds. Here, we review the techniques themselves for qualitative and quantitative metalloproteomics, and provide evidence in the form of several example of different kinds of expertise working together to produce coherent and effective results in the area.
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Metaloproteínas/metabolismo , Metais/metabolismo , Proteômica/métodos , Métodos Analíticos de Preparação de Amostras , Humanos , Marcação por Isótopo , Metaloproteínas/isolamento & purificação , Espectrofotometria AtômicaRESUMO
BACKGROUND: Imbalances in metal concentrations have been suggested to contribute to the pathophysiology of different brain disorders, such as bipolar disorder (BD) and schizophrenia (SCZ). OBJECTIVES: The aim of this exploratory study is to evaluate the association between the concentrations of macro/trace elements in serum from BD and SCZ patients considering the effects from different treatments. METHODS: Eleven subjects with SCZ, seven with BD treated with lithium (BDL) and eight subjects with BD treated with other medications except lithium (BDN) were recruited for the study, as well as eleven healthy controls (HC). Serum concentrations of eleven macro/trace elements (Se, Zn, Fe, K, Ca, Mg, P, Al, Cu, Mn, and Ni) were determined using inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: Se and Zn concentrations were significantly lower for patients with SCZ and BD in comparison to HC by one-way ANOVA test. Moreover, serum concentrations for Fe were significantly higher (p < 0.05) in BDN (548 ± 92 µg L-1) and SCZ (632 ± 279 µg L-1) in comparison to HC (421 ± 121 µg L-1). A significant negative correlation was reported between Se and Fe in BDL group (r = -0.935, p < 0.05). In addition, a significantly higher Cu/Zn ratio was determined in SCZ group against HC (ratio = 2.4, p = 0.028). CONCLUSIONS: The obtained results suggest that the imbalance in Fe concentrations is an effect of BD treatment. Lithium is supposed to have an antagonist effect for Se in BDL patients. A negative correlation reported between Fe and BMI in SCZ group could be related to antipsychotic treatment and the Cu/Zn ratio reported could be considered as a suggesting parameter to relate oxidative stress to SCZ. Future studies including larger number of patients with SCZ and BD before and after treatment are necessary to confirm the investigative results presented herein.
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Transtorno Bipolar/tratamento farmacológico , Lítio/farmacologia , Esquizofrenia/tratamento farmacológico , Oligoelementos/farmacologia , Adulto , Biomarcadores/sangue , Transtorno Bipolar/sangue , Transtorno Bipolar/diagnóstico , Estudos de Coortes , Feminino , Humanos , Lítio/administração & dosagem , Lítio/sangue , Masculino , Espectrometria de Massas , Metabolômica , Estresse Oxidativo/efeitos dos fármacos , Proteômica , Esquizofrenia/sangue , Esquizofrenia/diagnóstico , Oligoelementos/administração & dosagem , Oligoelementos/sangueRESUMO
Alongside the Brazil nut's role as an excellent source of vitamins, oil, fatty acids, lipids and nutrients, it is also recognized as a rich source of selenium. The pathway along which selenium and sulfur are metabolized in plants is theorized to be the same as that used for tellurium. Total tellurium content and its bioaccessibility are then evaluated by ICP-MS. Interferences and sample preparation are evaluated for the accurate determination of tellurium, and the accuracy determined through analysis of the certified reference material 1643e. A concentration of 4.02⯱â¯0.391â¯ngâ¯g-1 is obtained as an average concentration through external and internal calibrations. Through this reliable result, tellurium bioaccessibility in Brazil nuts is obtained via an in vitro validated unified bioaccessibility method. Values of 32% and 30% of total tellurium are available in the gastric and gastrointestinal fractions, respectively.
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Nozes/química , Nozes/metabolismo , Telúrio/análise , Telúrio/metabolismo , Brasil , Espectrometria de MassasRESUMO
In this paper, Cu, Fe, Mn and Zn contents in transgenic (T - MSOY7122RR) and non-transgenic (NT - MSOY8200) soybean seeds, sown at summer and winter cultivation periods are investigated using four microwave decomposition methods. Student's t tests demonstrate significant differences (p=0.05; n=4), for Cu, Mn and Zn (namely, 8, 9 and 26% higher concentrations in T compared to NT seeds, respectively). Through principal component analysis, precursor and successor soybean seeds are identified. Cu is demonstrated to play an important role in the differentiation of the cultivars, whereas Fe and Zn are of particular relevance in the classification of seeds cultivated in winter against those in summer. Using in vitro extraction based on the Unified Bioaccessibility Method, the bioaccessibility of the above nutrients is proven to differ in both the gastric and gastrointestinal phases on the basis of the transgenesis and the cultivation periods.
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Digestão , Glycine max/química , Micronutrientes/metabolismo , Plantas Geneticamente Modificadas , Sementes/química , Animais , Disponibilidade Biológica , Cobre/metabolismo , Ferro/metabolismo , Manganês/metabolismo , Zinco/metabolismoRESUMO
The uptake and accumulation of Cd in sunflower seeds represents an important pathway for imputing potentially toxic metals into human and animal food. In this way, bioimaging of Cd and micronutrients (Cu, Fe and Mn) in the seeds of sunflower grown in soil contaminated with Cd are performed. For this task, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used in quantitative approach, considering four groups: precursor, control, Cd-low (50mg) and Cd-high (700mg). For attaining our proposals, ICP-MS (nebulizer and auxiliary flow rates and radiofrequency power) and LA (laser intensity, frequency and spot size) parameters were optimized, and the analytical signal improved to 197%, 217%, 232%, and 283%, for 57Fe, 112Cd, 55Mn and 63Cu, respectively. The accuracy of proposed method using LA-ICP-MS is evaluated comparing the CRM results (Tomato leaves, NIST SRM 1573a). No difference is found at 95% confidence level. Regarding Cd accumulation in sunflower seeds, the results indicated that cadmium is translocated to seeds, and the cotyledons showed the highest concentration (Cd-high group), ranging from 10 to 20µgg-1. Considering both total concentration and the distribution in the seeds, Cd uptake is responsible to the homeostasis misbalance of micronutrients, which play an essential role in the sunflower metabolism. Such results highlight the importance of bioimaging evaluation, in the translocation and accumulation of metals, contributing to expand the information available of this culture.
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Helianthus/metabolismo , Lasers , Metais Pesados/metabolismo , Imagem Molecular , Sementes/metabolismo , Transporte Biológico , Cádmio/metabolismo , Calibragem , Cobre/metabolismo , Ferro/metabolismo , Manganês/metabolismoRESUMO
The mitigation of Cd-stress through Si addition to Arabidopsis thaliana cultivation is evaluated in terms of total metal content, proteomic and enzymatic approaches. Four different treatment are evaluated: TC (control, without Si or Cd addition), T1 (with Si addition), T2 (with Cd addition), and T3 (with Si and Cd addition). Through the total determination of Cd and Si in Arabidopsis leaves, the Cd concentration decreased by half when T2 is compared with T3 treatment. In terms of proteomic approach, some differential protein species are achieved by comparative proteomics through 2-D DIGE of all treatments evaluated. Fifty six differential abundant proteins spots (abundance factor ≥1.5) are detected, and 32 of them accurately characterized and identified through nESI-LC-MS/MS. These proteins are differentially produced due to Cd and/or Si treatments, which mainly include proteins associated with disease/defense, energy and metabolism. The most difference in the abundance of proteins is found due to the presence or absence of Si in plants treated with Cd. Regarding the enzymatic approaches, a major increase is found on APX, CAT and GR activities (5.0, 3.5, and 1.5-fold, respectively). The same is observed for the MDA concentration because an increase of 3-fold is found when TC are compared to those treated with T2. However, when T3 plants are evaluated, the enzymes activities are similar to TC plants. Differences ranging from 6.5 to 21% are detected considering the activity of SOD in the treatments (T1-T3 x TC). The decreased activities of CAT, APX and GR and lower MDA concentration indicate a lower reactive oxygen species production in plants treated with Cd and Si. Based on a proteomics point of view it is possible to conclude that Si-Cd interactions occur at protein level and allow plants to respond effectively to the Cd toxicity, revealing the active involvement of Si on mechanisms involved in Si-induced Cd tolerance in Arabidopsis plants. Additionally, from an enzymatic point of view, it is possible to conclude that Si positively interferes diminishing the negative effects of Cd in Arabidopsis by decreasing the reactive oxygen species generation and increasing the antioxidative enzyme activity.
Assuntos
Arabidopsis/enzimologia , Arabidopsis/crescimento & desenvolvimento , Cádmio/toxicidade , Metais/metabolismo , Proteômica , Silício/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/fisiologia , Cádmio/metabolismo , Eletroforese em Gel Bidimensional , Peroxidação de Lipídeos , Malondialdeído/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Ligação Proteica , Mapas de Interação de Proteínas , Silício/metabolismoRESUMO
This paper describes for the first time the use of paper-based analytical devices at crime scenes to estimate the post-mortem interval (PMI), based on the colorimetric determination of Fe2+ in vitreous humour (VH) samples. Experimental parameters such as the paper substrate, the microzone diameter, the sample volume and the 1,10-phenanthroline (o-phen) concentration were optimised in order to ensure the best analytical performance. Grade 1 CHR paper, microzone with diameter of 5 mm, a sample volume of 4 µL and an o-phen concentration of 0.05 mol/L were chosen as the optimum experimental conditions. A good linear response was observed for a concentration range of Fe2+ between 2 and 10 mg/L and the calculated values for the limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 0.9 mg/L, respectively. The specificity of the Fe2+ colorimetric response was tested in the presence of the main interfering agents and no significant differences were found. After selecting the ideal experimental conditions, four HV samples were investigated on paper-based devices. The concentration levels of Fe2+ achieved for samples #1, #2, #3 and #4 were 0.5 ± 0.1, 0.7 ± 0.1, 1.2 ± 0.1 and 15.1 ± 0.1 mg/L, respectively. These values are in good agreement with those calculated by ICP-MS. It important to note that the concentration levels measured using both techniques are proportional to the PMI. The limitation of the proposed analytical device is that it is restricted to a PMI greater than 1 day. The capability of providing an immediate answer about the PMI on the crime scene without any sophisticated instrumentation is a great achievement in modern instrumentation for forensic chemistry. The strategy proposed in this study could be helpful in many criminal investigations.
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Dispositivos Lab-On-A-Chip , Mudanças Depois da Morte , Corpo Vítreo/química , Autopsia , Crime , Humanos , Ferro/análiseRESUMO
The spatial distribution of chemical elements in different types of samples is an important field in several research areas such as biology, paleontology or biomedicine, among others. Elemental distribution imaging by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is an effective technique for qualitative and quantitative imaging due to its high spatial resolution and sensitivity. By applying this technique, vast amounts of raw data are generated to obtain high-quality images, essentially making the use of specific LA-ICP-MS imaging software that can process such data absolutely mandatory. Since existing solutions are usually commercial or hard-to-use for average users, this work introduces LA-iMageS, an open-source, free-to-use multiplatform application for fast and automatic generation of high-quality elemental distribution bioimages from LA-ICP-MS data in the PerkinElmer Elan XL format, whose results can be directly exported to external applications for further analysis. A key strength of LA-iMageS is its substantial added value for users, with particular regard to the customization of the elemental distribution bioimages, which allows, among other features, the ability to change color maps, increase image resolution or toggle between 2D and 3D visualizations.