Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
1.
Int J Mol Sci ; 25(6)2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38542366

RESUMO

The ongoing anthropogenic pollution of the biosphere with As, Cd, Hg and Pb will inevitably result in an increased influx of their corresponding toxic metal(loid) species into the bloodstream of human populations, including children and pregnant women. To delineate whether the measurable concentrations of these inorganic pollutants in the bloodstream are tolerable or implicated in the onset of environmental diseases urgently requires new insight into their dynamic bioinorganic chemistry in the bloodstream-organ system. Owing to the human exposure to multiple toxic metal(loid) species, the mechanism of chronic toxicity of each of these needs to be integrated into a framework to better define the underlying exposure-disease relationship. Accordingly, this review highlights some recent advances into the bioinorganic chemistry of the Cd2+, Hg2+ and CH3Hg+ in blood plasma, red blood cells and target organs and provides a first glimpse of their emerging mechanisms of chronic toxicity. Although many important knowledge gaps remain, it is essential to design experiments with the intent of refining these mechanisms to eventually establish a framework that may allow us to causally link the cumulative exposure of human populations to multiple toxic metal(loid) species with environmental diseases of unknown etiology that do not appear to have a genetic origin. Thus, researchers from a variety of scientific disciplines need to contribute to this interdisciplinary effort to rationally address this public health threat which may require the implementation of stronger regulatory requirements to improve planetary and human health, which are fundamentally intertwined.


Assuntos
Poluentes Ambientais , Mercúrio , Metais Pesados , Poluentes do Solo , Criança , Humanos , Feminino , Gravidez , Cádmio/análise , Mercúrio/análise , Intoxicação por Metais Pesados , Poluição Ambiental , Monitoramento Ambiental , Metais Pesados/toxicidade , Metais Pesados/análise , Medição de Risco , China
2.
Biometals ; 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37815752

RESUMO

The quantification of arsenic, mercury, cadmium and lead in the human bloodstream is routinely used today to assess exposure to these toxic metal(loid)s, but the interpretation of the obtained data in terms of their cumulative health relevance remains problematic. Seemingly unrelated to this, epidemiological studies strongly suggest that the simultaneous chronic exposure to these environmental pollutants is associated with the etiology of autism, type 2 diabetes, irritable bowel disease and other diseases. This from a public health point of view undesirable situation urgently requires research initiatives to establish functional connections between human exposure to multiple toxic metal(loid) species and adverse health effects. One way to establish causal exposure-response relationships is a molecular toxicology approach, which requires one to unravel the biomolecular mechanisms that unfold after individual toxic metal(loid)s enter the bloodstream/organ nexus as these interactions ultimately determine which metabolites impinge on target organs and thus provide mechanistic links to diseases of unknown etiology. In an attempt to underscore the importance of the toxicological chemistry of metal(loid)s in the bloodstream, this review summarizes recent progress into relevant bioinorganic processes that are implicated in the etiology of adverse organ-based health effects and possibly diseases. A better understanding of these bioinorganic processes will not only help to improve the regulatory framework to better protect humans from the adverse effects of toxic metal(loid) species, but also represents an important starting point for the development of treatments to ameliorate pollution-induced adverse health effects on human populations, including pregnant women, the fetus and children.

3.
Molecules ; 28(19)2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37836605

RESUMO

The anthropogenic release of Hg is associated with an increased human exposure risk. Since Hg2+ and MeHg+ have a high affinity for thiols, their interaction with L-glutathione (GSH) within mammalian cells is fundamentally involved in their toxicological chemistry and excretion. To gain insight into the interaction of these mercurials with multiple small molecular weight thiols, we have investigated their competitive interactions with GSH and N-acetylcysteine (NAC) at near-physiological conditions, using a liquid chromatographic approach. This approach involved the injection of each mercurial onto a reversed-phase (RP)-HPLC column (37 °C) using a PBS buffer mobile phase containing 5.0 mM GSH to simulate cytosolic conditions with Hg being detected in the column effluent by an inductively coupled plasma atomic emission spectrometer (ICP-AES). When the 5.0 mM GSH mobile phase was amended with up to 10 mM NAC, gradually increasing retention times of both mercurials were observed. To explain this behavior, the experiment with 5.0 mM NAC and 5.0 mM GSH was replicated using 50 mM Tris buffer (pH 7.4), and the Hg-containing fractions were analyzed by electrospray ionization mass spectrometry. The results revealed the presence of Hg(GS)(NAC) and Hg(NAC)2 for Hg2+ and MeHg(GS) and MeHg(NAC) for MeHg+, which suggests that the coordination/displacement of GS-moieties from each mercurial by the more hydrophobic NAC can explain their retention behavior. Since the biotransformations of both mercurials were observed at near-physiological conditions, they are of toxicological relevance as they provide a biomolecular explanation for some results that were obtained when animals were administered with each mercurial and NAC.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Animais , Humanos , Acetilcisteína , Compostos de Metilmercúrio/química , Mercúrio/análise , Glutationa/análise , Compostos de Sulfidrila , Mamíferos
4.
Molecules ; 26(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199902

RESUMO

Globally, human exposure to environmental pollutants causes an estimated 9 million deaths per year and it could also be implicated in the etiology of diseases that do not appear to have a genetic origin. Accordingly, there is a need to gain information about the biomolecular mechanisms that causally link exposure to inorganic environmental pollutants with distinct adverse health effects. Although the analysis of blood plasma and red blood cell (RBC) cytosol can provide important biochemical information about these mechanisms, the inherent complexity of these biological matrices can make this a difficult task. In this perspective, we will examine the use of metalloentities that are present in plasma and RBC cytosol as potential exposure biomarkers to assess human exposure to inorganic pollutants. Our primary objective is to explore the principal bioinorganic processes that contribute to increased or decreased metalloprotein concentrations in plasma and/or RBC cytosol. Furthermore, we will also identify metabolites which can form in the bloodstream and contain essential as well as toxic metals for use as exposure biomarkers. While the latter metal species represent useful biomarkers for short-term exposure, endogenous plasma metalloproteins represent indicators to assess the long-term exposure of an individual to inorganic pollutants. Based on these considerations, the quantification of metalloentities in blood plasma and/or RBC cytosol is identified as a feasible research avenue to better understand the adverse health effects that are associated with chronic exposure of various human populations to inorganic pollutants. Exposure to these pollutants will likely increase as a consequence of technological advances, including the fast-growing applications of metal-based engineering nanomaterials.


Assuntos
Biomarcadores/sangue , Intoxicação por Metais Pesados/diagnóstico , Metaloproteínas/sangue , Citosol/química , Eritrócitos/química , Regulação da Expressão Gênica , Intoxicação por Metais Pesados/sangue , Humanos , Metabolômica , Metais Pesados/sangue , Metais Pesados/toxicidade , Plasma/química
5.
J Environ Sci (China) ; 57: 249-257, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28647246

RESUMO

Although Cd is a pollutant of public health relevance, many dietary sources from which it can be absorbed into human tissues remain unknown. While it is well established that the biogeochemical cycle of Cd involves its complexation with environment-derived ligands (e.g., humic acids, HAs) and anthropogenic ones (e.g., chelating agents, CAs), the interaction of Cd with both of these ligands is less well understood. To gain insight, a HA-Cd complex was injected on a size-exclusion chromatography (SEC) column coupled on-line with a flame atomic absorption spectrometer (FAAS) using 10mmol/L Tris buffer (pH8.0) as the mobile phase. This approach allowed us to observe the intact HA-Cd complex and the retention behavior of Cd as a function of 2-20µmol/L concentrations of ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) or methylglycinediacetic acid (MGDA) that were added to the mobile phase. An increase of the retention time of Cd was indicative of a partial or complete abstraction of Cd from HA. Our results revealed that all CAs abstracted Cd from the HA-Cd complex at concentrations of 5µmol/L, while MGDA and DTPA were effective at 2µmol/L. The bioavailability of some of the on-column formed CA-Cd complexes explains the previously reported increased accumulation of Cd in periphyton in the ecosystem downstream of wastewater treatment plants. In addition, our results imply that the use of effluents which contain CAs and Cd for the irrigation of food crops can introduce Cd into the food supply and compromise food safety.


Assuntos
Cádmio/química , Substâncias Húmicas , Modelos Químicos , Poluentes do Solo/química , Cádmio/análise , Quelantes/química , Ácido Edético/química , Poluentes do Solo/análise
6.
Drug Discov Today Technol ; 16: 24-30, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26547418

RESUMO

Understanding the fate of metallodrugs in the bloodstream is critical to assess if the parent drug has a reasonable probability to reach the intended target tissue and to predict toxic side-effects. To gain insight into these processes, we have added pharmacologically relevant doses of metallodrugs to blood plasma and applied an LC-method to directly analyze the latter for metallodrug metabolites. Using human or rabbit plasma, this LC-method was employed to gain insight into the metabolism of clinically used as well as emerging anticancer metallodrugs and to unravel the mechanisms by which small molecular weight compounds that - when co-administered with a metallodrug - decrease the toxic side-effects of the metallodrug by modulating its metabolism. The results suggest that the developed LC-method is useful to probe the fate of biologically active novel metal-complexes in plasma to help select those which may be advanced to animal/clinical studies to ultimately develop safer metallodrugs.


Assuntos
Antineoplásicos/sangue , Antineoplásicos/metabolismo , Complexos de Coordenação/sangue , Complexos de Coordenação/metabolismo , Animais , Cromatografia Líquida/métodos , Humanos , Ligação Proteica/fisiologia , Coelhos
7.
J Biol Inorg Chem ; 19(6): 1049-53, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24458238

RESUMO

Single drug-based cancer therapies are frequently associated with the development of drug resistance. To overcome this problem, combination therapy with two or more anticancer drugs is a promising strategy, but clinical studies are logistically challenging and costly. Intermediary in vitro studies, however, can provide critical insight to decide whether one should proceed to in vivo studies. To this end, cisplatin and the Ru-based anticancer drug NAMI-A were added to human plasma and the size distribution of Pt-containing and Ru-containing entities was determined over a 2 h period. The results revealed a dramatically different rate of plasma protein binding for each drug and/or their hydrolysis products. Both drugs bound to the same apparent plasma proteins, but crucially they did not adversely affect each other's metabolism. Therefore, combination therapy of patients with these metallodrugs should be further assessed in clinical studies in order to systematically develop an effective combination therapy protocol to prevent the resurgence of cancer.


Assuntos
Cisplatino/sangue , Cisplatino/metabolismo , Dimetil Sulfóxido/análogos & derivados , Compostos Organometálicos/sangue , Compostos Organometálicos/metabolismo , Cisplatino/química , Dimetil Sulfóxido/sangue , Dimetil Sulfóxido/química , Dimetil Sulfóxido/metabolismo , Humanos , Compostos Organometálicos/química , Compostos de Rutênio , Espectrofotometria Atômica
8.
Anal Bioanal Chem ; 406(24): 5853-65, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25064598

RESUMO

The biochemical response of mice (Mus musculus) to acute subcutaneous inorganic-mercury exposure was assessed over a 14-day period by analyzing cytosolic extracts of the liver, the kidneys, and blood plasma. Integrated metallomic and metabolomic approaches using elemental and molecular-mass spectrometry were used to obtain comprehensive insight into the toxicological effects of mercury regarding its distribution and possible perturbation of metabolic pathways. The metallomic approach involved the use of size-exclusion chromatography (SEC) coupled with multiaffinity chromatography inductively coupled plasma-mass spectrometry (ICP-MS) and isotopic-dilution analysis. The metabolomic approach involved the direct infusion of polar and lipophilic tissue extracts into a mass spectrometer (DIMS) in the positive and negative acquisition mode (ESI+and ESI-). The use of SEC-ICP-MS enabled us to detect changes in the metalloproteome in the liver and the kidneys during the exposure period, and revealed that interactions between Hg and endogenous Cu and Zn adversely affected the homeostasis of these essential metals. The detection of an Hg-Se detoxification product in mouse plasma substantiated the known interaction between Hg and Se in mammals. Use of DIMS in conjunction with partial-least-squares discriminant analysis (PLS-DA) uncovered time-dependent changes of endogenous metabolites over time, corroborated by histopathology investigation of specific mouse tissues. The perturbations of endogenous metabolic profiles were explained in terms of the adverse effect of mercury on energy metabolism (e.g. glycolysis, Krebs cycle), the degradation of membrane phospholipids (apoptosis), and increased levels of specific lipids in plasma. In summary, use of an SEC-ICP-MS-based metallomics approach in conjunction with molecular-mass-spectrometry-based metabolomics is revealed as a promising strategy to more comprehensively investigate the toxicological effects of harmful environmental pollutants and xenobiotics.


Assuntos
Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Espectrometria de Massas/métodos , Mercúrio/análise , Mercúrio/toxicidade , Animais , Rim/química , Rim/metabolismo , Fígado/química , Fígado/metabolismo , Mercúrio/sangue , Metabolômica , Camundongos
9.
Metallomics ; 16(6)2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38811147

RESUMO

Red blood cells (RBCs) constitute ∼50% of the bloodstream and represent an important target for environmental pollutants and bacterial/viral infections, which can result in their rupture. In addition, diseases such as sickle cell anaemia and paroxysmal nocturnal haemoglobinuria can also result in the rupture of RBCs, which can be potentially life-threatening. With regard to the release of cytosolic metalloproteins from RBCs into the blood-organ system, the biochemical fate of haemoglobin is rather well understood, while comparatively little is known about another highly abundant Zn-metalloprotein, carbonic anhydrase (CA I). To gain insight into the interaction of CA I with human blood plasma constituents, we have employed a metallomics tool comprised of size-exclusion chromatography (SEC) coupled online with an inductively coupled plasma atomic emission spectrometer (ICP-AES), which allows to simultaneously observe all Cu, Fe, and Zn-metalloproteins. After the addition of CA I to human blood plasma incubated at 37°C, the SEC-ICP-AES analysis using phosphate buffered saline (pH 7.4) after 5 min, 1 h, and 2 h revealed that CA I eluted after all endogenous Zn-metalloproteins in the 30 kDa range. Matrix-assisted laser desorption-time of flight mass spectrometry analysis of the collected Zn-peak confirmed that CA I eluted from the column intact. Our in vitro results suggest that CA I released from RBCs to plasma remains free and may be actively involved in health-relevant adverse processes that unfold at the bloodstream-endothelial interface, including atherosclerosis and vision loss.


Assuntos
Anidrase Carbônica I , Eritrócitos , Humanos , Eritrócitos/metabolismo , Anidrase Carbônica I/metabolismo , Zinco/metabolismo , Zinco/sangue , Cromatografia em Gel , Plasma/metabolismo , Plasma/química , Espectrofotometria Atômica
10.
J Inorg Biochem ; 252: 112479, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38218139

RESUMO

Solution interactions of three organomercury compounds, i.e., methylmercury chloride, thimerosal and phenylmercury acetate, with a group of biochemically relevant proteins, namely cytochrome c (Cyt c), ribonuclease A (RNase A), carbonic anhydrase I (hCA I), superoxide dismutase (SOD), and serum albumin (HSA), were investigated using an established ESI MS approach. Temporal analysis of sample aliquots provided insight into the binding kinetics, while comparative analysis of the obtained mass spectra disclosed adduct formation of each mercurial with the tested proteins and the relative abundance of the species. The three organomercurials bind, exclusively and tightly, to free cysteine residues as no binding was observed in the case of proteins lacking such groups. hCA I, SOD and HSA formed distinct mercury adducts, preserving the Hg bound alkyl/aryl ligands; yet, the three organomercurials displayed significant differences in reactivity in relation to their chemical structure. The investigation was then extended to analyze the reactions with the C-terminal dodecapeptide of the enzyme human thioredoxin reductase, which contains a characteristic selenol-thiol moiety: tight Hg binding was observed. Notably, this peptide was able to remove effectively and completely the alkyl/aryl ligands of the three tested organomercurials; this behavior may be relevant to the detoxification mechanism of organomercurials in mammals. Finally, a competition experiment was carried out to establish whether protein bound mercury centers may be displaced by other competing metals. Interestingly, and quite unexpectedly, we observed that a protein bound mercury fragment may be partially displaced from its coordination site in hCA I by the medicinal gold compound auranofin.


Assuntos
Mercúrio , Compostos Organomercúricos , Animais , Humanos , Compostos Organomercúricos/metabolismo , Peptídeos , Ouro , Superóxido Dismutase , Mamíferos/metabolismo
11.
Toxics ; 11(7)2023 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-37505565

RESUMO

Although chronic low-level exposure to Hg2+ and Cd2+ causes human nephrotoxicity, the bioinorganic processes that deliver them to their target organs are poorly understood. Since the plasma protein human serum albumin (HSA) has distinct binding sites for these metal ions, we wanted to gain insight into these translocation processes and have employed size-exclusion chromatography coupled on-line to an inductively coupled plasma atomic emission spectrometer using phosphate-buffered saline mobile phases. When HSA 'labeled' with Hg2+ and Cd2+ (1:0.1:0.1) using 300 µM of L-methionine was analyzed, the co-elution of a single C, S, Cd, and Hg peak was observed, which implied the intact bis-metalated HSA complex. Since human plasma contains small molecular weight thiols and sulfur-containing metabolites, we analyzed the bis-metalated HSA complex with mobile phases containing 50-200 µM of L-cysteine (Cys), D,L-homocysteine (hCys), or glutathione (GSH), which provided insight into the comparative mobilization of each metal from their respective binding sites on HSA. Interestingly, 50 µM Cys, hCys, or GSH mobilized Hg2+ from its HSA binding site but only partially mobilized Cd2+ from its binding site. Since these findings were obtained at conditions simulating near-physiological conditions of plasma, they provide a feasible explanation for the higher 'mobility' of Hg2+ and its concomitant interaction with mammalian target organs compared to Cd2+. Furthermore, 50 µM Cys resulted in the co-elution of similar-sized Hg and Cd species, which provides a biomolecular explanation for the nephrotoxicity of Hg2+ and Cd2+.

12.
Toxics ; 11(4)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37112521

RESUMO

The exposure of humans to Cd exerts adverse human health effects at low chronic exposure doses, but the underlying biomolecular mechanisms are incompletely understood. To gain insight into the toxicologically relevant chemistry of Cd2+ in the bloodstream, we employed an anion-exchange HPLC coupled to a flame atomic absorption spectrometer (FAAS) using a mobile phase of 100 mM NaCl with 5 mM Tris-buffer (pH 7.4) to resemble protein-free blood plasma. The injection of Cd2+ onto this HPLC-FAAS system was associated with the elution of a Cd peak that corresponded to [CdCl3]-/[CdCl4]2- complexes. The addition of 0.1-10 mM L-cysteine (Cys) to the mobile phase significantly affected the retention behavior of Cd2+, which was rationalized by the on-column formation of mixed CdCysxCly complexes. From a toxicological point of view, the results obtained with 0.1 and 0.2 mM Cys were the most relevant because they resembled plasma concentrations. The corresponding Cd-containing (~30 µM) fractions were analyzed by X-ray absorption spectroscopy and revealed an increased sulfur coordination to Cd2+ when the Cys concentration was increased from 0.1 to 0.2 mM. The putative formation of these toxicologically relevant Cd species in blood plasma was implicated in the Cd uptake into target organs and underscores the notion that a better understanding of the metabolism of Cd in the bloodstream is critical to causally link human exposure with organ-based toxicological effects.

13.
Artigo em Inglês | MEDLINE | ID: mdl-22217093

RESUMO

Hg(2+) and CH(3)Hg(+) are frequently encountered in the environment either as free ions or complexed with organic matter, such as humic acids. The majority of the reported HPLC-based separations of environmental mercury species, however, separate Hg(2+) from CH(3)Hg(+) in which the former species elutes close to the void volume. To detect mercury-species in environmental waters that may have so far escaped detection, a separation method is needed that sufficiently retains both Hg(2+) and CH(3)Hg(+). One way to develop such a method is to increase the retention of Hg(2+) and CH(3)Hg(+) using existing HPLC separations. We here report on the improvement of a previously reported RP-HPLC-based separation of Hg(2+) and CH(3)Hg(+) that employed a 100 % aqueous mobile phase [10 mM L-cysteine (Cys) in 50 mM phosphate buffer (pH 7.5)]. To increase the retention of Hg(2+), Cys was replaced by the comparatively more hydrophobic N-acetylcysteine (N-Cys). To achieve a compromise between an increased retention of Hg(2+) and its baseline separation from CH(3)Hg(+) in the shortest possible analysis time, the retention behavior of both mercurials was investigated on two RP-HPLC columns with mobile phases that contained mixtures of Cys and N-Cys in which the overall thiol concentration was maintained at 10 mM. An optimal separation of both mercurials could be achieved in ∼540 s using a Gemini C(18) HPLC column (150 × 4.6 mm I.D.) and a mobile phase comprised of 7.5 mM N-Cys and 2.5 Cys in 50 mM phosphate buffer (pH 7.4). Coupling the developed HPLC separation with an inductively coupled plasma mass spectrometer should allow one to detect mercury species other than Hg(2+) and CH(3)Hg(+) in environmental waters. The detection of such species is critical to better understand the mobilization of mercury species from natural and anthropogenic pollution sources.


Assuntos
Mercúrio/isolamento & purificação , Compostos de Metilmercúrio/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Acetilcisteína/química , Cromatografia Líquida de Alta Pressão/métodos , Cisteína/química , Mercúrio/química , Compostos de Metilmercúrio/química , Espectrofotometria Atômica , Poluentes Químicos da Água/química
14.
Metallomics ; 14(3)2022 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35150279

RESUMO

Methylmercury (MeHg) is one of the most potent neurotoxins to which humans are exposed via the consumption of fish, from which it is effectively absorbed via the gastrointestinal tract into the bloodstream. Its interactions with plasma proteins, small-molecular-weight (SMW) molecules, and red blood cells, however, are incompletely understood, but critical as they determine whether and how much MeHg reaches target organs. To better define the role that SMW thiols play in the delivery of MeHg to known transporters located at the placental and blood-brain barrier, we have employed size exclusion chromatography-inductively coupled plasma-atomic emission spectroscopy to analyze MeHg-spiked rabbit plasma in the absence and presence of SMW thiols dissolved in the phosphate-buffered saline buffer mobile phase. While 300 µM methionine did not affect the binding of MeHg to rabbit serum albumin (RSA), cysteine (Cys), homocysteine (hCys), and glutathione resulted in the elution of the main Hg peak in the SMW elution range. In addition, 50 µM of hCys or Cys in the mobile phase resulted in the mobilization of MeHg from RSA in rabbit plasma and from pure RSA in solution. The Hg peak that eluted in the SMW elution range (50 µM of hCys) was identified by electrospray ionization-mass spectrometry as an MeHg-hCys complex. Since l-type amino acid transporters are present at the blood-brain barrier (BBB), which facilitate the uptake of MeHg-Cys species into the brain, our results contribute to establish the bioinorganic mechanisms that deliver MeHg to the BBB, which is critical to predict organ-based adverse health effects.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Animais , Feminino , Homocisteína , Compostos de Metilmercúrio/química , Placenta/metabolismo , Gravidez , Coelhos , Albumina Sérica/metabolismo , Compostos de Sulfidrila/metabolismo
15.
PLoS One ; 17(1): e0262160, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35020753

RESUMO

Advanced analytical methods play an important role in quantifying serum disease biomarkers. The problem of separating thousands of proteins can be reduced by analyzing for a 'sub-proteome', such as the 'metalloproteome', defined as all proteins that contain bound metals. We employed size exclusion chromatography (SEC) coupled to an inductively coupled plasma atomic emission spectrometer (ICP-AES) to analyze plasma from multiple sclerosis (MS) participants (n = 21), acute ischemic stroke (AIS) participants (n = 17) and healthy controls (n = 21) for Fe, Cu and Zn-metalloproteins. Using ANOVA analysis to compare the mean peak areas among the groups revealed no statistically significant differences for ceruloplasmin (p = 0.31), α2macroglobulin (p = 0.51) and transferrin (p = 0.31). However, a statistically significant difference was observed for the haptoglobin-hemoglobin (Hp-Hb) complex (p = 0.04), being driven by the difference between the control group and AIS (p = 0.012), but not with the MS group (p = 0.13), based on Dunnes test. A linear regression model for Hp-Hb complex with the groups now adjusted for age found no statistically significant differences between the groups (p = 0.95), but was suggestive for age (p = 0.057). To measure the strength of association between the Hp-Hb complex and age without possible modifications due to disease, we calculated the Spearman rank correlation in the healthy controls. The latter revealed a positive association (r = 0.39, 95% Confidence Interval = (-0.05, 0.83), which suggests that either the removal of Hp-Hb complexes from the blood circulation slows with age or that the release of Hb from red blood cells increases with age. We also observed that the Fe-peak corresponding to the Hp-Hb complex eluted ~100 s later in ~14% of all study samples, which was not correlated with age or disease diagnosis, but is consistent with the presence of the smaller Hp (1-1) isoform in 15% of the population.


Assuntos
Haptoglobinas/análise , Hemoglobinas/análise , Metaloproteínas/sangue , Adulto , Estudos de Casos e Controles , Ceruloplasmina/análise , Cromatografia em Gel , Cobre/análise , Cobre/isolamento & purificação , Feminino , Humanos , Ferro/análise , Ferro/isolamento & purificação , AVC Isquêmico/metabolismo , AVC Isquêmico/patologia , Masculino , Metaloproteínas/isolamento & purificação , Pessoa de Meia-Idade , Esclerose Múltipla/metabolismo , Esclerose Múltipla/patologia , alfa 2-Macroglobulinas Associadas à Gravidez/análise , Espectrofotometria Atômica , Transferrina/análise
16.
J Inorg Biochem ; 216: 111279, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33413916

RESUMO

The chronic exposure of human populations to toxic metals remains a global public health concern. Although chronic Cd exposure is linked to kidney damage, osteoporosis and cancer, the underlying biomolecular mechanisms remain incompletely understood. Since other diseases could also be causally linked to chronic Cd exposure, a systems toxicology-based approach is needed to gain new insight into the underlying exposure-disease relationship. This approach requires one to integrate the cascade of dynamic bioinorganic chemistry events that unfold in the bloodstream after Cd enters with toxicological events that unfold in target organs over time. To this end, we have conducted a systematic literature search to identify all molecular targets of Cd in plasma and in red blood cells (RBCs). Based on this information it is impossible to describe the metabolism of Cd and the toxicological relevance of it binding to molecular targets in/on RBCs is elusive. Perhaps most importantly, the role that peptides, amino acids and inorganic ions, including HCO3-, Cl- and HSeO3- play in terms of mediating the translocation of Cd to target organs and its detoxification is poorly understood. Causally linking human exposure to this metal with diseases requires a much better integration of the bioinorganic chemistry of Cd that unfolds in the bloodstream with target organs. This from a public health point of view important goal will require collaborations between scientists from different disciplines to untangle the complex mechanisms which causally link Cd exposure to disease.


Assuntos
Cádmio/farmacocinética , Cádmio/toxicidade , Eritrócitos/metabolismo , Humanos
17.
Curr Top Med Chem ; 21(1): 48-58, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32600232

RESUMO

Although metallodrugs are used to treat a variety of human disorders and exhibit a remarkable diversity of therapeutic properties, they constitute only a tiny minority of all medicinal drugs that are currently on the market. This undesirable situation must be partially attributed to our general lack of understanding the fate of metallodrugs in the extremely ligand-rich environment of the bloodstream. The challenge of gaining insight into these bioinorganic processes can be overcome by the application of 'metallomics tools', which involve the analysis of biological fluids (e.g., blood plasma) with a separation method in conjunction with multi-element specific detectors. To this end, we have developed a metallomics tool that is based on size-exclusion chromatography (SEC) hyphenated to an inductively coupled plasma atomic emission spectrometer (ICP-AES). After the successful application of SEC-ICPAES to analyze plasma for endogenous copper, iron and zinc-metalloproteins, it was subsequently applied to probe the metabolism of a variety of metal-based anticancer drugs in plasma. The versatility of this metallomics tool is exemplified by the fact that it has provided insight into the metabolism of individual Pt-based drugs, the modulation of the metabolism of cisplatin by sulfur-containing compounds, the metabolism of two metal-based drugs that contain different metals as well as a bimetallic anticancer drug, which contained two different metals. After adding pharmacologically relevant doses of metallodrugs to plasma, the temporal analysis of aliquots by SEC-ICP-AES allows to observe metal-protein adducts, metallodrug-derived degradation products and the parent metallodrug(s). This unique capability allows to obtain comprehensive insight into the fate of metal-based drugs in plasma and can be extended to in vivo studies. Thus, the application of this metallomics tool to probe the fate of novel metalcomplexes that exert the desired biological activity in plasma has the potential to advance more of these to animal/preclinical studies to fully explore the potential that metallodrugs inherently offer.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Metaloproteínas/metabolismo , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/sangue , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/sangue , Complexos de Coordenação/química , Humanos , Metaloproteínas/sangue , Metaloproteínas/química , Neoplasias/sangue , Neoplasias/patologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-32305711

RESUMO

The bimetallic metal complex Titanocref exhibits relevant anticancer activity, but it is unknown if it is stable to reach target tissues intact. To gain insight, a pharmacologically relevant dose was added to human blood plasma and the mixture was incubated at 37 °C. The obtained mixture was analyzed 5 and 60 min later by size-exclusion chromatography hyphenated to an inductively coupled plasma atomic emission spectrometer (SEC-ICP-AES). We simultaneously detected several titanium (Ti), gold (Au) and sulfur (S)-peaks, which corresponded to a Ti degradation product that eluted partially, and a Au degradation product that eluted entirely bound to plasma proteins (both time points). Although ~70% of the intact Titanocref was retained on the column after 60 min, our results allowed us to establish - for the first time - its likely degradation pathway in human plasma at near physiological conditions. These results suggest that ~70% of Titanocref remain in plasma after 60 min, which supports results from a recent in vivo study in which mice were treated with Titanocref and revealed Ti:Au molar ratios in tumors and organs close to 1:1. Thus, our stability studies suggest that the intact drug is able to reach target tissue. Overall, our results exemplify that SEC-ICP-AES enables the execution of intermediate in vitro studies with human plasma in the context of advancing bimetallic metal-based drugs to more costly clinical studies.


Assuntos
Antineoplásicos/sangue , Ouro/sangue , Plasma/química , Enxofre/sangue , Titânio/sangue , Antineoplásicos/isolamento & purificação , Proteínas Sanguíneas/química , Proteínas Sanguíneas/isolamento & purificação , Cromatografia em Gel , Ouro/isolamento & purificação , Humanos , Masculino , Ligação Proteica , Espectrofotometria Atômica , Titânio/isolamento & purificação
19.
Artigo em Inglês | MEDLINE | ID: mdl-32416595

RESUMO

The analysis of human plasma for biomarkers holds promise to revolutionize disease diagnosis, but is hampered by the inherent complexity of the plasma proteome. One way to overcome this problem is to analyze plasma for a sub-proteome, such as the metalloproteome. Previous studies employing size-exclusion chromatography (SEC) coupled on-line to an inductively coupled plasma-atomic emission spectrometer (ICP-AES) have revealed that plasma contains ~12 copper, iron and zinc metalloproteins. This included the iron metalloproteins transferrin (Tf) and a recently identified haptoglobin-hemoglobin (Hp-Hb) complex, which is formed in plasma when red blood cells rupture. Since this SEC-ICP-AES method required a sample volume of 500 µL to generate diagnostically useful results, we sought to develop an alternative SEC-based hyphenated approach using a smaller SEC column (150 × 5 mm I.D.) and a graphite furnace atomic absorption spectrometer (GFAAS) as the iron-specific detector. A designed interface enabled the integration of the SEC system with the GFAAS. Baseline separation between the Hp-Hb complex and Tf was achieved by developing a sample preparation procedure which involved the chelating agent-based mobilization of Fe from Tf to a small molecular weight Fe complex. Spiking of human plasma (1.0 mL) with red blood cell lysate (1-2 µL) increased only the intensity of the Fe peak corresponding to the Hp-Hb complex, but not that of Tf. Since the developed SEC-GFAAS method requires only 50 µL of plasma for analysis, it can now be employed for the cost-effective quantification of the clinically relevant Hb-Hp complex in human plasma in <50 min.


Assuntos
Cromatografia em Gel/métodos , Proteínas de Ligação ao Ferro/sangue , Proteínas de Ligação ao Ferro/isolamento & purificação , Espectrofotometria Atômica/métodos , Grafite/química , Haptoglobinas , Hemoglobinas , Humanos , Masculino , Transferrina
20.
Expert Rev Proteomics ; 6(3): 251-65, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19489698

RESUMO

Although blood plasma inherently contains protein biomarkers for human disease diagnosis, their determination is difficult since more than 3700 proteins are commonly present. The associated protein-separation problem can, however, be dramatically simplified by analyzing plasma for a subproteome, such as those proteins that contain bound metals. To this end, the analysis of plasma by size-exclusion chromatography (SEC) coupled with an inductively coupled plasma atomic-emission spectrometer (ICP-AES), which served as the simultaneous Cu-, Fe- and Zn-specific detector, revealed the presence of approximately 12 metalloproteins within 25 min. In the context of modern proteomics research, SEC-ICP-AES therefore represents a viable proteomic approach that can be applied to diagnose human diseases that are associated with increased or decreased concentrations of certain plasma metalloproteins. Furthermore, SEC-ICP-AES can be employed to probe the effect of environmental chemicals or drugs in blood at the metalloprotein level, which makes it a versatile research tool for applications in toxicology, applied medicine, pharmacology and nutritional science.


Assuntos
Cromatografia em Gel , Metabolômica , Metaloproteínas/sangue , Proteoma/análise , Proteômica , Espectrofotometria Atômica , Animais , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA