Biomarkers of effect as determined in human biomonitoring studies on hexavalent chromium and cadmium in the period 2008–2020

This research was supported by funding from the European Union's Horizon 2020 research and innovation Programme under grant agreement No 733032 HBM4EU.A number of human biomonitoring (HBM) studies have presented data on exposure to hexavalent chromium [Cr (VI)] and cadmium (Cd), but comparatively few include results on effect biomarkers. The latter are needed to identify associations between exposure and adverse outcomes (AOs) in order to assess public health implications. To support improved derivation of EU regulation and policy making, it is of great importance to identify the most reliable effect biomarkers for these heavy metals that can be used in HBM studies. In the framework of the Human Biomonitoring for Europe (HBM4EU) initiative, our study aim was to identify effect biomarkers linking Cr(VI) and Cd exposure to selected AOs including cancer, immunotoxicity, oxidative stress, and omics/epigenetics. A comprehensive PubMed search identified recent HBM studies, in which effect biomarkers were examined. Validity and applicability of the markers in HBM studies are discussed. The most frequently analysed effect biomarkers regarding Cr(VI) exposure and its association with cancer were those indicating oxidative stress (e.g., 8-hydroxy-2 & rsquo;-deoxyguanosine (8-OHdG), malondialdehyde (MDA), glutathione (GSH)) and DNA or chromosomal damage (comet and micronucleus assays). With respect to Cd and to some extent Cr, 0-2-microglobulin (B2-MG) and N-acetyl-0-D-glucosaminidase (NAG) are well-established, sensitive, and the most common effect biomarkers to relate Cd or Cr exposure to renal tubular dysfunction. Neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule (KIM)-1 could serve as sensitive biomarkers of acute kidney injury in response to both metals, but need further investigation in HBM studies. Omics-based biomarkers, i.e., changes in the (epi-)genome, transcriptome, proteome, and metabolome associated with Cr and/or Cd exposure, are promising effect biomarkers, but more HBM data are needed to confirm their significance. The combination of established effect markers and omics biomarkers may represent the strongest approach, especially if based on knowledge of mechanistic principles. To this aim, also mechanistic data were collected to provide guidance on the use of more sensitive and specific effect biomarkers. This also led to the identification of knowledge gaps relevant to the direction of future research.European Commission 733032 HBM4E

A Comprehensive Review

Funding: This project has received funding from the European Unions’ Horizon 2020 research and innovation Programme under grant agreement No 733032. HBM4EU.Polycyclic aromatic hydrocarbons (PAHs) are among the chemicals with proven impact on workers' health. The use of human biomonitoring (HBM) to assess occupational exposure to PAHs has become more common in recent years, but the data generated need an overall view to make them more usable by regulators and policymakers. This comprehensive review, developed under the Human Biomonitoring for Europe (HBM4EU) Initiative, was based on the literature available from 2008-2022, aiming to present and discuss the information on occupational exposure to PAHs, in order to identify the strengths and limitations of exposure and effect biomarkers and the knowledge needs for regulation in the workplace. The most frequently used exposure biomarker is urinary 1-hydroxypyrene (1-OH-PYR), a metabolite of pyrene. As effect biomarkers, those based on the measurement of oxidative stress (urinary 8-oxo-dG adducts) and genotoxicity (blood DNA strand-breaks) are the most common. Overall, a need to advance new harmonized approaches both in data and sample collection and in the use of appropriate biomarkers in occupational studies to obtain reliable and comparable data on PAH exposure in different industrial sectors, was noted. Moreover, the use of effect biomarkers can assist to identify work environments or activities of high risk, thus enabling preventive risk mitigation and management measures.publishersversionpublishe

Application of human biomonitoring to assess occupational exposure to polycyclic aromatic hydrocarbons in Europe: a literature review

Os hidrocarbonetos aromáticos policíclicos (HAPs) são produtos químicos com impacto em saúde ocupacional, pelo que a avaliação da exposição humana através de estudos de biomonitorização tem aumentado nos últimos anos. No entanto, os dados obtidos são ainda insuficientes para os reguladores e decisores políticos. Este trabalho, no contexto da Iniciativa Europeia em Biomonitorização Humana (HBM4EU), descreve uma revisão da literatura sobre a exposição ocupacional aos HAPs na Europa, entre 2008 e 2022, com o objetivo de identificar as vantagens e limitações dos vários biomarcadores de exposição e /ou de efeito, bem como o conhecimento em falta para melhorar a regulamentação. Os resultados da análise dos 42 artigos elegíveis para inclusão nesta revisão demonstram que o biomarcador de exposição mais utilizado é o 1-hidroxipireno urinário, sendo os biomarcadores de efeito mais comuns, biomarcadores de stresse oxidativo e genotoxicidade. Globalmente, verificou-se a necessidade de desenvolver novas abordagens de recolha de dados e amostras, bem como a seleção apropriada de biomarcadores de forma a obter dados fiáveis e comparáveis em diferentes setores industriais. Além disso, a aplicação de biomarcadores de efeito contribui para a identificação de ambientes de trabalho ou atividades de alto risco, possibilitando medidas de mitigação e gestão de risco.Polycyclic aromatic hydrocarbons (PAHs) are chemicals with impact on occupational health, therefore the assessment of human exposure using biomonitoring has increased in recent years. However, the data obtained are still insufficient to be useful to regulators and policy makers. This work, in the context of the Human Biomonitoring for Europe Initiative (HBM4EU), describes a review of the literature on occupational exposure to PAHs in Europe, between 2008 and 2022, with the aim of identifying the advantages and limitations of the various biomarkers of exposure and/or effect, as well as the missing knowledge to improve regulation in occupational settings. The results of the analysis of the 42 articles eligible for inclusion in this review demonstrate that the most used biomarker of exposure is urinary 1-hydroxypyrene, with the most common biomarkers of effect being the measurement of oxidative stress and genotoxicity. Overall, it was noted the need to develop new approaches to samples and data collection, as well as the appropriate selection of biomarkers in order to obtain reliable and comparable data in different industrial sectors. In addition, the application of effect biomarkers contributes to the identification of high-risk work environments or activities, enabling measures of risk mitigation and management.Este estudo recebeu financiamento do programa de investigação e inovação Horizonte 2020 da União Europeia sob o acordo de subvenção n.º 733032 e recebeu cofinanciamento das organizações dos autores.info:eu-repo/semantics/publishedVersio

uma revisão da literatura

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Prediction of human drug-induced liver injury (DILI) in relation to oral doses and blood concentrations

Drug-induced liver injury (DILI) cannot be accurately predicted by animal models. In addition, currently available in vitro methods do not allow for the estimation of hepatotoxic doses or the determination of an acceptable daily intake (ADI). To overcome this limitation, an in vitro/in silico method was established that predicts the risk of human DILI in relation to oral doses and blood concentrations. This method can be used to estimate DILI risk if the maximal blood concentration (Cmax) of the test compound is known. Moreover, an ADI can be estimated even for compounds without information on blood concentrations. To systematically optimize the in vitro system, two novel test performance metrics were introduced, the toxicity separation index (TSI) which quantifies how well a test differentiates between hepatotoxic and non-hepatotoxic compounds, and the toxicity estimation index (TEI) which measures how well hepatotoxic blood concentrations in vivo can be estimated. In vitro test performance was optimized for a training set of 28 compounds, based on TSI and TEI, demonstrating that (1) concentrations where cytotoxicity first becomes evident in vitro (EC10) yielded better metrics than higher toxicity thresholds (EC50); (2) compound incubation for 48 h was better than 24 h, with no further improvement of TSI after 7 days incubation; (3) metrics were moderately improved by adding gene expression to the test battery; (4) evaluation of pharmacokinetic parameters demonstrated that total blood compound concentrations and the 95%-population-based percentile of Cmax were best suited to estimate human toxicity. With a support vector machine-based classifier, using EC10 and Cmax as variables, the cross-validated sensitivity, specificity and accuracy for hepatotoxicity prediction were 100, 88 and 93%, respectively. Concentrations in the culture medium allowed extrapolation to blood concentrations in vivo that are associated with a specific probability of hepatotoxicity and the corresponding oral doses were obtained by reverse modeling. Application of this in vitro/in silico method to the rat hepatotoxicant pulegone resulted in an ADI that was similar to values previously established based on animal experiments. In conclusion, the proposed method links oral doses and blood concentrations of test compounds to the probability of hepatotoxicity

Comparative proteomic data of M13SV1 human breast epithelial cells and their tumorigenic variants under treatment with estrogenic compounds

Data from a comparative proteomic analysis of three human breast epithelial cell lines are presented. M13SV1 cells and their tumorigenic derivatives M13SV1-R2-2 and M13SV1-R2-N1 were used. Proteomic data were obtained using 2-dimensional gel electrophoresis and subsequent identification of proteins by MALDI-TOF mass spectrometry. In a second experiment, the three cell lines were treated with different concentrations of the estrogenic compounds β-estradiol or genistein and alterations in protein expression were monitored by 2-dimensional gel electrophoresis and MALDI-TOF mass spectrometry. Presented data provide a comprehensive overview of proteomic differences between the three cell lines and their response to estrogenic stimulation

Comparative proteomic analysis of hepatic effects induced by nanosilver, silver ions and nanoparticle coating in rats

The presence of nano-scaled particles in food and food-related products has drawn attention to the oral uptake of nanoparticles and their interactions with biological systems. In the present study, we used a toxico proteomics approach to allow for the untargeted experimental identification and comparative analysis of cellular responses in rat liver after repeated-dose treatment with silver nanoparticles, ions, and the coating matrix used for particle stabilization. The proteomic analysis revealed treatment-related effects caused by exposure to silver in particulate and ionic form. Both silver species induced similar patterns of signaling and metabolic alterations. Silver-induced cellular alterations comprised, amongst others, proteins involved in metal homeostasis, oxidative stress response, and energy metabolism. However, we discovered that secondary nano-scaled structures were formed from ionic silver. Furthermore, also the coating matrix alone gave rise to the formation of nano-scaled particles. The present data confirm, complement, and extend previous knowledge on silver toxicity in rodent liver by providing a comprehensive proteomic data set. The observation of secondary particle formation from non-particle controls underlines the difficulties in separating particle-, ion-, and matrix coating-related effects in biological systems. Awareness of this issue will support proper evaluation of nanotoxicology-related data in the future

Toxicogenomics directory of rat hepatotoxicants in vivo and in cultivated hepatocytes

Transcriptomics is developing into an invaluable tool in toxicology. The aim of this study was, using a transcriptomics approach, to identify genes that respond similar to many different chemicals (including drugs and industrial compounds) in both rat liver in vivo and in cultivated hepatocytes. For this purpose, we analyzed Affymetrix microarray expression data from 162 compounds that were previously tested in a concentration-dependent manner in rat livers in vivo and in rat hepatocytes cultivated in sandwich culture. These data were obtained from the Japanese Toxicogenomics Project (TGP) and North Rhine-Westphalian (NRW) data sets, which represent 138 and 29 compounds, respectively, and have only 5 compounds in common between them. The in vitro gene expression data from the NRW data set were generated in the present study, while TGP is publicly available. For each of the data sets, the overlap between up- or down-regulated genes in vitro and in vivo was identified, and named in vitro-in vivo consensus genes. Interestingly, the in vivo-in vitro consensus genes overlapped to a remarkable extent between both data sets, and were 21-times (upregulated genes) or 12-times (down-regulated genes) enriched compared to random expectation. Finally, the genes in the TGP and NRW overlap were used to identify the upregulated genes with the highest compound coverage, resulting in a seven-gene set of Cyp1a1, Ugt2b1, Cdkn1a, Mdm2, Aldh1a1, Cyp4a3, and Ehhadh. This seven-gene set was then successfully tested with structural analogues of valproic acid that are not present in the TGP and NRW data sets. In conclusion, the seven-gene set identified in the present study responds similarly in vitro and in vivo to a wide range of different chemicals. Despite these promising results with the seven-gene set, transcriptomics with cultivated rat hepatocytes remains a challenge, because in general many genes are up- or downregulated by in vitro culture per se, respond differently to test compounds in vitro and in vivo, and/or show higher variability in the in vitro system compared to the corresponding in vivo data