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1.
EMBO J ; 41(6): e110002, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35199384

RESUMO

The use of animals in neuroscience and biomedical research remains controversial. Policy is built around the "3R" principle of "Refining, Reducing and Replacing" animal experiments, and across the globe, different initiatives stimulate the use of animal-free methods. Based on an extensive literature screen to map the development and adoption of animal-free methods in Alzheimer's and Parkinson's disease research, we find that at least two in three examined studies rely on animals or on animal-derived models. Among the animal-free studies, the relative contribution of innovative models that may replace animal experiments is limited. We argue that the distinction between animal research and alternative models presents a false dichotomy, as the role and scientific value of both animal and animal-free approaches are intertwined. Calls to halt all animal experiments appear premature, as insufficient non-animal-based alternatives are available and their development lags behind. In light of this, we highlight the need for objective, unprejudiced monitoring, and more robust performance indicators of animal-free approaches.


Assuntos
Doença de Alzheimer , Doença de Parkinson , Animais , Modelos Animais
2.
Nano Lett ; 24(10): 2961-2971, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38477058

RESUMO

The delivery of RNA across biological barriers can be achieved by encapsulation in lipid nanoparticles (LNPs). Cationic amphiphilic drugs (CADs) are pharmacologically diverse compounds with ionizable lipid-like features. In this work, we applied CADs as a fifth component of state-of-the-art LNPs via microfluidic mixing. Improved cytosolic delivery of both siRNA and mRNA was achieved by partly replacing the cholesterol fraction of LNPs with CADs. The LNPs could cross the mucus layer in a mucus-producing air-liquid interface model of human primary bronchial epithelial cells following nebulization. Moreover, CAD-LNPs demonstrated improved epithelial and endothelial targeting following intranasal administration in mice, without a marked pro-inflammatory signature. Importantly, quantification of the CAD-LNP molar composition, as demonstrated for nortriptyline, revealed a gradual leakage of the CAD from the formulation during LNP dialysis. Altogether, these data suggest that the addition of a CAD prior to the rapid mixing process might have an impact on the composition, structure, and performance of LNPs.


Assuntos
Lipossomos , Nanopartículas , Camundongos , Animais , Humanos , Nanopartículas/química , RNA Interferente Pequeno/genética , Colesterol/química
3.
Virol J ; 21(1): 112, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750558

RESUMO

In 2018, SGS Belgium NV developed RSV-NICA (Respiratory Syncytial Virus-Nasobronchial Infective Challenge Agent), an RSV type A challenge agent for use in RSV Controlled Human Infection Model (CHIM) studies.It is widely recognized that the stability of RSV can be influenced by a variety of environmental parameters, such as temperature and pH. Consequently, our objective was to evaluate the stability of the viral titer of RSV-NICA following five years of controlled storage and to determine the uniformity of the viral titers across different vials of a GMP-qualified batch of RSV-NICA. In addition, we examined the capacity of RSV-NICA to infect human primary airway epithelial cells (MucilAir™), the principal target cells of RSV, and evaluated the influence of single and recurrent freeze-thaw cycles on the infectious viral titer of the challenge agent.The aliquoted RSV-NICA virus stock was subjected to standard virological and molecular methods to gather data on the titer and consistency of the viral titer contained within 24 representative vials of the stock. Our findings illustrate that over a span of five years of cryo-storage, the infectious viral titer in 75% of the tested vials exhibited a comparable average infectious viral titer (4.75 ± 0.06 vs 4.99 ± 0.11; p-value = 0.14). A considerable reduction down to an undetectable level of infectious virus was observed in the remaining vials. RSV-NICA demonstrated its capacity to effectively infect differentiated human airway epithelial cells, with active virus replication detected in these cells through increasing RSV genome copy number over time. Virus tropism for ciliated cells was suggested by the inhibition of cilia beating coupled with an increase in viral RNA titers. No discernable impact on membrane barrier function of the epithelial lung tissues nor cytotoxicity was detected. Pooling of vials with infectious titers > 4.0 log10 TCID50/ml and freeze-thawing of these combined vials showed no deterioration of the infectious titer. Furthermore, pooling and re-aliquoting of vials spanning the entire range of viral titers (including vials with undetectable infectious virus) along with subjecting the vials to three repeated freeze-thaw cycles did not result in a decrease of the infectious titers in the tested vials.Taken together, our findings indicate that long-term cryo-storage of vials containing RSV-NICA challenge agent may influence the infectious viral titer of the virus, leading to a decrease in the homogeneity of this titer throughout the challenge stock. However, our study also demonstrates that when heterogeneity of the infectious titer of an RSV stock is observed, rounds of pooling, re-aliquoting and subsequent re-titration serve as an effective method not only to restore the homogeneity of the infectious titer of an RSV-A stock, but also to optimize patient-safety, scientific and operational aspects of viral inoculation of study participants during at least the period of one RSV CHIM trial. RSV-NICA is a stable, suitable CHIM challenge agent that can be utilized in efficacy trials for RSV vaccines and antiviral entities.


Assuntos
Células Epiteliais , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Carga Viral , Humanos , Vírus Sincicial Respiratório Humano/fisiologia , Vírus Sincicial Respiratório Humano/genética , Infecções por Vírus Respiratório Sincicial/virologia , Células Epiteliais/virologia , Replicação Viral , Criopreservação/métodos , Células Cultivadas
4.
Environ Sci Technol ; 51(9): 5259-5269, 2017 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-28339192

RESUMO

A new prototype air-liquid interface (ALI) exposure system, a flatbed aerosol exposure chamber termed NAVETTA, was developed to investigate deposition of engineered nanoparticles (NPs) on cultured human lung A549 cells directly from the gas phase. This device mimics human lung cell exposure to NPs due to a low horizontal gas flow combined with cells exposed at the ALI. Electrostatic field assistance is applied to improve NP deposition efficiency. As proof-of-principle, cell viability and immune responses after short-term exposure to nanocopper oxide (CuO)-aerosol were determined. We found that, due to the laminar aerosol flow and a specific orientation of inverted transwells, much higher deposition rates were obtained compared to the normal ALI setup. Cellular responses were monitored with postexposure incubation in submerged conditions, revealing CuO dissolution in a concentration-dependent manner. Cytotoxicity was the result of ionic and nonionic Cu fractions. Using the optimized inverted ALI/postincubation procedure, pro-inflammatory immune responses, in terms of interleukin (IL)-8 promoter and nuclear factor kappa B (NFκB) activity, were observed within short time, i.e. One hour exposure to ALI-deposited CuO-NPs and 2.5 h postincubation. NAVETTA is a novel option for mimicking human lung cell exposure to NPs, complementing existing ALI systems.


Assuntos
Galvanoplastia , Pulmão , Aerossóis , Sobrevivência Celular , Humanos
5.
J Appl Toxicol ; 36(9): 1194-206, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26946349

RESUMO

Zebrafish phenotypic assays have shown promise to assess human hepatotoxicity, though scoring of liver morphology remains subjective and difficult to standardize. Liver toxicity in zebrafish larvae at 5 days was assessed using gene expression as the biomarker approach, complementary to phenotypic analysis and analytical data on compound uptake. This approach aimed to contribute to improved hepatotoxicity prediction, with the goal of identifying biomarker(s) as a step towards the development of transgenic models for prioritization. Morphological effects of hepatotoxic compounds (acetaminophen, amiodarone, coumarin, methapyrilene and myclobutanil) and saccharin as the negative control were assessed after exposure in zebrafish larvae. The hepatotoxic compounds induced the expected zebrafish liver degeneration or changes in size, whereas saccharin did not have any phenotypic adverse effect. Analytical methods based on liquid chromatography-mass spectrometry were optimized to measure stability of selected compounds in exposure medium and internal concentration in larvae. All compounds were stable, except amiodarone for which precipitation was observed. There was a wide variation between the levels of compound in the zebrafish larvae with a higher uptake of amiodarone, methapyrilene and myclobutanil. Detection of hepatocyte markers (CP, CYP3A65, GC and TF) was accomplished by in situ hybridization of larvae to coumarin and myclobutanil and confirmed by real-time reverse transcription-quantitative polymerase chain reaction. Experiments showed decreased expression of all markers. Next, other liver-specific biomarkers (i.e. FABP10a and NR1H4) and apoptosis (i.e. CASP-3 A and TP53) or cytochrome P450-related (CYP2K19) and oxidoreductase activity-related (ZGC163022) genes, were screened. Links between basic mechanisms of liver injury and results of biomarker responses are described. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Marcadores Genéticos , Fígado/efeitos dos fármacos , Peixe-Zebra/genética , Acetaminofen/toxicidade , Amiodarona/toxicidade , Animais , Apoptose/efeitos dos fármacos , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Ceruloplasmina/genética , Ceruloplasmina/metabolismo , Cumarínicos/toxicidade , Feminino , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Humanos , Hibridização In Situ , Larva/efeitos dos fármacos , Larva/genética , Fígado/metabolismo , Masculino , Metapirileno/toxicidade , Nitrilas/toxicidade , Oxirredutases N-Desmetilantes/genética , Oxirredutases N-Desmetilantes/metabolismo , Fenótipo , Testes de Toxicidade , Transferrina/genética , Transferrina/metabolismo , Triazóis/toxicidade , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
6.
Environ Res ; 134: 39-45, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25042035

RESUMO

Climate change is one of the major challenges in the world today. To reduce the amount of CO2 released into the atmosphere, CO2 at major sources, such as power plants, can be captured. Use of aqueous amine solutions is one of the most promising methods for this purpose. However, concerns have been raised regarding its impacts on human health and the environment due to the degradation products, such as nitrosamines and nitramines that may be produced during the CO2 capture process. While several toxicity studies have been performed investigating nitrosamines, little is known about the toxic potential of nitramines. In this study a preliminary screening was performed of the genotoxic and mutagenic potential of nitramines most likely produced during amine based CO2 capture; dimethylnitramine (DMA-NO2), methylnitramine (MA-NO2), ethanolnitramine (MEA-NO2), 2-methyl-2-(nitramino)-1-propanol (AMP-NO2) and piperazine nitramine (PZ-NO2), by the Bacterial Reverse Mutation (Ames) Test, the Cytokinesis Block Micronucleus (CBMN) Assay and the in vitro Single-Cell Gel Electrophoresis (Comet) Assay. MA-NO2 and MEA-NO2 showed mutagenic potential in the Ames test and a weak genotoxic response in the CBMN Assay. AMP-NO2 and PZ-NO2 significantly increased the amount of DNA strand breaks; however, the level of breaks was below background. Most previous studies on nitramines have been performed on DMA-NO2, which in this study appeared to be the least potent nitramine. Our results indicate that it is important to investigate other nitramines that are more likely to be produced during CO2 capture, to ensure that the risk is realistically evaluated.


Assuntos
Compostos de Anilina/toxicidade , Mutagênicos/toxicidade , Nitrobenzenos/toxicidade , Ensaio Cometa
7.
Toxicol Sci ; 195(2): 213-230, 2023 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-37498623

RESUMO

Inhalation is a major route by which human exposure to substances can occur. Resources have therefore been dedicated to optimize human-relevant in vitro approaches that can accurately and efficiently predict the toxicity of inhaled chemicals for robust risk assessment and management. In this study-the IN vitro Systems to PredIct REspiratory toxicity Initiative-2 cell-based systems were used to predict the ability of chemicals to cause portal-of-entry effects on the human respiratory tract. A human bronchial epithelial cell line (BEAS-2B) and a reconstructed human tissue model (MucilAir, Epithelix) were exposed to triethoxysilane (TES) and trimethoxysilane (TMS) as vapor (mixed with N2 gas) at the air-liquid interface. Cell viability, cytotoxicity, and secretion of inflammatory markers were assessed in both cell systems and, for MucilAir tissues, morphology, barrier integrity, cilia beating frequency, and recovery after 7 days were also examined. The results show that both cell systems provide valuable information; the BEAS-2B cells were more sensitive in terms of cell viability and inflammatory markers, whereas MucilAir tissues allowed for the assessment of additional cellular effects and time points. As a proof of concept, the data were also used to calculate human equivalent concentrations. As expected, based on chemical properties and existing data, the silanes demonstrated toxicity in both systems with TMS being generally more toxic than TES. Overall, the results demonstrate that these in vitro test systems can provide valuable information relevant to predicting the likelihood of toxicity following inhalation exposure to chemicals in humans.


Assuntos
Células Epiteliais , Silanos , Humanos , Silanos/toxicidade , Silanos/metabolismo , Linhagem Celular , Brônquios
8.
ALTEX ; 38(4): 550-564, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33882577

RESUMO

The goal is to optimize and show the validity of an in vitro method for inhalation testing of petroleum substances and their constituents at the air-liquid interface (ALI). The approach is demonstrated in a pilot study with ethylbenzene (EB), a mono-constituent petroleum substance, using a human alveolar epithelial cell line model. This included the development and validation of a generation facility to obtain EB vapors and the optimization of an exposure system for a negative control (clean air, CA), positive control (nitrogen dioxide), and EB vapors. The optimal settings for the VITROCELL® 24/48 system were defined. Cytotoxicity, cell viability, inflammation, and oxidative stress were assessed in A549 after exposure to EB vapors. A concentration-dependent significant decrease in mean cell viability was observed after exposure, which was confirmed by a cytotoxicity test. The oxidative stress marker superoxide dismutase 2 was sig­nificantly increased, but no concentration-response was observed. A concentration-dependent significant increase in pro-inflammatory markers C-C motif chemokine ligand 2, interleukin (IL)6, and IL8 was observed for EB-exposed A549 cells compared to CA. The data demonstrated consistency between in vivo air concentrations at which adverse respi­ratory effects were observed and ALI-concentrations affecting cell viability, provided that the actual measured in vitro delivery efficiency of the compound was considered. It can be concluded that extrapolating in vitro air concentrations (adjusted for delivery efficiency and absorption characteristics and applied for testing cell viability) to simulate in vivo air concentrations may be a promising method to screen for acute inhalation toxicity.


Assuntos
Petróleo , Células A549 , Linhagem Celular , Sobrevivência Celular , Humanos , Exposição por Inalação , Projetos Piloto
9.
MethodsX ; 7: 101085, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33088730

RESUMO

The "Peira LLBO 180" is a Laser Light-Based Opacitometer that can be used as an alternative for the standard OP-KIT device in the Bovine Corneal Opacity and Permeability (BCOP) test Organisation for Economic Co-operation and Development (OECD) Test Guideline (TG) 437 to identify chemicals inducing serious eye damage as defined by United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS), i.e. chemicals to be classified as UN GHS Category 1 and chemicals not requiring classification for eye irritation or serious eye damage under the UN GHS classification system (No Category). • The Peira LLBO 180 offers the advantage of analysing the complete corneal surface and is therefore able to detect more efficiently opaque spots located around the periphery of the excised corneas. • This new device will allow not only a more accurate definition of the eye irritating potential of compounds, but also a more precise ranking of moderate to mild and non-irritating compounds. • The value of Peira LLBO 180 is confirmed during in-house and multi-laboratory evaluation studies and is now included in the updated OECD TG 437, dated 26th of June 2020. The results demonstrate that the presented methodology is an improved new approach methodology (NAM) for ocular irritation testing of liquids and solids.

10.
Toxicol Appl Pharmacol ; 236(2): 221-30, 2009 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19371601

RESUMO

Early detection of the sensitizing potential of chemicals is an emerging issue for chemical, pharmaceutical and cosmetic industries. In our institute, an in vitro classification model for prediction of chemical-induced skin sensitization based on gene expression signatures in human CD34+ progenitor-derived dendritic cells (DC) has been developed. This primary cell model is able to closely mimic the induction phase of sensitization by Langerhans cells in the skin, but it has drawbacks, such as the availability of cord blood. The aim of this study was to investigate whether human in vitro cultured THP-1 monocytes or macrophages display a similar expression profile for 13 predictive gene markers previously identified in DC and whether they also possess a discriminating capacity towards skin sensitizers and non-sensitizers based on these marker genes. To this end, the cell models were exposed to 5 skin sensitizers (ammonium hexachloroplatinate IV, 1-chloro-2,4-dinitrobenzene, eugenol, para-phenylenediamine, and tetramethylthiuram disulfide) and 5 non-sensitizers (l-glutamic acid, methyl salicylate, sodium dodecyl sulfate, tributyltin chloride, and zinc sulfate) for 6, 10, and 24 h, and mRNA expression of the 13 genes was analyzed using real-time RT-PCR. The transcriptional response of 7 out of 13 genes in THP-1 monocytes was significantly correlated with DC, whereas only 2 out of 13 genes in THP-1 macrophages. After a cross-validation of a discriminant analysis of the gene expression profiles in the THP-1 monocytes, this cell model demonstrated to also have a capacity to distinguish skin sensitizers from non-sensitizers. However, the DC model was superior to the monocyte model for discrimination of (non-)sensitizing chemicals.


Assuntos
Antígenos CD34/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Macrófagos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Linhagem Celular Tumoral , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Marcadores Genéticos , Humanos , Macrófagos/fisiologia , Monócitos/fisiologia
11.
Toxicology ; 255(3): 151-9, 2009 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-19041681

RESUMO

Respiratory sensitization is a concern for occupational and environmental health in consumer product development. Despite international regulatory requirements there is no established protocol for the identification of chemical respiratory sensitizers. New tests should be based on mechanistic understanding and should be preferentially restricted to in vitro assays. The major goal of this study was to investigate the alterations in gene expression of human bronchial epithelial (BEAS-2B) cells after exposure to respiratory sensitizers and respiratory non-sensitizing chemicals, and to identify genes that are able to discriminate between both groups of chemicals. BEAS-2B cells were exposed during 6, 10, and 24h to the respiratory sensitizers ammonium hexachloroplatinate IV, hexamethylene diisocyanate, and trimellitic anhydride, the irritants acrolein and methyl salicylate, and the skin sensitizer 1-chloro-2,4-dinitrobenzene. Overall changes in gene expression were evaluated using Agilent Whole Human Genome 4x 44K oligonucleotide arrays. Fisher Linear Discriminant Analysis was used to obtain a ranking of genes that reflects their potential to discriminate between respiratory sensitizing and respiratory non-sensitizing chemicals. The 10 most discriminative genes were BC042064, A_24_P229834, DOCK11, THC2544911, DLGAP4, NINJ1, PFKM, FLJ10986, IL28RA, and CASP9. Based on the differentially expressed genes, pathway analysis was used to identify possible underlying mechanisms of respiratory sensitization. We demonstrated that in bronchial epithelial cells the canonical PTEN signaling pathway is probably the most specific pathway in the context of respiratory sensitization. Results are indicative that the BEAS-2B cell line can be used as an alternative cell model to screen chemical compounds for their respiratory sensitizing potential.


Assuntos
Brônquios/efeitos dos fármacos , Perfilação da Expressão Gênica , Marcadores Genéticos , Brônquios/citologia , Brônquios/metabolismo , Linhagem Celular , Análise Discriminante , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Técnicas In Vitro , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de Sinais
12.
Toxicol Lett ; 185(1): 16-22, 2009 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-19110044

RESUMO

There are currently no accepted biological prediction models for assessing the potential of a substance to cause respiratory sensitization. New tests should be based on mechanistic understanding and should be preferentially restricted to in vitro assays. The major goal of this study was to investigate the alterations in gene expression of human alveolar epithelial (A549) cells after exposure to respiratory sensitizing and non-respiratory sensitizing chemicals, and to identify genes that are able to discriminate between both groups of chemicals. A549 cells were exposed during 6, 10, and 24 h to the respiratory sensitizers ammonium hexachloroplatinate IV, hexamethylene diisocyanate, and trimellitic anhydride, the irritants acrolein and methyl salicylate, and the skin sensitizer 1-chloro-2,4-dinitrobenzene. Overall changes in gene expression were evaluated using Agilent Whole Human Genome 4x44K oligonucleotide arrays. A Fisher linear discriminant analysis was used to obtain a ranking of genes that reflects their potential to discriminate between respiratory sensitizing and respiratory non-sensitizing chemicals. Among the 20 most discriminating genes, which were categorized into molecular and biological gene ontology (GO) terms, CTLA4 could be associated with asthma and/or respiratory sensitization. When categorizing the top-1000 genes into biological GO terms, 22 genes were associated with immune function. Using a pathway analysis tool to identify possible underlying mechanisms of respiratory sensitization, no known canonical signaling pathway was observed to be activated in the A549 cell line.


Assuntos
Perfilação da Expressão Gênica , Marcadores Genéticos , Alvéolos Pulmonares/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Acroleína/toxicidade , Antígenos CD/genética , Antígeno CTLA-4 , Linhagem Celular , Dinitroclorobenzeno/toxicidade , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Alvéolos Pulmonares/metabolismo , Salicilatos/toxicidade
13.
Toxicol In Vitro ; 49: 2-5, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28629855

RESUMO

The main objective of the CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project (2015-2016) was to develop tiered, non-animal testing strategies for serious eye damage and eye irritation assessment in relation to the most important drivers of classification. The serious eye damage and eye irritation potential of a set of 80 chemicals was identified based on existing in vivo Draize eye test data and testing was conducted using the following eight alternative test methods: BCOP (Bovine Corneal Opacity and Permeability)+histopathology, BCOP-LLBO (BCOP Laser Light-Based Opacitometer), ICE (Isolated Chicken Eye)+histopathology, STE (Short Term Exposure), EpiOcular™ EIT (EpiOcular Eye Irritation Test), EpiOcular™ ET-50 (EpiOcular™ Time-to-toxicity), SkinEthic™ HCE EIT (SkinEthic™ Human Corneal Epithelial Eye Irritation Test), and SMI (Slug Mucosal Irritation). Project management decided to not include the ICE data in this project since the execution showed relevant, and not predictable, deviations from Organisation for Economic Co-operation and Development (OECD) Test Guideline (TG) 438 and Guidance Document 160. At this stage, the outcome of these deviations has not been fully assessed. In addition to these alternative test methods, the computational models Toxtree and Case Ultra were taken into account. This project assessed the relevance of these test methods, their applicability domains and limitations in terms of 'drivers of classification', and their strengths and weaknesses. In this way, methods were identified that fit into a tiered-testing strategy for serious eye damage/eye irritation assessment to distinguish United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS) Category 1 (Cat 1) chemicals from non-Cat 1 chemicals and address the gap namely distinguish between Category 2 (Cat 2) and Cat 1 chemicals.


Assuntos
Olho/efeitos dos fármacos , Irritantes/classificação , Irritantes/toxicidade , Testes de Toxicidade/métodos , Animais , União Europeia , Humanos , Organização para a Cooperação e Desenvolvimento Econômico , Nações Unidas
14.
Toxicol In Vitro ; 49: 34-52, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28866024

RESUMO

Assessment of acute eye irritation potential is part of the international regulatory requirements for testing of chemicals. The objective of the CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project was to develop tiered testing strategies for eye irritation assessment for all drivers of classification. A set of 80 reference chemicals (38 liquids and 42 solids) was tested with eight different alternative methods. Here, the results obtained with reconstructed human cornea-like epithelium (RhCE) EpiOcular™ in the EpiOcular time-to-toxicity Tests (Neat and Dilution ET-50 protocols) are presented. The primary aim of this study was to evaluate whether test methods can discriminate chemicals not requiring classification for serious eye damage/eye irritancy (No Category) from chemicals requiring classification and labelling for Category 1 and Category 2. In addition, the predictive capacity in terms of in vivo drivers of classification was investigated. The chemicals were tested in two independent runs by MatTek In Vitro Life Science Laboratories. Results of this study demonstrate very high specificity of both test protocols. With the existing prediction models described in the SOPs, the specificity of the Neat and Dilution method was 87% and 100%, respectively. The Dilution method was able to correctly predicting 66% of GHS Cat 2 chemicals, however, prediction of GHS Cat 1 chemicals was only 47%-55% using the current protocols. In order to achieve optimal prediction for all three classes, a testing strategy was developed which combines the most predictive time-points of both protocols and for tests liquids and solids separately. Using this new testing strategy, the sensitivity for predicting GHS Cat 1 and GHS Cat 2 chemicals was 73% and 64%, respectively and the very high specificity of 97% was maintained. None of the Cat 1 chemicals was underpredicted as GHS No Category. Further combination of the EpiOcular time-to-toxicity protocols with other validated in vitro systems evaluated in this project, should enable significant reduction and even possible replacement of the animal tests for the final assessment of the irritation potential in all of the GHS classes.


Assuntos
Olho/efeitos dos fármacos , Irritantes/classificação , Irritantes/toxicidade , Testes de Toxicidade/métodos , Alternativas aos Testes com Animais , Opacidade da Córnea/induzido quimicamente , Humanos , Reprodutibilidade dos Testes
15.
Toxicol In Vitro ; 49: 21-33, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28697962

RESUMO

Assessment of the acute eye irritation potential is part of the international regulatory requirements for testing of chemicals. The objective of the CON4EI project was to develop tiered testing strategies for eye irritation assessment. A set of 80 reference chemicals (38 liquids and 42 solids) was tested with eight different methods. Here, the results obtained with the EpiOcular™ Eye Irritation Test (EIT), adopted as OECD TG 492, are shown. The primary aim of this study was to evaluate of the performance of the test method to discriminate between chemicals not requiring classification for serious eye damage/eye irritancy (No Category) and chemicals requiring classification and labelling. In addition, the predictive capacity in terms of in vivo drivers of classification (i.e. corneal opacity, conjunctival redness and persistence at day 21) was investigated. EpiOcular™ EIT achieved a sensitivity of 97%, a specificity of 87% and accuracy of 95% and also confirmed its excellent reproducibility (100%) from the original validation. The assay was applicable to all chemical categories tested in this project and its performance was not limited to the particular driver of the classification. In addition to the existing prediction model for dichotomous categorization, a new prediction model for Cat 1 is suggested.


Assuntos
Olho/efeitos dos fármacos , Irritantes/classificação , Irritantes/toxicidade , Testes de Toxicidade/métodos , Alternativas aos Testes com Animais , Opacidade da Córnea/induzido quimicamente , Humanos , Reprodutibilidade dos Testes
16.
Toxicol In Vitro ; 49: 53-64, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29598995

RESUMO

Assessment of ocular irritation potential is an international regulatory requirement in the safety evaluation of industrial and consumer products. None in vitro ocular irritation assays are capable of fully categorizing chemicals as stand-alone. Therefore, the CEFIC-LRI-AIMT6-VITO CON4EI consortium assessed the reliability of eight in vitro test methods and computational models as well as established a tiered-testing strategy. One of the selected assays was Bovine Corneal Opacity and Permeability (BCOP). In this project, the same corneas were used for measurement of opacity using the OP-KIT, the Laser Light-Based Opacitometer (LLBO) and for histopathological analysis. The results show that the accuracy of the BCOP OP-KIT in identifying Cat 1 chemicals was 73.8% while the accuracy was 86.3% for No Cat chemicals. BCOP OP-KIT false negative results were often related to an in vivo classification driven by conjunctival effects only. For the BCOP LLBO, the accuracy in identifying Cat 1 chemicals was 74.4% versus 88.8% for No Cat chemicals. The BCOP LLBO seems very promising for the identification of No Cat liquids but less so for the identification of solids. Histopathology as an additional endpoint to the BCOP test method does not reduce the false negative rate substantially for in vivo Cat 1 chemicals.

17.
Immunol Lett ; 113(1): 6-18, 2007 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-17765979

RESUMO

Asthma is the most common chronic inflammatory disorder of the airways among children. It is a complex clinical disease characterized by airway obstruction, airway inflammation and airway hyperresponsiveness to a variety of stimuli. The development of allergic asthma exists of three phases, namely the induction phase, the early-phase asthmatic reaction (EAR) and the late-phase asthmatic reaction (LAR). Each phase is characterized by the production and interplay of various cell-derived mediators. In the induction phase, T helper cytokines are important in the development of asthma. Most important mediators in the EAR are preformed mediators, newly synthesized lipid mediators and cytokines that are produced by mast cells. During the LAR, inflammatory molecules are produced by various cell types, such as eosinophils, neutrophils, T cells, macrophages, dendritic cells, and structural cells. Chronical inflammation leads to structural changes of the airway architecture. In this review, the most important mediators involved in the induction phase, the early-phase and late-phase asthmatic reaction are discussed.


Assuntos
Alérgenos/imunologia , Asma/imunologia , Mediadores da Inflamação/química , Mediadores da Inflamação/metabolismo , Pulmão/química , Pulmão/imunologia , Alérgenos/metabolismo , Animais , Asma/metabolismo , Asma/patologia , Humanos , Imunidade Celular , Mediadores da Inflamação/fisiologia , Pulmão/patologia
18.
Toxicol In Vitro ; 44: 122-133, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28673559

RESUMO

Assessment of ocular irritation potential is an international regulatory requirement in the safety evaluation of industrial and consumer products. None in vitro ocular irritation assays are capable of fully categorizing chemicals as stand-alone. Therefore, the CEFIC-LRI-AIMT6-VITO CON4EI consortium assessed the reliability of eight in vitro test methods and computational models as well as established a tiered-testing strategy. One of the selected assays was Bovine Corneal Opacity and Permeability (BCOP). In this project, the same corneas were used for measurement of opacity using the OP-KIT, the Laser Light-Based Opacitometer (LLBO) and for histopathological analysis. The results show that the accuracy of the BCOP OP-KIT in identifying Cat 1 chemicals was 73.8% while the accuracy was 86.3% for No Cat chemicals. BCOP OP-KIT false negative results were often related to an in vivo classification driven by conjunctival effects only. For the BCOP LLBO, the accuracy in identifying Cat 1 chemicals was 74.4% versus 88.8% for No Cat chemicals. The BCOP LLBO seems very promising for the identification of No Cat liquids but less so for the identification of solids. Histopathology as an additional endpoint to the BCOP test method does not reduce the false negative rate substantially for in vivo Cat 1 chemicals.


Assuntos
Alternativas aos Testes com Animais , Opacidade da Córnea/induzido quimicamente , Olho/efeitos dos fármacos , Irritantes/classificação , Irritantes/toxicidade , Permeabilidade/efeitos dos fármacos , Animais , Bovinos , Olho/metabolismo , Rotulagem de Produtos
19.
Toxicol In Vitro ; 28(2): 209-17, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24211530

RESUMO

For the classification of respiratory sensitizing chemicals, no validated in vivo nor in vitro tests are currently available. In this study, we evaluated whether respiratory sensitizers trigger specific signals in human bronchial epithelial (BEAS-2B) cells at the level of the transcriptome. The cells were exposed during 6, 10, and 24h to 4 respiratory sensitizers and 6 non-respiratory sensitizers (3 skin sensitizers and 3 respiratory irritants) at a concentration inducing 20% cell viability loss after 24h. Changes in gene expression were evaluated using Agilent Whole Human Genome 4×44K oligonucleotide arrays. A limited number of 11 transcripts could be identified as potential biomarkers to identify respiratory sensitizers. Three of these transcripts are associated to immune system processes (HSPA5, UPP1, and SEPRINE1). In addition, the transcriptome was screened for transcripts that are differentially expressed compared to vehicle control for each chemical. The results show that the NRF2-mediated oxidative stress response is activated in the cell line after stimulation with all of the chemicals that were selected in our study, and that - at the level of gene expression - this pathway shows no potential to discriminate between any of the three compound groups: respiratory sensitizers, skin sensitizers, or electrophilic respiratory irritants.


Assuntos
Brônquios/metabolismo , Células Epiteliais/metabolismo , Expressão Gênica/fisiologia , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/fisiologia , Mucosa Respiratória/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Brônquios/citologia , Linhagem Celular , Interpretação Estatística de Dados , Chaperona BiP do Retículo Endoplasmático , Marcadores Genéticos/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Hibridização Genética , Irritantes/toxicidade , Análise em Microsséries , Estresse Oxidativo/fisiologia , RNA/biossíntese , RNA/isolamento & purificação , Mucosa Respiratória/citologia
20.
Toxicol Lett ; 228(3): 157-69, 2014 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-24821434

RESUMO

Fragmentary knowledge exists on cellular signaling responses underlying possible adverse health effects of CoO- and CeO2-nanoparticles (NP)s after inhalation. We aimed to perform a time kinetic study of gene expression profiles induced by these NPs in alveolar A549 and bronchial BEAS-2B epithelial cells, and investigated possible immune system modulation. The kinetics of the cell responses induced by the NPs were different between the lung epithelial models. Both CoO- and CeO2-NP exposure induced mainly downregulation of gene transcription. BEAS-2B cells were found to be more sensitive, as they showed a higher number of differentially expressed transcripts (DET) at a 10-fold lower NP-concentration than A549 cells. Hierarchical clustering of all DET indicated that the transcriptional responses were heterogeneous among the two cell types and two NPs. Between 1% and 14% DET encoding markers involved in immune processes were observed. The transcriptional impact of the metal oxide NPs appeared to be cell-dependent, both at the general and immune response level, whereas each lung epithelial cell model responded differently to the two NP types. Thus, the study provides gene expression markers and immune processes involved in CoO- and CeO2-NP-induced toxicity, and demonstrates the usefulness of comprehensive-omics studies to differentiate between NP responses.


Assuntos
Cério/toxicidade , Cobalto/toxicidade , Células Epiteliais/efeitos dos fármacos , Perfilação da Expressão Gênica , Pulmão/efeitos dos fármacos , Nanopartículas Metálicas , Óxidos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Análise por Conglomerados , Biologia Computacional , Relação Dose-Resposta a Droga , Células Epiteliais/imunologia , Células Epiteliais/patologia , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Humanos , Cinética , Pulmão/imunologia , Pulmão/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Transcrição Gênica/efeitos dos fármacos
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