Toxicology
Innovation examples
ToxicologyIn vitro
Combatting the worlds deadliest infections using groundbreaking human-mimetic tools
Combatting the worlds deadliest infections using groundbreaking human-mimetic tools.
Zika, dengue & other viruses are typically tested in monkeys & mice. But is using animals really the most effective way? Find out what Dr. David Pamies of the @jhucaat - along with his colleagues at @JohnsHopkins - are doing to upend the status quo.
More information on:
https://www.eurekalert.org/pub_releases/2019-06/hsi-ctw061319.php
and
https://www.frontiersin.org/articles/10.3389/fcimb.2019.00223/
Expert interviews
Toxicology
How do we use human data in risk assessment
How do we use human data in risk assessment
Projects and initiatives
HealthToxicologyInnovationIn vitro
Cells4Thought: using iPSCs for neurodevelopmental health
The prevalence of neurodevelopmental disorders (NDDs), including cognitive impairments, is increasing worldwide with great impact on daily life quality. There is evidence that exposure to chemicals may contribute to the incidence of NDD. However, a causal link is lacking. Towards this goal, a human-relevant in vitro model system mimicking parts of brain development, such as neuronal network functioning, could be used for mechanistic research on how gene-environment interactions contribute to the development of NDD. This is going to be studied in the project Cells4Thought, using induced pluripotent stem cells form different individuals to study the effect of chemicals on neuronal differentiation.
Meetings & conferences
HelpathonsHealthToxicologyIn silico
ONTOX Hackathon: Hack To Save Lives And Avoid Animal Suffering
Artificial Intelligence (AI) in toxicology – a potential driver for reducing or replacing laboratory animals in the future. ONTOX project is looking for solutions and innovative ideas to move forward. Are you going to help ONTOX to hack into these complex challenges?
The hackathon will be held from 21 to 23 April 2024 in Utrecht Science Park. The whole event is open to a diverse community of forward-thinkers and problem-solvers interested in the intersection of AI and ethical toxicology. The goal is to bring together passionate individuals who seek innovative solutions to critical challenges in toxicology.
Read more about the hackathon and register here (https://ontox-project.eu/hackathon/).
Innovation examples
HealthToxicologyInnovationIn vitro
Human based 3D liver models
Human-based in vitro models are increasingly being used in the hepatology field. And in addition to the obvious ethical arguments, they offer several advantages over the classical animal models. One of them is the ability to perform mechanistic research at the molecular level in a well-controlled setting and reduce species differences. These liver-based in vitro models can range from simple monolayer cultures of hepatocytes to the liver-on-chips systems in which all liver cells are cultured in a 3D configuration on a microfluidic platform. Liver-based in vitro models must be selected on a case-by-case basis and should fit the purpose of the research, which might go from fundamental to translational research.
Innovation examples
HealthToxicologyInnovationIn vitro
Platform for in vitro airborne inhalation testing
The air-liquid interface (ALI) technique uses lung cells cultured on a tiny polymer membrane in a cup. On one side of the membrane is a liquid containing the medium necessary for the cells to survive, while the other side is in contact with air. This is similar to the situation in the human lung. The compound to be tested is administered via an aerosol, vapor, or gas to mimic the situation in human lungs. By monitoring different parameters in the cell model before and after the compound is added, it is possible to measure the effects on lung cells. Depending on the test to be carried out, the lung cells can come from different regions in the respiratory tract and even from a variety of people, including individuals who smoke a lot or have specific diseases such as chronic obstructive pulmonary disease or asthma.
In vitro ALI inhalation testing (https://doi.org/10.1021/acs.est.7b00493) adds value for e.g. pre-clinical trials and research in the pharmaceutical industry and testing (new) compounds for the chemical sector and beyond. The advantages of ALI inhalation testing are that it is a non-animal method, it reduces the use of in vivo experiments, pre-clinical testing with human-derived cell models is more realistic and limits clinical trial failures and it provides faster and more efficient testing of compound
Innovation examples
ToxicologyIn vitro
Stem cell differentiation assays for animal-free developmental neurotoxicity assessment
Victoria de Leeuw was a PhD candidate in the research group of prof. dr. Aldert Piersma at the RIVM and Institute for Risk Assessment Sciences at Utrecht University. Piersma's lab studies the effects of compounds on development of the embryo during pregnancy with, among other techniques, stem cell cultures. The project of Victoria was aimed to differentiate embryonic stem cells of mouse and human origin into neuronal and glial cells, which could mimic parts of differentiation as seen during embryonic brain development. These models were able to show some of the known toxic mechanisms induced by these compounds, congruent with what they we hypothesised to mimic. This provides mechanistic information into how chemical compounds can be toxic to brain development. Therefore, these two stem cell assays make a useful contribution to the animal-free assessment of developmental neurotoxicity potential of compounds.
Victoria is nominated for the Hugo van Poelgeest prize 2022 for excellent research to replace animal testing.
Meetings & conferences
ToxicologyIn vitroAdvanced
Biotransformation of proteratogenic anti-epileptics in the zebrafish embryo
The zebrafish (Danio rerio) embryo has gained interest as an alternative model for developmental toxicity testing, which still mainly relies on in vivo mammalian models (e.g., rat, rabbit). However, cytochrome P450 (CYP)-mediated drug metabolism, which is critical for the bioactivation of several proteratogens, is still under debate for this model. Therefore, we investigated the potential capacity of zebrafish embryos/larvae to bioactivate two known mammalian proteratogens, carbamazepine (CBZ) and phenytoin (PHE) into their mammalian active metabolites, carbamazepine-10,11-epoxide (E-CBZ) and 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH), respectively. Zebrafish embryos were exposed to three concentrations (31.25, 85, and 250 μM) of CBZ and PHE from 51⁄4 to 120 hours post fertilization (hpf) at 28.5°C under a 14/10 hour light/dark cycle. For species comparison, also adult zebrafish, rat, rabbit and human liver microsomes (200 μg/ml) were exposed to 100 μM of CBZ or PHE for 240 minutes at 28.5°C. Potential formation of the mammalian metabolites was assessed in the embryo medium (48, 96, and 120 hpf); pooled (n=20) whole embryos/larvae extracts (24 and 120 hpf); and in the microsomal reaction mixtures (at 5 and 240 minutes) by targeted investigation using a UPLC–Triple Quadrupole MS system with lamotrigine (0.39 μM) as internal standard. Our study showed that zebrafish embryos metabolize CBZ to E-CBZ, but only at the end of organogenesis (from 96 hpf onwards), and no biotransformation of PHE to HPPH occurred. In contrast, our in vitro drug metabolism assay showed that adult zebrafish metabolize both compounds into their active mammalian metabolites. However, significant differences in metabolic rate were observed among the investigated species. These results highlight the importance of including the zebrafish in the in vitro drug metabolism testing battery
for accurate species selection in toxicity studies.
Meetings & conferences
HealthToxicologyIn vitroAdvanced
Characterisation and cytotoxicity assessment of Helleborus with NAMs
Helleborus sp. is a member of the Ranunculaceae family, and are small, perennial herbs common in Central and Southern Europe and Asia. Their distribution in Europe elevated their position in therapeutic remedies since the ancient time and mythology. Due to their potent and rich extracts from their roots, hellebores have been used in traditional and folklore remedies as they present rich sources in glycosides. Mainly, these plants have exhibited cathartic, anthelmintic and other beneficial aspects to treat diseases, however, hellebores have also been known for their adverse and poisonous aspects. It is also because of their cytotoxic aspect that these species have also been explored as alternative approaches to cancer treatment and are mainly reported as sporadic patient cases in literature. In this study, we first focused on the phytochemical characterisation of Helleborus odorus subsp. cyclophyllus combining biochemical assays and a detailed characterisation of its antioxidant and antibacterial properties. Furthermore, regarding its toxic potential, we explored the cytotoxic toxic properties and the mechanisms of toxicity mediated effects using in vitro cell systems primary human aortic endothelial cells (HAECs). HAECs are useful for studying vascular diseases such as thrombosis, atherosclerosis, and hypertension as well as for stent-graft compatibility testing and within the 3Rs principles, avoiding animals in these studies. Results showed the cytotoxic and reactive oxygen species potential of Helleborus extract in dose and time dependent manner. Further investigation (not shown here) revealed more mechanistic effects relevant to inhibition of proliferation.
Contact: https://www.researchgate.net/profile/Anna-Michalaki
Meetings & conferences
ToxicologyIn vitroAdvanced
Toxicoepigenetics on histones using mass spectrometry
Toxicoepigenetics is an emerging field that studies the toxicological impact of compounds on protein expression through heritable, non-genetic mechanisms, such as histone post-translational modifications (hPTMs). Due to substantial progress in the large-scale study of hPTMs, integration into the field of toxicology is promising and offers the opportunity to gain novel insights into toxicological phenomena. Moreover, there is a growing demand for high-throughput human-based in vitro assays for toxicity testing, especially for developmental toxicity. Consequently, we developed a mass spectrometry-based proof-of-concept to assess a histone code screening assay capable of simultaneously detecting multiple hPTM-changes in human embryonic stem cells. To prove the applicability and performance, we first validated the untargeted workflow with valproic acid (VPA), a histone deacetylase inhibitor. These results demonstrate that our workflow is capable of mapping the hPTM-dynamics, with a general increase in acetylations as an internal control. To illustrate the scalability, a dose-response study was performed on a proof-of-concept library of ten compounds i) with a known effect on the hPTMs (BIX-01294, 3-Deazaneplanocin A, Trichostatin A, and VPA), ii) classified as highly embryotoxic by the European Centre for the Validation of Alternative Methods (ECVAM) (Methotrexate, and All-trans retinoic acid), iii) classified as non-embryotoxic by ECVAM (Penicillin G), and iv) compounds of abuse with presumed developmental toxicity (ethanol, caffeine, and nicotine). In conclusion, we show that toxicoepigenetic screening on histones is feasible and yields very rich data that can contribute to the (safe) development of drugs and holds potential, not only for applications in the pharmaceutical industry, but also for environmental toxicity and food safety.
Lab website: https://www.progentomics.ugent.be/
Linkedin: https://www.linkedin.com/in/sigrid-verhelst-a54798172/
ResearchGate: https://www.researchgate.net/profile/Sigrid-Verhelst
Innovation examples
HealthToxicologyIn vitroOrgan-on-Chip
GUTS BV - small intestine-on-a-chip and advanced computational analysis for compound and protein screening
GUTS BV is a contract research organization offering its 3-dimensional state-of-the-art small intestinal in vitro model in combination with custom computational analysis approaches. The small intestinal model was developed during Dr. Paul Jochems PhD research at Utrecht University in the group of Prof. Roos Masereeuw. In comparison to the current gold standard (Transwell model), they show improvement in cell differentiation (all major specialized cell types present), physiological structure (3D tube- and villi-like structures) and a functional epithelial barrier. After acquiring experimental data from this model computational analysis approaches are used to score and compare measured compounds for all tested biological parameters at once. The combined effort of improved in vitro modelling and data analysis is believed to result in an enhanced preclinical predictability.
GUTS BV was nominated for the Venture Challenge 2021 for their development of an intestinal model combined with advanced computational analysis for protein and chemical compound screening.
Research papers:
https://www.sciencedirect.com/science/article/pii/S0887233318307811
https://www.mdpi.com/2072-6643/12/9/2782/htm
https://www.nature.com/articles/s41538-020-00082-z
LinkedIn: https://www.linkedin.com/company/71016128/
Innovation examples
ToxicologyInnovationIn vitro
Human neuronal cell models for in vitro neurotoxicity screening and seizure liability assessment
Anke Tukker was a PhD candidate in the Neurotoxicology Research group of Dr. Remco Westerink at the Institute for Risk Assessment Sciences at Utrecht University. Dr Westerink’s research group investigates the mechanisms of action of toxic substances on a cellular and molecular level using in vitro systems. Anke's project aimed to develop a human induced pluripotent stem cell (hiPSC)-derived neuronal model for in vitro neurotoxicity screening and seizure liability assessment. Using micro-electrode arrays (MEAs), she showed that these models mimic in vivo neuronal network activity. When these hiPSC-derived neurons are mixed with hiPSC-derived astrocytes, they can be used for in vitro seizure liability assessment. Comparing these data with data obtained from the current used model of ex vivo rodent cortical cultures, she found that these human cells outperform the rodent model. Here research thus contributes towards animal-free neurotoxicity testing.
Anke Tukker has won the public vote of the Hugo van Poelgeest prize 2020 for her research on human neuronal cell models for in vitro neurotoxicity screening and seizure liability assessment.
Neurotoxicology Research Group, IRAS, Utrecht University: https://ntx.iras.uu.nl/NTXatIras