Ingested Engineered Nanomaterials Affect the Expression of Mucin Genes—An In Vitro-In Vivo Comparison

The increasing use of engineered nanomaterials (ENM) in food has fueled the development of intestinal in vitro models for toxicity testing. However, ENM effects on intestinal mucus have barely been addressed, although its crucial role for intestinal health is evident. We investigated the effects of ENM on mucin expression and aimed to evaluate the suitability of four in vitro models of increasing complexity compared to a mouse model exposed through feed pellets. We assessed the gene expression of the mucins MUC1, MUC2, MUC5AC, MUC13 and MUC20 and the chemokine interleukin-8 in pre-confluent and confluent HT29-MTX-E12 cells, in stable and inflamed triple cultures of Caco-2, HT29-MTX-E12 and THP-1 cells, and in the ileum of mice following exposure to TiO2, Ag, CeO2 or SiO2. All ENM had shared and specific effects. CeO2 downregulated MUC1 in confluent E12 cells and in mice. Ag induced downregulation of Muc2 in mice. Overall, the in vivo data were consistent with the findings in the stable triple cultures and the confluent HT29-MTX-E12 cells but not in pre-confluent cells, indicating the higher relevance of advanced models for hazard assessment. The effects on MUC1 and MUC2 suggest that specific ENM may lead to an elevated susceptibility towards intestinal infections and inflammations.

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In Vitro Methods as a Tool in Neurotoxicity Studies

Alternatives to Laboratory Animals ◽

10.1177/026119299502300412 ◽

1995 ◽

Vol 23 (4) ◽

pp. 491-496

Author(s):

Hanna Tähti ◽

Leila Vaalavirta ◽

Tarja Toimela

Keyword(s):

Risk Evaluation ◽

Toxicity Testing ◽

In Vitro Models ◽

In Vitro Tests ◽

Industrial Chemicals ◽

Mercury Compounds ◽

Toxicological Data ◽

In Vivo Tests

— There are several hundred industrial chemicals with neurotoxic potential. The neurotoxic risks of most of these chemicals are unknown. Additional methods are needed to assess the risks more effectively and to elucidate the mechanisms of neurotoxicity more accurately than is possible with the conventional methods. This paper deals with general tasks concerning the use of in vitro models in the evaluation of neurotoxic risks. It is based on our previous studies with various in vitro models and on recent literature. The induction of glial fibrillary acidic protein in astrocyte cultures after treatment with known neurotoxicants (mercury compounds and aluminium) is discussed in more detail as an important response which can be detected in vitro. When used appropriately with in vivo tests and with previous toxicological data, in vitro neurotoxicity testing considerably improves risk assessment. The incorporation of in vitro tests into the early stages of risk evaluation can reduce the number of animals used in routine toxicity testing, by identifying chemicals with high neurotoxic potential.

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Computational fluid dynamics applied to the ventilation of small-animal laboratory cages

Laboratory Animals ◽

10.1177/0023677220937718 ◽

2020 ◽

pp. 002367722093771

Author(s):

Ira Katz ◽

Kateryna Voronetska ◽

Mickaël Libardi ◽

Matthieu Chalopin ◽

Patricia Privat ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Noble Gas ◽

Small Animal ◽

Toxicity Testing ◽

Exposure Period ◽

In Vitro Models ◽

Gas Distribution

Several studies based on in vivo or in vitro models have found promising results for the noble gas argon in neuroprotection against ischaemic pathologies. The development of argon as a medicinal product includes the requirement for toxicity testing through non-clinical studies. The long exposure period of animals (rats) during several days results in technical and logistic challenges related to the gas administration. In particular, a minimum of 10 air changes per hour (ACH) to maintain animal welfare results in extremely large volumes of experimental gas required if the gas is not recirculated. The difficulty with handling the many cylinders prompted the development of such a recirculation-based design. To distribute the recirculating gas to individually ventilated cages and monitor them properly was deemed more difficult than constructing a single large enclosure that will hold several open cages. To address these concerns, a computational fluid dynamics (CFD) analysis of the preliminary design was performed. A purpose-made exposure chamber was designed based on the CFD simulations. Comparisons of the simulation results to measurements of gas concentration at two cage positions while filling show that the CFD results compare well to these limited experiments. Thus, we believe that the CFD results are representative of the gas distribution throughout the enclosure. The CFD shows that the design provides better gas distribution (i.e. a higher effective air change rate) than predicted by 10 ACH.

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Modulation of Matrix Metalloproteinases by Plant-Derived Products

Current Cancer Drug Targets ◽

10.2174/1568009620666201120144838 ◽

2020 ◽

Vol 20 ◽

Author(s):

Nur Najmi Mohamad Anuar ◽

Nurul Iman Natasya Zulkafali ◽

Azizah Ugusman

Keyword(s):

Clinical Trials ◽

Natural Products ◽

Matrix Metalloproteinases ◽

Animal Studies ◽

Current Knowledge ◽

In Vitro Models ◽

In Vivo Studies ◽

Extracellular Matrix Components

: Matrix metalloproteinases (MMPs) are a group of zinc-dependent metallo-endopeptidase that are responsible towards the degradation, repair and remodelling of extracellular matrix components. MMPs play an important role in maintaining a normal physiological function and preventing diseases such as cancer and cardiovascular diseases. Natural products derived from plants have been used as traditional medicine for centuries. Its active compounds, such as catechin, resveratrol and quercetin, are suggested to play an important role as MMPs inhibitors, thereby opening new insights into their applications in many fields, such as pharmaceutical, cosmetic and food industries. This review summarises the current knowledge on plant-derived natural products with MMP-modulating activities. Most of the reviewed plant-derived products exhibit an inhibitory activity on MMPs. Amongst MMPs, MMP-2 and MMP-9 are the most studied. The expression of MMPs is inhibited through respective signalling pathways, such as MAPK, NF-κB and PI3 kinase pathways, which contribute to the reduction in cancer cell behaviours, such as proliferation and migration. Most studies have employed in vitro models, but a limited number of animal studies and clinical trials have been conducted. Even though plant-derived products show promising results in modulating MMPs, more in vivo studies and clinical trials are needed to support their therapeutic applications in the future.

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Three-dimensional Growth of Renal Epithelial Cells in Vitro: A Tool in Toxicity Testing

Alternatives to Laboratory Animals ◽

10.1177/026119299302100212 ◽

1993 ◽

Vol 21 (2) ◽

pp. 191-195 ◽

Cited By ~ 1

Author(s):

Knut-Jan Andersen ◽

Erik Ilsø Christensen ◽

Hogne Vik

Keyword(s):

Epithelial Cells ◽

Three Dimensional ◽

Toxicity Testing ◽

Renal Tissue ◽

Epithelial Cell Line ◽

Multicellular Spheroids ◽

Renal Epithelial Cell ◽

Renal Epithelial Cells

The tissue culture of multicellular spheroids from the renal epithelial cell line LLC-PK1 (proximal tubule) is described. This represents a biological system of intermediate complexity between renal tissue in vivo and simple monolayer cultures. The multicellular structures, which show many similarities to kidney tubules in vivo, including a vectorial water transport, should prove useful for studying the potential nephrotoxicity of drugs and chemicals in vitro. In addition, the propagation of renal epithelial cells as multicellular spheroids in serum-free culture may provide information on the release of specific biological parameters, which may be suppressed or masked in serum-supplemented media.

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Human Saliva-Mediated Hydrolysis of Eugenyl-β-D-Glucoside and Fluorescein-di-β-D-Glucoside in In Vivo and In Vitro Models

Biomolecules ◽

10.3390/biom11020172 ◽

2021 ◽

Vol 11 (2) ◽

pp. 172

Author(s):

Mariusz Dziadas ◽

Adam Junka ◽

Henryk Jeleń

Keyword(s):

Oral Cavity ◽

Control Sample ◽

Rapid Test ◽

Human Saliva ◽

In Vitro Models ◽

Microbial Hydrolysis ◽

Amoxicillin Trihydrate ◽

Potassium Clavulanate

Eugenyl-β-D-glucopyranoside, also referred to as Citrusin C, is a natural glucoside found among others in cloves, basil and cinnamon plants. Eugenol in a form of free aglycone is used in perfumeries, flavourings, essential oils and in medicinal products. Synthetic Citrusin C was incubated with human saliva in several in vitro models together with substrate-specific enzyme and antibiotics (clindamycin, ciprofloxacin, amoxicillin trihydrate and potassium clavulanate). Citrusin C was detected using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Citrusin C was completely degraded only when incubated with substrate-specific A. niger glucosidase E.C 3.2.1.21 (control sample) and when incubated with human saliva (tested sample). The addition of antibiotics to the above-described experimental setting, stopped Citrusin C degradation, indicating microbiologic origin of hydrolysis observed. Our results demonstrate that Citrusin C is subjected to complete degradation by salivary/oral cavity microorganisms. Extrapolation of our results allows to state that in the human oral cavity, virtually all β-D-glucosides would follow this type of hydrolysis. Additionally, a new method was developed for an in vivo rapid test of glucosidase activity in the human mouth on the tongue using fluorescein-di-β-D-glucoside as substrate. The results presented in this study serve as a proof of concept for the hypothesis that microbial hydrolysis path of β-D-glucosides begins immediately in the human mouth and releases the aglycone directly into the gastrointestinal tract.

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O23: CHARACTERISING PATIENT-DERIVED COLORECTAL CANCER TISSUE-ORIGINATED ORGANOIDAL SPHEROIDS FOR HIGH-THROUGHPUT MICROFLUIDIC APPLICATIONS

British Journal of Surgery ◽

10.1093/bjs/znab117.023 ◽

2021 ◽

Vol 108 (Supplement_1) ◽

Author(s):

MI Khot ◽

M Levenstein ◽

R Coppo ◽

J Kondo ◽

M Inoue ◽

...

Keyword(s):

Colorectal Cancer ◽

Fluid Flow ◽

High Throughput ◽

Microfluidic Devices ◽

In Vitro Models ◽

Fluorescent Imaging ◽

Cancer Tissue ◽

Cell Models

Abstract Introduction Three-dimensional (3D) cell models have gained reputation as better representations of in vivo cancers as compared to monolayered cultures. Recently, patient tumour tissue-derived organoids have advanced the scope of complex in vitro models, by allowing patient-specific tumour cultures to be generated for developing new medicines and patient-tailored treatments. Integrating 3D cell and organoid culturing into microfluidics, can streamline traditional protocols and allow complex and precise high-throughput experiments to be performed with ease. Method Patient-derived colorectal cancer tissue-originated organoidal spheroids (CTOS) cultures were acquired from Kyoto University, Japan. CTOS were cultured in Matrigel and stem-cell media. CTOS were treated with 5-fluorouracil and cytotoxicity evaluated via fluorescent imaging and ATP assay. CTOS were embedded, sectioned and subjected to H&E staining and immunofluorescence for ABCG2 and Ki67 proteins. HT29 colorectal cancer spheroids were produced on microfluidic devices using cell suspensions and subjected to 5-fluorouracil treatment via fluid flow. Cytotoxicity was evaluated through fluorescent imaging and LDH assay. Result 5-fluorouracil dose-dependent reduction in cell viability was observed in CTOS cultures (p<0.01). Colorectal CTOS cultures retained the histology, tissue architecture and protein expression of the colonic epithelial structure. Uniform 3D HT29 spheroids were generated in the microfluidic devices. 5-fluorouracil treatment of spheroids and cytotoxic analysis was achieved conveniently through fluid flow. Conclusion Patient-derived CTOS are better complex models of in vivo cancers than 3D cell models and can improve the clinical translation of novel treatments. Microfluidics can streamline high-throughput screening and reduce the practical difficulties of conventional organoid and 3D cell culturing. Take-home message Organoids are the most advanced in vitro models of clinical cancers. Microfluidics can streamline and improve traditional laboratory experiments.

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The common antitussive agent dextromethorphan protects against hyperoxia-induced cell death in established in vivo and in vitro models of neonatal brain injury

Neuroscience ◽

10.1016/j.neuroscience.2014.05.059 ◽

2014 ◽

Vol 274 ◽

pp. 260-272 ◽

Cited By ~ 4

Author(s):

A. Posod ◽

K. Pinzer ◽

M. Urbanek ◽

K. Wegleiter ◽

M. Keller ◽

...

Keyword(s):

Cell Death ◽

Brain Injury ◽

In Vitro Models ◽

Neonatal Brain ◽

Neonatal Brain Injury ◽

The Common

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Homozygous MTAP deletion in primary human glioblastoma is not associated with elevation of methylthioadenosine

Nature Communications ◽

10.1038/s41467-021-24240-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yasaman Barekatain ◽

Jeffrey J. Ackroyd ◽

Victoria C. Yan ◽

Sunada Khadka ◽

Lin Wang ◽

...

Keyword(s):

Clinical Relevance ◽

Homozygous Deletion ◽

In Vitro Models ◽

Arginine Methyltransferase ◽

Human Glioblastoma ◽

Primary Glioblastoma ◽

Methylthioadenosine Phosphorylase ◽

Metabolomic Profiling

AbstractHomozygous deletion of methylthioadenosine phosphorylase (MTAP) in cancers such as glioblastoma represents a potentially targetable vulnerability. Homozygous MTAP-deleted cell lines in culture show elevation of MTAP’s substrate metabolite, methylthioadenosine (MTA). High levels of MTA inhibit protein arginine methyltransferase 5 (PRMT5), which sensitizes MTAP-deleted cells to PRMT5 and methionine adenosyltransferase 2A (MAT2A) inhibition. While this concept has been extensively corroborated in vitro, the clinical relevance relies on exhibiting significant MTA accumulation in human glioblastoma. In this work, using comprehensive metabolomic profiling, we show that MTA secreted by MTAP-deleted cells in vitro results in high levels of extracellular MTA. We further demonstrate that homozygous MTAP-deleted primary glioblastoma tumors do not significantly accumulate MTA in vivo due to metabolism of MTA by MTAP-expressing stroma. These findings highlight metabolic discrepancies between in vitro models and primary human tumors that must be considered when developing strategies for precision therapies targeting glioblastoma with homozygous MTAP deletion.

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Modelling the Human Placental Interface In Vitro—A Review

Micromachines ◽

10.3390/mi12080884 ◽

2021 ◽

Vol 12 (8) ◽

pp. 884

Author(s):

Marta Cherubini ◽

Scott Erickson ◽

Kristina Haase

Keyword(s):

Drug Testing ◽

Cell Types ◽

In Vitro Models ◽

Placental Development ◽

Scientific Challenge ◽

Induced Pluripotent ◽

And Function ◽

And Control

Acting as the primary link between mother and fetus, the placenta is involved in regulating nutrient, oxygen, and waste exchange; thus, healthy placental development is crucial for a successful pregnancy. In line with the increasing demands of the fetus, the placenta evolves throughout pregnancy, making it a particularly difficult organ to study. Research into placental development and dysfunction poses a unique scientific challenge due to ethical constraints and the differences in morphology and function that exist between species. Recently, there have been increased efforts towards generating in vitro models of the human placenta. Advancements in the differentiation of human induced pluripotent stem cells (hiPSCs), microfluidics, and bioprinting have each contributed to the development of new models, which can be designed to closely match physiological in vivo conditions. By including relevant placental cell types and control over the microenvironment, these new in vitro models promise to reveal clues to the pathogenesis of placental dysfunction and facilitate drug testing across the maternal–fetal interface. In this minireview, we aim to highlight current in vitro placental models and their applications in the study of disease and discuss future avenues for these in vitro models.

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