Biology subjects

Ingelman-Sundberg, M.

Publications and source records attributed to Ingelman-Sundberg, M..

3 recordsLinked to original sources

bioRxiv2022

3D Spheroid Primary Human Hepatocytes for Prediction of Cytochrome P450 and Drug Transporter Induction

Primary human hepatocytes (PHHs) have been the gold standard in vitro model for the human liver and are crucial to predict hepatic drug-drug interactions. The aim of this work was to assess the utility of 3D spheroid PHHs to study induction of important cytochrome P450 (CYP) enzymes and drug transporters. 3D spheroid PHHs from three different donors were treated for four days with rifampicin, dicloxacillin, flucloxacillin, phenobarbital, carbamazepine, efavirenz, omeprazole or {beta}-naphthoflavone. Induction of CYPs 1A1, 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4, P-gp/ABCB1, MRP2/ABCC2, ABCG2, OCT1/SLC22A1, SLC22A7, SLCO1B1 and SLCO1B3 were evaluated at mRNA and protein levels. Enzyme activity of CYP3A4, CYP2B6, CYP2C19 and CYP2D6 were also assessed. Induction of CYP3A4 protein and mRNA correlated well for all donors and compounds and had a maximal induction of 5-to 6-fold for rifampicin, which closely correlates to induction observed in clinical studies. Similar estimates were found for dicloxacillin and flucloxacillin, which also correlates to findings from clinical studies. Rifampicin induced the mRNA of CYP2B6 and CYP2C8 by 9- and 12-fold, while the protein levels of these CYPs reached 2- and 3-fold induction, respectively. Rifampicin induced CYP2C9 protein by 1.4-fold, while the induction of CYP2C9 mRNA was over 2-fold in all donors. Rifampicin induced ABCB1, ABCC2 and ABCG2 by 2-fold. In conclusion, 3D spheroid PHHs is a valid model to investigate mRNA and protein induction of hepatic drug metabolizing enzymes and transporters, and this model provides a solid basis to study induction of CYPs and transporters, which translates to clinical relevance.

pharmacology and toxicology↗

bioRxiv2022

Humanized CYP2C19 transgenic mouse as an animal model of cerebellar ataxia

BackgroundAnimal models are essential for understanding etiology and pathophysiology of movement disorders. Previously, we have found that mice transgenic for the human CYP2C19 gene, expressed in the liver and developing brain, exhibit altered neurodevelopment associated with impairments of their motor function and emotionality. ObjectivesTo characterize motoric phenotype of the CYP2C19 transgenic mice and validate its usefulness as an animal model of ataxia. MethodsThe rotarod and beam-walking tests were utilized to quantify the functional alterations induced by motoric phenotype. Dopaminergic system was assessed by tyrosine hydroxylase immunohistochemistry and by chromatographic quantification of the whole-brain dopamine levels. Beam-walking test was also repeated after the treatment with the dopamine receptor antagonists, ecopipam and raclopride. The volumes of 20 brain regions in the CYP2C19 transgenic mice and controls were quantified by 9.4T gadolinium-enhanced postmortem structural neuroimaging. ResultsCYP2C19 transgenic mice were found to exhibit abnormal, unilateral ataxia-like gait, clasping reflex and 5.6-fold more paw-slips using the beam-walking test (p<0.0001, n=89); the phenotype was more pronounced in younger animals. Hyperdopaminergism was observed in the CYP2C19 mice; however, the motoric impairment was not ameliorated by dopamine receptor antagonists and there was also no midbrain dopamine neuron loss in CYP2C19 mice. However, in these mice, cerebellar volume was drastically decreased (11.8% [95%CI: -14.7, -9.0], q<0.0001, n=59), whereas a moderate decrease in hippocampal volume was observed (-4.2% [95%CI: -6.4%, -1.9%], q=0.015, n=59). ConclusionsHumanized CYP2C19 transgenic mice exhibit altered motoric function and functional motoric impairments; this phenotype is likely caused by an aberrant cerebellar development.

neuroscience↗

bioRxiv2020

A unifying model to predict variable drug response for personalised medicine

Pharmacogenomics is a key component of personalized medicine. It promises a safer and more effective drug treatment by individualizing the choice of drug and dose based on an individuals genetic profile1,2. The majority of commonly prescribed drugs are metabolized by a small set of Cytochrome P450 (CYP) enzymes3. In clinical practice, genetic biomarkers are being used to categorize patients into predefined *-alleles to predict CYP450 enzyme activity and adjust drug dosages accordingly. Yet, this approach has important limitations as it leaves a large part of variability in drug response unexplained4,5. Here, we present a novel approach and introduce a continuous scale (instead of categorical) assignments to predict metabolic enzyme activity. The proposed strategy uses full gene sequencing data, a neural network model and CYP2D6 mediated tamoxifen metabolism from a prospective study of 561 breast cancer patients. The model explains 79% of the interindividual variability in CYP2D6 activity compared to 54% with the conventional approach. It is capable of assigning accurate enzyme activity to alleles containing previously uncharacterized combinations of variants and were replicated in an independent cohort of tamoxifen treated patients, a cohort of Venlafaxine users as well as in vitro functional assays using HEK cells. These results demonstrate the advantage of a continuous scale and a completely phased genotype for prediction of CYP450 enzyme activity and thereby enables more accurate prediction of individual drug response.

pharmacology and toxicology↗