Biology subjects

Stage, T. B.

Publications and source records attributed to Stage, T. B..

4 recordsLinked to original sources

bioRxiv2025

Dicloxacillin and flucloxacillin inhibit hepatic uptake transporters - in vitro investigations and physiological based pharmacokinetic modelling

Dicloxacillin and flucloxacillin are {beta}-lactamase-resistant penicillin antibiotics that have been in clinical use for over 50 years. While both antibiotics are known to induce cytochrome P450 enzymes, there is limited information available regarding their interactions with drug transporters. Here, we investigated the in vitro transport and inhibition of hepatic organic anion transporting polypeptides (OATPs) and renal organic anion transporters (OATs) by these antibiotics in recombinant transporter overexpressing HEK293 cells. We also investigated the transport of these antibiotics by efflux transporters, as well as their inhibition of breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp) using a HEK293 membrane vesicle transport assay. Dicloxacillin and flucloxacillin inhibited rosuvastatin transport by OATP1B1, OATP1B3 and OATP2B1, and the inhibition was strongest for OATP1Bs with IC50 values of 3.9 {micro}M and 31 {micro}M (OATP1B1) and 6.7 {micro}M and 21 {micro}M (OATP1B3) for dicloxacillin and flucloxacillin, respectively. Both antibiotics also inhibited BCRP-mediated rosuvastatin transport with IC50 values of 166 {micro}M (dicloxacillin) and 379 {micro}M (flucloxacillin), while P-gp-mediated transport of N-methyl-quinidine was inhibited to a lesser extent. All OATPs and OATs transported dicloxacillin and flucloxacillin. Static model predictions indicated that the inhibition of OATPs, BCRP and P-glycoprotein by both compounds may be clinically relevant. We further developed and verified physiologically based pharmacokinetic (PBPK) models for dicloxacillin and flucloxacillin. PBPK model simulations predicted no major change in rosuvastatin, a substrate for OATPs and BCRP, pharmacokinetics, when co-administered with dicloxacillin or flucloxacillin. Simulations with dicloxacillin and P-gp substrates dabigatran or digoxin also predicted limited inhibition of P-gp transport.

pharmacology and toxicology↗

bioRxiv2023

Paclitaxel- and vincristine-induced neurotoxicity and drug transport in sensory neurons

Chemotherapy-induced peripheral neuropathy (CIPN) constitutes a significant health problem due to the increasing prevalence and the lack of therapies for treatment and prevention. Patients with CIPN primarily present with sensory symptoms, such as sensory disturbances that may progress to neuropathic pain in hands and feet. While pivotal for routine cancer treatment, paclitaxel and vincristine frequently cause CIPN and impact the quality of life among cancer patients and survivors. We utilized a model of human sensory neurons derived from induced pluripotent stem cells (iPSC-SNs) to provide mechanistic understanding of CIPN caused by paclitaxel and vincristine. The morphological phenotype of iPSC-SNs following paclitaxel exposure was characterized by retraction and thickening of axons while vincristine caused fragmentation and abolishment of axons. Both agents increased the mRNA expression of the pain receptor, transient receptor potential vanilloid (TRPV1), and highly induced neuronal damage, as measured by activating transcription factor 3 (ATF3) mRNA. iPSC-SNs express the efflux transporters, P-glycoprotein (P-gp, encoded by ABCB1) and multidrug resistance-associated protein 1 (MPR1, encoded by ABCC1). Inhibition of P-gp and MRP1 in iPSC-SNs exacerbated neurotoxicity of paclitaxel and vincristine respectively. We further show that pre-treatment with the P-gp inducer rifampicin alleviated chemotherapy-induced structural and transcriptional alterations in iPSC-SNs. iPSC-SNs are a valuable and robust model to study the role of efflux transporters and other mechanistic targets in CIPN. Efflux transporters play a critical role in CIPN pathogenesis as they regulate the disposition of chemotherapy to the peripheral nervous system.

pharmacology and toxicology↗

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↗

bioRxiv2020

Human Induced Pluripotent Stem Cell Derived Sensory Neurons are Sensitive to the Neurotoxic Effects of Paclitaxel

Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting adverse event associated with treatment with paclitaxel and other chemotherapeutic agents. The prevention and treatment of CIPN are limited by a lack of understanding of the molecular mechanisms underlying this toxicity. In the current study, a human induced pluripotent stem cell–derived sensory neuron (iPSC-SN) model was developed for the study of chemotherapy-induced neurotoxicity. The iPSC-SNs express proteins characteristic of nociceptor, mechanoreceptor and proprioceptor sensory neurons and show Ca2+ influx in response to capsaicin, α,β-meATP and glutamate. iPSC-SNs are relatively resistant to the cytotoxic effects of paclitaxel, with IC50 values of 38.1 μM (95% CI: 22.9 – 70.9 μM) for 48 hr exposure and 9.3 μM (95% CI: 5.7 – 16.5 μM) for 72 hr treatment. Paclitaxel causes dose- and time-dependent changes in neurite network complexity detected by βIII-tubulin staining and high content imaging. The IC50 for paclitaxel reduction of neurite area was 1.4 μM (95% CI: 0.3 - 16.9 μM) for 48 hr exposure and 0.6 μM (95% CI: 0.09 - 9.9 μM) for 72 hr exposure. Decreased mitochondrial membrane potential, slower movement of mitochondria down the neurites and changes in glutamate-induced neuronal excitability were also observed with paclitaxel exposure. The iPSC-SNs were also sensitive to docetaxel, vincristine and bortezomib. Collectively, these data support the use of iPSC-SNs for detailed mechanistic investigations of genes and pathways implicated in chemotherapy-induced neurotoxicity and the identification of novel therapeutic approaches for its prevention and treatment.Competing Interest StatementThe authors have declared no competing interest.View Full Text

pharmacology and toxicology↗