TNF-α and IL-1ß Exposure Modulates the Expression and Functionality of P-Glycoprotein in Intestinal and Renal Barriers.

Inflammation is characterized by an increased secretion of proinflammatory cytokines known to alter the expression and functionality of drug transporters. Since P-glycoprotein (P-gp) plays a key role in the pharmacokinetics of several drugs, these modulations could further affect drug exposure. In this context, this study aims to investigate the impact of in vitro cytokine exposure on the expression and activity of P-gp using the intestinal model Caco-2 and the human renal cells RPTEC/TERT1. Cells were exposed to various concentrations of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß for 24 or 72 h. Gene expression was then assessed by RT-qPCR followed by absolute quantification of P-gp using liquid chromatography coupled with mass spectrometry. Then, the activity of P-gp was assessed by the intracellular accumulation of rhodamine 123. TNF-α increased both the gene expression and P-gp activity by 15-40% in each model. Minor modulations were observed at the protein level with increases of up to 8% for RPTEC/TERT1 cells and 24% for Caco-2 cells. Conversely, IL-1ß led to a downregulation of gene, protein, and functionality by 48 and 25% in intestinal and renal cells, respectively. Taken together, these data highlighted that gene expression levels and functional activity of P-gp are altered by the pro-inflammatory cytokines in intestinal and renal cells. Such pronounced changes in human P-gp could result in altered exposure to drug substrates. Further in vivo studies are needed to confirm the impact of inflammation on drug pharmacokinetics.

Tyrosine kinase inhibitors and direct oral anticoagulants: In vitro evaluation of drug-drug interaction mediated by P-glycoprotein.

Direct oral anticoagulants (DOACs) are now an option in the prevention and treatment of venous thromboembolic events (VTE) in patients with active cancer. Pharmacokinetics of DOACs are largely influenced by efflux transporters derived from ABC transporters, notably by P-glycoprotein (P-gp). The aim of this study was to assess the potential P-gp-mediated drug-drug interactions between 11 tyrosine kinase inhibitors (TKIs) with apixaban and rivaroxaban. Bidirectional permeabilities of apixaban and rivaroxaban were investigated across MDCK-MDR1 models, to determine half maximal inhibitory concentration (IC50 ). Several categories of interaction risks based on IC50 values can be distinguished depending on the TKI and DOAC used. IC50 values of less than 10 µM were observed with the combination of erlotinib, nilotinib with both DOACs, and with dabrafenib and apixaban. IC50 values between 10 and 100 µM were seen for axitinib, crizotinib, dasatinib, imatinib, and lapatinib with apixaban, and for axitinib, crizotinib, dabrafenib, idelalisib, imatinib, and vemurafenib with rivaroxaban. A risk of drug-drug interaction was found in vitro between TKIs and DOACs. In vivo pharmacokinetic studies are needed to ensure the safety of prescribing DOACs in cancer patients on TKI therapy, in order to avoid major, potentially preventable bleeding events.

Three-dimensional dispersion entropy for uterine fibroid texture quantification and post-embolization evaluation.

BACKGROUND AND OBJECTIVE: Uterine fibroids are benign tumors that could lead to symptoms complicating a patient's daily life. Those fibroids can be treated using uterine fibroid embolization (UFE), an effective non-surgical procedure. However, objectively quantifying the benefits of such a procedure, and the patient's quality of life, is rather challenging. METHODS: With a novel multiscale three-dimensional (3D) entropy-based texture analysis, the multiscale 3D dispersion entropy (MDispEn3D), this work aims to objectively quantify the evolution -  after UFE  -  of patients' health in terms of quality of life, symptoms severity, and sexual function. For this purpose, clinical data and magnetic resonance imaging (MRI) scans of fibroids are analyzed before UFE (D0), ten days after (D10), and six months after (M6). RESULTS: An inverse correlation is observed between MDispEn3D entropy values and both size and volume of fibroids. An inverse correlation is also observed between MDispEn3D at M6 and the scores of symptoms severity. Moreover, the patient age is found to be related to the relative difference of DispEn3D and MDispEn3D values, between D0 and M6, translating into an increasing entropy value. Furthermore, we show that history of fibroma plays a role in determining the obtained DispEn3D values at D0. Finally, we observe that the lower MDispEn3D values at D0, the larger the size of the fibroid at M6. CONCLUSIONS: The proposed MDispEn3D method - by quantifying fibroid texture - could assist the medical doctors in the prognosis of uterine fibroids and the patients' quality of life assessment post-UFE. It could therefore favor the choice of this treatment compared to other more invasive surgical treatments.

In Vitro Evaluation of P-gp-Mediated Drug-Drug Interactions Using the RPTEC/TERT1 Human Renal Cell Model.

BACKGROUND AND OBJECTIVES: In vitro evaluation of the P-glycoprotein (P-gp) inhibitory potential is an important issue when predicting clinically relevant drug-drug interactions (DDIs). Located within all physiological barriers, including intestine, liver, and kidneys, P-gp plays a major role in the pharmacokinetics of various therapeutic classes. However, few data are available about DDIs involving renal transporters during the active tubular secretion of drugs. In this context, the present study was designed to investigate the application of the human renal cell line RPTEC/TERT1 to study drug interactions mediated by P-gp. METHODS: The P-gp inhibitory potentials of a panel of drugs were first determined by measuring the intracellular accumulation of rhodamine 123 in RPTEC/TERT1 cells. Then four drugs were selected to assess the half-maximal inhibitor concentration (IC50) values by measuring the intracellular accumulation of two P-gp-substrate drugs, apixaban and rivaroxaban. Finally, according to the FDA guidelines, the [I1]/IC50 ratio was calculated for each combination of drugs to assess the clinical relevance of the DDIs. RESULTS: The data showed that drugs which are known P-gp inhibitors, including cyclosporin A, ketoconazole, and verapamil, caused great increases in rhodamine 123 retention, whereas noninhibitors did not affect the intracellular accumulation of the P-gp substrate. The determined IC50 values were in accordance with the inhibition profiles observed in the rhodamine 123 accumulation assays, confirming the reliability of the RPTEC/TERT1 model. CONCLUSIONS: Taken together, the data demonstrate the feasibility of the application of the RPTEC/TERT1 model for evaluating the P-gp inhibitory potentials of drugs and consequently predicting renal drug interactions.

Inflammation Induces Changes in the Functional Expression of P-gp, BCRP, and MRP2: An Overview of Different Models and Consequences for Drug Disposition.

The ATP-binding cassette (ABC) transporters play a key role in drug pharmacokinetics. These membrane transporters expressed within physiological barriers can be a source of pharmacokinetic variability. Changes in ABC transporter expression and functionality may consequently affect the disposition of substrate drugs, resulting in different drug exposure. Inflammation, present in several acute and chronic diseases, has been identified as a source of modulation in drug transporter expression leading to variability in drug response. Its regulation may be particularly dangerous for drugs with a narrow therapeutic index. In this context, numerous in vitro and in vivo models have shown up- or downregulation in the expression and functionality of ABC transporters under inflammatory conditions. Nevertheless, the existence of contradictory data and the lack of standardization for the models used have led to a less conclusive interpretation of these data.

Is the human model RPTEC/TERT1 a relevant model for assessing renal drug efflux?

Active tubular secretion plays a major role in renal excretion of drugs thanks to the presence of many membrane transporters such as ABC transporters. These proteins facilitate drug transfer into the urine and could be a source of pharmacokinetic variabilities. Up to now, several human in vitro models of proximal tubule have been proposed but few of them have been characterized for predicting drugs renal efflux. The aim of this study was to determine whether the human model RPTEC/TERT1 meets all the criteria expected of a good model to assess renal drug transport. First, in vitro barrier properties were investigated. Then, the expression of several ABC transporters was assessed by immunofluorescence and relative quantification by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) in comparison to the MDCK model. Finally, bidirectional transport studies were performed to evaluate the functionality of transporters and the abilities of model to discriminate several drugs. The RPTEC/TERT1 model formed a tight structure (192 Ω.cm2 ) that was confirmed by paracellular permeability assays. Proteomic analysis and immunofluorescence staining showed the expression of several ABC transporters. Then, only the functionality of P-gp was confirmed by the active efflux of apixaban in this study. In addition, the RPTEC/TERT1 model presents the key criteria of a renal barrier and expresses several ABC transporters. Nevertheless, the BCRP and MRP's functionality was not confirmed and further investigations are required to valid this model as in vitro model for assessing renal drug efflux.