Human liver cell-based assays for the prediction of hepatic bile acid efflux transporter inhibition by drugs.

Introduction: Drug-mediated inhibition of bile salt efflux transporters may cause liver injury. In vitro prediction of drug effects toward canalicular and/or sinusoidal efflux of bile salts from human hepatocytes is therefore a major issue, which can be addressed using liver cell-based assays.

Area Covered: This review, based on a thorough literature search in the scientific databases PubMed and Web of Science, provides key information about hepatic transporters implicated in bile salt efflux, the human liver cell models available for investigating functional inhibition of bile salt efflux, the different methodologies used for this purpose, and the modes of expression of the results.

Induction of drug metabolizing enzyme and drug transporter expression by antifungal triazole pesticides in human HepaSH hepatocytes.

Triazole pesticides are widely used fungicides, to which humans are rather highly exposed. They are known to activate drug-sensing receptors regulating expression of hepatic drug metabolizing enzymes and drug transporters, thus suggesting that the hepatic drug detoxification system is modified by these agrochemicals. To investigate this hypothesis, the effects of 9 triazole fungicides towards expression of drug metabolizing enzymes and transporters were characterized in cultured human HepaSH cells, that are human hepatocytes deriving from chimeric humanized liver TK-NOG mice.

Inhibition of human drug transporter activities by succinate dehydrogenase inhibitors.

Succinate dehydrogenase inhibitors (SDHIs) are widely-used fungicides, to which humans are exposed and for which putative health risks are of concern. In order to identify human molecular targets for these environmental chemicals, the interactions of 15 SDHIs with activities of main human drug transporters implicated in pharmacokinetics were investigated in vitro. 5/15 SDHIs, i.

Induction of human hepatic cytochrome P-450 3A4 expression by antifungal succinate dehydrogenase inhibitors.

Succinate dehydrogenase inhibitors (SDHIs) are widely-used fungicides, to which humans are exposed and for which putative health risks are of concern. In order to identify human molecular targets for these agrochemicals, the interactions of 15 SDHIs with expression and activity of human cytochrome P-450 3A4 (CYP3A4), a major hepatic drug metabolizing enzyme, were investigated in vitro. 12/15 SDHIs, i.

Interactions of organophosphate flame retardants with human drug transporters.

Organophosphate flame retardants (OPFRs) are environmental pollutants of increasing interest, widely distributed in the environment and exerting possible deleterious effects towards the human health. The present study investigates in vitro their possible interactions with human drug transporters, which are targets for environmental chemicals and actors of their toxicokinetics. Some OPFRs, i.

Inhibition of canalicular and sinusoidal taurocholate efflux by cholestatic drugs in human hepatoma HepaRG cells.

HepaRG cells are highly-differentiated human hepatoma cells, which are increasingly recognized as a convenient cellular model for in vitro evaluation of hepatic metabolism, transport, and/or toxicity of drugs. The present study was designed to evaluate whether HepaRG cells can also be useful for studying drug-mediated inhibition of canalicular and/or sinusoidal hepatic efflux of bile acids, which constitutes a major mechanism of drug-induced liver toxicity. For this purpose, HepaRG cells, initially loaded with the bile acid taurocholate (TC), were reincubated in TC-free transport assay medium, in the presence or absence of calcium or drugs, before analysis of TC retention.

Substrate-Dependent -Stimulation of Organic Cation Transporter 2 Activity.

The search of substrates for solute carriers (SLCs) constitutes a major issue, owing notably to the role played by some SLCs, such as the renal electrogenic organic cation transporter (OCT) 2 (), in pharmacokinetics, drug-drug interactions and drug toxicity. For this purpose, substrates have been proposed to be identified by their -inhibition and -stimulation properties towards transporter activity. To get insights on the sensitivity of this approach for identifying SLC substrates, 15 various exogenous and endogenous OCT2 substrates were analysed in the present study, using 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (DiASP) as a fluorescent OCT2 tracer substrate.

Differential Inhibition of Equilibrative Nucleoside Transporter 1 (ENT1) Activity by Tyrosine Kinase Inhibitors.

Background And Objectives: Equilibrative nucleoside transporter (ENT) 1 is a widely-expressed drug transporter, handling nucleoside analogues as well as endogenous nucleosides. ENT1 has been postulated to be inhibited by some marketed tyrosine kinase inhibitors (TKIs). To obtain insights into this point, the interactions of 24 TKIs with ENT1 activity have been analyzed.

Inhibition of organic cation transporter 3 activity by tyrosine kinase inhibitors.

Organic cation transporter (OCT) 3 (SLC22A3) is a widely expressed drug transporter, handling notably metformin and platinum derivatives, as well as endogenous compounds like monoamine neurotransmitters. OCT3 has been shown to be inhibited by a few marketed tyrosine kinase inhibitors (TKIs). The present study was designed to determine whether additional TKIs may interact with OCT3.

Differential interactions of the Janus kinase inhibitor ruxolitinib with human SLC drug transporters.

Interactions of the Janus kinase (JAK) inhibitor ruxolitinib with solute carriers (SLCs) remain incompletely characterised. The present study was therefore designed to investigate this issue.The interactions of ruxolitinib with SLCs were analysed using transporter-overexpressing human embryonic kidney HEK293 cells.

Interactions of janus kinase inhibitors with drug transporters and consequences for pharmacokinetics and toxicity.

: Janus kinase inhibitors (JAKinibs) constitute an emerging and promising pharmacological class of anti-inflammatory or anti-cancer drugs, used notably for the treatment of rheumatoid arthritis and some myeloproliferative neoplasms.: This review provides an overview of the interactions between marketed JAKinibs and major uptake and efflux drug transporters. Consequences regarding pharmacokinetics, drug-drug interactions and toxicity are summarized.

DI-5-Cuffs: Lumbar Intervertebral Disc Proteoglycan and Water Content Changes in Humans after Five Days of Dry Immersion to Simulate Microgravity.

Most astronauts experience back pain after spaceflight, primarily located in the lumbar region. Intervertebral disc herniations have been observed after real and simulated microgravity. Spinal deconditioning after exposure to microgravity has been described, but the underlying mechanisms are not well understood.

Differential interactions of carbamate pesticides with drug transporters.

Pesticides are now recognised to interact with drug transporters, but only few data are available on this issue for carbamate pesticides, a widely used class of agrochemicals, to which humans are highly exposed. The present study was therefore designed to determine whether four representative carbamate pesticides, i.e.

Janus kinase-dependent regulation of drug detoxifying protein expression by interleukin-22 in human hepatic cells.

Interleukin (IL)-22 is a cytokine up-regulated in inflammatory situations and known to exert various hepatic effects. The potential impact of IL-22 towards liver drug detoxifying proteins remains nevertheless unknown, but may be important to determine owing to the well-established alterations of liver detoxification occuring during inflammation. The present study was therefore designed to analyze the effects of IL-22 towards drug metabolizing enzyme and drug transporter expression and activity in cultured human hepatic cells.

Induction of multidrug resistance-associated protein 3 expression by diesel exhaust particle extract in human bronchial epithelial BEAS-2B cells.

Diesel exhaust particles (DEPs) are common environmental air pollutants known to impair expression and activity of drug detoxifying proteins, including hepatic ATP-binding cassette (ABC) drug transporters. The present study was designed to determine whether organic DEP extract (DEPe) may also target ABC drug transporters in bronchial cells. DEPe (10 μg/mL) was demonstrated to induce mRNA and protein expression of the multidrug resistance-associated protein (MRP) 3 in cultured bronchial epithelial BEAS-2B cells, whereas mRNA levels of other MRPs, multidrug resistance gene 1 or breast cancer resistance protein were unchanged, reduced or not detected.

mRNA Expression and Activity of Nucleoside Transporters in Human Hepatoma HepaRG Cells.

The HepaRG cell line is a highly differentiated human hepatoma cell line, displaying the expression of various drug transporters. However, functional expression of nucleoside transporters remains poorly characterized in HepaRG cells, although these transporters play a key role in hepatic uptake of antiviral and anticancer drugs. The present study was, therefore, designed to characterize the expression, activity and regulation of equilibrative (ENT) and concentrative (CNT) nucleoside transporter isoforms in differentiated HepaRG cells.

Functional polarization of human hepatoma HepaRG cells in response to forskolin.

HepaRG is an original human hepatoma cell line, acquiring highly differentiated hepatic features when exposed to dimethylsulfoxide (DMSO). To search alternatives to DMSO, which may exert some toxicity, we have analyzed the effects of forskolin (FSK), a cAMP-generating agent known to favor differentiation of various cell types. FSK used at 50 µM for 3 days was found to promote polarization of high density-plated HepaRG cells, i.

Carrier-mediated uptake of clonidine in cultured human lung cells.

The lung is a preferential organ site for accumulation of lipophilic basic amine drugs, so-called pneumophilic drugs and belonging to various pharmacological classes, which can result in lung toxicity. In order to investigate the mechanism involved in such pulmonary accumulation of drugs, uptake of clonidine, used here as a prototypical basic amine drug, was characterized in cultured human lung cells. Clonidine accumulation in lung alveolar A549 cells was found to be temperature- and pH-dependent; it was saturable, with a Michaelis-Menten affinity constant (Km) value of 569.

Effect of Gevokizumab on Interleukin-1β-Mediated Cytochrome P450 3A4 and Drug Transporter Repression in Cultured Human Hepatocytes.

Background And Objectives: Gevokizumab is a potent anti-interleukin (IL)-1β neutralizing monoclonal antibody (mAb), which may be used for treating inflammatory or autoimmune diseases. The present study was designed to characterize the potential effects of this mAb towards well-established IL-1β-mediated repression of hepatic drug detoxifying proteins, like cytochrome P450 (CYP) 3A4 and drug transporters.

Methods: Primary cultured human hepatocytes were exposed to various concentrations of IL-1β in the absence or presence of gevokizumab (5 µg/mL); mRNA expression and activity of CYP3A4 and transporters were next determined.

Drug Transporter Expression and Activity in Human Hepatoma HuH-7 Cells.

Human hepatoma cells may represent a valuable alternative to the use of human hepatocytes for studying hepatic drug transporters, which is now a regulatory issue during drug development. In the present work, we have characterized hepatic drug transporter expression, activity and regulation in human hepatoma HuH-7 cells, in order to determine the potential relevance of these cells for drug transport assays. HuH-7 cells displayed notable multidrug resistance-associated protein (MRP) activity, presumed to reflect expression of various hepatic MRPs, including MRP2.

Alteration of human hepatic drug transporter activity and expression by cigarette smoke condensate.

Smoking is well-known to impair pharmacokinetics, through inducing expression of drug metabolizing enzymes. In the present study, we demonstrated that cigarette smoke condensate (CSC) also alters activity and expression of hepatic drug transporters, which are now recognized as major actors of hepatobiliary elimination of drugs. CSC thus directly inhibited activities of sinusoidal transporters such as OATP1B1, OATP1B3, OCT1 and NTCP as well as those of canalicular transporters like P-glycoprotein, MRP2, BCRP and MATE1, in hepatic transporters-overexpressing cells.

Evaluation of P-Glycoprotein Inhibitory Potential Using a Rhodamine 123 Accumulation Assay.

In vitro evaluation of P-glycoprotein (P-gp) inhibitory potential is now a regulatory issue during drug development, in order to predict clinical inhibition of P-gp and subsequent drug-drug interactions. Assays for this purpose, commonly based on P-gp-expressing cell lines and digoxin as a reference P-gp substrate probe, unfortunately exhibit high variability, raising thus the question of developing alternative or complementary tests for measuring inhibition of P-gp activity. In this context, the present study was designed to investigate the use of the fluorescent dye rhodamine 123 as a reference P-gp substrate probe for characterizing P-gp inhibitory potential of 16 structurally-unrelated drugs known to interact with P-gp.

The probiotic Propionibacterium freudenreichii as a new adjuvant for TRAIL-based therapy in colorectal cancer.

TNF-Related Apoptosis-Inducing Ligand (TRAIL) is a well-known apoptosis inducer, which activates the extrinsic death pathway. TRAIL is pro-apoptotic on colon cancer cells, while not cytotoxic towards normal healthy cells. However, its clinical use is limited by cell resistance to cell death which occurs in approximately 50% of cancer cells.

Protein Kinase C-Independent Inhibition of Organic Cation Transporter 1 Activity by the Bisindolylmaleimide Ro 31-8220.

Ro 31-8220 is a potent protein kinase C (PKC) inhibitor belonging to the chemical class of bisindolylmaleimides (BIMs). Various PKC-independent effects of Ro 31-8220 have however been demonstrated, including inhibition of the ATP-binding cassette drug transporter breast cancer resistance protein. In the present study, we reported that the BIM also blocks activity of the solute carrier organic cation transporter (OCT) 1, involved in uptake of marketed drugs in the liver, in a PKC-independent manner.

Aryl hydrocarbon receptor-dependent up-regulation of the heterodimeric amino acid transporter LAT1 (SLC7A5)/CD98hc (SLC3A2) by diesel exhaust particle extract in human bronchial epithelial cells.

The heterodimeric L-type amino acid transporter (LAT) 1/CD98hc is overexpressed in lung cancers with a poor prognosis factor. Factors that contribute to LAT1/CD98hc overexpression in lung cells remain however to be determined, but the implication of atmospheric pollution can be suspected. The present study was therefore designed to analyze the effects of diesel exhaust particle (DEP) extract (DEPe) on LAT1/CD98hc expression in bronchial epithelial BEAS-2B cells.