N-Methylnicotinamide Is an Endogenous Probe for Evaluation of Drug-Drug Interactions Involving Multidrug and Toxin Extrusions (MATE1 and MATE2-K).
ABSTRACT Multidrug and toxin extrusion 1 (MATE1) and MATE2-K are H(+)/organic cation exchangers mediating the efflux of cationic drugs into the urine. N-methylnicotinamide (NMN) was found to be an endogenous substrate of MATE1 (Michaelis constant (K(m)) 301 ± 18 µmol/l) and MATE2-K (K(m) 422 ± 63 µmol/l) as well as a basolateral influx transporter, organic cation transporter 2 (K(m) 318 ± 29 µmol/l). A potent MATE inhibitor, pyrimethamine, competitively inhibited the uptake by MATE1 and MATE2-K with inhibition constant (K(i)) values of 83 ± 15 and 56 ± 11 nmol/l, respectively. The uptake of NMN by human kidney brush border membrane vesicles with a H(+) gradient was saturable (K(m) 360 ± 55 µmol/l) and completely inhibited by pyrimethamine. The renal clearance of endogenous NMN was 403 ± 61 in healthy male subjects, and it was significantly decreased to 119 ± 16 ml/min/kg by an oral dose of pyrimethamine (50 mg). These results support the utility of NMN as an endogenous in vivo probe for investigating MATE1 and MATE2-K in humans.
- [Show abstract] [Hide abstract]
ABSTRACT: Vandetanib was evaluated as an inhibitor of human OAT1, OAT3 (organic anion transporter 1 and 3), OCT2 (organic cation transporter 2), and multidrug and toxin extrusion (MATE1 and MATE2K) transfected (individually) into human embryonic kidney (HEK) 293 cells. Although no inhibition of OAT1 and OAT3 was observed, inhibition of OCT2-mediated uptake of 1-methyl-4-phenylpyridinium (MPP+) and metformin was evident (IC50 of 73.4 ± 14.8 μM and 8.8 ± 1.9 μM, respectively). However, vandetanib was an even more potent inhibitor of MATE1- and MATE2K-mediated uptake of MPP(+) (IC50 of 1.23 ± 0.05 μM and 1.26 ± 0.06 μM, respectively) and metformin (IC50 of 0.16 ± 0.05 μM and 0.30 ± 0.09 μM, respectively). Subsequent cytotoxicity studies demonstrated that transport inhibition by vandetanib (2.5 μM) significantly decreased the sensitivity (right shift in concentration of cisplatin giving rise to 50% cell death; IC50(CN)) of MATE1-HEK and MATE2K-HEK cells to cisplatin (IC50(CN) of 1.12 ± 0.13 versus 2.39 ± 0.44 μM; 0.85 ± 0.09 versus 1.99 ± 0.16 μM; P < 0.05), but not OCT2-HEK cells (1.36 ± 0.19 versus 1.47 ± 0.24 μM), versus vandetanib untreated cells and Mock-HEK cells (IC50(CN) of 2.34 ± 0.31 μM). In summary, the results show that vandetanib is a potent inhibitor of MATE1 and MATE2K (versus OCT2). Inhibition of the two transporters may explain why there are reports of decreased creatinine clearance, and increased cisplatin nephrotoxicity (reduced cisplatin clearance), in some subjects receiving vandetanib therapy.Drug metabolism and disposition: the biological fate of chemicals 09/2013; · 3.74 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Abstract Drug transporters and drug metabolism enzymes govern drug absorption, distribution, metabolism and elimination. Many literature works presenting important aspects related to stereochemistry of drug metabolism are available. However, there is very little literature on stereoselectivity of chiral drug transport and enantiomer-transporter interaction. In recent years, the experimental research within this field showed good momentum. Herein, an up-to-date review on this topic was presented. Breast Cancer Resistance Protein (BCRP), Multidrug Resistance Proteins (MRP), P-glycoprotein (P-gp), Organic Anion Transporters (OATs), Organic Anion Transporting Polypeptides (OATPs), Organic Cation Transporters (OCTs), Peptide Transport Proteins (PepTs), Human Proton-Coupled Folate Transporter (PCFT) and Multidrug and Toxic Extrusion Proteins (MATEs), have been reported to exhibit either positive or negative enantio-selective substrate recognition. The approaches utilized to study chirality in enantiomer-transporter interaction include inhibition experiments of specific transporters in cell models (e.g. Caco-2 cells), transport study using drug resistance cell lines or transgenic cell lines expressing transporters in wild type or variant, the use of transporter knockout mice, pharmacokinetics association of single nucleotide polymorphism in transporters, pharmacokinetic interaction study of racemate in the presence of specific transporter inhibitor or inducer, molecule cellular membrane affinity chromatography and pharmacophore modeling. Enantiomer-enantiomer interactions exist in chiral transport. The strength and/or enantiomeric preference of stereoselectivity may be species or tissue-specific, concentration-dependent and transporter family member-dependent. Modulation of specific drug transporter by pure enantiomers might exhibit opposite stereoselectivity. Further studies with integrated approaches will open up new horizons in stereochemistry of pharmacokinetics.Drug Metabolism Reviews 05/2014; · 5.54 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: 6β-hydroxycortisol (6β-OHF) is a substrate of the organic anion transporter 3 (OAT3) and the multidrug and toxin extrusion proteins, MATE1 and MATE-2K, in the corresponding cDNA-transfected cells. This study aimed to examine the contribution of OAT3 and MATEs to the urinary excretion of 6β-OHF in humans using the appropriate in vivo inhibitors, probenecid and pyrimethamine, for OAT3 and MATEs, respectively. Oat3(-/-) mice showed significantly reduced renal clearance of 6β-OHF (CLrenal, 6β-OHF) compared with wild-type mice (18.1±1.5 versus 7.60±1.8 ml/min/kg). 6β-OHF uptake by human kidney slices was inhibited significantly by probenecid to 20-45% of the control values and partly by 1-methyl-4-phenylpyridinium. 6β-OHF plasma concentration and the urinary excretion of 6β-OHF (X6β-OHF) were measured in healthy subjects enrolled in drug-drug interaction studies of benzylpenicillin alone or with probenecid (Study 1), adefovir alone or with probenecid (Study 2), and metformin alone or with pyrimethamine (Study 3). Probenecid treatment caused a 57% and 76% increase in the area under the plasma concentration-time curve for 6β-OHF (AUC6β-OHF) in Study 1 and 2, respectively, but did not affect X6β-OHF. Consequently, CLrenal, 6β-OHF (ml/min) decreased significantly from 231±11 to 135±9 and from 225±26 to 141±12 after probenecid administration in Study 1 and 2, respectively. By contrast, neither AUC6β-OHF nor CLrenal, 6β-OHF was significantly altered by pyrimethamine administration. Taken together, these data suggest that OAT3 plays a significant role in the urinary excretion of 6β-OHF, and that 6β-OHF can be used to investigate the perpetrators of the pharmacokinetic drug interactions involving OAT3 in humans.Drug metabolism and disposition: the biological fate of chemicals 01/2014; · 3.74 Impact Factor