Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 92
Filtrar
Filtros adicionais











País/Região como assunto
Intervalo de ano
1.
Clin Transl Sci ; 12(4): 388-399, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30982223

RESUMO

Understanding transporter-mediated drug-drug interactions is an integral part of risk assessment in drug development. Recent studies support the use of hexadecanedioate (HDA), tetradecanedioate (TDA), coproporphyrin (CP)-I, and CP-III as clinical biomarkers for evaluating organic anion-transporting polypeptide (OATP)1B1 (SLCO1B1) inhibition. The current study investigated the effect of OATP1B1 genotype c.521T>C (OATP1B1-Val174Ala) on the extent of interaction between cyclosporin A (CsA) and pravastatin, and associated endogenous biomarkers of the transporter (HDA, TDA, CP-I, and CP-III), in 20 healthy volunteers. The results show that the levels of each clinical biomarker and pravastatin were significantly increased in plasma samples of the volunteers following administration of pravastatin plus CsA compared with pravastatin plus placebo. The overall fold change in the area under the concentration-time curve (AUC) and maximum plasma concentration (Cmax ) was similar among the four biomarkers (1.8-2.5-fold, paired t-test P value < 0.05) in individuals who were homozygotes or heterozygotes of the major allele, c.521T. However, the fold change in AUC and Cmax for HDA and TDA was significantly abolished in the subjects who were c.521-CC, whereas the respective fold change in AUC and Cmax for pravastatin and CP-I and CP-III were slightly weaker in individuals who were c.521-CC compared with c.521-TT/TC genotypes. In addition, this study provides the first evidence that SLCO1B1 c.521T>C genotype is significantly associated with CP-I but not CP-III levels. Overall, these results suggest that OATP1B1 genotype can modulate the effects of CsA on biomarker levels; the extent of modulation differs among the biomarkers.

2.
Drug Metab Dispos ; 47(4): 350-357, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30622164

RESUMO

Suspended (SH), plated (PH), and sandwich-cultured hepatocytes (SCH) are commonly used models to predict in vivo transporter-mediated hepatic uptake (SH or PH) or biliary (SCH) clearance of drugs. When doing so, the total and the plasma membrane abundance (PMA) of transporter are assumed not to differ between hepatocytes and liver tissue (LT). This assumption has never been tested. In this study, we tested this assumption by measuring the total and PMA of the transporters in human hepatocyte models versus LT (total only) from which they were isolated. Total abundance of OATP1B1/2B1/1B3, OCT1, and OAT2 was not significantly different between the hepatocytes and LT. The same was true for the PMA of these transporters across the hepatocyte models. In contrast, total abundance of the sinusoidal efflux transporter, MRP3, and the canalicular efflux transporters, MRP2 and P-gp, was significantly greater (P < 0.05) in SCH versus LT. Of the transporters tested, only the percentage of PMA of OATP1B1, P-gp, and MRP3, in SCH (82.8% ± 7.3%, 57.5% ± 10.9%, 69.3% ± 5.7%) was significantly greater (P < 0.05) than in SH (73.3% ± 6.4%, 27.4% ± 6.4%, 53.6% ± 4.1%). If the transporters measured in the plasma membrane are functional and the PMA in SH is representative of that in LT, these data suggest that SH, PH, and SCH will result in equal prediction of hepatic uptake clearance of drugs mediated by the transporters tested above. However, SCH will predict higher sinusoidal efflux and biliary clearance of drugs if the change in PMA of these transporters is not taken into consideration.

3.
Clin Pharmacol Ther ; 106(1): 228-237, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30673124

RESUMO

For in vitro to in vivo extrapolation (IVIVE) of brain distribution of drugs that are transported at the human blood-brain barrier (BBB), it is important to quantify the interindividual and regional variability of drug transporter abundance at this barrier. Therefore, using quantitative targeted proteomics, we compared the abundance of adenosine triphosphate-binding cassette and solute carrier transporters in brain microvascular endothelial cells (BMECs) isolated from postmortem specimens of two matched brain regions, the occipital (Brodmann Area (BA)17) and parietal (BA39) lobe, from 30 adults. Of the quantifiable transporters, the abundance ranked: glucose transporter (GLUT)1 > breast cancer resistance protein > P-glycoprotein (P-gp) > equilibrative nucleoside transporter (ENT)1 > organic anion-transporting polypeptide (OATP)2B1. The abundance of multidrug resistance protein 1/2/3/4, OATP1A2, organic anion transporter (OAT)3, organic cation transporter (OCT)1/2, OCTN1/2, or ENT2 was below the limit of quantification. Transporter abundance per gram of tissue (scaled using GLUT1 abundance in BMEC vs. brain homogenate) in BA17 was 30-42% higher than BA39. The interindividual variability in transporter abundance (percentage of coefficient of variation (%CV)) was 35-57% (BA17) and 27-46% (BA39). These data can be used in proteomics-informed bottom-up IVIVE to predict human brain drug distribution.

4.
J Pharmacol Exp Ther ; 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30361237

RESUMO

Plasma pyridoxic acid (PDA) and homovanillic acid (HVA) were recently identified as novel endogenous biomarkers of OAT1/3 function in monkeys. Consequently, this clinical study assessed the dynamic changes and utility of plasma PDA and HVA as an initial evaluation of OAT1/3 inhibition in early-phase drug development. The study was designed as a single dose randomized, three-phase, crossover study; 14 Indian healthy volunteers received probenecid (PROB) (1,000 mg orally) alone, furosemide (FSM) (40 mg orally) alone, or FSM 1 h after receiving PROB (40 mg and 1,000 mg orally) on Days 1, 8, and 15, respectively. PDA and HVA plasma concentrations remained stable over time in the prestudy and FSM groups. Administration of PROB significantly increased AUC of PDA by 3.1-fold (dosed alone; p < 0.05), and 3.2-fold (coadministered with FSM; p < 0.01), as compared with the prestudy and FSM groups, respectively. The corresponding increase in HVA AUC was 1.8-fold (p > 0.05) and 2.1-fold (p < 0.05), respectively. The increases in PDA AUC are similar to those in FSM AUC whereas those of HVA are smaller (3.1-3.2 and 1.8-2.1 versus 3.3, respectively). PDA and HVA CLR were decreased by PROB to smaller extents compared to FSM (0.35-0.37 and 0.67-0.73 versus 0.23, respectively). These data demonstrate that plasma PDA is a promising endogenous biomarker for OAT1/3 function and its plasma exposure respond in a similar fashion to FSM upon OAT1/3 inhibition by PROB. The magnitude and variability of response in PDA AUC and CLR between subjects is more favourable relative to HVA.

5.
Acta Pharm Sin B ; 8(2): 252-260, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29719786

RESUMO

In the present study, total membrane proteins from tumor cell lines including HepG2, Hep3B2, H226, Ovcar3 and N87 were extracted and digested with γLysC and trypsin. The resulting peptide lysate were pre-fractionated and subjected to untargeted quantitative proteomics analysis using a high resolution mass spectrometer. The mass spectra were processed by the MaxQuant and the protein abundances were estimated using total peak area (TPA) method. A total of 6037 proteins were identified, and the analysis resulted in the identification of 2647 membrane proteins. Of those, tumor antigens and absorption, metabolism, disposition and elimination (ADME) proteins including UDP-glucuronosyltransferase, cytochrome P450, solute carriers and ATP-binding cassette transporters were detected and disclosed significant variations among the cell lines. The principal component analysis was performed for the cluster of cell lines. The results demonstrated that H226 is closely related with N87, while Hep3B2 aligned with HepG2. The protein cluster of Ovcar3 was apart from that of other cell lines investigated. By providing for the first time quantitative untargeted proteomics analysis, the results delineated the expression profiles of membrane proteins. These findings provided a useful resource for selecting targets of choice for anticancer therapy through advancing data obtained from preclinical tumor cell line models to clinical outcomes.

6.
Drug Metab Dispos ; 46(8): 1075-1082, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29777022

RESUMO

In a recent study, limited to South Asian Indian subjects (n = 12), coproporphyrin (CP) I and CPIII demonstrated properties appropriate for an organic anion-transporting polypeptide (OATP) 1B endogenous probe. The current studies were conducted in healthy volunteers of mixed ethnicities, including black, white, and Hispanic subjects, to better understand the utility of these biomarkers in broader populations. After oral administration with 600 mg rifampin, AUC(0-24h) values were 2.8-, 3.7-, and 3.6-fold higher than predose levels for CPI and 2.6-, 3.1-, and 2.4-fold higher for CPIII, for the three populations, respectively. These changes in response to rifampin were consistent with previous results. The sensitivity toward OATP1B inhibition was also investigated by evaluating changes of plasma CP levels in the presence of diltiazem and itraconazole [administered as part of an unrelated drug-drug interaction (DDI) investigation], two compounds that were predicted to have minimal inhibitory effect on OATP1B. Administration of diltiazem and itraconazole did not increase plasma CPI and CPIII concentrations relative to prestudy levels, in agreement with predictions from in vitro parameters. Additionally, the basal CP concentrations in subjects with SLCO1B1 c.521TT genotype were comparable to those with SLCO1B1 c.521TC genotype, similar to studies with probe substrates. However, subjects with SLCO1B1 c.388AG and c.388GG genotypes (i.e., increased OATP1B1 transport activity for certain substrates) had lower concentrations of CPI than those with SLCO1B1 c.388AA. Collectively, these findings provide further evidence supporting the translational value of CPI and CPIII as suitable endogenous clinical probes to gauge OATP1B activity and potential for OATP1B-mediated DDIs.


Assuntos
Transporte Biológico/fisiologia , Biomarcadores/metabolismo , Coproporfirinas/metabolismo , Transportador 1 de Ânion Orgânico Específico do Fígado/antagonistas & inibidores , Transportadores de Ânions Orgânicos/metabolismo , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/antagonistas & inibidores , Adulto , Transporte Biológico/efeitos dos fármacos , Coproporfirinas/genética , Interações de Medicamentos/fisiologia , Genótipo , Humanos , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Transportador 1 de Ânion Orgânico Específico do Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Transportadores de Ânions Orgânicos/genética , Rifampina/farmacologia , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/genética , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/metabolismo , Adulto Jovem
7.
Drug Metab Dispos ; 46(6): 865-878, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29487142

RESUMO

Since the introduction of metabolites in safety testing (MIST) guidance by the Food and Drug Administration in 2008, major changes have occurred in the experimental methods for the identification and quantification of metabolites, ways to evaluate coverage of metabolites, and the timing of critical clinical and nonclinical studies to generate this information. In this cross-industry review, we discuss how the increased focus on human drug metabolites and their potential contribution to safety and drug-drug interactions has influenced the approaches taken by industry for the identification and quantitation of human drug metabolites. Before the MIST guidance was issued, the method of choice for generating comprehensive metabolite profile was radio chromatography. The MIST guidance increased the focus on human drug metabolites and their potential contribution to safety and drug-drug interactions and led to changes in the practices of drug metabolism scientists. In addition, the guidance suggested that human metabolism studies should also be accelerated, which has led to more frequent determination of human metabolite profiles from multiple ascending-dose clinical studies. Generating a comprehensive and quantitative profile of human metabolites has become a more urgent task. Together with technological advances, these events have led to a general shift of focus toward earlier human metabolism studies using high-resolution mass spectrometry and to a reduction in animal radiolabel absorption/distribution/metabolism/excretion studies. The changes induced by the MIST guidance are highlighted by six case studies included herein, reflecting different stages of implementation of the MIST guidance within the pharmaceutical industry.


Assuntos
Descoberta de Drogas/normas , Inativação Metabólica/fisiologia , Preparações Farmacêuticas/metabolismo , Animais , Indústria Farmacêutica/normas , Interações de Medicamentos/fisiologia , Humanos , Estados Unidos , United States Food and Drug Administration
8.
Drug Metab Dispos ; 46(2): 189-196, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29138286

RESUMO

Protein expression of major hepatobiliary drug transporters (NTCP, OATPs, OCT1, BSEP, BCRP, MATE1, MRPs, and P-gp) in cancerous (C, n = 8) and adjacent noncancerous (NC, n = 33) liver tissues obtained from patients with chronic hepatitis C with hepatocellular carcinoma (HCV-HCC) were quantified by LC-MS/MS proteomics. Herein, we compare our results with our previous data from noninfected, noncirrhotic (control, n = 36) and HCV-cirrhotic (n = 30) livers. The amount of membrane protein yielded from NC and C HCV-HCC tissues decreased (31%, 67%) relative to control livers. In comparison with control livers, with the exception of NTCP, MRP2, and MATE1, transporter expression decreased in NC (38%-76%) and C (56%-96%) HCV-HCC tissues. In NC HCV-HCC tissues, NTCP expression increased (113%), MATE1 expression decreased (58%), and MRP2 expression was unchanged relative to control livers. In C HCV-HCC tissues, NTCP and MRP2 expression decreased (63%, 56%) and MATE1 expression was unchanged relative to control livers. Compared with HCV-cirrhotic livers, aside from NTCP, OCT1, BSEP, and MRP2, transporter expression decreased in NC (41%-71%) and C (54%-89%) HCV-HCC tissues. In NC HCV-HCC tissues, NTCP and MRP2 expression increased (362%, 142%), whereas OCT1 and BSEP expression was unchanged. In C HCV-HCC tissues, OCT1 and BSEP expression decreased (90%, 80%) relative to HCV-cirrhotic livers, whereas NTCP and MRP2 expression was unchanged. Expression of OATP2B1, BSEP, MRP2, and MRP3 decreased (56%-72%) in C HCV-HCC tissues in comparison with matched NC tissues (n = 8), but the expression of other transporters was unchanged. These data will be helpful in the future to predict transporter-mediated hepatocellular drug concentrations in patients with HCV-HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Hepatite C Crônica/metabolismo , Neoplasias Hepáticas/metabolismo , Fígado/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Cromatografia Líquida/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos
9.
Drug Metab Dispos ; 46(2): 178-188, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29162614

RESUMO

Perturbation of organic anion transporter (OAT) 1- and OAT3-mediated transport can alter the exposure, efficacy, and safety of drugs. Although there have been reports of the endogenous biomarkers for OAT1/3, none of these have all of the characteristics required for a clinical useful biomarker. Cynomolgus monkeys were treated with intravenous probenecid (PROB) at a dose of 40 mg/kg in this study. As expected, PROB increased the area under the plasma concentration-time curve (AUC) of coadministered furosemide, a known substrate of OAT1 and OAT3, by 4.1-fold, consistent with the values reported in humans (3.1- to 3.7-fold). Of the 233 plasma metabolites analyzed using a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolomics method, 29 metabolites, including pyridoxic acid (PDA) and homovanillic acid (HVA), were significantly increased after either 1 or 3 hours in plasma from the monkeys pretreated with PROB compared with the treated animals. The plasma of animals was then subjected to targeted LC-MS/MS analysis, which confirmed that the PDA and HVA AUCs increased by approximately 2- to 3-fold by PROB pretreatments. PROB also increased the plasma concentrations of hexadecanedioic acid (HDA) and tetradecanedioic acid (TDA), although the increases were not statistically significant. Moreover, transporter profiling assessed using stable cell lines constitutively expressing transporters demonstrated that PDA and HVA are substrates for human OAT1, OAT3, OAT2 (HVA), and OAT4 (PDA), but not OCT2, MATE1, MATE2K, OATP1B1, OATP1B3, and sodium taurocholate cotransporting polypeptide. Collectively, these findings suggest that PDA and HVA might serve as blood-based endogenous probes of cynomolgus monkey OAT1 and OAT3, and investigation of PDA and HVA as circulating endogenous biomarkers of human OAT1 and OAT3 function is warranted.


Assuntos
Biomarcadores/sangue , Ácido Homovanílico/sangue , Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Ácido Piridóxico/sangue , Animais , Transporte Biológico/fisiologia , Linhagem Celular , Células HEK293 , Humanos , Macaca fascicularis , Metabolômica/métodos , Probenecid/metabolismo
10.
Clin Pharmacol Ther ; 104(3): 564-574, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29243231

RESUMO

This study evaluated coproporphyrin I (CPI) as a selective endogenous biomarker of OATP1B-mediated drug-drug interactions (DDIs) relative to clinical probe rosuvastatin using nonlinear mixed-effect modeling. Plasma and urine CPI data in the presence/absence of rifampicin were modeled to describe CPI synthesis, elimination clearances, and obtain rifampicin in vivo OATP Ki. The biomarker showed stable interoccasion baseline concentrations and low interindividual variability (<25%) in subjects with wildtype SLCO1B1. Biliary excretion was the dominant CPI elimination route (maximal >85%). Estimated rifampicin in vivo unbound OATP Ki (0.13 µM) using CPI data was 2-fold lower relative to rosuvastatin. Model-based simulations and power calculations confirmed sensitivity of CPI to identify moderate and weak OATP1B inhibitors in an adequately powered clinical study. Current analysis provides the most detailed evaluation of CPI as an endogenous OATP1B biomarker to support optimal DDI study design; further pharmacogenomic and DDI data with a panel of inhibitors are required.

11.
Drug Metab Dispos ; 45(8): 908-919, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28576766

RESUMO

Multiple endogenous compounds have been proposed as candidate biomarkers to monitor organic anion transporting polypeptide (OATP) function in preclinical species or humans. Previously, we demonstrated that coproporphyrins (CPs) I and III are appropriate clinical markers to evaluate OATP inhibition and recapitulate clinical drug-drug interactions (DDIs). In the present study, we investigated bile acids (BAs) dehydroepiandrosterone sulfate (DHEAS), hexadecanedioate (HDA), and tetradecanedioate (TDA) in plasma as endogenous probes for OATP inhibition and compared these candidate probes to CPs. All probes were determined in samples from a single study that examined their behavior and their association with rosuvastatin (RSV) pharmacokinetics after administration of an OATP inhibitor rifampin (RIF) in healthy subjects. Among endogenous probes examined, RIF significantly increased maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC)(0-24h) of fatty acids HDA and TDA by 2.2- to 3.2-fold. For the 13 bile acids in plasma examined, no statistically significant changes were detected between treatments. Changes in plasma DHEAS did not correlate with OATP1B inhibition by RIF. On the basis of the magnitude of effects for the endogenous compounds that demonstrated significant changes from baseline over interindividual variations, the overall rank order for the AUC change was found to be CP I > CP III > HDA ≈ TDA ≈ RSV > > BAs. Collectively, these results reconfirmed that CPs are novel biomarkers suitable for clinical use. In addition, HDA and TDA are useful for OATP functional assessment. Since these endogenous markers can be monitored in conjunction with pharmacokinetics analysis, the CPs and fatty acid dicarboxylates, either alone or in combination, offer promise of earlier diagnosis and risk stratification for OATP-mediated DDIs.


Assuntos
Ácidos e Sais Biliares/sangue , Biomarcadores/sangue , Coproporfirinas/sangue , Sulfato de Desidroepiandrosterona/sangue , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Ácidos Palmíticos/sangue , Adolescente , Adulto , Área Sob a Curva , Transporte Biológico/efeitos dos fármacos , Linhagem Celular , Interações de Medicamentos/fisiologia , Células HEK293 , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Rifampina/farmacologia , Rosuvastatina Cálcica/farmacologia , Adulto Jovem
12.
J Pharmacol Exp Ther ; 362(3): 385-394, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28645914

RESUMO

The interference of bile acid secretion through bile salt export pump (BSEP) inhibition is one of the mechanisms for troglitazone (TGZ)-induced hepatotoxicity. Here, we investigated the impact of single or repeated oral doses of TGZ (200 mg/kg/day, 7 days) on bile acid homoeostasis in wild-type (WT) and Bsep knockout (KO) rats. Following oral doses, plasma exposures of TGZ were not different between WT and KO rats, and were similar on day 1 and day 7. However, plasma exposures of the major metabolite, troglitazone sulfate (TS), in KO rats were 7.6- and 9.3-fold lower than in WT on day 1 and day 7, respectively, due to increased TS biliary excretion. With Bsep KO, the mRNA levels of multidrug resistance-associated protein 2 (Mrp2), Mrp3, Mrp4, Mdr1, breast cancer resistance protein (Bcrp), sodium taurocholate cotransporting polypeptide, small heterodimer partner, and Sult2A1 were significantly altered in KO rats. Following seven daily TGZ treatments, Cyp7A1 was significantly increased in both WT and KO rats. In the vehicle groups, plasma exposures of individual bile acids demonstrated variable changes in KO rats as compared with WT. WT rats dosed with TGZ showed an increase of many bile acid species in plasma on day 1, suggesting the inhibition of Bsep. Conversely, these changes returned to base levels on day 7. In KO rats, alterations of most bile acids were observed after seven doses of TGZ. Collectively, bile acid homeostasis in rats was regulated through bile acid synthesis and transport in response to Bsep deficiency and TGZ inhibition. Additionally, our study is the first to demonstrate that repeated TGZ doses can upregulate Cyp7A1 in rats.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Ácidos e Sais Biliares/metabolismo , Cromanos/farmacologia , Homeostase/efeitos dos fármacos , Homeostase/genética , Hipoglicemiantes/farmacologia , Tiazolidinedionas/farmacologia , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Animais , Bile/metabolismo , Colesterol 7-alfa-Hidroxilase/biossíntese , Colesterol 7-alfa-Hidroxilase/genética , Técnicas de Inativação de Genes , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Troglitazona , Regulação para Cima/efeitos dos fármacos
14.
Chem Res Toxicol ; 29(12): 2040-2057, 2016 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-27989144

RESUMO

The formation of drug-protein adducts is considered an important feature in the pharmacological and toxicological profiles of many drugs. Mechanistic insights into the role of specific protein adduct formation in pharmacology and toxicology remain scarce, partly due to the availability of tools to identify and characterize the specific protein adducts, and partly due to the scarcity of relevant in vitro and in vivo predictive models. This review serves to provide a review on the current state of science on the chemistry, toxicology, and methods of detection and characterization of drug-protein adducts and to offer some perspective on the future directions of research into the role of protein adducts in drug effects and toxicity.


Assuntos
Preparações Farmacêuticas/química , Proteínas/química , Testes de Toxicidade , Animais , Humanos , Modelos Biológicos
15.
Acta Pharm Sin B ; 6(5): 460-467, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27709015

RESUMO

To assess targeting of an epothilone folate conjugate (BMS-753493) to the folate receptor (FR)-overexpressed tumor in mice bearing both FR+ and FR- tumors, a series of experiments were conducted by quantitative whole-body autoradiography (QWBA) and LC-MS/MS following i.v. administration of BMS-753493 or its active moiety, BMS-748285 in mice bearing FR+ (98M109) and FR- (M109) tumors. QWBA showed [3H]BMS-753493-derived radioactivity was extensively distributed to various tissues. The FR over-expressing 98M109 tumors showed consistently higher level of radioactivity than FR-negative tumors (i.e., M109 tumors) up to 48 h post dose of [3H]BMS-753493, despite the magnitude of difference between the tumors is relatively small (generally 3~5-fold). The radioactivity level in 98M109 tumors was 2~12-fold of normal tissues except intestine/content at 48 h post dose. No selective radioactivity uptake into 98M109 tumors over M109 or normal tissues was observed after i.v. administration of the active epothilone, [3H]BMS-748285. LC-MS/MS measurements demonstrated that the concentrations of BMS-748285, presumably from hydrolysis of the folate conjugate, in 98M109 tumors were greater than those in M109 tumors after i.v. administration of BMS-753493 (2-3-fold) whereas no differential uptake in the tumors following BMS-748285 administration. Those data were consistent with radioactivity determinations. Those results demonstrated that the folate conjugation in BMS-753493 enabled moderately preferential distribution of the active epothilone to FR over-expressing 98M109 tumors, thereby supporting targeted delivery of cytotoxics through the folate receptor.

16.
Drug Metab Dispos ; 44(8): 1372-80, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27226352

RESUMO

Asunaprevir (ASV), daclatasvir (DCV), and beclabuvir (BCV) are three drugs developed for the treatment of chronic hepatitis C virus infection. Here, we evaluated the CYP3A4 induction potential of each drug, as well as BCV-M1 (the major metabolite of BCV), in human hepatocytes by measuring CYP3A4 mRNA alteration. The induction responses were quantified as induction fold (mRNA fold change) and induction increase (mRNA fold increase), and then fitted with four nonlinear regression algorithms. Reversible inhibition and time-dependent inhibition (TDI) on CYP3A4 activity were determined to predict net drug-drug interactions (DDIs). All four compounds were CYP3A4 inducers and inhibitors, with ASV demonstrating TDI. The curve-fitting results demonstrated that fold increase is a better assessment to determine kinetic parameters for compounds inducing weak responses. By summing the contribution of each inducer, the basic static model was able to correctly predict the potential for a clinically meaningful induction signal for single or multiple perpetrators, but with over prediction of the magnitude. With the same approach, the mechanistic static model improved the prediction accuracy of DCV and BCV when including both induction and inhibition effects, but incorrectly predicted the net DDI effects for ASV alone or triple combinations. The predictions of ASV or the triple combination could be improved by only including the induction and reversible inhibition but not the ASV CYP3A4 TDI component. Those results demonstrated that static models can be applied as a tool to help project the DDI risk of multiple perpetrators using in vitro data.


Assuntos
Antivirais/uso terapêutico , Benzazepinas/uso terapêutico , Indutores do Citocromo P-450 CYP3A/uso terapêutico , Inibidores do Citocromo P-450 CYP3A/uso terapêutico , Citocromo P-450 CYP3A/metabolismo , Hepatite C Crônica/tratamento farmacológico , Imidazóis/uso terapêutico , Indóis/uso terapêutico , Isoquinolinas/uso terapêutico , Fígado/enzimologia , Midazolam/uso terapêutico , Modelos Biológicos , Sulfonamidas/uso terapêutico , Algoritmos , Antivirais/efeitos adversos , Benzazepinas/efeitos adversos , Biotransformação , Células Cultivadas , Citocromo P-450 CYP3A/genética , Indutores do Citocromo P-450 CYP3A/efeitos adversos , Inibidores do Citocromo P-450 CYP3A/efeitos adversos , Relação Dose-Resposta a Droga , Interações de Medicamentos , Quimioterapia Combinada , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Humanos , Imidazóis/efeitos adversos , Indóis/efeitos adversos , Isoquinolinas/efeitos adversos , Cinética , Fígado/efeitos dos fármacos , Midazolam/efeitos adversos , Dinâmica não Linear , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Medição de Risco , Fatores de Risco , Sulfonamidas/efeitos adversos
17.
Drug Metab Dispos ; 44(6): 809-20, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27029743

RESUMO

Daclatasvir is a first-in-class, potent, and selective inhibitor of the hepatitis C virus nonstructural protein 5A replication complex. In support of nonclinical studies during discovery and exploratory development, liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance were used in connection with synthetic and radiosynthetic approaches to investigate the biotransformation of daclatasvir in vitro and in cynomolgus monkeys, dogs, mice, and rats. The results of these studies indicated that disposition of daclatasvir was accomplished mainly by the release of unchanged daclatasvir into bile and feces and, secondarily, by oxidative metabolism. Cytochrome P450s were the main enzymes involved in the metabolism of daclatasvir. Oxidative pathways included δ-oxidation of the pyrrolidine moiety, resulting in ring opening to an aminoaldehyde intermediate followed by an intramolecular reaction between the aldehyde and the proximal imidazole nitrogen atom. Despite robust formation of the resulting metabolite in multiple systems, rates of covalent binding to protein associated with metabolism of daclatasvir were modest (55.2-67.8 pmol/mg/h) in nicotinamide adenine dinucleotide phosphate (reduced form)-supplemented liver microsomes (human, monkey, rat), suggesting that intramolecular rearrangement was favored over intermolecular binding in the formation of this metabolite. This biotransformation profile supported the continued development of daclatasvir, which is now marketed for the treatment of chronic hepatitis C virus infection.


Assuntos
Biotransformação/fisiologia , Imidazóis/metabolismo , Pirrolidinas/metabolismo , Animais , Bile/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Sistema Enzimático do Citocromo P-450/metabolismo , Cães , Haplorrinos , Hepatócitos/metabolismo , Humanos , Macaca fascicularis , Espectroscopia de Ressonância Magnética/métodos , Masculino , Espectrometria de Massas/métodos , Camundongos , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Oxirredução , Ratos , Ratos Sprague-Dawley
18.
Biopharm Drug Dispos ; 37(5): 276-86, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27059119

RESUMO

The bile salt export pump (BSEP) is expressed on the canalicular membrane of hepatocytes regulating liver bile salt excretion, and impairment of BSEP function may lead to cholestasis in humans. This study explored drug biliary excretion, as well as serum chemistry, individual bile acid concentrations and liver transporter expressions, in the SAGE Bsep knockout (KO) rat model. It was observed that the Bsep protein in KO rats was decreased to 15% of that in the wild type (WT), as quantified using LC-MS/MS. While the levels of Ntcp and Mrp2 were not significantly altered, Mrp3 expression increased and Oatp1a1 decreased in KO animals. Compared with the WT rats, the KO rats had similar serum chemistry and showed normal liver transaminases. Although the total plasma bile salts and bile flow were not significantly changed in Bsep KO rats, individual bile acids in plasma and liver demonstrated variable changes, indicating the impact of Bsep KO. Following an intravenous dose of deuterium labeled taurocholic acid (D4-TCA, 2 mg/kg), the D4-TCA plasma exposure was higher and bile excretion was delayed by approximately 0.5 h in the KO rats. No differences were observed for the pravastatin plasma concentration-time profile or the biliary excretion after intravenous administration (1 mg/kg). Collectively, the results revealed that these rats have significantly lower Bsep expression, therefore affecting the biliary excretion of endogenous bile acids and Bsep substrates. However, these rats are able to maintain a relatively normal liver function through the remaining Bsep protein and via the regulation of other transporters. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Bile/metabolismo , Pravastatina/farmacocinética , Ácido Taurocólico/farmacocinética , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Anticolesterolemiantes/sangue , Anticolesterolemiantes/farmacocinética , Ácidos e Sais Biliares/metabolismo , Colagogos e Coleréticos/sangue , Colagogos e Coleréticos/farmacocinética , Fígado/metabolismo , Masculino , Pravastatina/sangue , Ratos Sprague-Dawley , Ratos Transgênicos , Ácido Taurocólico/sangue
20.
Mol Pharm ; 13(4): 1206-16, 2016 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-26910619

RESUMO

In the present study, we characterized in vitro biosynthesis and disposition of bile acids (BAs) as well as hepatic transporter expression followed by ABCB11 (BSEP) gene knockout in HepaRG cells (HepaRG-KO cells). BSEP KO in HepaRG cells led to time-dependent BA accumulation, resulting in reduced biosynthesis of BAs and altered BA disposition. In HepaRG-KO cells, the expression of NTCP, OATP1B1, OATP2B1, BCRP, P-gp, and MRP2 were reduced, whereas MRP3 and OCT1 were up-regulated. As a result, BSEP KO altered the disposition of BAs and subsequently underwent adaptive regulations of BA synthesis and homeostasis to enable healthy growth of the cells. Although BSEP inhibitors caused no or slight increase of BAs in HepaRG wild type cells (HepaRG-WT cells), excessive intracellular accumulation of BAs was observed in HepaRG-KO cells exposed to bosentan and troglitazone, but not dipyridamole. LDH release in the medium was remarkably increased in HepaRG-KO cultures exposed to troglitazone (50 µM), suggesting drug-induced cellular injury. The results revealed that functional impairment of BSEP predisposes the cells to altered BA disposition and is a susceptive factor to drug-induced cholestatic injury. In total, BSEP inhibition might trigger the processes but is not a sole determinant of cholestatic cellular injury. As intracellular BA accumulation is determined by BSEP function and the subsequent adaptive gene regulation, assessment of intracellular BA accumulation in HepaRG-KO cells could be a useful approach to evaluate drug-induced liver injury (DILI) potentials of drugs that could disrupt other BA homeostasis pathways beyond BSEP inhibition.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Ácidos e Sais Biliares/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Linhagem Celular , Doença Hepática Induzida por Substâncias e Drogas/genética , Colestase/metabolismo , Humanos , Fígado/metabolismo , Modelos Biológicos , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA