RESUMO
Rifampin demonstrated dose-dependent relative induction between cytochrome P (CYP)3A and P-glycoprotein (P-gp), organic anion transporting polypeptides (OATPs), or CYP2C9; P-gp, OATP, and CYP2C9 induction was one drug-drug interaction (DDI) category lower than that observed for CYP3A across a wide range of pregnane X receptor (PXR) agonism. The objective of this study was to determine if these relationships could be utilized to predict transporter induction by other CYP3A inducers (rifabutin and carbamazepine) and of another P-gp substrate, sofosbuvir. Healthy subjects received sofosbuvir and a six-probe drug cassette before and after 300 mg q.d. rifabutin or 300 mg b.i.d. carbamazepine. Induction of P-gp, CYP2C9, and decreased sofosbuvir exposure were successfully predicted by observed CYP3A induction. Carbamazepine induction of OATP was underpredicted, likely due to reported additional non-PXR agonism. The results demonstrate that the effect of a PXR agonist on CYP3A can be leveraged to inform on induction liability for other primarily PXR-regulated P450s/transporters, allowing for prioritization of targeted DDI assessments during new drug development.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/agonistas , Carbamazepina/administração & dosagem , Citocromo P-450 CYP3A/biossíntese , Indutores das Enzimas do Citocromo P-450/administração & dosagem , Moduladores de Transporte de Membrana/administração & dosagem , Receptor de Pregnano X/agonistas , Rifabutina/administração & dosagem , Rifampina/administração & dosagem , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Adolescente , Adulto , Biotransformação , Carbamazepina/efeitos adversos , Simulação por Computador , Citocromo P-450 CYP2C9/biossíntese , Indutores das Enzimas do Citocromo P-450/efeitos adversos , Relação Dose-Resposta a Droga , Interações Medicamentosas , Indução Enzimática , Feminino , Voluntários Saudáveis , Humanos , Masculino , Moduladores de Transporte de Membrana/efeitos adversos , Pessoa de Meia-Idade , Modelos Biológicos , Transportadores de Ânions Orgânicos/agonistas , Transportadores de Ânions Orgânicos/metabolismo , Receptor de Pregnano X/metabolismo , Rifabutina/efeitos adversos , Rifampina/efeitos adversos , Medição de Risco , Sofosbuvir/metabolismo , Especificidade por Substrato , Adulto JovemRESUMO
Drug transporter and cytochrome P450 expression is regulated by shared nuclear receptors and, hence, an inducer should induce both, although the magnitude may differ. The objective of this study was to establish relative induction relationships between CYP3A and drug transporters (P-glycoprotein (P-gp), organic anion transporting polypeptide (OATP), and breast cancer resistance protein (BCRP)) or other P450s (CYP2C9 and CYP1A2) using ascending doses of the prototypical pregnane xenobiotic receptor (PXR) agonist, rifampin, to elicit weak, moderate, and strong PXR agonism. Healthy subjects received dabigatran etexilate, pravastatin, rosuvastatin, and a midazolam/tolbutamide/caffeine cocktail before and after rifampin 2, 10, 75, or 600 mg q.d. Unlike CYP3A, only moderate induction of P-gp, OATP, and CYP2C9 was observed and dose-dependent induction of P-gp, OATP, and CYP2C9 was always one drug-drug interaction category lower than observed for CYP3A, even when correcting for probe drug sensitivity. Data from this study establish proof-of-concept that P450 induction data can be leveraged to inform on the effect on transporters.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/agonistas , Citocromo P-450 CYP3A/biossíntese , Indutores das Enzimas do Citocromo P-450/administração & dosagem , Moduladores de Transporte de Membrana/administração & dosagem , Receptor de Pregnano X/agonistas , Rifampina/administração & dosagem , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Adolescente , Adulto , Biotransformação , Simulação por Computador , Indutores das Enzimas do Citocromo P-450/efeitos adversos , Relação Dose-Resposta a Droga , Interações Medicamentosas , Indução Enzimática , Feminino , Voluntários Saudáveis , Humanos , Masculino , Moduladores de Transporte de Membrana/efeitos adversos , Pessoa de Meia-Idade , Modelos Biológicos , Transportadores de Ânions Orgânicos/agonistas , Transportadores de Ânions Orgânicos/metabolismo , Farmacocinética , Receptor de Pregnano X/metabolismo , Rifampina/efeitos adversos , Medição de Risco , Especificidade por Substrato , Adulto JovemRESUMO
TaALMT1 from wheat (Triticum aestivum) and AtALMT1 from Arabidopsis thaliana encode aluminum (Al)-activated malate transporters, which confer acid-soil tolerance by releasing malate from roots. Chimeric proteins from TaALMT1 and AtALMT1 (Ta::At, At::Ta) were previously analyzed in Xenopus laevis oocytes. Those studies showed that Al could activate malate efflux from the Ta::At chimera but not from At::Ta. Here, functions of TaALMT1, AtALMT1 and the chimeric protein Ta::At were compared in cultured tobacco BY-2 cells. We focused on the sensitivity and specificity of their activation by trivalent cations. The activation of malate efflux by Al was at least two-fold greater in the chimera than the native proteins. All proteins were also activated by lanthanides (erbium, ytterbium, gadolinium, and lanthanum), but the chimera again released more malate than TaALMT1 or AtALMT1. In Xenopus oocytes, Al, ytterbium, and erbium activated inward currents from the native TaALMT1 and the chimeric protein, but gadolinium only activated currents from the chimera. Lanthanum inhibited currents from both proteins. These results demonstrated that function of the chimera protein was altered compared to the native proteins and was more responsive to a range of trivalent cations when expressed in plant cells.
Assuntos
Alumínio/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Malatos/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Triticum/metabolismo , Animais , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/agonistas , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/genética , Transporte Biológico/efeitos dos fármacos , Células Cultivadas , Érbio/farmacologia , Gadolínio/farmacologia , Expressão Gênica , Cinética , Lantânio/farmacologia , Oócitos/citologia , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Transportadores de Ânions Orgânicos/agonistas , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Transportadores de Ânions Orgânicos/genética , Células Vegetais/efeitos dos fármacos , Células Vegetais/metabolismo , Proteínas Recombinantes de Fusão/genética , Nicotiana/genética , Nicotiana/metabolismo , Triticum/efeitos dos fármacos , Triticum/genética , Xenopus laevis , Itérbio/farmacologiaRESUMO
We examined whether lysophosphatidic acid affects prostaglandin biosynthesis, transport, and signalling in bovine steroidogenic luteal cells. The aim of the present study was to determine the influence of LPA on PGE2 and PGF2α synthesis and on the expression of enzymes involved in PG biosynthesis (PTGS2, mPGES-1, cPGES, mPGES-2, PGFS and 9-KPR), prostaglandin transporter (PGT), and prostaglandin receptors (EP1, EP2, EP3, EP4 and FP) in bovine steroidogenic luteal cells. We found that LPA inhibited PGF2α synthesis in steroidogenic luteal cells. Moreover, LPA increased mPGES1 and cPGES and decreased PGFS expression in cultured bovine steroidogenic luteal cells. Additionally, LPA stimulated EP2 and EP4 receptor and PGT expression. This study suggests that LPA activity in the bovine CL directs the physiological intraluteal balance between the two main prostanoids towards luteotropic PGE2.
Assuntos
Oxirredutases Intramoleculares/metabolismo , Células Lúteas/metabolismo , Lisofosfolipídeos/metabolismo , Transportadores de Ânions Orgânicos/agonistas , Receptores de Prostaglandina E Subtipo EP2/agonistas , Receptores de Prostaglandina E Subtipo EP4/agonistas , Matadouros , Animais , Transporte Biológico , Bovinos , Células Cultivadas , Indústria de Laticínios , Dinoprosta/antagonistas & inibidores , Dinoprosta/metabolismo , Dinoprostona/agonistas , Dinoprostona/metabolismo , Ciclo Estral/metabolismo , Feminino , Regulação da Expressão Gênica , Hidroxiprostaglandina Desidrogenases/antagonistas & inibidores , Hidroxiprostaglandina Desidrogenases/genética , Hidroxiprostaglandina Desidrogenases/metabolismo , Oxirredutases Intramoleculares/química , Oxirredutases Intramoleculares/genética , Isoenzimas/antagonistas & inibidores , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Células Lúteas/citologia , Células Lúteas/enzimologia , Hormônio Luteinizante/metabolismo , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Prostaglandina-E Sintases , Receptores de Prostaglandina E Subtipo EP2/genética , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Receptores de Prostaglandina E Subtipo EP4/genética , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Transdução de SinaisRESUMO
Anthocyans (anthocyanins and their aglycones anthocyanidins) are colorful pigments, naturally occurring in fruits. They exhibit many biological effects and have potent health benefits. Anthocyans are widely used as dietary supplements and the safety of products containing them is of great importance. To investigate whether anthocyans influence the expression of hepatic uptake transporters from the organic anion transporting polypeptide (SLCO gene/OATP protein) family, we carried out studies on primary cultures of human hepatocytes. The hepato-cellular accumulation of widely used drugs such as statins and some anticancer drugs is mediated by the liver-specific OATP1B1 and OATP1B3, thus any interference with expression of these particular transporters might influence therapeutic outcomes. We evaluated the effects of 21 anthocyanins and their corresponding 6 anthocyanidins on the expression levels of SLCO1B1/SLCO1B3 by RT-qPCR. Changes in OATP protein levels were confirmed by western blotting. Our data show that OATP1B1 responds differently to anthocyans compared with OATP1B3. We observed the induction of SLCO1B1 gene and OATP1B1 protein in four hepatocyte samples by the anthocyanins malvin chloride, malvidin-3-O-galactoside chloride and cyanidin-3-O-sophoroside chloride. For SLCO1B3, a reduction in the expression levels was seen with delphin chloride and the anthocyanidin pelargonidin. Although the values varied considerably between primary hepatocyte isolates from different individuals, a mean induction of SLCO1B1 (up to 60%) and reduction of SLCO1B3 (by less than 25%) were detected. We propose that the effects of anthocyans derived from high dose dietary supplements may have to be taken into account in patients undergoing a therapy with drugs transported by OATP1B1 and OATP1B3.
Assuntos
Antocianinas/metabolismo , Anticarcinógenos/metabolismo , Suplementos Nutricionais , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/antagonistas & inibidores , Transportadores de Ânions Orgânicos/agonistas , Adulto , Antocianinas/química , Anticarcinógenos/química , Células Cultivadas , Frutas/química , Galactosídeos/química , Galactosídeos/metabolismo , Glucosídeos/química , Glucosídeos/metabolismo , Hepatócitos/citologia , Humanos , Transportador 1 de Ânion Orgânico Específico do Fígado , Masculino , Pessoa de Meia-Idade , Estrutura Molecular , Transportadores de Ânions Orgânicos/genética , Transportadores de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de SolutoRESUMO
Urate is mainly excreted into urine in humans. Serum urate level is regulated by a urate transport system located on the renal proximal tubule. Urate transporter 1 (URAT1) is located on the apical side of the renal proximal tubule and is responsible for the reabsorption of urate from the luminal side into tubular cells. At the same site, it has been hypothesized that sodium-coupled monocarboxylate transporters (SMCTs) are responsible for the transportation of monocarboxylates such as lactate and nicotinate, which are exchanged for urate transport via URAT1. Accordingly, SMCTs could enhance URAT1-mediated urate reabsorption by providing monocarboxylates for the exchange. The present study was carried out to clarify the hypothesized functional cooperative relationship between URAT1 and SMCTs in the reabsorptive transport of urate. By preloading nicotinate in SMCT1/URAT1-coexpressing Xenopus oocytes, URAT1-mediated urate transport was stimulated. Nicotinate was taken up by SMCT1 but not by URAT1. When removing sodium ions from the uptake medium, the stimulation effect was decreased. When adding SMCT1 inhibitors, the stimulation effect was also reduced. The results from this study indicate the cooperative relationship of URAT1 and SMCT1, and that SMCT1 is a potential target for the alteration of renal handling of urate indirectly.