查找使用阿拉丁产品的科研文献

Regulation of BCRP expression and sulfasalazine pharmacokinetics by the nuclear receptor REV-ERBα

Chunhong Wu,Yifei Xiao,Caimei Wu,Dihao Xie,Meixue Luo,Dingyi Yao,Min Chen,Danyi Lu

BCRP (breast cancer resistance protein) is a crucial efflux transporter involved in the regulation of the pharmacokinetics and pharmacodynamics of a wide range of drugs. Herein, we aimed to investigate a potential role for the nuclear receptor REV-ERBα in the regulation of BCRP expression and sulfasalazine (a BCRP probe substrate) pharmacokinetics.Regulation of BCRP expression by REV-ERBα was assessed using Rev-erbα-/- mice and AML12 and CT26 cells. Pharmacokinetic analysis was performed with Rev-erbα-/- and wild-type mice after sulfasalazine administration.We found that the expression levels of BCRP mRNA and protein were downregulated in the liver and small intestine of Rev-erbα-dificient mice. In line with this, Rev-erbα ablation increased the systemic exposures of oral sulfasalazine.Positive regulation of BCRP expression and function by REV-ERBα was furtherly confirmed in AML12 and CT26 cells. Moreover, indirect regulation of Bcrp expression by REV-ERBα was potentially mediated by a negative transcription factor DEC2, which is a downstream target of REV-ERBα.In conclusion, REV-ERBα positively regulates BCRP expression in mice, thereby affecting sulfasalazine pharmacokinetics.

Disposition of mianserin and cyclizine in UGT2B10-overexpressing HEK293 cells: Identification of UGT2B10 as a novel N-glucosidation enzyme and BCRP as an N-glucoside transporter

Danyi Lu,Dong Dong,Qian Xie,Zhijie Li,Baojian Wu

UDP-glucuronosyltransferases (UGTs) play an important role in metabolism and detoxification of amine-containing chemicals. However, the disposition mechanisms for amines via UGT metabolism are not fully clear. Here we aim to investigate a potential role of UGT2B10 in N-glucosidation, and to determine the transporters for excretion of N-glucosides. We first established a HEK293 cell line stably overexpressing UGT2B10. Incubation of mianserin or cyclizine with the cells generated one N-glucuronide and one N-glucoside. Chemical inhibition (using specific chemical inhibitor Ko143) and biological inhibition (using specific shRNA) of BCRP resulted in a significant reduction in efflux of N-glucuronide. Similar results were observed when MRP4 was inhibited. Furthermore, inhibition of BCRP led to increased intracellular N-glucoside, whereas inhibition of MRP4 caused no changes in disposition of N-glucosides. The data overall indicated that BCRP not MRP4 was responsible for excretion of N-glucosides, whereas both BCRP and MRP4 contributed to excretion of N-glucuronides. Interestingly, down-regulation of N-glucuronidation led to increased N-glucosidation in the cells, supporting the glucosidation as a potential complementary pathway for conventional glucuronidation. In conclusion, UGT2B10 was for the first time identified as a N-glucosidation enzyme. Generated N-glucosides were excreted primarily by the BCRP transporter.

The roles of breast cancer resistance protein (BCRP/ABCG2) and multidrug resistance-associated proteins (MRPs/ABCCs) in the excretion of cycloicaritin-3-O-glucoronide in UGT1A1-overexpressing HeLa cells

Shishi Li,Jinjin Xu,Zhihong Yao,Liufang Hu,Zifei Qin,Hao Gao,Kristopher W. Krausz,Frank J. Gonzalez,Xinsheng Yao

Cycloicaritin is a bioactive natural phenolic compound from Epimedium species. However, the glucuronidation and excretion which would influence oral bioavailability and pharmacokinetics of cycloicaritin still remain unknown. Here we aimed to establish UGT1A1 stably transfected HeLa cells, and to determine the contributions of BCRP and MRPs transporters to excretion of cycloicaritin-3- O -glucuronide. First, β-estradiol was used to validate the expression of active UGT1A1 protein in engineered HeLa1A1 cells. Furthermore, Ko143 (5 and 20 μM) led to a significant decrease (42.4%–63.8%, p  < 0.01) in CICT-3-G excretion and obvious accumulation (19.7%–54.2%, p  < 0.05) of intracellular CICT-3-G, while MK571 (5 and 20 μM) caused a significant reduction (46.8%–64.8%, p  < 0.05) in the excretion and obvious elevation (50.7%–85.2%, p  < 0.01) of intracellular level of CICT-3-G. Furthermore, BCRP knocked-down brought marked reduction in excretion rates of CICT-3-G (26.0%–42.2%, p  < 0.01), whereas MRP1 and MRP4-mediated silencing led to significant decrease in the excretion of CICT-3-G (23.8%–35.4%, p  < 0.05 for MRP1 and 11.9%–16.0%, p  < 0.05 for MRP4). By contrast, neither CICT-3-G excretion nor CICT-3-G accumulation altered in MRP3 knocked-down cells as compared to scramble cells. Taken together, BCRP, MRP1 and MRP4 were identified as the most important contributors for CICT-3-G excretion. Meanwhile, the UGT1A1 modified HeLa cells were a simple and practical tool to study UGT1A1-mediated glucuronidation and to characterize BCRP and MRPs-mediated glucuronide transport at a cellular level.

Metabolism and disposition of corylifol A from Psoralea corylifolia: metabolite mapping, isozyme contribution, species differences and identification of efflux transporters for corylifol A-O-glucuronide in HeLa1A1 cells

Yang Li,Jinjin Xu,Chunxia Xu,Zifei Qin,Shishi Li,Liufang Hu,Zhihong Yao,Frank J. Gonzalez,Xinsheng Yao

Corylifol A (CA), a phenolic compound from Psoralea corylifolia, possessed several biological properties but poor bioavailability. Here we aimed to investigate the roles of cytochromes P450s (CYPs), UDP-glucuronosyltransferases (UGTs) and efflux transporters in metabolism and disposition of CA.Metabolism of CA was evaluated in HLM, expressed CYPs and UGTs. Chemical inhibitors and shRNA-mediated gene silencing of multidrug resistance-associated proteins (MRPs) and breast cancer resistance protein (BCRP) were performed to assess the roles of transporters in CA disposition.Three oxidated metabolites (M1–M3) and two glucuronides (M4–M5) were detected. The intrinsic clearances (CLint) values of M1 and M4 in HLM were 48.10 and 184.03 μL/min/mg, respectively. Additionally, CYP1A1, 2C8 and 2C19 were identified as main contributors with CLint values of 13.01–49.36 μL/min/mg, while UGT1A1, 1A7, 1A8 and 1A9 were with CLint values ranging from 85.01 to 284.07 μL/min/mg. Furthermore, activity correlation analysis proved CYP2C8, UGT1A1 and 1A9 were the main active hepatic isozymes. Besides, rats and monkeys were appropriate model animals. Moreover, dipyridamole and MK571 both could significantly inhibit M4 efflux. Gene silencing results also indicated MRP4 and BCRP were major contributors in HeLa1A1 cells.Taken together, CYPs, UGTs, MRP4 and BCRP were important determinants of CA pharmacokinetics.

Identification of UGTs and BCRP as potential pharmacokinetic determinants of the natural flavonoid alpinetin

Chunli Qi,Jiangnan Fu,Huinan Zhao,Huijie Xing,Dong Dong,Baojian Wu

Evaluation of a Clinically Relevant Drug–Drug Interaction Between Rosuvastatin and Clopidogrel and the Risk of Hepatotoxicity

Ning Chen,Su Shengdi,Li Jiaming,Kong Dexuan,Cai Hui,Qin Zhiying,Xing Han,Chen Xijing,He Jiake

Purpose: The combination therapy of rosuvastatin (RSV) and the platelet inhibitor clopidogrel (CP) is widely accepted in the management of cardiovascular diseases. The objective of the present study was to identify the mechanism of RSV–CP DDI and evaluate the risk of hepatotoxicity associated with the concomitant use of CP.Methods: We first studied the effect of CP and its major circulating metabolite, carboxylic acid metabolite (CPC), on RSV transport by overexpressing cells and membrane vesicles. Second, we investigated whether a rat model could replicate this DDI and then be used to conduct mechanistic studies and assess the risk of hepatotoxicity. Then, cytotoxicity assay in hepatocytes, biochemical examination, and histopathology were performed to measure the magnitude of liver injury in the presence and absence of DDI.Results: CP inhibited OATP1B1-mediated transport of RSV with an IC50 value of 27.39 μM. CP and CPC inhibited BCRP-mediated RSV transport with IC50 values of <0.001 and 5.96 μM, respectively. The CP cocktail (0.001 μM CP plus 2 μM CPC) significantly inhibited BCRP-mediated transport of RSV by 26.28%. Multiple p.o. doses of CP significantly increased intravenous RSV plasma AUC0-infinity by 76.29% and decreased intravenous RSV CL by 42.62%. Similarly, multiple p.o. doses of CP significantly increased p.o. RSV plasma AUC0-infinity by 87.48% and decreased p.o. RSV CL by 43.27%. CP had no effect on cell viability, while RSV exhibited dose-dependent cytotoxicity after 96 h incubation. Co-incubation of 100 μM CP and RSV for 96 h significantly increased intracellular concentrations and cell-to-medium concentration ratios of RSV and reduced hepatocyte viability. Histological evaluation of liver specimens showed patterns of drug-induced liver injury. Cholestasis was found in rats in the presence of DDI.Conclusion: CP is not a clinically relevant inhibitor for OATP1B1 and OATP1B3. The primary mechanism of RSV–CP DDI can be attributed to the inhibition of intestinal BCRP by CP combined with the inhibition of hepatic BCRP by CPC. The latter is likely to be more clinically relevant and be a contributing factor for increased hepatotoxicity in the presence of DDI.

Potential metabolism determinants and drug–drug interactions of a natural flavanone bavachinin

Xinqiang Li,Han Xing,Zifei Qin,Jing Yang,Peile Wang,Xiaojian Zhang,Zhihong Yao,Xinsheng Yao

Bavachinin, a natural bioactive flavanone, is reported to have many pharmacological proprieties, especially anti-osteoporosis activity. Here we aim to determine the roles of cytochrome P450s (CYP), UDP-glucuronosyltransferases (UGT), and efflux transporters in metabolism and drug–drug interactions (DDI) of bavachinin. Phase I metabolism and glucuronidation were performed by human liver microsomes (HLM) and human intestine microsomes (HIM). Reaction phenotyping was used to identify the main CYPs and UGTs. Gene silencing methods were employed to investigate the roles of breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins (MRPs) in HeLa1A1 cells. Inhibition mechanisms towards CYPs and UGTs were explored through kinetic modeling. Three phase I metabolites (M1–M3) and one glucuronide (G1) were detected after incubation of bavachinin with HLM and HIM. The intrinsic clearance (CLint) values of M1 and G1 by HLM were 89.4 and 270.2 μL min−1 mg−1, respectively, while those of M3 and G1 by HIM were 25.8 and 247.1 μL min−1 mg−1, respectively. CYP1A1, 1A2, 1B1, 2C8, 2C19, and UGT1A1, 1A8 participated more in bavachinin metabolism. The metabolism showed marked species difference. BCRP and MRP4 were identified as the main contributors. Bavachinin displayed potent inhibitory effects against several CYP and UGT isozymes (Ki = 0.28–2.53 μM). Bavachinin was subjected to undergo metabolism and disposition by CYPs, UGTs, BCRP, MRP4, and was also a potent non-selective inhibitor against several CYPs and UGTs.

Stable Knock-down of Efflux Transporters Leads to Reduced Glucuronidation in UGT1A1-Overexpressing HeLa Cells: The Evidence for Glucuronidation-Transport Interplay

Xingwang Zhang,Dong Dong,Huailing Wang,Zhiguo Ma,Yifei Wang,Baojian Wu

Efflux of glucuronide is facilitated by the membrane transporters including BCRP and MRPs. In this study, we aimed to determine the effects of transporter expression on glucuronide efflux and cellular glucuronidation. Single efflux transporter (i.e., BCRP, MRP1, MRP3, or MRP4) was stably knocked-down in UGT1A1-overexpressing HeLa cells. Knock-down of transporters was performed by stable transfection of short-hairpin RNA (shRNA) using lentiviral vectors. Glucuronidation and glucuronide transport in the cells were characterized using three different aglycones (i.e., genistein, apigenin, and emodin) with distinct metabolic activities. BCRP knock-down resulted in significant reductions in excretion of glucuronides (42.9% for genistein glucuronide (GG), 21.1% for apigenin glucuronide (AG) , and 33.7% for emodin glucuronide (EG); p < 0.01) and in cellular glucuronidation (38.3% for genistein, 38.6% for apigenin, and 34.7% for emodin; p < 0.01). Knock-down of a MRP transporter led to substantial decreases in excretion of GG (32.3% for MRP1, 36.7% for MRP3, and 36.6% for MRP4; p < 0.01) and AG (59.3% for MRP1, 24.7% for MRP3, and 34.1% for MRP4; p < 0.01). Also, cellular glucuronidation of genistein (38.3% for MRP1, 32.3% for MRP3, and 31.1% for MRP4; p < 0.01) and apigenin (40.6% for MRP1, 32.4% for MRP3, and 34.6% for MRP4; p < 0.001) was markedly suppressed. By contrast, silencing of MRPs did not cause any changes in either excretion of EG or cellular glucuronidation of emodin. In conclusion, cellular glucuronidation was significantly altered by decreasing expression of efflux transporters, revealing a strong interplay of glucuronidation with efflux transport.

Bile duct ligation enhances AZT CNS toxicity partly by impairing the expression and function of BCRP in rat brain

Qin Yuan-yuan,Xu Ping,Wu Tong,Qian Chao-qun,Fan Yi-lin,Gen Dong-hao,Zhu Liang,Kong Wei-min,Yang Han-yu,Xu Feng,Yang Yi-ting,Liu Li,Liu Xiao-dong

Breast cancer resistance protein (BCRP) is one of ATP-binding cassette (ABC) transporters in brain microvessel endothelial cells that transport their substrates from brain to blood, thus limiting substrates to crossing into brain through blood–brain barrier. Our previous works show that bile duct ligation (BDL) impairs expression and function of brain BCRP in rats. Since zidovudine (AZT) is BCRP substrate, we investigated whether impaired expression and function of BCRP increased brain distribution and toxicity of AZT in BDL-D7 rats. After administration of AZT (10 mg/kg, i.v.), BDL markedly increased brain AZT concentrations, compared with sham-operated (SO) rats. The ratio of AZT brain-to-plasma area under concentration curve (AUC) in BDL rats was increased to 1.6-folds of SO rats. After treatment with AZT (100 mg/kg every day, i.v.) for 7 days, BDL significantly impaired cognitive functions compared with SO rats, evidenced by the significantly decreased percentage of alternation in Y-maze test and prolonged escaped latency in two-way passive avoidance trial. Furthermore, AZT treatment caused significant decrease in copies of mitochondrial DNA and mitochondrial membrane potential in hippocampus of BDL rats. Moreover, AZT treatment caused a significant decrease of cortex microtubule-associated protein 2 and hippocampus synaptophysin levels in BDL rats. AZT-induced CNS adverse alterations in BDL rats were not observed in SO rats treated with AZT. In conclusion, BDL decreases the function and expression of brain BCRP in rats, leading to increased brain distribution of AZT, which in turn enhances AZT CNS toxicity, leading to mitochondrial dysfunction, neuronal damage, and ultimately cognitive dysfunction.

Baicalein Enhances the Oral Bioavailability and Hepatoprotective Effects of Silybin Through the Inhibition of Efflux Transporters BCRP and MRP2

Xu Peng,Zhou Hua,Li Ya-Zhuo,Yuan Zhong-Wen,Liu Chang-Xiao,Liu Liang,Xie Ying

Although hepatoprotective properties of silybin are well documented, the clinical therapeutic efficacy is limited by its low bioavailability due to absorption rates, extensive phase II metabolism, and biliary excretion. As our previous study indicated that metabolic enzymes may have limited effects on the pharmacokinetic (PK) behavior of silymarin, here, we intended to increase the oral bioavailability and bio-efficacy of silybin through the inhibition of active efflux. In Caco-2 and transfected MDCKII cell models, flavone baicalein significantly inhibited the efflux of silybin as a BCRP and MRP2 inhibitor. In addition, baicalein reduced the biliary excretion index (BEI) and biliary clearance of silybin conjugates in the sandwich-cultured rat hepatocyte (SCH) model, indicating the inhibition of baicalein in biliary excretion of conjugated silybin metabolites. PK study demonstrated that baicalein significantly increased the area under the curve (AUC) and Cmax of silybin and its conjugates, suggesting enhanced absorption in vivo. Moreover, coadministration of silybin with baicalein boosted the liver protective, antioxidant, and anti-inflammatory effects of silybin in the carbon tetrachloride (CCl4)-induced liver injury model in comparison with silybin given alone. In summary, efflux transporters play a critical role in the low bioavailability of silybin, while inhibition of breast cancer resistance protein (BCRP) and multi-drug resistance protein 2 (MRP2) by baicalein can significantly increase the absorption and bio-efficacy of silybin, which provides a new combination therapeutic approach for the treatment of chronic liver diseases.

Multiple Drug Transporters Contribute to the Placental Transfer of Emtricitabine

Qingquan Zeng,Mengru Bai,Cui Li,Shuanghui Lu,Zhiyuan Ma,Yunchun Zhao,Hui Zhou,Huidi Jiang,Dongli Sun,Caihong Zheng

Emtricitabine (FTC) is a first-line antiviral drug recommended for the treatment of AIDS during pregnancy. We hypothesized that transporters located in the placenta contribute to FTC transfer across the blood-placenta barrier. BeWo cells, cell models with stable or transient expression of transporter genes, primary human trophoblast cells (PHTCs), and small interfering RNAs (siRNAs) were applied to demonstrate which transporters were involved. FTC accumulation in BeWo cells was reduced markedly by inhibitors of equilibrative nucleoside transporters (ENTs), concentrative nucleoside transporters (CNTs), organic cation transporters (OCTs), and organic cation/carnitine transporter 1 (OCTN1) and increased by inhibitors of breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins (MRPs). ENT1, CNT1, OCTN1, MRP1/2/3, and BCRP, but not ENT2, CNT3, OCTN2, or multidrug resistance protein 1 (MDR1), were found to transport FTC. FTC accumulation in PHTCs was decreased significantly by inhibitors of ENTs and OCTN1. These results suggest that ENT1, CNT1, and OCTN1 probably contribute to FTC uptake from maternal circulation to trophoblasts and that ENT1, CNT1, and MRP1 are likely involved in FTC transport between trophoblasts and fetal blood, whereas BCRP and MRP1/2/3 facilitate FTC transport from trophoblasts to maternal circulation. Coexistence of tenofovir or efavirenz with FTC in the cell medium did not influence FTC accumulation in BeWo cells or PHTCs.

Hepatic uptake of estradiol-3-glucuronide and estradiol-3-sulfate-17β-glucuronide by human OATP1B1, 1B3, and 2B1

Lanjing Li,Ru Huan,Ting Liang,Han Liu,Yao Dong,Shuang Chen,Chen Zhang,Chunshan Gui

Estradiol is the most potent and biologically active form of estrogen with glucuronide as its predominant conjugation form. Major estradiol glucuronides include estradiol-3-glucuronide (E 2 3G), estradiol-17β-glucuronide (E 2 17βG), and estradiol-3-sulfate-17β-glucuronide (E 2 3S17βG). Hepatic disposition of E 2 17βG involves basolateral uptake transporters organic anion transporting polypeptide (OATP) 1B1/1B3 and apical efflux transporters multidrug resistance-associated protein 2 (MRP2)/breast cancer resistance protein (BCRP). In addition, E 2 3G and E 2 3S17βG are substrates for MRP2/BCRP. However, whether E 2 3G and E 2 3S17βG across the basolateral membrane of hepatocytes are transporter-mediated and which transporters play the most significant roles are largely unknown. Therefore, in the present study we investigated the human hepatic uptake transporters for E 2 3G and E 2 3S17βG. Our results showed that E 2 3G and E 2 3S17βG are transported by human OATPs. Specifically, E 2 3G is a substrate for OATP1B1, 1B3, and 2B1, with K m values being of 16.0, 23.8, and 6.4 μM, respectively, and OATP2B1 possesses the highest transport efficiency. E 2 3S17βG is a substrate for OATP1B1 and 1B3, with K m values being of 0.5 and 23.7 μM, respectively, and OATP1B1 has a higher transport efficiency. At low concentrations, E 2 3G and E 2 3S17βG are selective substrates for OATP2B1 and OATP1B1, respectively. Furthermore, mutual and differential inhibition between E 2 3G/E 2 3S17βG and known OATP substrates/inhibitors has been observed. In summary, our results demonstrated that basolateral OATPs and apical MRP2/BCRP could constitute the hepatic vectorial transport of E 2 3G and E 2 3S17βG from the blood to the bile. Significance Statement This study demonstrated that OATP1B1/1B3/2B1 are hepatic uptake transporters for E 2 3G, and OATP1B1/1B3 are hepatic uptake transporters for E 2 3S17βG. At low concentrations, E 2 3G and E 2 3S17βG are selectively transported by OATP2B1 and OATP1B1, respectively. The findings in this study unveil the underlying molecular mechanisms for the hepatic disposition of estradiol glucuronides E 2 3G and E 2 3S17βG.