Multidrug Resistance Protein 2 (MRP2) is an ATP-dependent transmembrane protein that plays a pivotal role in the efflux of a wide variety of physiological substrates across the plasma membrane. Several studies have sh...Multidrug Resistance Protein 2 (MRP2) is an ATP-dependent transmembrane protein that plays a pivotal role in the efflux of a wide variety of physiological substrates across the plasma membrane. Several studies have shown that MRP2 can significantly affect the absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles of many therapeutic drugs and chemicals found in the environment and diet. This transporter can also efflux newly developed anticancer agents that target specific signaling pathways and are major clinical markers associated with multidrug resistance (MDR) of several types of cancers. MDR remains a major limitation to the advancement of the combinatorial chemotherapy regimen in cancer treatment. In addition to anticancer agents, MRP2 reduces the efficacy of various drug classes such as antivirals, antimalarials, and antibiotics. The unique role of MRP2 and its contribution to MDR makes it essential to profile drug-transporter interactions for all new and promising drugs. Thus, this current research seeks to identify modulators of MRP2 protein expression levels using cell-based assays. A unique recently approved FDA library (372 drugs) was screened using a high-throughput In-Cell ELISA assay to determine the effect of these therapeutic agents on protein expression levels of MRP2. A total of 49 FDA drugs altered MRP2 protein expression levels by more than 50% representing 13.17% of the compounds screened. Among the identified hits, thirty-nine (39) drugs increased protein expression levels whereas 10 drugs lowered protein expression levels of MRP2 after drug treatment. Our findings from this initial drug screening showed that modulators of MRP2 peregrinate multiple drug families and signify the importance of profiling drug interactions with this transporter. Data from this study provides essential information to improve combinatorial drug therapy and precision medicine as well as reduce the drug toxicity of various cancer chemotherapies.展开更多
To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hamme...To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.展开更多
目的探讨胆盐载体MRP1、MRP2在妊娠期肝内胆汁淤积症(ICP)胎盘的表达,分析胎盘胆盐载体与ICP发病的关系。方法收集8例正常早孕妇女绒毛组织、7例正常中孕妇女胎盘组织、20例正常晚孕妇女(对照组)胎盘组织,以及20例ICP患者胎盘组织,检测...目的探讨胆盐载体MRP1、MRP2在妊娠期肝内胆汁淤积症(ICP)胎盘的表达,分析胎盘胆盐载体与ICP发病的关系。方法收集8例正常早孕妇女绒毛组织、7例正常中孕妇女胎盘组织、20例正常晚孕妇女(对照组)胎盘组织,以及20例ICP患者胎盘组织,检测收集组织中胆盐载体MRP1和MRP2 mRNA的表达。结果ICP和正常妊娠各期胎盘组织中均有MRP2 mRNA的表达,而MRP1 mRNA在大部分标本上有表达;ICP组MRP1 mRNA和MRP2 mRNA表达量与对照组相比(99.94±73.17 vs 99.20±68.65;95.78±56.50 vs 142.20±91.27)差异无统计学意义(P>0.05);ICP组未用地塞米松治疗胎盘MRP2 mRNA表达量低于对照组(91.82±48.08 vs 142.20±91.27,P<0.05)。结论在未用地塞米松治疗的ICP患者胎盘组织中,MRP2 mRNA的表达量降低,这可能是引起ICP患者胎盘胆汁酸转运障碍,从而引起胎儿体内胆汁淤积的机制之一。展开更多
目的体外HepG2细胞培养观察芒果苷(mangiferin)对多耐药相关蛋白3(multidrug resistance-associate protein 3,MRP3)和核受体孕烷X受体(pregnane X receptor,PXR)、CYP7A启动子结合因子(CYP7A promoter-binding factor,CPF)表达的影响...目的体外HepG2细胞培养观察芒果苷(mangiferin)对多耐药相关蛋白3(multidrug resistance-associate protein 3,MRP3)和核受体孕烷X受体(pregnane X receptor,PXR)、CYP7A启动子结合因子(CYP7A promoter-binding factor,CPF)表达的影响。方法用芒果苷刺激HepG2细胞72 h后,分别抽提细胞RNA、膜蛋白及核蛋白,采用半定量RT-PCR和蛋白免疫印迹检测膜转运蛋白MRP3和核受体PXR、CPF在转录与蛋白水平的表达变化。熊脱氧胆酸(ursode-oxycholic acid,UDCA)处理的HepG2细胞作为阳性对照、DMSO处理细胞为阴性对照。结果芒果苷可显著刺激HepG2细胞膜转运蛋白MRP3的mRNA(比阴性对照组高3.0倍,P<0.05)和蛋白(比阴性对照组高3.3倍,P<0.05)表达,其作用强于UDCA。芒果苷也可明显上调核受体PXR[mRNA水平增高1.7倍(P<0.05),蛋白水平增高3.7倍(P<0.01)]、CPF[mRNA水平增高2.1倍(P<0.05),蛋白水平增高4.9倍(P<0.05)]的表达。结论芒果苷刺激肝癌细胞HepG2细胞膜转运蛋白MRP3的表达上调可能与核受体PXR、CPF途径相关。展开更多
目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXR...目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXRα)表达的关系。方法用鹅去氧胆酸(chenodeoxycholic ac id,CDCA)或苯巴比妥(phenobarb ital,PB)分别刺激培养的肝癌细胞HepG2并建立DBL阻塞性胆汁淤积大鼠模型后,分别抽提HepG2细胞总蛋白、核蛋白和大鼠肝脏细胞膜蛋白和核蛋白,W estern b lot方法检测MRP3和RXRα蛋白表达水平的变化。结果在细胞水平,CDCA和PB可诱导HepG2细胞膜MRP3蛋白表达增高,并抑制细胞核RXRα蛋白表达;在动物体内,BDL大鼠肝脏MRP3明显增加,同时RXRα表达明显下降。结论肝细胞膜蛋白MRP3表达的上调可能与核受体RXRα表达抑制有关。展开更多
文摘Multidrug Resistance Protein 2 (MRP2) is an ATP-dependent transmembrane protein that plays a pivotal role in the efflux of a wide variety of physiological substrates across the plasma membrane. Several studies have shown that MRP2 can significantly affect the absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles of many therapeutic drugs and chemicals found in the environment and diet. This transporter can also efflux newly developed anticancer agents that target specific signaling pathways and are major clinical markers associated with multidrug resistance (MDR) of several types of cancers. MDR remains a major limitation to the advancement of the combinatorial chemotherapy regimen in cancer treatment. In addition to anticancer agents, MRP2 reduces the efficacy of various drug classes such as antivirals, antimalarials, and antibiotics. The unique role of MRP2 and its contribution to MDR makes it essential to profile drug-transporter interactions for all new and promising drugs. Thus, this current research seeks to identify modulators of MRP2 protein expression levels using cell-based assays. A unique recently approved FDA library (372 drugs) was screened using a high-throughput In-Cell ELISA assay to determine the effect of these therapeutic agents on protein expression levels of MRP2. A total of 49 FDA drugs altered MRP2 protein expression levels by more than 50% representing 13.17% of the compounds screened. Among the identified hits, thirty-nine (39) drugs increased protein expression levels whereas 10 drugs lowered protein expression levels of MRP2 after drug treatment. Our findings from this initial drug screening showed that modulators of MRP2 peregrinate multiple drug families and signify the importance of profiling drug interactions with this transporter. Data from this study provides essential information to improve combinatorial drug therapy and precision medicine as well as reduce the drug toxicity of various cancer chemotherapies.
基金Supported by Fund of Shenzhen Bureau of Science and Technology, China(No.20008).
文摘To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.
文摘目的探讨胆盐载体MRP1、MRP2在妊娠期肝内胆汁淤积症(ICP)胎盘的表达,分析胎盘胆盐载体与ICP发病的关系。方法收集8例正常早孕妇女绒毛组织、7例正常中孕妇女胎盘组织、20例正常晚孕妇女(对照组)胎盘组织,以及20例ICP患者胎盘组织,检测收集组织中胆盐载体MRP1和MRP2 mRNA的表达。结果ICP和正常妊娠各期胎盘组织中均有MRP2 mRNA的表达,而MRP1 mRNA在大部分标本上有表达;ICP组MRP1 mRNA和MRP2 mRNA表达量与对照组相比(99.94±73.17 vs 99.20±68.65;95.78±56.50 vs 142.20±91.27)差异无统计学意义(P>0.05);ICP组未用地塞米松治疗胎盘MRP2 mRNA表达量低于对照组(91.82±48.08 vs 142.20±91.27,P<0.05)。结论在未用地塞米松治疗的ICP患者胎盘组织中,MRP2 mRNA的表达量降低,这可能是引起ICP患者胎盘胆汁酸转运障碍,从而引起胎儿体内胆汁淤积的机制之一。
文摘目的体外HepG2细胞培养观察芒果苷(mangiferin)对多耐药相关蛋白3(multidrug resistance-associate protein 3,MRP3)和核受体孕烷X受体(pregnane X receptor,PXR)、CYP7A启动子结合因子(CYP7A promoter-binding factor,CPF)表达的影响。方法用芒果苷刺激HepG2细胞72 h后,分别抽提细胞RNA、膜蛋白及核蛋白,采用半定量RT-PCR和蛋白免疫印迹检测膜转运蛋白MRP3和核受体PXR、CPF在转录与蛋白水平的表达变化。熊脱氧胆酸(ursode-oxycholic acid,UDCA)处理的HepG2细胞作为阳性对照、DMSO处理细胞为阴性对照。结果芒果苷可显著刺激HepG2细胞膜转运蛋白MRP3的mRNA(比阴性对照组高3.0倍,P<0.05)和蛋白(比阴性对照组高3.3倍,P<0.05)表达,其作用强于UDCA。芒果苷也可明显上调核受体PXR[mRNA水平增高1.7倍(P<0.05),蛋白水平增高3.7倍(P<0.01)]、CPF[mRNA水平增高2.1倍(P<0.05),蛋白水平增高4.9倍(P<0.05)]的表达。结论芒果苷刺激肝癌细胞HepG2细胞膜转运蛋白MRP3的表达上调可能与核受体PXR、CPF途径相关。
文摘目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXRα)表达的关系。方法用鹅去氧胆酸(chenodeoxycholic ac id,CDCA)或苯巴比妥(phenobarb ital,PB)分别刺激培养的肝癌细胞HepG2并建立DBL阻塞性胆汁淤积大鼠模型后,分别抽提HepG2细胞总蛋白、核蛋白和大鼠肝脏细胞膜蛋白和核蛋白,W estern b lot方法检测MRP3和RXRα蛋白表达水平的变化。结果在细胞水平,CDCA和PB可诱导HepG2细胞膜MRP3蛋白表达增高,并抑制细胞核RXRα蛋白表达;在动物体内,BDL大鼠肝脏MRP3明显增加,同时RXRα表达明显下降。结论肝细胞膜蛋白MRP3表达的上调可能与核受体RXRα表达抑制有关。
