孕烷X受体(Pregnane X receptor,PXR)是核受体超家族(NRs)中NR1I的重要成员之一,在保护机体免于内源性和外源性物质损伤方面具有重要作用。利用CRISPR/Cas9基因编辑技术建立PXR基因敲除的斑马鱼模型,为研究环境污染物的毒性机理及代谢...孕烷X受体(Pregnane X receptor,PXR)是核受体超家族(NRs)中NR1I的重要成员之一,在保护机体免于内源性和外源性物质损伤方面具有重要作用。利用CRISPR/Cas9基因编辑技术建立PXR基因敲除的斑马鱼模型,为研究环境污染物的毒性机理及代谢过程提供基础模型。根据PXR基因序列,设计gRNA靶位点,体外转录合成gRNA。同时,将设计合成的gRNA与Cas9 mRNA通过显微注射转入斑马鱼受精卵,经孵化、筛选出有效的突变体,并逐代培养杂交筛选出PXR基因敲除突变体。结果表明利用CRISPR/Cas9基因编辑技术成功敲除PXR基因,经测序分析获得稳定的PXR(+4/+4)基因纯合体。展开更多
The human pregnane X receptor（hPXR） plays a critical role in the metabolism, transport and clearance of xenobiotics in the liver and intestine. The hPXR can be activated by a structurally diverse of drugs to initiat...The human pregnane X receptor（hPXR） plays a critical role in the metabolism, transport and clearance of xenobiotics in the liver and intestine. The hPXR can be activated by a structurally diverse of drugs to initiate clinically relevant drug-drug interactions. In this article, in silico investigation was performed on a structurally diverse set of drugs to identify critical structural features greatly related to their agonist activity towards h PXR. Heuristic method（HM）-Best Subset Modeling（BSM） and HM-Polynomial Neural Networks（PNN） were utilized to develop the linear and non-linear quantitative structure-activity relationship models. The applicability domain（AD） of the models was assessed by Williams plot. Statistically reliable models with good predictive power and explain were achieved（for HM-BSM, r^2=0.881, q^2_（LOO）=0.797, q^2_（EXT）=0.674; for HM-PNN, r^2=0.882, q^2_（LOO）=0.856, q^2_（EXT）=0.655）. The developed models indicated that molecular aromatic and electric property, molecular weight and complexity may govern agonist activity of a structurally diverse set of drugs to h PXR.展开更多
孕烷X受体(pregnane X receptor,PXR)是机体对有毒物质适应性防卫机制的一个重要组成部分,PXR被大量的外源性和内源性化学物质激活,这些物质包括类固醇、抗生素、抗真菌的物质和胆汁酸等。PXR配体结合区域三维结构显示它具有一个特殊球...孕烷X受体(pregnane X receptor,PXR)是机体对有毒物质适应性防卫机制的一个重要组成部分,PXR被大量的外源性和内源性化学物质激活,这些物质包括类固醇、抗生素、抗真菌的物质和胆汁酸等。PXR配体结合区域三维结构显示它具有一个特殊球形配体结合腔,这种结构允许PXR与广泛的疏水性化学物质结合。PXR与9-顺式维甲酸受体(9-cisretinoic aid receptor,RXR)以异型二聚体的形式与细胞色素氧化酶P450 3A家族和其他参与药物代谢的Ⅱ相药物代谢酶以及药物转运蛋白的DNA响应元件结合,通过外源物刺激诱导多个基因的表达。分析PXR的结构与功能对药物设计和筛选具有重要的应用价值。展开更多
孕烷X受体(pregnane X receptor,PXR)是核受体超家族的成员之一,其本质是配体激活型转录因子。PXR高表达于肝脏和肠道,在肾脏和脑等器官也有表达。自发现以来,PXR就被公认为是外源物质和内源物质的感受器,在激活状态下,可以调节药物代...孕烷X受体(pregnane X receptor,PXR)是核受体超家族的成员之一,其本质是配体激活型转录因子。PXR高表达于肝脏和肠道,在肾脏和脑等器官也有表达。自发现以来,PXR就被公认为是外源物质和内源物质的感受器,在激活状态下,可以调节药物代谢酶、转运蛋白和其他代谢相关蛋白质的表达,从而起到解毒等作用。由于PXR高表达于肝脏和肠道,所以其在消化系统的功能被大量研究报道。近年来,随着PXR在越来越多的脑区被检测到,其在中枢神经系统中的生理和病生理功能被广泛关注。本文主要就PXR在中枢神经系统的表达谱、在血脑屏障中的功能,以及其与神经疾病和神经毒性的关系,与行为学的相关性等进行综述。上述内容一方面可指导临床合理用药,另一方面可拓展科研工作者新药研发的思路;同时,也为未来PXR在中枢神经系统中功能的进一步研究提供了理论基础和方法思路。展开更多
Polychlorinated biphenyls(PCBs) can antagonize human pregnane X receptor(hPXR) activation.Such chemicals could pose a serious threat to the reproductive and developmental ability of humans.The quantitative structure a...Polychlorinated biphenyls(PCBs) can antagonize human pregnane X receptor(hPXR) activation.Such chemicals could pose a serious threat to the reproductive and developmental ability of humans.The quantitative structure activity relationship(QSAR) provides a promising method for the estimation of PCBs' antagonistic activity.In this investigation,a QSAR model was developed by using heuristic method and best subset modeling(r2 = 0.873,q2LOO=0.742).The built model was validated externally by splitting the original data set into training and prediction sets.The results of the model derived are as follows:r2 = 0.907,q2LOO=0.709,r2pred=0.676,suggesting developed QSAR model had good robustness and predictive ability.The applicability domain(AD) of the model was assessed by Williams plot.The antagonistic activity(?logKi) of 108 PCBs,which are unavailable by experiment at present,was predicted within the applicability domain of the model.The critical structural features related to the activity of PCBs were identified.展开更多
Background and aims:The herbal supplement Gancao,also known as licorice,belongs to the genus Glycyrrhiza and has been used worldwide for its hepatoprotective effect.Recent studies have raised concerns about potential ...Background and aims:The herbal supplement Gancao,also known as licorice,belongs to the genus Glycyrrhiza and has been used worldwide for its hepatoprotective effect.Recent studies have raised concerns about potential herb-drug interactions associated with Gancao via pregnane X receptor(PXR)-mediated induction of hepatic cytochrome P4503A4(CYP3A4).The current work aimed to determine the phytochemicals in Gancao that activate PXR and induce CYP3A4.Methods:DPX2 cells were used for cell-based PXR reporter assays.The phytochemicals in Gancao extract were identified using a metabolomics approach.The effects of PXR activators identified from in vitro studies were further investigated in PXR-and CYP3A4-humanized mouse models.Results:Gancao was verified to be a PXR-activating herb.Two major phytochemicals in Gancao,gly-cyrrhizin(GZ)and glycyrrhetinic acid(GA),did not activate PXR in the cell-based reporter assays.However,glabridin was shown to activate PXR in a dose-dependent manner.In vivo studies confirmed that GZ is not a PXR activator and glabridin is a weak PXR activator.Although GA did not active PXR in vitro,it induced CYP3A4 expression in a PXR-dependent manner in the PXR-and CYP3A4-humanized mice.展开更多
The pregnane X receptor(PXR)is a ligand activated nuclear receptor that is highly expressed in the liver and regulates many cellular functions including drug metabolism,endobiotic metabolism,oxidative stress response,...The pregnane X receptor(PXR)is a ligand activated nuclear receptor that is highly expressed in the liver and regulates many cellular functions including drug metabolism,endobiotic metabolism,oxidative stress response,apoptosis,inflammation,cell proliferation and regeneration.PXR activation promotes drug-induced liver injury(DILI)through its ability to increase the expression of phaseⅠand phaseⅡdrug metabolizing enzymes.The PXR also increases lipid synthesis and fatty acid uptake into the liver,leading to lipid accumulation and steatosis.In recent years,PXR has been explored as an important target in DILI and liver diseases.This review will highlight the roles of PXR in modulating DILI.PXR polymorphisms that have been associated with DILI will also be discussed.展开更多
孕烷受体(pregnane X receptor,PXR)是核受体亚家族的成员之一,是机体内环境稳态调节的重要环节,对多种基因的表达起着调节作用。CYP3A是生物体内化学物代谢的关键酶,孕烷X受体(PXR)是CYP3A基因表达的转录活化因子。PXR分子结构的不同导...孕烷受体(pregnane X receptor,PXR)是核受体亚家族的成员之一,是机体内环境稳态调节的重要环节,对多种基因的表达起着调节作用。CYP3A是生物体内化学物代谢的关键酶,孕烷X受体(PXR)是CYP3A基因表达的转录活化因子。PXR分子结构的不同导致CYP3A的种属差异。化学物通过PXR调节CYP3A的表达可能是影响化学物体内代谢的一条重要途径。由于PXR在机体适应环境中的重要作用,它已成为药理学、生理学等学科研究的热点。本文对PXR的基因结构和功能、对代谢酶和转运体及其它基因的调节、及其重要作用等研究进展作一简单综述。展开更多
目的建立基于人孕烷X受体(human pregnane X receptor,hPXR)的UGT1A1的报告基因模型,研究中药提取物通过人孕烷X受体途径对UGT1A1的潜在诱导能力。方法以人基因组DNA为模板扩增UGT1A1的远端和近端启动子,连接到pGL3载体上,构建pGL3-PXR...目的建立基于人孕烷X受体(human pregnane X receptor,hPXR)的UGT1A1的报告基因模型,研究中药提取物通过人孕烷X受体途径对UGT1A1的潜在诱导能力。方法以人基因组DNA为模板扩增UGT1A1的远端和近端启动子,连接到pGL3载体上,构建pGL3-PXRE重组质粒,并与人孕烷X受体表达质粒共转染HepG2细胞,从而建立报告基因模型。运用该模型考察了9种常见中药对人孕烷X受体的激活作用,即对UGT1A1的潜在诱导作用。结果将UGT1A1启动子片段克隆到pGL3载体上,构建了pGL3-PXRE重组质粒,成功构建了报告基因模型,并考察了多种常见中药的提取物通过人孕烷X受体途径对UGT1A1的诱导作用。结论成功地建立了基于人孕烷X受体的UGT1A1的报告基因模型,为人孕烷X受体激活剂的体外筛选提供了一种有效的方法。展开更多
文摘孕烷X受体(Pregnane X receptor,PXR)是核受体超家族(NRs)中NR1I的重要成员之一,在保护机体免于内源性和外源性物质损伤方面具有重要作用。利用CRISPR/Cas9基因编辑技术建立PXR基因敲除的斑马鱼模型,为研究环境污染物的毒性机理及代谢过程提供基础模型。根据PXR基因序列,设计gRNA靶位点,体外转录合成gRNA。同时,将设计合成的gRNA与Cas9 mRNA通过显微注射转入斑马鱼受精卵,经孵化、筛选出有效的突变体,并逐代培养杂交筛选出PXR基因敲除突变体。结果表明利用CRISPR/Cas9基因编辑技术成功敲除PXR基因,经测序分析获得稳定的PXR(+4/+4)基因纯合体。
基金supported by grants from the Natural Science Research Project of Institution of Higher Education of Jiangsu Province(No.11KJB180006)National Natural Science Foundation of China(No.21277074 and No.81302458)
文摘The human pregnane X receptor（hPXR） plays a critical role in the metabolism, transport and clearance of xenobiotics in the liver and intestine. The hPXR can be activated by a structurally diverse of drugs to initiate clinically relevant drug-drug interactions. In this article, in silico investigation was performed on a structurally diverse set of drugs to identify critical structural features greatly related to their agonist activity towards h PXR. Heuristic method（HM）-Best Subset Modeling（BSM） and HM-Polynomial Neural Networks（PNN） were utilized to develop the linear and non-linear quantitative structure-activity relationship models. The applicability domain（AD） of the models was assessed by Williams plot. Statistically reliable models with good predictive power and explain were achieved（for HM-BSM, r^2=0.881, q^2_（LOO）=0.797, q^2_（EXT）=0.674; for HM-PNN, r^2=0.882, q^2_（LOO）=0.856, q^2_（EXT）=0.655）. The developed models indicated that molecular aromatic and electric property, molecular weight and complexity may govern agonist activity of a structurally diverse set of drugs to h PXR.
文摘孕烷X受体(pregnane X receptor,PXR)是机体对有毒物质适应性防卫机制的一个重要组成部分,PXR被大量的外源性和内源性化学物质激活,这些物质包括类固醇、抗生素、抗真菌的物质和胆汁酸等。PXR配体结合区域三维结构显示它具有一个特殊球形配体结合腔,这种结构允许PXR与广泛的疏水性化学物质结合。PXR与9-顺式维甲酸受体(9-cisretinoic aid receptor,RXR)以异型二聚体的形式与细胞色素氧化酶P450 3A家族和其他参与药物代谢的Ⅱ相药物代谢酶以及药物转运蛋白的DNA响应元件结合,通过外源物刺激诱导多个基因的表达。分析PXR的结构与功能对药物设计和筛选具有重要的应用价值。
文摘孕烷X受体(pregnane X receptor,PXR)是核受体超家族的成员之一,其本质是配体激活型转录因子。PXR高表达于肝脏和肠道,在肾脏和脑等器官也有表达。自发现以来,PXR就被公认为是外源物质和内源物质的感受器,在激活状态下,可以调节药物代谢酶、转运蛋白和其他代谢相关蛋白质的表达,从而起到解毒等作用。由于PXR高表达于肝脏和肠道,所以其在消化系统的功能被大量研究报道。近年来,随着PXR在越来越多的脑区被检测到,其在中枢神经系统中的生理和病生理功能被广泛关注。本文主要就PXR在中枢神经系统的表达谱、在血脑屏障中的功能,以及其与神经疾病和神经毒性的关系,与行为学的相关性等进行综述。上述内容一方面可指导临床合理用药,另一方面可拓展科研工作者新药研发的思路;同时,也为未来PXR在中枢神经系统中功能的进一步研究提供了理论基础和方法思路。
基金supported by the Science and Technology Development Foundation Key Project of Nanjing Medical University (09NJMUZ16)Natural Science Research Project of Institution of Higher Education of Jiangsu Province (11KJB180006)
文摘Polychlorinated biphenyls(PCBs) can antagonize human pregnane X receptor(hPXR) activation.Such chemicals could pose a serious threat to the reproductive and developmental ability of humans.The quantitative structure activity relationship(QSAR) provides a promising method for the estimation of PCBs' antagonistic activity.In this investigation,a QSAR model was developed by using heuristic method and best subset modeling(r2 = 0.873,q2LOO=0.742).The built model was validated externally by splitting the original data set into training and prediction sets.The results of the model derived are as follows:r2 = 0.907,q2LOO=0.709,r2pred=0.676,suggesting developed QSAR model had good robustness and predictive ability.The applicability domain(AD) of the model was assessed by Williams plot.The antagonistic activity(?logKi) of 108 PCBs,which are unavailable by experiment at present,was predicted within the applicability domain of the model.The critical structural features related to the activity of PCBs were identified.
基金This work was supported by the USA National Center for Com-plementary and Integrative Health Grant R21AT011088(to X.Ma)in part by Grant U54AT008909(to M.F.Paine)+1 种基金in part by the USA National Institute of Allergy and Infectious Diseases Grant R01AI131983(to X.Ma)National Institute of Diabetes and Digestive and Kidney Diseases Grant R01DK126875(to X.Ma).
文摘Background and aims:The herbal supplement Gancao,also known as licorice,belongs to the genus Glycyrrhiza and has been used worldwide for its hepatoprotective effect.Recent studies have raised concerns about potential herb-drug interactions associated with Gancao via pregnane X receptor(PXR)-mediated induction of hepatic cytochrome P4503A4(CYP3A4).The current work aimed to determine the phytochemicals in Gancao that activate PXR and induce CYP3A4.Methods:DPX2 cells were used for cell-based PXR reporter assays.The phytochemicals in Gancao extract were identified using a metabolomics approach.The effects of PXR activators identified from in vitro studies were further investigated in PXR-and CYP3A4-humanized mouse models.Results:Gancao was verified to be a PXR-activating herb.Two major phytochemicals in Gancao,gly-cyrrhizin(GZ)and glycyrrhetinic acid(GA),did not activate PXR in the cell-based reporter assays.However,glabridin was shown to activate PXR in a dose-dependent manner.In vivo studies confirmed that GZ is not a PXR activator and glabridin is a weak PXR activator.Although GA did not active PXR in vitro,it induced CYP3A4 expression in a PXR-dependent manner in the PXR-and CYP3A4-humanized mice.
基金This work was supported by the US National Institute of Allergy and Infectious Diseases(R01AI131983)in part by the National Institute of Diabetes and Digestive and Kidney Diseases(DK090305).
文摘The pregnane X receptor(PXR)is a ligand activated nuclear receptor that is highly expressed in the liver and regulates many cellular functions including drug metabolism,endobiotic metabolism,oxidative stress response,apoptosis,inflammation,cell proliferation and regeneration.PXR activation promotes drug-induced liver injury(DILI)through its ability to increase the expression of phaseⅠand phaseⅡdrug metabolizing enzymes.The PXR also increases lipid synthesis and fatty acid uptake into the liver,leading to lipid accumulation and steatosis.In recent years,PXR has been explored as an important target in DILI and liver diseases.This review will highlight the roles of PXR in modulating DILI.PXR polymorphisms that have been associated with DILI will also be discussed.
文摘孕烷受体(pregnane X receptor,PXR)是核受体亚家族的成员之一,是机体内环境稳态调节的重要环节,对多种基因的表达起着调节作用。CYP3A是生物体内化学物代谢的关键酶,孕烷X受体(PXR)是CYP3A基因表达的转录活化因子。PXR分子结构的不同导致CYP3A的种属差异。化学物通过PXR调节CYP3A的表达可能是影响化学物体内代谢的一条重要途径。由于PXR在机体适应环境中的重要作用,它已成为药理学、生理学等学科研究的热点。本文对PXR的基因结构和功能、对代谢酶和转运体及其它基因的调节、及其重要作用等研究进展作一简单综述。
文摘目的建立基于人孕烷X受体(human pregnane X receptor,hPXR)的UGT1A1的报告基因模型,研究中药提取物通过人孕烷X受体途径对UGT1A1的潜在诱导能力。方法以人基因组DNA为模板扩增UGT1A1的远端和近端启动子,连接到pGL3载体上,构建pGL3-PXRE重组质粒,并与人孕烷X受体表达质粒共转染HepG2细胞,从而建立报告基因模型。运用该模型考察了9种常见中药对人孕烷X受体的激活作用,即对UGT1A1的潜在诱导作用。结果将UGT1A1启动子片段克隆到pGL3载体上,构建了pGL3-PXRE重组质粒,成功构建了报告基因模型,并考察了多种常见中药的提取物通过人孕烷X受体途径对UGT1A1的诱导作用。结论成功地建立了基于人孕烷X受体的UGT1A1的报告基因模型,为人孕烷X受体激活剂的体外筛选提供了一种有效的方法。
