炎症反应过程中药物转运体调控的研究进展

炎症状态下机体对药物的处置过程会发生显著改变,众多药物代谢酶及转运体的表达和功能发生下调。研究表明机体在该状态下会释放一系列炎症细胞因子对药物代谢酶的表达和功能产生调控,而近年来的研究表明在炎症状态下药物转运体也受到这些细胞因子的调控,且部分转运体的调控呈现明显的种属差异性。进一步的机制研究表明,一些转录因子在调控的信号通路中发挥了重要的作用。本文对炎症状态下药物转运体的调控研究进展进行综述。     

microRNA对药物体内过程调控的研究进展

药物的体内过程需经一系列的生物转化和转运途径,依赖于药物代谢酶和转运体的参与。而个体对同一药物的代谢、转运能力存在差异,这一差异不能完全用药物基因组学解释。microRNA作为表观遗传修饰的一个重要方面,是对传统遗传学的强有力补充。人体内多种药物代谢酶和转运体均受到不同的microRNA调控,同一microRNA又可同时调控不同的代谢酶或(和)转运体,二者均提示microRNA极有可能实现较为广泛的宏观调控。该文分别从microRNA对药物代谢酶的调控、对药物转运体的调控以及同时调控代谢酶及转运体的microRNA三个方向综合分析,为研究药物个体差异提出一个极好的切入点,并为合理用药和个体化医疗提供理论基础。     

孕烷X受体介导的代谢酶和转运体转录调控及其在化疗药物耐药中的作用

孕烷X受体(PXR,NR1I2)是生物体内药物代谢酶和转运体基因表达的主要调控因子之一.近来研究发现,PXR介导的药物代谢酶和转运体的过表达,与化疗药物多药耐药的产生密切相关.鉴于PXR在药物代谢酶和转运体调控中的重要性和PXR转录调控的多样性,有必要对其导致的多药耐药形成机制进行更深入的研究.本文综述了PXR介导的代谢酶和转运体基因表达调控机制,及其引起化疗药物多药耐药的相关研究进展,为提高化疗药物敏感性、逆转化疗药物的多药耐药提供有效的治疗策略.     

转运体和代谢酶在胆汁淤积性肝损伤中的作用机制

胆汁淤积性肝损伤是临床常见的肝脏疾病,主要由体内胆汁酸平衡失调引起,其发病机制与胆汁酸转运体、合成酶和代谢酶的表达和功能变化直接相关。核受体通过调控胆汁酸转运体及代谢酶的表达,在胆汁淤积所致的肝损伤中发挥重要作用。对肝脏转运体和代谢酶在胆汁淤积性肝损伤中的作用及核受体对转运体和代谢酶的调控机制作一综述。     

慢性肾脏病对药物转运和代谢的影响

本文介绍了慢性肾脏病状态下,肾脏、肝脏及肠道中主要代谢酶和药物转运体介导药物转运和代谢的最新研究进展,以期为临床合理用药提供参考。肾脏疾病对肾脏、肝脏和肠道转运体及代谢酶均有一定的影响,是与肾脏本身器质性病变协同进展而表现出来的病理生理过程。在科研及临床实践中,有必要将肾脏疾病对其他器官的影响一并分析、综合考虑,以作出最客观最合理的判断。     

肾脏转运体和/或代谢酶介导药物排泄及药物相互作用的研究进展

肾脏是人体最重要的排泄器官。肾单元近端小管细胞具有多种药物转运体和代谢酶,在药物及其代谢物处置中发挥关键作用。近端小管细胞中主要转运体包括有机阴离子转运体、有机阳离子转运体、有机阳离子/肉毒碱转运体、多药及毒素外排转运蛋白、P-糖蛋白、乳腺癌耐药蛋白和多药耐药相关蛋白;主要代谢酶包括细胞色素P450酶,UDP-葡萄糖醛酸基转移酶、磺酸基转移酶、谷胱甘肽S-转移酶。肾脏转运体和/或代谢酶介导药物相互作用(DDIs)是临床关注的重要问题。肾脏转运体和代谢酶存在密切协作关系,在肾脏也存在多种相互作用现象(包括转运-转运相互作用,代谢-代谢相互作用和转运-代谢相互作用),其显著影响药物肾脏处置、临床疗效和肾毒性。本文系统阐述了这些相互作用对药物及其代谢物的肾脏排泄、药动学、DDIs和肾毒性的影响。今后需要进一步阐明肾脏转运-代谢相互作用机制,将有助于研究体内药物肾脏处置和DDIs,促进临床合理用药。     

MicroRNA对药物转运体调控作用的研究进展

MicroRNA作为一类单链非编码小分子RNA,通过与靶基因mRNA 3＇端非编码区（3＇-untranslated region,3＇-UTR）的互补结合来调节靶基因的表达,在生物发育、细胞分化、增殖和凋亡中发挥重要作用,与人类多种疾病如恶性肿瘤、糖尿病等的发生发展密切相关。MicroRNA表达的变化可影响药物代谢酶和转运体的表达,进而影响药物效应。目前有关药物代谢酶的研究较为深入,而对转运体的研究则相对较少。本文通过总结近几年国内外相关研究,从MicroRNA的作用机制及其对药物转运体的调控作用方面进行综述,以期为指导临床个体化用药提供理论依据。     

microRNA介导低氧对药物代谢酶和转运体的调控

低氧条件下机体的循环系统、神经系统、内分泌系统等的功能发生显著改变,这些变化影响药物在体内的吸收、分布、代谢和排泄.药物代谢酶和转运体是影响药物代谢的主要因素,微小RNA(microRNA,miRNA)除调控与药物代谢相关的基因如缺氧诱导因子、炎症因子、核受体等,还可直接作用于药物代谢酶和转运体,影响药物的体内代谢.本...     

肝脏转运体和代谢酶在化学性肝损伤中的作用

肝脏是机体重要的代谢和解毒器官。肝细胞膜上存在多种功能性膜蛋白即肝脏药物转运体,它的功能是介导许多内源性及外源性物质如药物摄取进入肝脏,在肝脏内经过一定的代谢转化,最终将其从肝脏排入胆汁。研究发现,转运体和代谢酶在化学性肝损伤的发展过程中发挥重要的作用,其涉及的多种调控机制成为研究热点。就肝脏转运体和代谢酶的分类、转运体和代谢酶在化学性肝损伤中的变化及其调控机制作一综述。     

高原缺氧对药物转运体影响的研究进展

高原具有的低氧、低气压等环境特点,会使机体产生一系列生理性变化,并影响药物的体内代谢过程。影响这个过程的因素有很多,包括胃排空、血液流变学、心肺功能、肝肾功能、药物代谢酶和药物转运体。其中,药物转运体是介导大部分药物透过细胞膜进入体内发挥药效的关键因素,研究缺氧对药物转运体的影响,对于明确药物的体内代谢过程具有重要的意义。因此,该文将从药物转运体的分类、介导的药物底物、缺氧对药物转运体表达的影响及缺氧条件下药物转运体的调控机制等方面进行综述,为深入研究高原缺氧对药物转运体的影响和药物代谢动力学参数变化提供理论依据。     

Regulation of drug metabolism and toxicity by multiple factors of genetics,epigenetics, lncRNAs,gut microbiota,and diseases: a meeting report of the 21st International Symposium on Microsomes and Drug Oxidations (MDO)

Variations in drug metabolism may alter drug efficacy and cause toxicity; better understanding of the mechanisms and risks shall help to practice precision medicine. At the 21^st International Symposium on Microsomes and Drug Oxidations held in Davis, California, USA, in October 2–6, 2016, a number of speakers reported some new findings and ongoing studies on the regulation mechanisms behind variable drug metabolism and toxicity, and discussed potential implications to personalized medications. A considerably insightful overview was provided on genetic and epigenetic regulation of gene expression involved in drug absorption, distribution, metabolism, and excretion (ADME) and drug response. Altered drug metabolism and disposition as well as molecular mechanisms among diseased and special populations were presented. In addition, the roles of gut microbiota in drug metabolism and toxicology as well as long non-coding RNAs in liver functions and diseases were discussed. These findings may offer new insights into improved understanding of ADME regulatory mechanisms and advance drug metabolism research.     

Ultrasensitive Quantification of Drug-metabolizing Enzymes and Transporters in Small Sample Volume by Microflow LC-MS/MS

Protein abundance data of drug-metabolizing enzymes and transporters (DMETs) are broadly applicable to the characterization of in vitro and in vivo models, in vitro to in vivo extrapolation (IVIVE), and interindividual variability prediction. However, the emerging need of DMET quantification in small sample volumes such as organ-on a chip effluent, organoids, and biopsies requires ultrasensitive protein quantification methods. We present an ultrasensitive method that relies on an optimized sample preparation approach involving acetone precipitation coupled with a microflow-based liquid chromatography-tandem mass spectrometry (µLC-MS/MS) for the DMET quantification using limited sample volume or protein concentration, i.e., liver tissues (1-100 mg), hepatocyte counts (~4000 to 1 million cells), and microsomal protein concentration (0.01-1 mg/ml). The method was applied to quantify DMETs in differential tissue S9 fractions (liver, intestine, kidney, lung, and heart) and cryopreserved human intestinal mucosa (i.e., CHIM). The method successfully quantified >75% of the target DMETs in the trypsin digests of 1 mg tissue homogenate, 15,000 hepatocytes, and 0.06 mg/ml microsomal protein concentration. The precision of DMET quantification measured as the coefficient of variation across different tissue weights, cell counts, or microsomal protein concentration was within 30%. The method confirmed significant extrahepatic abundance of non-cytochrome P450 enzymes such as dihydropyridine dehydrogenase (DPYD), epoxide hydrolases (EPXs), arylacetamide deacetylase (AADAC), paraoxonases (PONs), and glutathione S-transferases (GSTs). The ultrasensitive method developed here is applicable to characterize emerging miniaturized in vitro models and small volume biopsies. In addition, the differential tissue abundance data of the understudied DMETs will be important for physiologically-based pharmacokinetic (PBPK) modeling of drugs.     

Regulation of drug intake

Regulation of drug intake refers to the maintenance of relatively constant levels of drug over a specified time period. An understanding of regulation of drug intake may be critical in determining how drugs function as reinforcers and how their reinforcing effects may be modified. However, little is known about regulation of drug intake, and the mechanisms underlying it are poorly understood. Three mechanisms that have proposed to account for findings of regulation of drug intake were discussed to determine their relevance for drug-reinforced responding. These mechanisms include aversive effects, direct effects, and satiation. Although a greater role for satiation was supported in this review, drugs may vary on the degree to which they can produce satiation and whether satiation acts in concert with either the aversive effects or the direct effects of drugs is unclear.     

耐万古霉素肠球菌的耐药机制及耐药基因调控的研究进展

耐万古霉素肠球菌现已成为重要的医院感染病原菌,其对万古霉素耐药方式分为获得性耐药和先天性耐药,其中获得性耐药的类型包括VanA、VanB、VanD、VanG和VanE,先天性耐药的类型有VanC1／C2／C3。本文针对耐万古霉素肠球菌的耐药机制及其耐药基因的调控进行综述,以供参考。     

miRNA对药物成瘾行为的调控

目的介绍miRNA调控药物成瘾行为的研究进展。方法对最近关于基因表达转录后调控机制对成瘾行为的影响的研究进展作出归纳和总结。结果药物能诱导miRNA表达水平的变化,而成瘾相关脑区中miRNA表达的改变则参与了对成瘾行为的调节。结论 miRNA调控药物成瘾行为的研究对于揭示药物滥用等精神疾病的病理机制、治疗慢性药物依赖具有重大意义。     

Novel advances in cytochrome P450 research

The cytochrome P450 (CYP) enzymes, involved in the metabolism of therapeutic drugs, are the major determinants of drug half-life. From a drug industry perspective, variability in drug response owing to CYP polymorphisms makes CYP profiling a commercially interesting option for diagnosis, prognosis and predicting response to drug treatment. Recent studies highlighting microRNA-mediated regulation of CYP genes represents a major advance in our understanding of variations in individual drug responses. Herein we review new perspectives on the molecular mechanisms of CYP regulation and genotyping technologies. Together, these developments present novel therapeutic opportunities and help to explain the integrated response of cells to xenobiotic drug metabolism.     

Drug resistance in Giardia: clinical versus laboratory isolates.

The advantages and limitations of determining mechanisms of drug resistance in Giardia duodenalis laboratory isolates, which have been generated in a number of ways, is weighed against the difficulty of analysing mechanisms in clinical isolates with a large diversity of genetic and expression capabilities. Using isogenic strains to follow changes in enzyme regulation involved in drug resistance, we have been able to assess the full capability of the parasite in developing drug resistance mechanisms. The complementarity of the two approaches, clinical versus laboratory induced drug resistance, and continuing comparison with other organisms, particularly the anaerobic bacteria with which Giardia has strong affiliations, is emphasized. These considerations lead to the study of the population genetics of drug resistance, and strategies critical for rational drug usage, design and therapy.