Article
Refine
Year of publication
Institute
- Fachbereich Chemie und Biotechnologie (472) (remove)
Language
- English (472) (remove)
Document Type
- Article (472) (remove)
Keywords
- Heparin (3)
- Bacillaceae (2)
- Biotechnological application (2)
- Butanol (2)
- Chemometrics (2)
- IR spectroscopy (2)
- NMR spectroscopy (2)
- Principal component analysis (2)
- Standardization (2)
- Subtilases (2)
- Subtilisin (2)
- bubble column (2)
- methanation (2)
- plug flow reactor (2)
- qNMR (2)
- (Poly)saccharides (1)
- ABE (1)
- Acid crash (1)
- Algal Turf Scrubber (1)
- Algal–bacterial bioflm (1)
- Alginate beads (1)
- Alkalihalobacillus okhensis (1)
- Aloe vera (1)
- Authenticity (1)
- Biofuel (1)
- Biogas (1)
- Biological hydrogen (1)
- Biomass (1)
- Biorefinery (1)
- Bragg peak (1)
- Broad pH spectrum (1)
- C. acetobutylicum (1)
- CRISPR/Cas9 (1)
- Carrier solvents (1)
- Chondroitin sulfate (1)
- Circular bioeconomy (1)
- Clostridium acetobutylicum (1)
- Crude heparin (1)
- Cyclotron production (1)
- Dark fermentation (1)
- Dehydrogenase (1)
- Detergent protease (1)
- Deuterated solvents (1)
- Deuterium NMR (1)
- Diaphorase (1)
- Dietary supplements (1)
- Electronic cigarettes (1)
- Enzymatic biosensor (1)
- Extracellular enzymes (1)
- Free-base nicotine (1)
- Ga-68 (1)
- Glucosamine (1)
- Halotolerant protease (1)
- High-field NMR (1)
- Hydrolysis (1)
- Hypersecretion (1)
- IR (1)
- Inorganic ions (1)
- Ions (1)
- Lignocellulose (1)
- Linear discriminant analysis (1)
- Low field NMR (1)
- Manufacturer (1)
- Marker-free mutagenesis (1)
- Medical radionuclide production (1)
- Metabolic shift (1)
- Metal contaminants (1)
- Methane (1)
- Microfluidic solvent extraction (1)
- Molecular modelling (1)
- Molecular weight determination (1)
- NMR (1)
- Organic acids (1)
- Organic waste (1)
- P2G (1)
- PLS-regression (1)
- Polysaccharides (1)
- Pre-culture (1)
- Pretreatment (1)
- Quality control (1)
- Quantum chemistry (1)
- Simultaneous determination (1)
- Soft independent modeling of class analogy (1)
- Spectroscopy (1)
- Stenotrophomonas maltophilia (1)
- Streptomyces griseus (1)
- Streptomyces lividans (1)
- USP (1)
- Uracil-phosphoribosyltransferase (1)
- Weak organic acids (1)
- acetoin (1)
- acetoin reductase (1)
- actuator-sensor system (1)
- alcoholic beverages (1)
- aspergillus (1)
- bacterial cellulose (1)
- bi-enzyme biosensor (1)
- bio-methane (1)
- bioavailability (1)
- biodegradable polymers (1)
- biological dosimeter (1)
- biomethane (1)
- biosensors (1)
- borehole disposal (1)
- capacitive field-effect sensor (1)
- capacitive field-effect sensors (1)
- coculture (1)
- deficit irrigation (1)
- detergent protease (1)
- disposal facility (1)
- drug metabolising enzymes (1)
- drug–drug interactions (1)
- elastomers (1)
- enzyme kinetics (1)
- enzyme-logic gate (1)
- exopolysaccharides (1)
- filamentous fungi (1)
- genome engineering (1)
- geological disposal (1)
- glycine (1)
- halotolerant protease (1)
- high-alkaline subtilisin (1)
- human metabolites (1)
- hydrogel (1)
- hydrogels (1)
- light-addressable electrode (1)
- light-addressable potentiometric sensor (1)
- mechanical properties (1)
- microfluidics (1)
- micronutrients (1)
- neutrons (1)
- nuclear waste (1)
- onion (1)
- optical fibers (1)
- oxidative stable protease (1)
- penicillinase (1)
- polyaspartic acid (1)
- power-to-gas (1)
- prebiotic (1)
- proton therapy (1)
- protons (1)
- pullulan (1)
- recombinant expression (1)
- relative dosimetry (1)
- retention time (1)
- rubber (1)
- superabsorbent polymers (1)
- supramolecular structures (1)
- swelling properties (1)
- theory and modeling (1)
- tobacco mosaic virus (TMV) (1)
- transporters (1)
- urease (1)
- water economy (1)
- yield (1)
- α-aminoacylase (1)
- ε-lysine acylase (1)
Breast cancer resistance protein (BCRP) is expressed in various tissues, such as the gut, liver, kidney and blood brain barrier (BBB), where it mediates the unidirectional transport of substrates to the apical/luminal side of polarized cells. Thereby BCRP acts as an efflux pump, mediating the elimination or restricting the entry of endogenous compounds or xenobiotics into tissues and it plays important roles in drug disposition, efficacy and safety. Bcrp knockout mice (Bcrp−/−) have been used widely to study the role of this transporter in limiting intestinal absorption and brain penetration of substrate compounds. Here we describe the first generation and characterization of a mouse line humanized for BCRP (hBCRP), in which the mouse coding sequence from the start to stop codon was replaced with the corresponding human genomic region, such that the human transporter is expressed under control of the murine Bcrp promoter. We demonstrate robust human and loss of mouse BCRP/Bcrp mRNA and protein expression in the hBCRP mice and the absence of major compensatory changes in the expression of other genes involved in drug metabolism and disposition. Pharmacokinetic and brain distribution studies with several BCRP probe substrates confirmed the functional activity of the human transporter in these mice. Furthermore, we provide practical examples for the use of hBCRP mice to study drug-drug interactions (DDIs). The hBCRP mouse is a promising model to study the in vivo role of human BCRP in limiting absorption and BBB penetration of substrate compounds and to investigate clinically relevant DDIs involving BCRP.
Generation and Characterization of a Novel Multidrug Resistance Protein 2 Humanized Mouse Line
(2012)
The multidrug resistance protein (MRP) 2 is predominantly expressed in liver, intestine, and kidney, where it plays an important role in the excretion of a range of drugs and their metabolites or endogenous compounds into bile, feces, and urine. Mrp knockout [Mrp2(−/−)] mice have been used recently to study the role of MRP2 in drug disposition. Here, we describe the first generation and initial characterization of a mouse line humanized for MRP2 (huMRP2), which is nulled for the mouse Mrp2 gene and expresses the human transporter in the organs and cell types where MRP2 is normally expressed. Analysis of the mRNA expression for selected cytochrome P450 and transporter genes revealed no major changes in huMRP2 mice compared with wild-type controls. We show that human MRP2 is able to compensate functionally for the loss of the mouse transporter as demonstrated by comparable bilirubin levels in the humanized mice and wild-type controls, in contrast to the hyperbilirubinemia phenotype that is observed in MRP2(−/−) mice. The huMRP2 mouse provides a model to study the role of the human transporter in drug disposition and in assessing the in vivo consequences of inhibiting this transporter by compounds interacting with human MRP2.
Compared with rodents and many other animal species, the human cytochrome P450 (P450) Cyp2c gene cluster varies significantly in the multiplicity of functional genes and in the substrate specificity of its enzymes. As a consequence, the use of wild-type animal models to predict the role of human CYP2C enzymes in drug metabolism and drug-drug interactions is limited. Within the human CYP2C cluster CYP2C9 is of particular importance, because it is one of the most abundant P450 enzymes in human liver, and it is involved in the metabolism of a wide variety of important drugs and environmental chemicals. To investigate the in vivo functions of cytochrome P450 Cyp2c genes and to establish a model for studying the functions of CYP2C9 in vivo, we have generated a mouse model with a deletion of the murine Cyp2c gene cluster and a corresponding humanized model expressing CYP2C9 specifically in the liver. Despite the high number of functional genes in the mouse Cyp2c cluster and the reported roles of some of these proteins in different biological processes, mice deleted for Cyp2c genes were viable and fertile but showed certain phenotypic alterations in the liver. The expression of CYP2C9 in the liver also resulted in viable animals active in the metabolism and disposition of a number of CYP2C9 substrates. These mouse lines provide a powerful tool for studying the role of Cyp2c genes and of CYP2C9 in particular in drug disposition and as a factor in drug-drug interaction.
Disruption experiments targeted at the Bacillus licheniformis degSU operon and GFP-reporter analysis provided evidence for promoter activity immediately upstream of degU. pMutin mediated concomitant introduction of the degU32 allele – known to cause hypersecretion in Bacillus subtilis – resulted in a marked increase in protease activity. Application of 5-fluorouracil based counterselection through establishment of a phosphoribosyltransferase deficient Δupp strain eventually facilitated the marker-free introduction of degU32 leading to further protease enhancement achieving levels as for hypersecreting wild strains in which degU was overexpressed. Surprisingly, deletion of rapG – known to interfere with DegU DNA-binding in B. subtilis – did not enhance protease production neither in the wild type nor in the degU32 strain. The combination of degU32 and Δupp counterselection in the type strain is not only equally effective as in hypersecreting wild strains with respect to protease production but furthermore facilitates genetic strain improvement aiming at biological containment and effectiveness of biotechnological processes.
1. Drug metabolizing enzymes and transporters play important roles in the absorption, metabolism, tissue distribution and excretion of various compounds and their metabolites and thus can significantly affect their efficacy and safety. Furthermore, they can be involved in drug–drug interactions which can result in adverse responses, life-threatening toxicity or impaired efficacy. Significant species differences in the interaction of compounds with drug metabolizing enzymes and transporters have been described.
2. In order to overcome the limitation of animal models in accurately predicting human responses, a large variety of mouse models humanized for drug metabolizing enzymes and to a lesser extent drug transporters have been created.
3. This review summarizes the literature describing these mouse models and their key applications in studying the role of drug metabolizing enzymes and transporters in drug bioavailability, tissue distribution, clearance and drug–drug interactions as well as in human metabolite testing and risk assessment.
4. Though such humanized mouse models have certain limitations, there is great potential for their use in basic research and for testing and development of new medicines. These limitations and future potentials will be discussed.