TY - JOUR A1 - Infantino, Angelo A1 - Paulßen, Elisabeth A1 - Mostacci, Domiziano A1 - Schaffer, Paul A1 - Trinczek, Michael A1 - Hoehr, Cornelia T1 - Assessment of the production of medical isotopes using the Monte Carlo code FLUKA: Simulations against experimental measurements JF - Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms N2 - The Monte Carlo code FLUKA is used to simulate the production of a number of positron emitting radionuclides, ¹⁸F, ¹³N, ⁹⁴Tc, ⁴⁴Sc, ⁶⁸Ga, ⁸⁶Y, ⁸⁹Zr, ⁵²Mn, ⁶¹Cu and ⁵⁵Co, on a small medical cyclotron with a proton beam energy of 13 MeV. Experimental data collected at the TR13 cyclotron at TRIUMF agree within a factor of 0.6 ± 0.4 with the directly simulated data, except for the production of ⁵⁵Co, where the simulation underestimates the experiment by a factor of 3.4 ± 0.4. The experimental data also agree within a factor of 0.8 ± 0.6 with the convolution of simulated proton fluence and cross sections from literature. Overall, this confirms the applicability of FLUKA to simulate radionuclide production at 13 MeV proton beam energy. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.nimb.2015.10.067 SN - 1872-9584 VL - 366 SP - 117 EP - 123 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Liu, Z. A1 - Schaap, K. S. A1 - Ballemans, L. A1 - de Blois, E. A1 - Rohde, M. A1 - Paulßen, Elisabeth T1 - Measurement of reaction kinetics of [177Lu]Lu-DOTA-TATE using a microfluidic system JF - Dalton Transactions Y1 - 2017 U6 - http://dx.doi.org/10.1039/C7DT01830D SN - 1477-9234 VL - 46 IS - 42 SP - 14669 EP - 14676 ER - TY - JOUR A1 - Druckenmüller, Katharina A1 - Günther, Klaus A1 - Elbers, Gereon T1 - Near-infrared spectroscopy (NIRS) as a tool to monitor exhaust air from poultry operations JF - Science of the Total Environment N2 - Intensive poultry operation systems emit a considerable volume of inorganic and organic matter in the surrounding environment. Monitoring cleaning properties of exhaust air cleaning systems and to detect small but significant changes in emission characteristics during a fattening cycle is important for both emission and fattening process control. In the present study, we evaluated the potential of near-infrared spectroscopy (NIRS) combined with chemometric techniques as a monitoring tool of exhaust air from poultry operation systems. To generate a high-quality data set for evaluation, the exhaust air of two poultry houses was sampled by applying state-of-the-art filter sampling protocols. The two stables were identical except for one crucial difference, the presence or absence of an exhaust air cleaning system. In total, twenty-one exhaust air samples were collected at the two sites to monitor spectral differences caused by the cleaning device, and to follow changes in exhaust air characteristics during a fattening period. The total dust load was analyzed by gravimetric determination and included as a response variable in multivariate data analysis. The filter samples were directly measured with NIR spectroscopy. Principal component analysis (PCA), linear discriminant analysis (LDA), and factor analysis (FA) were effective in classifying the NIR exhaust air spectra according to fattening day and origin. The results indicate that the dust load and the composition of exhaust air (inorganic or organic matter) substantially influence the NIR spectral patterns. In conclusion, NIR spectroscopy as a tool is a promising and very rapid way to detect differences between exhaust air samples based on still not clearly defined circumstances triggered during a fattening period and the availability of an exhaust air cleaning system. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.scitotenv.2018.02.072 SN - 0048-9697 VL - 630 SP - 536 EP - 543 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Molinnus, Denise A1 - Muschallik, Lukas A1 - Gonzalez, Laura Osorio A1 - Bongaerts, Johannes A1 - Wagner, Torsten A1 - Selmer, Thorsten A1 - Siegert, Petra A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Development and characterization of a field-effect biosensor for the detection of acetoin JF - Biosensors and Bioelectronics N2 - A capacitive electrolyte-insulator-semiconductor (EIS) field-effect biosensor for acetoin detection has been presented for the first time. The EIS sensor consists of a layer structure of Al/p-Si/SiO₂/Ta₂O₅/enzyme acetoin reductase. The enzyme, also referred to as butane-2,3-diol dehydrogenase from B. clausii DSM 8716T, has been recently characterized. The enzyme catalyzes the (R)-specific reduction of racemic acetoin to (R,R)- and meso-butane-2,3-diol, respectively. Two different enzyme immobilization strategies (cross-linking by using glutaraldehyde and adsorption) have been studied. Typical biosensor parameters such as optimal pH working range, sensitivity, hysteresis, linear concentration range and long-term stability have been examined by means of constant-capacitance (ConCap) mode measurements. Furthermore, preliminary experiments have been successfully carried out for the detection of acetoin in diluted white wine samples. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.bios.2018.05.023 VL - 115 SP - 1 EP - 6 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pilas, Johanna A1 - Yazici, Y. A1 - Selmer, Thorsten A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Application of a portable multi-analyte biosensor for organic acid determination in silage JF - Sensors N2 - Multi-analyte biosensors may offer the opportunity to perform cost-effective and rapid analysis with reduced sample volume, as compared to electrochemical biosensing of each analyte individually. This work describes the development of an enzyme-based biosensor system for multi-parametric determination of four different organic acids. The biosensor array comprises five working electrodes for simultaneous sensing of ethanol, formate, d-lactate, and l-lactate, and an integrated counter electrode. Storage stability of the biosensor was evaluated under different conditions (stored at +4 °C in buffer solution and dry at −21 °C, +4 °C, and room temperature) over a period of 140 days. After repeated and regular application, the individual sensing electrodes exhibited the best stability when stored at −21 °C. Furthermore, measurements in silage samples (maize and sugarcane silage) were conducted with the portable biosensor system. Comparison with a conventional photometric technique demonstrated successful employment for rapid monitoring of complex media. Y1 - 2018 U6 - http://dx.doi.org/10.3390/s18051470 SN - 1424-8220 VL - 18 IS - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Aboulnaga, E. A. A1 - Zou, H. A1 - Selmer, Thorsten A1 - Xian, M. T1 - Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16 JF - Journal of Biotechnology N2 - Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.jbiotec.2018.03.007 SN - 0168-1656 VL - 274 SP - 15 EP - 27 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Teumer, T. A1 - Capitain, C. A1 - Ross-Jones, J. A1 - Tippkötter, Nils A1 - Rädle, M. A1 - Methner, F.-J. T1 - In-line Haze Monitoring Using a Spectrally Resolved Back Scattering Sensor JF - BrewingScience N2 - In the present work an optical sensor in combination with a spectrally resolved detection device for in-line particle-size-monitoring for quality control in beer production is presented. The principle relies on the size and wavelength dependent backscatter of growing particles in fluids. Measured interference structures of backscattered light are compared with calculated theoretical values, based on Mie-Theory, and fitted with a linear least square method to obtain particle size distributions. For this purpose, a broadband light source in combination with a process-CCD-spectrometer (charge ? coupled device spectrometer) and process adapted fiber optics are used. The goal is the development of an easy and flexible measurement device for in-line-monitoring of particle size. The presented device can be directly installed in product fill tubes or vessels, follows CIP- (cleaning in place) and removes the need of sample taking. A proof of concept and preliminary results, measuring protein precipitation, are presented. Y1 - 2018 SN - 1613-2041 VL - 71 IS - 5/6 SP - 49 EP - 55 PB - Fachverlag Hans Carl CY - Nürnberg ER - TY - JOUR A1 - Eckert, Alexander A1 - Rudolph, Tobias A1 - Guo, Jiaqi A1 - Mang, Thomas A1 - Walther, Andreas T1 - Exceptionally Ductile and Tough Biomimetic Artificial Nacre with Gas Barrier Function JF - Advanced Materials N2 - Synthetic mimics of natural high-performance structural materials have shown great and partly unforeseen opportunities for the design of multifunctional materials. For nacre-mimetic nanocomposites, it has remained extraordinarily challenging to make ductile materials with high stretchability at high fractions of reinforcements, which is however of crucial importance for flexible barrier materials. Here, highly ductile and tough nacre-mimetic nanocomposites are presented, by implementing weak, but many hydrogen bonds in a ternary nacre-mimetic system consisting of two polymers (poly(vinyl amine) and poly(vinyl alcohol)) and natural nanoclay (montmorillonite) to provide efficient energy dissipation and slippage at high nanoclay content (50 wt%). Tailored interactions enable exceptional combinations of ductility (close to 50% strain) and toughness (up to 27.5 MJ m⁻³). Extensive stress whitening, a clear sign of high internal dynamics at high internal cohesion, can be observed during mechanical deformation, and the materials can be folded like paper into origami planes without fracture. Overall, the new levels of ductility and toughness are unprecedented in highly reinforced bioinspired nanocomposites and are of critical importance to future applications, e.g., as barrier materials needed for encapsulation and as a printing substrate for flexible organic electronics. Y1 - 2018 U6 - http://dx.doi.org/10.1002/adma.201802477 VL - 30 IS - 32 SP - Article number 1802477 PB - Wiley-VCH ER - TY - JOUR A1 - Müller, Janina A1 - Beckers, Mario A1 - Mußmann, Nina A1 - Bongaerts, Johannes A1 - Büchs, Jochen T1 - Elucidation of auxotrophic deficiencies of Bacillus pumilus DSM 18097 to develop a defined minimal medium JF - Microbial Cell Factories N2 - Background Culture media containing complex compounds like yeast extract or peptone show numerous disadvantages. The chemical composition of the complex compounds is prone to significant variations from batch to batch and quality control is difficult. Therefore, the use of chemically defined media receives more and more attention in commercial fermentations. This concept results in better reproducibility, it simplifies downstream processing of secreted products and enable rapid scale-up. Culturing bacteria with unknown auxotrophies in chemically defined media is challenging and often not possible without an extensive trial-and-error approach. In this study, a respiration activity monitoring system for shake flasks and its recent version for microtiter plates were used to clarify unknown auxotrophic deficiencies in the model organism Bacillus pumilus DSM 18097. Results Bacillus pumilus DSM 18097 was unable to grow in a mineral medium without the addition of complex compounds. Therefore, a rich chemically defined minimal medium was tested containing basically all vitamins, amino acids and nucleobases, which are essential ingredients of complex components. The strain was successfully cultivated in this medium. By monitoring of the respiration activity, nutrients were supplemented to and omitted from the rich chemically defined medium in a rational way, thus enabling a systematic and fast determination of the auxotrophic deficiencies. Experiments have shown that the investigated strain requires amino acids, especially cysteine or histidine and the vitamin biotin for growth. Conclusions The introduced method allows an efficient and rapid identification of unknown auxotrophic deficiencies and can be used to develop a simple chemically defined tailor-made medium. B. pumilus DSM 18097 was chosen as a model organism to demonstrate the method. However, the method is generally suitable for a wide range of microorganisms. By combining a systematic combinatorial approach based on monitoring the respiration activity with cultivation in microtiter plates, high throughput experiments with high information content can be conducted. This approach facilitates media development, strain characterization and cultivation of fastidious microorganisms in chemically defined minimal media while simultaneously reducing the experimental effort. Y1 - 2018 U6 - http://dx.doi.org/10.1186/s12934-018-0956-1 SN - 1475-2859 VL - 17 IS - 1 SP - Article No. 106 PB - BioMed Central ER - TY - JOUR A1 - Röhlen, Desiree A1 - Pilas, Johanna A1 - Dahmen, Markus A1 - Keusgen, Michael A1 - Selmer, Thorsten A1 - Schöning, Michael Josef T1 - Toward a Hybrid Biosensor System for Analysis of Organic and Volatile Fatty Acids in Fermentation Processes JF - Frontiers in Chemistry N2 - Monitoring of organic acids (OA) and volatile fatty acids (VFA) is crucial for the control of anaerobic digestion. In case of unstable process conditions, an accumulation of these intermediates occurs. In the present work, two different enzyme-based biosensor arrays are combined and presented for facile electrochemical determination of several process-relevant analytes. Each biosensor utilizes a platinum sensor chip (14 × 14 mm²) with five individual working electrodes. The OA biosensor enables simultaneous measurement of ethanol, formate, d- and l-lactate, based on a bi-enzymatic detection principle. The second VFA biosensor provides an amperometric platform for quantification of acetate and propionate, mediated by oxidation of hydrogen peroxide. The cross-sensitivity of both biosensors toward potential interferents, typically present in fermentation samples, was investigated. The potential for practical application in complex media was successfully demonstrated in spiked sludge samples collected from three different biogas plants. Thereby, the results obtained by both of the biosensors were in good agreement to the applied reference measurements by photometry and gas chromatography, respectively. The proposed hybrid biosensor system was also used for long-term monitoring of a lab-scale biogas reactor (0.01 m³) for a period of 2 months. In combination with typically monitored parameters, such as gas quality, pH and FOS/TAC (volatile organic acids/total anorganic carbonate), the amperometric measurements of OA and VFA concentration could enhance the understanding of ongoing fermentation processes. Y1 - 2018 U6 - http://dx.doi.org/10.3389/fchem.2018.00284 IS - 6 PB - Frontiers CY - Lausanne ER - TY - JOUR A1 - Engel, Mareike A1 - Holtmann, Dirk A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - Increased Biobutanol Production by Mediator‐Less Electro‐Fermentation JF - Biotechnology Journal N2 - A future bio-economy should not only be based on renewable raw materials but also in the raise of carbon yields of existing production routes. Microbial electrochemical technologies are gaining increased attention for this purpose. In this study, the electro-fermentative production of biobutanol with C. acetobutylicum without the use of exogenous mediators is investigated regarding the medium composition and the reactor design. It is shown that the use of an optimized synthetic culture medium allows higher product concentrations, increased biofilm formation, and higher conductivities compared to a synthetic medium supplemented with yeast extract. Moreover, the optimization of the reactor system results in a doubling of the maximum product concentrations for fermentation products. When a working electrode is polarized at −600 mV vs. Ag/AgCl, a shift from butyrate to acetone and butanol production is induced. This leads to an increased final solvent yield of Yᴀᴃᴇ = 0.202 gg⁻¹ (control 0.103 gg⁻¹), which is also reflected in a higher carbon efficiency of 37.6% compared to 23.3% (control) as well as a fourfold decrease in simplified E-factor to 0.43. The results are promising for further development of biobutanol production in bioelectrochemical systems in order to fulfil the principles of Green Chemistry. Y1 - 2018 U6 - http://dx.doi.org/10.1002/biot.201800514 SN - 1860-7314 IS - Volume 14, Issue 4 SP - Artikel 1800514 PB - Wiley-VCH ER - TY - JOUR A1 - Wilson, C. E. A1 - Dickie, A. P. A1 - Schreiter, K. A1 - Wehr, R. A1 - Wilson, E. M. A1 - Bial, J. A1 - Scheer, Nico A1 - Wilson, I. D. A1 - Riley, R. J. T1 - The pharmacokinetics and metabolism of diclofenac in chimeric humanized and murinized FRG mice JF - Archives of Toxicology N2 - The pharmacokinetics of diclofenac were investigated following single oral doses of 10 mg/kg to chimeric liver humanized and murinized FRG and C57BL/6 mice. In addition, the metabolism and excretion were investigated in chimeric liver humanized and murinized FRG mice. Diclofenac reached maximum blood concentrations of 2.43 ± 0.9 µg/mL (n = 3) at 0.25 h post-dose with an AUCinf of 3.67 µg h/mL and an effective half-life of 0.86 h (n = 2). In the murinized animals, maximum blood concentrations were determined as 3.86 ± 2.31 µg/mL at 0.25 h post-dose with an AUCinf of 4.94 ± 2.93 µg h/mL and a half-life of 0.52 ± 0.03 h (n = 3). In C57BL/6J mice, mean peak blood concentrations of 2.31 ± 0.53 µg/mL were seen 0.25 h post-dose with a mean AUCinf of 2.10 ± 0.49 µg h/mL and a half-life of 0.51 ± 0.49 h (n = 3). Analysis of blood indicated only trace quantities of drug-related material in chimeric humanized and murinized FRG mice. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles in humanized mice were different to those of both murinized and wild-type animals, e.g., a higher proportion of the dose was detected in the form of acyl glucuronide metabolites and much reduced amounts as taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57BL/6J mice and humans revealed a greater, though not complete, match between chimeric humanized mice and humans, such that the liver humanized FRG model may represent a model for assessing the biotransformation of such compounds in humans. Y1 - 2018 U6 - http://dx.doi.org/10.1007/s00204-018-2212-1 SN - 1432-0738 VL - 92 IS - 6 SP - 1953 EP - 1967 PB - Springer ER - TY - JOUR A1 - Wilson, Ian D. A1 - Wilson, Claire E. A1 - Scheer, Nico A1 - Dickie, A.P. A1 - Schreiter, K. A1 - Wilson, E. M. A1 - Riley, R. J. A1 - Wehr, R. A1 - Bial, J. T1 - The Pharmacokinetics and Metabolism of Lumiracoxib in Chimeric Humanized and Murinized FRG Mice JF - Biochemical pharmacology Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.bcp.2017.03.015 SN - 1873-2968 VL - Volume 135 SP - 139 EP - 150 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Zhang, Jin A1 - Heimbach, Tycho A1 - Scheer, Nico A1 - Barve, Avantika A1 - Li, Wenkui A1 - Lin, Wen A1 - He, Handan T1 - Clinical Exposure Boost Predictions by Integrating Cytochrome P450 3A4–Humanized Mouse Studies With PBPK Modeling JF - Journal of Pharmaceutical Sciences N2 - NVS123 is a poorly water-soluble protease 56 inhibitor in clinical development. Data from in vitro hepatocyte studies suggested that NVS123 is mainly metabolized by CYP3A4. As a consequence of limited solubility, NVS123 therapeutic plasma exposures could not be achieved even with high doses and optimized formulations. One approach to overcome NVS123 developability issues was to increase plasma exposure by coadministrating it with an inhibitor of CYP3A4 such as ritonavir. A clinical boost effect was predicted by using physiologically based pharmacokinetic (PBPK) modeling. However, initial boost predictions lacked sufficient confidence because a key parameter, fraction of drug metabolized by CYP3A4 (ƒₘCYP3A4), could not be estimated with accuracy on account of disconnects between in vitro and in vivo preclinical data. To accurately estimate ƒₘCYP3A4 in human, an in vivo boost effect study was conducted using CYP3A4-humanized mouse model which showed a 33- to 56-fold exposure boost effect. Using a top-down approach, human ƒₘCYP3A4 for NVS123 was estimated to be very high and included in the human PBPK modeling to support subsequent clinical study design. The combined use of the in vivo boost study in CYP3A4-humanized mouse model mice along with PBPK modeling accurately predicted the clinical outcome and identified a significant NVS123 exposure boost (∼42-fold increase) with ritonavir. Y1 - 2016 U6 - http://dx.doi.org/doi.org/10.1016/j.xphs.2016.01.021 SN - 0022-3549 VL - Volume 105 IS - Issue 4 SP - 1398 EP - 1404 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dallas, Shannon A1 - Salphati, Laurent A1 - Gomez-Zepeda, David A1 - Wanek, Thomas A1 - Chen, Liangfu A1 - Chu, Xiaoyan A1 - Kunta, Jeevan A1 - Mezler, Mario A1 - Menet, Marie-Claude A1 - Chasseigneaux, Stephanie A1 - Declèves, Xavier A1 - Langer, Oliver A1 - Pierre, Esaie A1 - DiLoreto, Karen A1 - Hoft, Carolin A1 - Laplanche, Loic A1 - Pang, Jodie A1 - Pereira, Tony A1 - Andonian, Clara A1 - Simic, Damir A1 - Rode, Anja A1 - Yabut, Jocelyn A1 - Zhang, Xiaolin A1 - Scheer, Nico T1 - Generation and Characterization of a Breast Cancer Resistance Protein Humanized Mouse Model JF - Molecular Pharmacology N2 - 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. Y1 - 2016 U6 - http://dx.doi.org/10.1124/mol.115.102079 SN - 1521-0111 VL - 89 IS - 5 SP - 492 EP - 504 PB - ASPET CY - Bethesda, Md. ER - TY - JOUR A1 - Scheer, Nico A1 - Kapelyukh, Yury A1 - Rode, Anja A1 - Oswald, Stefan A1 - Busch, Diana A1 - Mclaughlin, Lesley A. A1 - Lin, De A1 - Henderson, Colin J. A1 - Wolf, C. Roland T1 - Defining Human Pathways of Drug Metabolism In Vivo through the Development of a Multiple Humanized Mouse Model JF - Drug Metabolism and Disposition Y1 - 2015 U6 - http://dx.doi.org/10.1124/dmd.115.065656 SN - 1521-009x VL - 43 IS - 11 SP - 1679 EP - 1690 PB - ASPET CY - Bethesda ER - TY - JOUR A1 - Hough, Lindsay B. A1 - Nalwalk, Julia W. A1 - Ding, Xinxin A1 - Scheer, Nico T1 - Opioid Analgesia in P450 Gene Cluster Knockout Mice: A Search for Analgesia-Relevant Isoforms JF - Drug Metabolism and Disposition Y1 - 2015 U6 - http://dx.doi.org/10.1124/dmd.115.065490 SN - 1521-009x VL - 43 IS - 9 SP - 1326 EP - 1330 ER - TY - JOUR A1 - Henderson, Colin J. A1 - Mclaughlin, Lesley A. A1 - Scheer, Nico A1 - Stanley, Lesley A. A1 - Wolf, C. Roland T1 - Cytochrome b5 Is a Major Determinant of Human Cytochrome P450 CYP2D6 and CYP3A4 Activity In Vivo s JF - Molecular Pharmacology Y1 - 2015 U6 - http://dx.doi.org/10.1124/mol.114.097394 SN - 1521-0111 VL - 87 IS - 4 SP - 733 EP - 739 PB - ASPET CY - Bethesda ER - TY - JOUR A1 - Luisier, Raphaëlle A1 - Lempiäinen, Harri A1 - Scherbichler, Nina A1 - Braeuning, Albert A1 - Geissler, Miriam A1 - Dubost, Valerie A1 - Müller, Arne A1 - Scheer, Nico A1 - Chibout, Salah-Dine A1 - Hara, Hisanori A1 - Picard, Frank A1 - Theil, Diethilde A1 - Couttet, Philippe A1 - Vitobello, Antonio A1 - Grenet, Olivier A1 - Grasl-Kraupp, Bettina A1 - Ellinger-Ziegelbauer, Heidrung A1 - Thomson, John P. A1 - Meehan, Richard R. A1 - Elcombe, Clifford R. A1 - Henderson, Colin J. A1 - Wolf, C. Roland A1 - Schwarz, Michael A1 - Moulin, Pierre A1 - Terranova, Remi A1 - Moggs, Jonathan G. T1 - Phenobarbital Induces Cell Cycle Transcriptional Responses in Mouse Liver Humanized for Constitutive Androstane and Pregnane X Receptors JF - Toxicological Sciences N2 - The constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) are closely related nuclear receptors involved in drug metabolism and play important roles in the mechanism of phenobarbital (PB)-induced rodent nongenotoxic hepatocarcinogenesis. Here, we have used a humanized CAR/PXR mouse model to examine potential species differences in receptor-dependent mechanisms underlying liver tissue molecular responses to PB. Early and late transcriptomic responses to sustained PB exposure were investigated in liver tissue from double knock-out CAR and PXR (CARᴷᴼ-PXRᴷᴼ), double humanized CAR and PXR (CARʰ-PXRʰ), and wild-type C57BL/6 mice. Wild-type and CARʰ-PXRʰ mouse livers exhibited temporally and quantitatively similar transcriptional responses during 91 days of PB exposure including the sustained induction of the xenobiotic response gene Cyp2b10, the Wnt signaling inhibitor Wisp1, and noncoding RNA biomarkers from the Dlk1-Dio3 locus. Transient induction of DNA replication (Hells, Mcm6, and Esco2) and mitotic genes (Ccnb2, Cdc20, and Cdk1) and the proliferation-related nuclear antigen Mki67 were observed with peak expression occurring between 1 and 7 days PB exposure. All these transcriptional responses were absent in CARᴷᴼ-PXRᴷᴼ mouse livers and largely reversible in wild-type and CARʰ-PXRʰ mouse livers following 91 days of PB exposure and a subsequent 4-week recovery period. Furthermore, PB-mediated upregulation of the noncoding RNA Meg3, which has recently been associated with cellular pluripotency, exhibited a similar dose response and perivenous hepatocyte-specific localization in both wild-type and CARʰ-PXRʰ mice. Thus, mouse livers coexpressing human CAR and PXR support both the xenobiotic metabolizing and the proliferative transcriptional responses following exposure to PB. Y1 - 2014 U6 - http://dx.doi.org/https://doi.org/10.1093/toxsci/kfu038 SN - 1094-2025 VL - 139 IS - 2 SP - 501 EP - 511 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Salpati, Laurent A1 - Chu, Xiaoyan A1 - Chen, Liangfu A1 - Prasad, Bhagwat A1 - Dallas, Shannon A1 - Evers, Raymond A1 - Mamaril-Fishman, Donna A1 - Geier, Ethan G. A1 - Kehler, Jonathan A1 - Kunta, Jeevan A1 - Mezler, Mario A1 - Laplanche, Loic A1 - Pang, Jodie A1 - Soars, Matthew G. A1 - Unadkat, Jashvant D. A1 - van Waterschoot, Robert A.B. A1 - Yabut, Jocelyn A1 - Schinkel, Alfred H. A1 - Scheer, Nico A1 - Rode, Anja T1 - Evaluation of organic anion transporting polypeptide 1B1 and 1B3 humanized mice as a translational model to study the pharmacokinetics of statins JF - Drug Metabolism and Disposition N2 - Organic anion transporting polypeptide (Oatp) 1a/1b knockout and OATP1B1 and -1B3 humanized mouse models are promising tools for studying the roles of these transporters in drug disposition. Detailed characterization of these models will help to better understand their utility for predicting clinical outcomes. To advance this approach, we carried out a comprehensive analysis of these mouse lines by evaluating the compensatory changes in mRNA expression, quantifying the amounts of OATP1B1 and -1B3 protein by liquid chromatography–tandem mass spectrometry, and studying the active uptake in isolated hepatocytes and the pharmacokinetics of some prototypical substrates including statins. Major outcomes from these studies were 1) mostly moderate compensatory changes in only a few genes involved in drug metabolism and disposition, 2) a robust hepatic expression of OATP1B1 and -1B3 proteins in the respective humanized mouse models, and 3) functional activities of the human transporters in hepatocytes isolated from the humanized models with several substrates tested in vitro and with pravastatin in vivo. However, the expression of OATP1B1 and -1B3 in the humanized models did not significantly alter liver or plasma concentrations of rosuvastatin and pitavastatin compared with Oatp1a/1b knockout controls under the conditions used in our studies. Hence, although the humanized OATP1B1 and -1B3 mice showed in vitro and/or in vivo functional activity with some statins, further characterization of these models is required to define their potential use and limitations in the prediction of drug disposition and drug-drug interactions in humans. Y1 - 2014 U6 - http://dx.doi.org/10.1124/dmd.114.057976 SN - 1521-009X VL - 42 IS - 8 SP - 1301 EP - 1313 PB - ASPET CY - Bethesda, Md. ER -