TY - GEN A1 - Knauer, Jan Felix A1 - Schulz, Christian A1 - Zemella, Anne A1 - Wüstenhagen, Doreen A. A1 - Walter, Ruben Magnus A1 - Küpper, Jan-Heiner A1 - Kubick, Stefan T1 - Synthesis of mono Cytochrome P450 in a modified CHO-CPR cell-free protein production platform T2 - Scientific Reports N2 - AbstractCytochromes P450 (CYPs) are a group of monooxygenases that can be found in almost all kinds of organisms. For CYPs to receive electrons from co-substrate NADPH, the activity of NADPH-Cytochrome-P450-oxidoreductase (CPR) is required as well. In humans, CYPs are an integral part of liver-based phase-1 biotransformation, which is essential for the metabolization of multiple xenobiotics and drugs. Consequently, CYPs are important players during drug development and therefore these enzymes are implemented in diverse screening applications. For these applications it is usually advantageous to use mono CYP microsomes containing only the CYP of interest. The generation of mono-CYP containing mammalian cells and vesicles is difficult since endogenous CYPs are present in many cell types that contain the necessary co-factors. By obtaining translationally active lysates from a modified CHO-CPR cell line, it is now possible to generate mono CYPs in a cell-free protein synthesis process in a straightforward manner. As a proof of principle, the synthesis of active human CYPs from three different CYP450 gene families (CYP1A2, CYP2B6 and CYP3A4), which are of outstanding interest in industry and academia was demonstrated. Luciferase based activity assays confirm the activity of the produced CYPs and enable the individual adaptation of the synthesis process for efficient cell-free enzyme production. Furthermore, they allow for substrate and inhibitor screenings not only for wild-type CYPs but also for mutants and further CYP isoforms and variants. As an example, the turnover of selected CYP substrates by cell-free synthesized CYPs was demonstrated via an indirect luciferase assay-based screening setup. KW - Multidisciplinary Y1 - 2024 U6 - https://doi.org/10.1038/s41598-024-51781-6 SN - 2045-2322 VL - 14 ER - TY - GEN A1 - Schulz, Christian A1 - Krüger-Genge, Anne A1 - Lendlein, Andreas A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich T1 - Potential Effects of Nonadherent on Adherent Human Umbilical Venous Endothelial Cells in Cell Culture T2 - International Journal of Molecular Science N2 - The adherence and shear-resistance of human umbilical venous endothelial cells (HUVEC) on polymers is determined in vitro in order to qualify cardiovascular implant materials. In these tests, variable fractions of HUVEC do not adhere to the material but remain suspended in the culture medium. Nonadherent HUVEC usually stop growing, rapidly lose their viability and can release mediators able to influence the growth and function of the adherent HUVEC. The aim of this study was the investigation of the time dependent behaviour of HUVEC under controlled nonadherent conditions, in order to gain insights into potential influences of these cells on their surrounding environment in particular adherent HUVEC in the context of in vitro biofunctionality assessment of cardiovascular implant materials. Data from adherent or nonadherent HUVEC growing on polystyrene-based cell adhesive tissue culture plates (TCP) or nonadhesive low attachment plates (LAP) allow to calculate the number of mediators released into the culture medium either from adherent or nonadherent cells. Thus, the source of the inflammatory mediators can be identified. For nonadherent HUVEC, a time-dependent aggregation without further proliferation was observed. The rate of apoptotic/dead HUVEC progressively increased over 90% within two days. Concomitant with distinct blebbing and loss of membrane integrity over time, augmented releases of prostacyclin (PGI2, up to 2.91 ± 0.62 fg/cell) and platelet-derived growth factor BB (PDGF-BB, up to 1.46 ± 0.42 fg/cell) were detected. The study revealed that nonadherent, dying HUVEC released mediators, which can influence the surrounding microenvironment and thereby the results of in vitro biofunctionality assessment of cardiovascular implant materials. Neglecting nonadherent HUVEC bears the risk for under- or overestimation of the materials endothelialization potential, which could lead to the loss of relevant candidates or to uncertainty with regard to their suitability for cardiac applications. One approach to minimize the influence from nonadherent endothelial cells could be their removal shortly after observing initial cell adhesion. However, this would require an individual adaptation of the study design, depending on the properties of the biomaterial used. KW - human venous endothelial cells KW - adherent KW - non-adherent KW - viability KW - mediator release Y1 - 2021 UR - https://www.mdpi.com/1422-0067/22/3/1493 U6 - https://doi.org/10.3390/ijms22031493 VL - 22 IS - 3 ER - TY - GEN A1 - Liu, Yue A1 - Korolov, Ihor A1 - Trieschmann, Jan A1 - Steuer, David A1 - Schulz-von der Gathen, Volker A1 - Böke, Marc A1 - Bischoff, Lena A1 - Hübner, Gerrit A1 - Schulze, Julian A1 - Mussenbrock, Thomas T1 - Micro Atmospheric Pressure Plasma Jets Excited in He/O2 by Voltage Waveform Tailoring: A Study Based on a Numerical Hybrid Model and Experiments T2 - Plasma Sources Science and Technology Y1 - 2021 U6 - https://doi.org/10.1088/1361-6595/abd0e0 SN - 1361-6595 VL - 30 IS - 6 SP - 1 EP - 30 ER - TY - GEN A1 - Wägele, J. Wolfgang A1 - Bodesheim, Paul A1 - Bourlat, Sarah J. A1 - Denzler, Joachim A1 - Diepenbroek, Michael A1 - Fonseca, Vera A1 - Frommolt, Karl-Heinz A1 - Geiger, Matthias F. A1 - Gemeinholzer, Birgit A1 - Glöckner, Frank Oliver A1 - Haucke, Timm A1 - Kirse, Ameli A1 - Kölpin, Alexander A1 - Kostadinov, Ivaylo A1 - Kühl, Hjalmar S. A1 - Kurth, Frank A1 - Lasseck, Mario A1 - Liedke, Sascha A1 - Losch, Florian A1 - Müller, Sandra A1 - Petrovskaya, Natalia A1 - Piotrowski, Krzysztof A1 - Radig, Bernd A1 - Scherber, Christoph A1 - Schoppmann, Lukas A1 - Schulz, Jan A1 - Steinhage, Volker A1 - Tschan, Georg F. A1 - Vautz, Wolfgang A1 - Velotto, Domenico A1 - Weigend, Maximilian A1 - Wildermann, Stefan T1 - Towards a Multisensor Station for Automated Biodiversity Monitoring T2 - Basic and Applied Ecology Y1 - 2022 U6 - https://doi.org/10.1016/j.baae.2022.01.003 SN - 1439-1791 VL - 59 SP - 105 EP - 138 ER - TY - GEN A1 - Schulz, Christian A1 - Jung, Friedrich A1 - Küpper, Jan-Heiner T1 - Inhibition of phase-1 biotransformation and cytostatic effects of diphenyleneiodonium on hepatoblastoma cell line HepG2 and a CYP3A4-overexpressing HepG2 cell clone T2 - Clinical Hemorheology and Microcirculation N2 - Cell-based in vitro liver models are an important tool in the development and evaluation of new drugs in pharmacological and toxicological drug assessment. Hepatic microsomal enzyme complexes, consisting of cytochrome P450 oxidoreductase (CPR) and cytochrome P450 monooxygenases (CYPs), play a decisive role in catalysing phase-1 biotransformation of pharmaceuticals and xenobiotics. For a comprehensive understanding of the phase-1 biotransformation of drugs, the availability of well-characterized substances for the targeted modulation of in vitro liver models is essential. In this study, we investigated diphenyleneiodonium (DPI) for its ability to inhibit phase-1 enzyme activity and further its toxicological profile in an in vitro HepG2 cell model with and without recombinant expression of the most important drug metabolization enzyme CYP3A4. Aim of the study was to identify effective DPI concentrations for CPR/CYP activity modulation and potentially associated dose and time dependent hepatotoxic effects. The cells were treated with DPI doses up to 5,000nM (versus vehicle control) for a maximum of 48 h and subsequently examined for CYP3A4 activity as well as various toxicological relevant parameters such as cell morphology, integrity and viability, intracellular ATP level, and proliferation. Concluding, the experiments revealed a time- and concentration-dependent DPI mediated partial and complete inhibition of CYP3A4 activity in CYP3A4 overexpressing HepG2-cells (HepG2-CYP3A4). Other cell functions, including ATP synthesis and consequently the proliferation were negatively affected in both in vitro cell models. Since neither cell integrity nor cell viability were reduced, the effect of DPI in HepG2 can be assessed as cytostatic rather than cytotoxic. KW - Phase-1 KW - biotransformation KW - CYP KW - cytochrome P450 monooxygenase KW - CYP3A4 KW - diphenyleneiodonium KW - DPI KW - HepG2 KW - HepG2-CYP3A4 KW - hepatocytes KW - NADPH-cytochrome P450 oxidoreductase KW - POR KW - CPR Y1 - 2021 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch219117 U6 - https://doi.org/10.3233/CH-219117 SN - 1875-8622 SN - 1386-0291 VL - 79 IS - 1 SP - 231 EP - 243 ER - TY - GEN A1 - Krüger-Genge, Anne A1 - Köhler, Susanne A1 - Laube, Markus A1 - Haileka, Vanessa A1 - Lemm, Sandy A1 - Majchrzak, Karolina A1 - Kammerer, Sarah A1 - Schulz, Christian A1 - Storsberg, Joachim A1 - Pietzsch, Jens A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich T1 - Anti-Cancer Prodrug Cyclophosphamide Exerts Thrombogenic Effects on Human Venous Endothelial Cells Independent of CYP450 Activation—Relevance to Thrombosis T2 - Cells N2 - Cancer patients are at a very high risk of serious thrombotic events, often fatal. The causes discussed include the detachment of thrombogenic particles from tumor cells or the adverse effects of chemotherapeutic agents. Cytostatic agents can either act directly on their targets or, in the case of a prodrug approach, require metabolization for their action. Cyclophosphamide (CPA) is a widely used cytostatic drug that requires prodrug activation by cytochrome P450 enzymes (CYP) in the liver. We hypothesize that CPA could induce thrombosis in one of the following ways: (1) damage to endothelial cells (EC) after intra-endothelial metabolization; or (2) direct damage to EC without prior metabolization. In order to investigate this hypothesis, endothelial cells (HUVEC) were treated with CPA in clinically relevant concentrations for up to 8 days. HUVECs were chosen as a model representing the first place of action after intravenous CPA administration. No expression of CYP2B6, CYP3A4, CYP2C9 and CYP2C19 was found in HUVEC, but a weak expression of CYP2C18 was observed. CPA treatment of HUVEC induced DNA damage and a reduced formation of an EC monolayer and caused an increased release of prostacyclin (PGI2) and thromboxane (TXA) associated with a shift of the PGI2/TXA balance to a prothrombotic state. In an in vivo scenario, such processes would promote the risk of thrombus formation. KW - cancer KW - cyclophosphamide KW - human umbilical vein endothelial cells KW - HUVEC KW - liver KW - cytochrome P450 enzymes (CYP) KW - thrombosis Y1 - 2023 UR - https://www.mdpi.com/2073-4409/12/15/1965 U6 - https://doi.org/10.3390/cells12151965 SN - 2073-4409 VL - 12 IS - 15 ER - TY - GEN A1 - Schulz, Christian A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner T1 - NADPH-cytochrome P450 reductase expression and enzymatic activity in primary-like human hepatocytes and HepG2 cells for in vitro biotransformation studies T2 - Clinical Hemorheology and Microcirculation Y1 - 2019 U6 - https://doi.org/10.3233/CH-199226 SN - 1386-0291 VL - 73 IS - 1 SP - 249 EP - 260 ER - TY - GEN A1 - Steinbrecht, Susanne A1 - Pfeifer, Nadine A1 - Herzog, Natalie A1 - Katzenberger, Nadine A1 - Schulz, Christian A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner T1 - HepG2-1A2 C2 and C7: Lentivirus vector-mediated stable and functional overexpression of cytochrome P450 1A2 in human hepatoblastoma cells T2 - Toxicology Letters N2 - Novel HepG2 cell clones 1A2 C2 and 1A2 C7 were independently generated by lentiviral transduction to functionally overexpress cytochrome P450 1A2 (CYP1A2). We found similar and stable CYP1A2 transcript and protein levels in both cell clones leading to specific enzyme activities of about 370 pmol paracetamol x min-1 x mg-1 protein analyzed by phenacetin conversion. Both clones showed dramatically increased sensitivity to the hepatotoxic compound aflatoxin B1 (EC50<100 nM) when compared to parental HepG2 cells (EC50 ∼5 μM). Thus, newly established cell lines are an appropriate tool to study metabolism and toxicity of substances depending on conversion by CYP1A2. KW - HepG2 KW - CYP1A2 KW - Cytochrome P450 KW - Liver metabolism Y1 - 2020 U6 - https://doi.org/10.1016/j.toxlet.2019.11.006 SN - 0378-4274 VL - 319 SP - 155 EP - 159 ER - TY - GEN A1 - Charissé, Daniel A1 - Erus, Guray A1 - Pomponio, Raymond A1 - Gorges, Martin A1 - Schmidt, Nele A1 - Schneider, Christine A1 - Liepelt-Scarfone, Inga A1 - Riedel, Oliver A1 - Reetz, Kathrin A1 - Schulz, Jörg B. A1 - Berg, Daniela A1 - Storch, Alexander A1 - Witt, Karsten A1 - Dodel, Richard A1 - Kalbe, Elke A1 - Kassubek, Jan A1 - Hilker-Roggendorf, Rüdiger A1 - Baudrexel, Simon T1 - Brain age and Alzheimer's-like atrophy are domain-specific predictors of cognitive impairment in Parkinson's disease T2 - Neurobiology of Aging N2 - Recently, it was shown that patients with Parkinson's disease (PD) who exhibit an “Alzheimer's disease (AD)-like” pattern of brain atrophy are at greater risk for future cognitive decline. This study aimed to investigate whether this association is domain-specific and whether atrophy associated with brain aging also relates to cognitive impairment in PD. SPARE-AD, an MRI index capturing AD-like atrophy, and atrophy-based estimates of brain age were computed from longitudinal structural imaging data of 178 PD patients and 84 healthy subjects from the LANDSCAPE cohort. All patients underwent an extensive neuropsychological test battery. Patients diagnosed with mild cognitive impairment or dementia were found to have higher SPARE-AD scores as compared to patients with normal cognition and healthy controls. All patient groups showed increased brain age. SPARE-AD predicted impairment in memory, language and executive functions, whereas advanced brain age was associated with deficits in attention and working memory. Data suggest that SPARE-AD and brain age are differentially related to domain-specific cognitive decline in PD. The underlying pathomechanisms remain to be determined. KW - Alzheimer's disease KW - Brain Age KW - MRI KW - Parkinson's disease KW - Pattern classification Y1 - 2022 UR - https://www.sciencedirect.com/science/article/pii/S0197458021002748?via%3Dihub U6 - https://doi.org/10.1016/j.neurobiolaging.2021.08.020 SN - 0197-4580 VL - 109 SP - 31 EP - 42 ER - TY - GEN A1 - Schulz, Christian A1 - Herzog, Natalie A1 - Kubick, Stefan A1 - Jung, Friedrich A1 - Küpper, Jan-Heiner T1 - Stable Chinese Hamster Ovary Suspension Cell Lines Harboring Recombinant Human Cytochrome P450 Oxidoreductase and Human Cytochrome P450 Monooxygenases as Platform for In Vitro Biotransformation Studies T2 - Cells N2 - In the liver, phase-1 biotransformation of drugs and other xenobiotics is largely facilitated by enzyme complexes consisting of cytochrome P450 oxidoreductase (CPR) and cytochrome P450 monooxygenases (CYPs). Generated from human liver-derived cell lines, recombinant in vitro cell systems with overexpression of defined phase-1 enzymes are widely used for pharmacological and toxicological drug assessment and laboratory-scale production of drug-specific reference metabolites. Most, if not all, of these cell lines, however, display some background activity of several CYPs, making it difficult to attribute effects to defined CYPs. The aim of this study was to generate cell lines with stable overexpression of human phase-1 enzymes based on Chinese hamster ovary (CHO) suspension cells. Cells were sequentially modified with cDNAs for human CPR in combination with CYP1A2, CYP2B6, or CYP3A4, using lentiviral gene transfer. In parallel, CYP-overexpressing cell lines without recombinant CPR were generated. Successful recombinant expression was demonstrated by mRNA and protein analyses. Using prototypical CYP-substrates, generated cell lines proved to display specific enzyme activities of each overexpressed CYP while we did not find any endogenous activity of those CYPs in parental CHO cells. Interestingly, cell lines revealed some evidence that the dependence of CYP activity on CPR could vary between CYPs. This needs to be confirmed in further studies. Recombinant expression of CPR was also shown to enhance CYP3A4-independent metabolisation of testosterone to androstenedione in CHO cells. We propose the novel serum-free CHO suspension cell lines with enhanced CPR and/or defined CYP activity as a promising “humanised” in vitro model to study the specific effects of those human CYPs. This could be relevant for toxicology and/or pharmacology studies in the pharmaceutical industry or medicine. KW - Chinese hamster ovary cells KW - CHO-K1 KW - CPR KW - CYP450 KW - cytochrome P450 monooxygenase KW - liver KW - NADPH P450 oxidoreductase KW - phase-1 biotransformation KW - serum-free KW - suspension cells Y1 - 2023 UR - https://www.mdpi.com/2073-4409/12/17/2140#metrics U6 - https://doi.org/10.3390/cells12172140 SN - 2073-4409 VL - 12 IS - 17 ER -