TY - GEN A1 - Nghinaunye, Theopolina A1 - Waldeck, Peter A1 - Jung, C. G. H. A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich A1 - Braune, Steffen T1 - Response of Arthrospira platensis to different temperatures regarding growth and biochemical composition T2 - Clinical Hemorheology and Microcirculation N2 - The growth of cyanobacteria can vary considerably depending on the ambient temperature. Since the optimal growth temperature for Arthrospira platensis (strain SAG21.99) is not yet known, this was investigated in the present study. The study revealed that a process temperature of 30°C seems to be optimal for the Arthrospira strain SAG21.99 cultivation in terms of a maximum biomass productivity. This was also true for the phycocyanin content which was at 30°C significantly higher than at 20 or 40°C. KW - Arthrospira platensis KW - growth KW - temperature KW - bioreactor Y1 - 2023 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch238104 U6 - https://doi.org/10.3233/CH-238104 SN - 1386-0291 SP - 1 EP - 7 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 - Haas, Manuel A1 - Wirachowski, Karina A1 - Thibol, Lea A1 - Küpper, Jan-Heiner A1 - Schrenk, Dieter A1 - Fahrer, Jörg T1 - Potency ranking of pyrrolizidine alkaloids in metabolically competent human liver cancer cells and primary human hepatocytes using a genotoxicity test battery T2 - Archives of Toxicology N2 - Pyrrolizidine alkaloids (PAs) occur as contaminants in plant-based foods and herbal medicines. Following metabolic activation by cytochrome P450 (CYP) enzymes, PAs induce DNA damage, hepatotoxicity and can cause liver cancer in rodents. There is ample evidence that the chemical structure of PAs determines their toxicity. However, more quantitative genotoxicity data are required, particularly in primary human hepatocytes (PHH). Here, the genotoxicity of eleven structurally different PAs was investigated in human HepG2 liver cells with CYP3A4 overexpression and PHH using an in vitro test battery. Furthermore, the data were subject to benchmark dose (BMD) modeling to derive the genotoxic potency of individual PAs. The cytotoxicity was initially determined in HepG2-CYP3A4 cells, revealing a clear structure–toxicity relationship for the PAs. Importantly, experiments in PHH confirmed the structure-dependent toxicity and cytotoxic potency ranking of the tested PAs. The genotoxicity markers γH2AX and p53 as well as the alkaline Comet assay consistently demonstrated a structure-dependent genotoxicity of PAs in HepG2-CYP3A4 cells, correlating well with their cytotoxic potency. BMD modeling yielded BMD values in the range of 0.1–10 µM for most cyclic and open diesters, followed by the monoesters. While retrorsine showed the highest genotoxic potency, monocrotaline and lycopsamine displayed the lowest genotoxicity. Finally, experiments in PHH corroborated the genotoxic potency ranking, and revealed genotoxic effects even in the absence of detectable cytotoxicity. In conclusion, our findings strongly support the concept of grouping PAs into potency classes and help to pave the way for a broader acceptance of relative potency factors in risk assessment. KW - Cytotoxicity KW - Genotoxicity KW - Benchmark dose modeling KW - Pyrrolizidine alkaloids KW - Primary human hepatocytes KW - Potency ranking KW - γH2AX KW - p53 KW - DNA damage Y1 - 2023 UR - https://link.springer.com/article/10.1007/s00204-023-03482-8 U6 - https://doi.org/10.1007/s00204-023-03482-8 SN - 0340-5761 VL - 97 IS - 5 SP - 1413 EP - 1428 ER - TY - GEN A1 - Krüger-Genge, Anne A1 - Jung, Friedrich A1 - Hufert, Frank A1 - Jung, Ernst Michael A1 - Küpper, Jan-Heiner A1 - Storsberg, J. T1 - Effects of gut microbial metabolite trimethylamine N-oxide (TMAO) on platelets and endothelial cells T2 - Clinical Hemorheology and Microcirculation N2 - Thrombotic events result from different pathologies and are the underlying causes of severe diseases like stroke or myocardial infarction. Recent basic research now revealed a link between food uptake, food conversion and gut metabolism. Gut microbial production of trimethylamine N-oxide (TMAO) from dietary nutrients like choline, lecithin and L-carnitine was associated with the development of cardiovascular diseases. Within this review we give a systematic overview about the influence of TMAO on blood components like platelets and endothelial cells which both are involved as key players in thrombotic processes. In summary, a mechanistic correlation between the gut microbiome, TMAO and cardiovascular diseases becomes obvious and emphasizes to the significance of the intestinal microbiome. KW - Microbiome KW - trimethylamin-N-oxide KW - platelets KW - endothelial cells KW - atherosclerosis Y1 - 2020 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch209206 U6 - https://doi.org/10.3233/CH-209206 SN - 1875-8622 SN - 1386-0291 VL - 76 IS - 2 SP - 309 EP - 316 ER - TY - GEN A1 - Rahman, Ateeq A1 - Moola, Nyambe A1 - Küpper, Jan-Heiner T1 - Namibian algae species: A review of their distribution, medicinal uses and chemical constituents T2 - Journal of Cellular Biotechnology N2 - The use of indigenous or remote popular knowledge to identify new drugs against diseases or infections is a well-known approach in medicine. The inhabitants of coastal regions in Namibia and other African countries are known to prepare algae extracts for the treatment of disorders and ailments such as wounds, fever and stomach aches, as well as for the prevention of arrhythmia, cancer, and many other diseases. Algae survive in a competitive environment and, therefore, developed defense strategies that have resulted in a significant level of chemical structural diversity in various metabolic pathways. The exploration of these organisms for pharmaceutical, nutritional and medical purposes has provided important chemical candidates for the discovery of new agents against neglected tropical diseases and stimulated the use of sophisticated physical techniques. This current review provides a broad picture on the taxonomy, various medical and nutritional uses of algae, which thus should be of relevance for the African continent and underdeveloped countries in the Global South. Y1 - 2020 UR - https://content.iospress.com/articles/journal-of-cellular-biotechnology/jcb209010 U6 - https://doi.org/10.3233/JCB-209010 VL - 6 IS - 2 SP - 139 EP - 159 ER - TY - GEN A1 - Gehre, Christian P. A1 - Flechner, Marie A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Coleman, Charles Dominic A1 - Püschel, Gerhard Paul A1 - Uhlig, Katja A1 - Duschl, Claus T1 - Real time monitoring of oxygen uptake of hepatocytes in a microreactor using optical microsensors T2 - Scientific Reports N2 - Most in vitro test systems for the assessment of toxicity are based on endpoint measurements and cannot contribute much to the establishment of mechanistic models, which are crucially important for further progress in this field. Hence, in recent years, much effort has been put into the development of methods that generate kinetic data. Real time measurements of the metabolic activity of cells based on the use of oxygen sensitive microsensor beads have been shown to provide access to the mode of action of compounds in hepatocytes. However, for fully exploiting this approach a detailed knowledge of the microenvironment of the cells is required. In this work, we investigate the cellular behaviour of three types of hepatocytes, HepG2 cells, HepG2-3A4 cells and primary mouse hepatocytes, towards their exposure to acetaminophen when the availability of oxygen for the cell is systematically varied. We show that the relative emergence of two modes of action, one NAPQI dependent and the other one transient and NAPQI independent, scale with expression level of CYP3A4. The transient cellular response associated to mitochondrial respiration is used to characterise the influence of the initial oxygen concentration in the wells before exposure to acetaminophen on the cell behaviour. A simple model is presented to describe the behaviour of the cells in this scenario. It demonstrates the level of control over the role of oxygen supply in these experiments. This is crucial for establishing this approach into a reliable and powerful method for the assessment of toxicity. KW - Biophysics KW - Biotechnology KW - Cell biology KW - Drug discovery Y1 - 2020 UR - https://www.nature.com/articles/s41598-020-70785-6 U6 - https://doi.org/10.1038/s41598-020-70785-6 SN - 2045-2322 VL - 10 ER - TY - GEN A1 - Steinbrecht, Susanne A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner T1 - HepG2 cells with recombinant cytochrome P450 enzyme overexpression: Their use and limitation as in vitro liver model T2 - Journal of Cellular Biotechnology Y1 - 2019 U6 - https://doi.org/10.3233/JCB-189013 SN - 2352-3697 SN - 2352-3689 VL - 5 IS - 1 SP - 55 EP - 64 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 - Hofman, Jakub A1 - Sorf, Ales A1 - Vagiannis, Dimitrios A1 - Sucha, Simona A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Chen, Si A1 - Guo, Lei A1 - Ceckova, Martina A1 - Staud, Frantisek T1 - Brivanib Exhibits Potential for Pharmacokinetic Drug-Drug Interactions and the Modulation of Multidrug Resistance through the Inhibition of Human ABCG2 Drug Efflux Transporter and CYP450 Biotransformation Enzymes T2 - Molecular Pharmaceutics Y1 - 2019 U6 - https://doi.org/10.1021/acs.molpharmaceut.9b00361 VL - 16 IS - 11 SP - 4436 EP - 4450 ER - TY - GEN A1 - Hofman, Jakub A1 - Sorf, Ales A1 - Vagiannis, Dimitrios A1 - Sucha, Simona A1 - Novotna, Eva A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Ceckova, Martina A1 - Staud, Frantisek T1 - Interactions of Alectinib with Human ATP-Binding Cassette Drug Efflux Transporters and Cytochrome P450 Biotransformation Enzymes: Effect on Pharmacokinetic Multidrug Resistance T2 - Drug Metabolism and Disposition Y1 - 2019 U6 - https://doi.org/10.1124/dmd.119.086975 SN - 1521-009X SN - 0090-9556 VL - 47 IS - 7 SP - 699 EP - 709 ER - TY - GEN A1 - Jung, Friedrich A1 - Krüger-Genge, Anne A1 - Waldeck, Peter A1 - Küpper, Jan-Heiner T1 - Spirulina platensis, a super food? T2 - Journal of Cellular Biotechnology N2 - Spirulina platensis, a multicelluar, photosynthetic prokaryote (algae) contains a high amount of proteins, vitamins and minerals superior to many foods as e.g. soybeans. Thus, Spirulina platensis was recognized as nutritious food by the United Nations World Food Conference. Due to the high amount of nutritive ingredients Spirulina has a long history as dietary supplement. In addition, spirulina platensis is also efficiently used as forage with known effects on flesh, egg and plumage color, milk yield and fertility. The versatile utilization of the alga can be explained on the one hand with the nutrient levels and on the other hand with recognized effects as anti-viral, anti-bacterial, anti-oxidant, anti-diabetic, anti-cancer and anti-inflammatory substance. Therefore, this alga is named as “superfood”. Beyond, these algae convert carbon dioxide into organic substances and produce oxygen during their growth in alkaline and saline water thereby not wasting fresh water allowing the production in barren areas. Despite this diverse use of Spirulina platensis due to its beneficial properties, many basic mechanisms on a molecular and cellular level are not well understood and should be explored in future studies. KW - Spirulina KW - health effects KW - dietary supplements KW - liver protection KW - virus infection KW - HIV KW - nutrition KW - animal feeding Y1 - 2019 UR - https://content.iospress.com/articles/journal-of-cellular-biotechnology/jcb189012 U6 - https://doi.org/10.3233/JCB-189012 SN - 2352-3689 SN - 2352-3697 VL - 5 IS - 1 SP - 43 EP - 54 ER - TY - GEN A1 - Jung, Conrad H. G. A1 - Waldeck, Peter A1 - Sykora, Shadi A1 - Braune, Steffen A1 - Petrick, Ingolf A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich T1 - Influence of Different Light-Emitting Diode Colors on Growth and Phycobiliprotein Generation of Arthrospira platensis T2 - Life Y1 - 2022 U6 - https://doi.org/10.3390/life12060895 SN - 2075-1729 VL - 12 IS - 6 ER - TY - GEN A1 - Lemm, Sandy A1 - Köhler, Susanne A1 - Wodtke, Robert A1 - Jung, Friedrich A1 - Küpper, Jan-Heiner A1 - Pietzsch, Jens A1 - Laube, Markus T1 - Investigation of radiotracer metabolic stability in vitro with CYP-overexpressing hepatoma cell lines T2 - Cells Y1 - 2022 U6 - https://doi.org/10.3390/cells11152447 SN - 2073-4409 VL - 11 IS - 15 ER - TY - GEN A1 - Lemm, Sandy A1 - Köhler, Susanne A1 - Wodtke, Robert A1 - Jung, Friedrich A1 - Küpper, Jan-Heiner A1 - Pietzsch, Jens A1 - Laube, Markus T1 - Enabling insights into the cytochrome P450 isoform specific metabolism of radiotracers by CYP overexpressing hepatoblastoma cell lines T2 - Nuclear Medicine and Biology Y1 - 2022 SN - 1872-9614 IS - 108-109, Supplement  SP - S66 EP - S67 ER - TY - GEN A1 - Jung, Friedrich A1 - Braune, Steffen A1 - Jung, Conrad H. G. A1 - Krüger-Genge, Anne A1 - Waldeck, Peter A1 - Petrick, Ingolf A1 - Küpper, Jan-Heiner T1 - Lipophilic and Hydrophilic Compounds from Arthrospira platensis and Its Effects on Tissue and Blood Cells—An Overview T2 - Life Y1 - 2022 U6 - https://doi.org/10.3390/life12101497 SN - 2075-1729 VL - 12 IS - 10 ER - TY - GEN A1 - Jung, Conrad H. G. A1 - Braune, Steffen A1 - Waldeck, Peter A1 - Küpper, Jan-Heiner A1 - Petrick, Ingolf A1 - Jung, Friedrich T1 - Morphology and Growth of Arthrospira platensis during Cultivation in a Flat-Type Bioreactor T2 - Life N2 - Arthrospira platensis (AP) is a cyanobacterium with a high economic value and is nowadays one of the most important industrially cultivated microalgae. Knowledge of its growth is essential for the understanding of its physiology and yield. The growth of AP biomass occurs through two mechanisms: (1) propagation by fragmentation of trichomes, and (2) the trichomes are extended by binary fission until they reach their mature status. These phases are visualized by live cell light and laser scanning microscopy, demonstrating the different phases of AP growth. KW - Arthrospira platensis KW - Spirulina KW - life cycle KW - morphology KW - fragmentation KW - fission Y1 - 2021 UR - https://www.mdpi.com/2075-1729/11/6/536/htm U6 - https://doi.org/10.3390/life11060536 SN - 2075-1729 VL - 11 IS - 6 ER - TY - GEN A1 - Küpper, Jan-Heiner A1 - Krüger-Genge, Anne A1 - Jung, Friedrich T1 - 40th conference of the German society for clinical microcirculation and hemorheology (DGKMH) T2 - Clinical Hemorheology and Microcirculation Y1 - 2021 U6 - https://doi.org/10.3233/ch-219100 SN - 1875-8622 SN - 1386-0291 VL - 79 IS - 1 SP - 1 EP - 2 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 - Haas, M. A1 - Wirachowski, K. A1 - Küpper, Jan-Heiner A1 - Schrenk, Dieter A1 - Fahrer, J. T1 - Structure‐dependent genotoxicity and cytotoxicity of eleven pyrrolizidine alkaloids in human liver cells with CYP3A4 overexpression T2 - Lebensmittelchemie : Volume 75: Vorträge und Poster des 49. Deutschen Lebensmittelchemikertags Y1 - 2021 U6 - https://doi.org/10.1002/lemi.202158135 SN - 0937-1478 SN - 1521-3811 SP - S134 ER - TY - PAT A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich T1 - Arthrospira for use in the treatment of diseases Y1 - 2021 UR - https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwik1t7QrOL5AhVTO-wKHT97CKAQFnoECAQQAQ&url=https%3A%2F%2Fdata.epo.org%2Fpublication-server%2Frest%2Fv1.0%2Fpublication-dates%2F20220302%2Fpatents%2FEP3960193NWA1%2Fdocument.pdf&usg=AOvVaw20GVY_ywjb2xbS0TwSDArJ ER - TY - GEN A1 - Vagiannis, Dimitrios A1 - Budagaga, Youssif A1 - Morell, Anselm A1 - Zhang, Yu A1 - Novotna, Eva A1 - Skarka, Adam A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Hanke, Ivo A1 - Rozkoš, Tomáš A1 - Hofman, Jakub T1 - Tepotinib Inhibits Several Drug Efflux Transporters and Biotransformation Enzymes: The Role in Drug-Drug Interactions and Targeting Cytostatic Resistance In Vitro and Ex Vivo T2 - International Journal of Molecular Sciences Y1 - 2021 U6 - https://doi.org/10.3390/ijms222111936 SN - 1422-0067 SN - 1661-6596 VL - 22 IS - 21 ER - TY - GEN A1 - Künzel, Stephan R. A1 - Hoffmann, Maximilian A1 - Weber, Silvio A1 - Künzel, Karolina A1 - Kämmerer, Susanne A1 - Günscht, Mario A1 - Klapproth, Erik A1 - Rausch, Johanna S. E. A1 - Sadek, Mirna S. A1 - Kolanowski, Tomasz A1 - Meyer-Roxlau, Stefanie A1 - Piorkowski, Christopher A1 - Tugtekin, Sems M. A1 - Rose-John, Stefan A1 - Yin, Xiaoke A1 - Mayr, Manuel A1 - Kuhlmann, Jan Dominik A1 - Wimberger, Pauline A1 - Grützmann, Konrad A1 - Herzog, Natalie A1 - Küpper, Jan-Heiner A1 - O’Reilly, Molly A1 - Kabir, S. Nashitha A1 - Sommerfeld, Laura C. A1 - Guan, Kaomei A1 - Wielockx, Ben A1 - Fabritz, Larissa A1 - Nattel, Stanley A1 - Ravens, Ursula A1 - Dobrev, Dobromir A1 - Wagner, Michael A1 - El-Armouche, Ali T1 - Diminished PLK2 Induces Cardiac Fibrosis and Promotes Atrial Fibrillation T2 - Circulation Research N2 - Rationale: Fibrosis promotes the maintenance of atrial fibrillation (AF), making it resistant to therapy. Improved understanding of the molecular mechanisms leading to atrial fibrosis will open new pathways toward effective antifibrotic therapies. Objective: This study aims to decipher the mechanistic interplay between PLK2 (polo-like kinase 2) and the profibrotic cytokine OPN (osteopontin) in the pathogenesis of atrial fibrosis and AF. Methods and Results: Atrial PLK2 mRNA expression was 10-fold higher in human fibroblasts than in cardiomyocytes. Compared with sinus rhythm, right atrial appendages and isolated right atrial fibroblasts from patients with AF showed downregulation of PLK2 mRNA and protein, along with increased PLK2 promotor methylation. Genetic deletion as well as pharmacological inhibition of PLK2 induced profibrotic phenotype conversion in cardiac fibroblasts and led to a striking de novo secretion of OPN. Accordingly, PLK2-deficient (PLK2 knockout) mice showed cardiac fibrosis and were prone to experimentally induced AF. In line with these findings, OPN plasma levels were significantly higher only in patients with AF with atrial low-voltage zones (surrogates of fibrosis) compared with sinus rhythm controls. Mechanistically, we identified ERK1/2 as the relevant downstream mediator of PLK2 leading to increased OPN expression. Finally, oral treatment with the clinically available drug mesalazine, known to inhibit ERK1/2, prevented cardiac OPN overexpression and reversed the pathological PLK2 knockout phenotype in PLK2 knockout mice. Conclusions: Abnormal PLK2/ERK1/2/OPN axis function critically contributes to AF-related atrial fibrosis, suggesting reinforcing PLK2 activity and/or OPN inhibition as innovative targets to prevent fibrosis progression in AF. Mesalazine derivatives may be used as lead compounds for the development of novel anti-AF agents targeting fibrosis. KW - atrial fibrillation KW - fibroblasts KW - fibrosis KW - mesalamine KW - osteopontin Y1 - 2021 UR - https://www.ahajournals.org/doi/full/10.1161/CIRCRESAHA.121.319425 U6 - https://doi.org/10.1161/CIRCRESAHA.121.319425 SN - 1524-4571 SN - 0009-7330 VL - 129 IS - 8 SP - 804 EP - 820 ER - TY - GEN A1 - Lau, S. A1 - Rangarajan, R. A1 - Krüger-Genge, Anne A1 - Braune, Steffen A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Lendlein, Andreas A1 - Jung, Friedrich T1 - Effects of acrolein in comparison to its prodrug cyclophosphamide on human primary endothelial cells in vitro T2 - Toxicology in Vitro N2 - Cyclophosphamide (CPA) is one of the most successful anticancer prodrugs that becomes effective after biotransformation in the liver resulting in the toxic metabolite acrolein. Cancer is often accompanied by thromboembolic events, which might be a result of dysfunctional endothelial cells due to CPA treatment. Here, the effect of 1 mM CPA or acrolein (10/50/100/500 μM) on human umbilical vein endothelial cells (HUVECs) was analyzed after two days of treatment. The addition of CPA or 10 μM acrolein did not affect HUVECs. However, concentrations of 100 μM and 500 μM acrolein significantly reduced the number of adherent cells by 86 ± 13% and 99 ± 1% and cell viability by 51 ± 29% and 93 ± 8% compared to the control. Moreover, pronounced stress fibers as well as multiple nuclei were observed and von Willebrand factor (vWF) was completely released. Lactate dehydrogenase was 8.5 ± 7.0-fold and 252.9 ± 42.9-fold increased showing a loss of cell membrane integrity. The prostacyclin and thromboxane secretion was significantly increased by the addition of 500 μM acrolein (43.1 ± 17.6-fold and 246.4 ± 106.3-fold) indicating cell activation/pertubation. High doses of acrolein led to HUVEC death and loss of vWF production. This effect might be associated with the increased incidence of thromboembolic events in cancer patients treated with high doses of CPA. KW - Human umbilical venous endothelial cells KW - Acrolein KW - Aneuploidy KW - von Willebrand factor KW - in vitro study Y1 - 2020 U6 - https://doi.org/10.1016/j.tiv.2019.104685 SN - 0887-2333 VL - 62 ER - TY - GEN A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich A1 - Krieger, Volker A1 - Hufert, Frank T1 - A comparison of mortality rates between European and Asian States T2 - Clinical Hemorheology and Microcirculation Y1 - 2020 U6 - https://doi.org/10.3233/CH-209008 SN - 1875-8622 SN - 1386-0291 VL - 75 IS - 1 SP - 3 EP - 5 ER - TY - GEN A1 - Vagiannis, Dimitrios A1 - Novotna, Eva A1 - Skarka, Adam A1 - Kammerer, Sarah A1 - Küpper, Jan-Heiner A1 - Chen, Si A1 - Guo, Lei A1 - Staud, Frantisek A1 - Hofman, Jakub T1 - Ensartinib (X-396) Effectively Modulates Pharmacokinetic Resistance Mediated by ABCB1 and ABCG2 Drug Efflux Transporters and CYP3A4 Biotransformation Enzyme T2 - Cancers N2 - Ensartinib (X-396) is a promising tyrosine kinase inhibitor currently undergoing advanced clinical evaluation for the treatment of non-small cell lung cancer. In this work, we investigate possible interactions of this promising drug candidate with ATP-binding cassette (ABC) drug efflux transporters and cytochrome P450 biotransformation enzymes (CYPs), which play major roles in multidrug resistance (MDR) and pharmacokinetic drug-drug interactions (DDIs). Accumulation studies showed that ensartinib is a potent inhibitor of ABCB1 and ABCG2 transporters. Additionally, incubation experiments with recombinant CYPs showed that ensartinib significantly inhibits CYP3A4 and CYP2C9. Subsequent molecular docking studies confirmed these findings. Drug combination experiments demonstrated that ensartinib synergistically potentiates the antiproliferative effects of daunorubicin, mitoxantrone, and docetaxel in ABCB1, ABCG2, and CYP3A4-overexpressing cellular models, respectively. Advantageously, ensartinib’s antitumor efficiency was not compromised by the presence of MDR-associated ABC transporters, although it acted as a substrate of ABCB1 in Madin-Darby Canine Kidney II (MDCKII) monolayer transport assays. Finally, we demonstrated that ensartinib had no significant effect on the mRNA-level expression of examined transporters and enzymes in physiological and lung tumor cellular models. In conclusion, ensartinib may perpetrate clinically relevant pharmacokinetic DDIs and modulate ABCB1-, ABCG2-, and CYP3A4-mediated MDR. The in vitro findings presented here will provide a valuable foundation for future in vivo investigations. KW - ensartinib KW - cancer KW - multidrug resistance KW - drug-drug interaction KW - ABC transporter KW - cytochrome P450 Y1 - 2020 UR - https://www.mdpi.com/2072-6694/12/4/813 U6 - https://doi.org/10.3390/cancers12040813 SN - 2072-6694 VL - 12 IS - 4 ER - TY - GEN A1 - Jung, Friedrich A1 - Krieger, Volker A1 - Hufert, Frank A1 - Küpper, Jan-Heiner T1 - How we should respond to the Coronavirus SARS-CoV-2 outbreak: A German perspective T2 - Clinical Hemorheology and Microcirculation N2 - BACKGROUND: In the early phase of the COVID-19 pandemic Germany missed to set up efficient containment measures. Consequently, the number of cases increased exponentially until a lockdown was implemented to suppress the spread of SARS-CoV-2. Fortunately, Germany has a high capability for coronavirus lab testing and more than 30,000 ICU beds. These capabilities and the lockdown turned out to be an advantage to combat the pandemic and to prevent a health-system overload. AIM: The aim was to predict the plateau day of SARS-CoV-2 infections or deaths. RESULTS: The effect on the viral spread of the German measures taken and the impact on the peak of new infection cases is shown. By normalizing daily case numbers, the plateau day of the current outbreak in Germany could be calculated to be reached at April 12, 2020 (day 103 of 2020). CONCLUSION: Normalized case number curves are helpful to predict the time point at which no further new infections will occur if the epidemic situation remains stable. Upon reaching the plateau day during a lockdown phase, a residual time-period of about 2-3 weeks can be utilized to prepare a safe unlocking period. As can be learned from Asian countries such as South Korea and Taiwan there must be strict rules to keep the risk of infection low. Those include social distancing, face mask wearing in combination with digital contact tracing and serosurveillance studies. Following those rules, a safe dance around the infection curve allows to keep the population at a reduced infection rate. KW - Corona virus KW - SARS-CoV-2 KW - COVID-19 KW - herd immunity KW - hammer and dance strategy Y1 - 2020 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch209004 U6 - https://doi.org/10.3233/CH-209004 SN - 1875-8622 SN - 1386-0291 VL - 74 IS - 4 SP - 363 EP - 372 ER - TY - GEN A1 - Kammerer, Sarah A1 - Nowak, Elisabeth A1 - Mantke, René A1 - Jung, Friedrich A1 - Küpper, Jan-Heiner T1 - In vitro simulation of the liver first-pass effect with biotransformation-competent HepG2 cells to study effects of MG-132 on liver and cancer cells T2 - Clinical Hemorheology and Microcirculation N2 - BACKGROUND: Liver biotransformation is the major route for drug metabolism in humans, often catalysed by cytochrome P450 (CYP) enzymes. This first-pass effect can lead to hepatotoxicity and influences the bioavailability of drugs. OBJECTIVE: We aimed to establish in vitro culture systems simulating the liver first-pass to study effects of the proteasome inhibitor MG-132 simultaneously on hepatocytes and cancer cells. METHODS: The first-pass effect was simulated by conditioned medium transfer (CMT) from pre-treated HepG2 CYP3A4-overexpressing cells to either pancreatic cancer cell line PANC-1 or primary colon cancer cells, and by indirect co-culture (CC) of liver and cancer cells in a shared medium compartment. Experimental proteasome inhibitor MG-132 was used as test substance as it is detoxified by CYP3A4. RESULTS: Cancer cells showed higher viabilities in the first-pass simulation by CMT and CC formats when compared to monocultures indicating effective detoxification of MG-132 by HepG2 CYP3A4-overexpressing cells. HepG2-CYP3A4 cells showed reduced viabilites after treatment with MG-132. CONCLUSIONS: We successfully established two different culture systems to simulate the liver first-pass effect in vitro. Such systems easily allow to study drug effects simultaneously on liver and on target cancer cells. They are of great value in pre-clinical cancer research, pharmaceutical research and drug development. KW - Liver biotransformation KW - first-pass effect KW - CYP3A4 KW - MG-132 KW - cancer cells KW - in vitro culture systems Y1 - 2024 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch238108 U6 - https://doi.org/10.3233/CH-238108 SN - 1386-0291 VL - 86 IS - 1-2 SP - 159 EP - 168 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 - 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 -