@misc{HerzogHansenMiethbaueretal., author = {Herzog, Natalie and Hansen, Max and Miethbauer, Sebastian and Schmidtke, Kai-Uwe and Anderer, Ursula and Lupp, Amelie and Sperling, Sebastian and Seehofer, Daniel and Damm, Georg and Scheibner, Katrin and K{\"u}pper, Jan-Heiner}, title = {Primary-like human hepatocytes genetically engineered to obtain proliferation competence display hepatic differentiation characteristics in monolayer and organotypical spheroid cultures}, series = {Cell Biology International}, volume = {40}, journal = {Cell Biology International}, number = {3}, issn = {1095-8355}, doi = {10.1002/cbin.10574}, pages = {341 -- 353}, abstract = {Primary human hepatocytes are in great demand during drug development and in hepatology. However, both scarcity of tissue supply and donor variability of primary cells create a need for the development of alternative hepatocyte systems. By using a lentivirus vector system to transfer coding sequences of Upcyte® proliferation genes, we generated non-transformed stable hepatocyte cultures from human liver tissue samples. Here, we show data on newly generated proliferation-competent HepaFH3 cells investigated as conventional two-dimensional monolayer and as organotypical three-dimensional (3D) spheroid culture. In monolayer culture, HepaFH3 cells show typical cobblestone-like hepatocyte morphology and anchorage-dependent growth for at least 20 passages. Immunofluorescence staining revealed that characteristic hepatocyte marker proteins cytokeratin 8, human serum albumin, and cytochrome P450 (CYP) 3A4 were expressed. Quantitative real-time PCR analyses showed that expression levels of analyzed phase I CYP enzymes were at similar levels compared to those of cultured primary human hepatocytes and considerably higher than in the liver carcinoma cell line HepG2. Additionally, transcripts for phase II liver enzymes and transporter proteins OATP-C, MRP2, Oct1, and BSEP were present in HepaFH3. The cells produced urea and converted model compounds such as testosterone, diclofenac, and 7-OH-coumarin into phases I and II metabolites. Interestingly, phases I and II enzymes were expressed at about the same levels in convenient monolayer cultures and complex 3D spheroids. In conclusion, HepaFH3 cells and related primary-like hepatocyte lines seem to be promising tools for in vitro research of liver functions and as test system in drug development and toxicology analysis.}, language = {en} } @misc{KadeHerzogSchmidtkeetal., author = {Kade, S. and Herzog, Natalie and Schmidtke, Kai-Uwe and K{\"u}pper, Jan-Heiner}, title = {Chronic ethanol treatment depletes glutathione regeneration capacity in hepatoma cell line HepG2}, series = {Journal of Cellular Biotechnology}, volume = {1}, journal = {Journal of Cellular Biotechnology}, number = {2}, issn = {2352-3697}, doi = {10.3233/JCB-15019}, pages = {183 -- 190}, language = {en} } @misc{HerzogHansenMiethbaueretal., author = {Herzog, Natalie and Hansen, Max and Miethbauer, Sebastian and Schmidtke, Kai-Uwe and Anderer, Ursula and Lupp, Amelie and Sperling, Sebastian and Seehofer, Daniel and Damm, Georg and Scheibner, Katrin and K{\"u}pper, Jan-Heiner}, title = {Primary like human hepatocytes genetically engineered to obtain proliferation competence display liver biotransformation activity in 2D and 3D culture systems}, series = {Cell Biology International}, volume = {40}, journal = {Cell Biology International}, number = {3}, issn = {1095-8355}, pages = {341 -- 353}, language = {en} } @misc{GeorgeRoedigerSchroederetal., author = {George, Sandra and R{\"o}diger, Stefan and Schr{\"o}der, Christian and Knaut, Michael and K{\"u}pper, Jan-Heiner}, title = {Development of multiplex PCR systems for expression profiling of human cardiomyocytes induced to profilerate by lentivirus transduction of upcyte genes}, series = {Journal of Cellular Biotechnology}, volume = {2}, journal = {Journal of Cellular Biotechnology}, number = {1}, issn = {2352-3697}, doi = {10.3233/JCB-15025}, pages = {35 -- 55}, language = {en} } @misc{MeyerMeyerFiccaKuepper, author = {Meyer, Ralph G. and Meyer-Ficca, Mirella and K{\"u}pper, Jan-Heiner}, title = {Adenoviral vectors for modulation of poly(ADP-ribose) polymerase-1 (PARP1) - dependent DNA repair as a predictive tool for chemotherapy}, series = {Journal of Cellular Biotechnology}, volume = {2}, journal = {Journal of Cellular Biotechnology}, number = {1}, issn = {2352-3697}, doi = {10.3233/JCB-15026}, pages = {57 -- 68}, language = {en} } @misc{HerzogKatzenbergerMartinetal., author = {Herzog, Natalie and Katzenberger, Nadine and Martin, Frank and Schmidtke, Kai-Uwe and K{\"u}pper, Jan-Heiner}, title = {Generation of cytochrome P450 3A4-overexpressing HepG2 cell clones for standardization of hepatocellular testosterone 6β-hydroxylation activity}, series = {Journal of Cellular Biotechnology}, volume = {1}, journal = {Journal of Cellular Biotechnology}, number = {1}, issn = {2352-3697}, doi = {10.3233/JCB-15002}, pages = {15 -- 26}, language = {en} } @misc{GeorgeNoackVaneketal., author = {George, Sandra and Noack, M. and Vanek, Monika and Rentzsch, J. and R{\"o}ber, Nadja and Roggenbuck, Dirk and Conrad, Karsten and K{\"u}pper, Jan-Heiner}, title = {Expression of nicotinic acetylcholine receptor subunits in HEp-2 cells for immunodetection of autoantibody specificities in sera fro Myasthenia gravis patients}, series = {Clinical Hemorheology and Microcirculation}, volume = {61}, journal = {Clinical Hemorheology and Microcirculation}, number = {2}, issn = {1875-8622}, doi = {10.3233/CH-151999}, pages = {385 -- 396}, language = {en} } @misc{GeorgePaulickKnuetteretal., author = {George, Sandra and Paulick, Silvia and Kn{\"u}tter, Ilka and R{\"o}ber, Nadja and Hiemann, Rico and Roggenbuck, Dirk and Conrad, Karsten and K{\"u}pper, Jan-Heiner}, title = {Stable Expression of Human Muscle-Specific Kinase in HEp-2 M4 Cells for Automatic Immunofluorescence Diagnostics of Myasthenia Gravis}, series = {PLOS one}, volume = {9}, journal = {PLOS one}, number = {1}, issn = {1932-6203}, doi = {10.1371/journal.pone.0083924}, pages = {e83924}, language = {en} } @misc{GeorgeGeorgiRoggenbucketal., author = {George, Sandra and Georgi, M. and Roggenbuck, Dirk and Conrad, Karsten and K{\"u}pper, Jan-Heiner}, title = {A strategy for cell-based multiplex diagnostics of Myasthenia gravis and autoimmune encephalitis by modifying the subcellular localization of cell membrane autoantigensgravis}, series = {Clinical Hemorheology and Microcirculation}, volume = {58}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1386-0291}, doi = {10.3233/CH-141897}, pages = {211 -- 228}, language = {en} } @incollection{ConradKuepper, author = {Conrad, Karsten and K{\"u}pper, Jan-Heiner}, title = {Tumor-associated autoantibodies}, series = {Autoantibodies}, booktitle = {Autoantibodies}, editor = {Shoenfeld, Yehuda and Meroni, Pier Luigi and Gershwin, M. Eric}, edition = {3rd edition}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, isbn = {978-0-444-56378-1}, pages = {275 -- 287}, language = {en} } @misc{NowakMartinGeorgeetal., author = {Nowak, Elisabeth and Martin, F. and George, Sandra and R{\"o}ber, Nadja and Conrad, Karsten and K{\"u}pper, Jan-Heiner}, title = {Bacterial production and purification of immunoreactive paraneoplastic neurological syndrome autoantigen Ma2}, series = {Journal of Cellular Biotechnology}, volume = {2}, journal = {Journal of Cellular Biotechnology}, number = {2}, issn = {2352-3697}, doi = {10.3233/JCB-15029}, pages = {85 -- 91}, abstract = {Paraneoplastic neurological syndromes (PNS) are caused by an immune response against neuronal proteins upon their ectopical expression in tumor cells. Ma2 belongs to the protein family of paraneoplastic Ma antigens (PNMA). Detection of Ma2-specific autoantibodies is relevant for diagnostics of anti-Ma2 PNS and an underlying tumor such as germ testicular cancer, small cell lung cancer or breast cancer. Thus, early tumor treatment should improve the outcome for PNS therapy either. Dot blot immunoassay based on recombinantly expressed and purified autoantigens could offer a sensitive method for identification of paraneoplastic autoantibodies from sera of PNS patients. Here we present purification with IMAC and FPLC of human Ma2 autoantigen upon its recombinant expression in E.coli. Furthermore, we provide evidence that dot blot immunoassays with purified Ma2 autoantigen can be used for detection of Ma2-specific autoantibodies from sera of PNS patients.}, language = {en} } @book{PaumenKuepper, author = {Paumen, Anja and K{\"u}pper, Jan-Heiner}, title = {It's the planet, stupid! Sieben Perspektiven zum Klimawandel : mit Interviewbeitr{\"a}gen von Hartmut Graßl, Hans-Werner Sinn, Ernst-Ulrich von Weizs{\"a}cker, Meinhard Miegel, Mathias Binswanger, Enoch zu Guttenberg und Wulf Schiefenh{\"o}vel}, publisher = {oekom Verlag}, address = {M{\"u}nchen}, isbn = {978-3-86581-739-6}, pages = {303}, language = {de} } @misc{Kuepper, author = {K{\"u}pper, Jan-Heiner}, title = {Vorrichtung und Verfahren zur Sequestrierung von atmosph{\"a}rischen Kohlendioxid}, language = {de} } @inproceedings{GeorgeNoackVaneketal., author = {George, Sandra and Noack, Monika and Vanek, Monika and Rentzsch, Juliane and R{\"o}ber, Nadja and Conrad, Karsten and Roggenbuck, Dirk and K{\"u}pper, Jan-Heiner}, title = {Expression of nicotinic acetylcholine receptor subunits in HEp-2 cells for immunodetection of autoantibody specificities in sera from Myasthenia gravis patients}, series = {From autoantibody research to standardized diagnostic assays in the management of human diseases, report on the 12th Dresden Symposium on Autoantibodies, September 23-26, 2015}, booktitle = {From autoantibody research to standardized diagnostic assays in the management of human diseases, report on the 12th Dresden Symposium on Autoantibodies, September 23-26, 2015}, publisher = {Pabst Science Publishers}, address = {Lengerich}, isbn = {978-3-95853-104-8}, pages = {195 -- 196}, language = {en} } @misc{KruegerGengeSteinbrechtKuepperetal., author = {Kr{\"u}ger-Genge, Anne and Steinbrecht, Susanne and K{\"u}pper, Jan-Heiner and Lendlein, Andreas and Jung, Friedrich}, title = {Evidence for cytostatic effect of cyclophosphamide on human vein endothelial cells in cancer therapy: preliminary in vitro results.}, series = {Clinical Hemorheology and Microcirculation}, volume = {69}, journal = {Clinical Hemorheology and Microcirculation}, number = {1-2}, issn = {1875-8622}, doi = {10.3233/CH-189125}, pages = {267 -- 276}, language = {en} } @misc{KammererKuepper, author = {Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {Human Hepatocyte Systems for in vitro Toxicology Analysis.}, series = {Journal of Cellular Biotechnology}, volume = {3}, journal = {Journal of Cellular Biotechnology}, number = {2}, issn = {2352-3697}, doi = {10.3233/JCB-179012}, pages = {85 -- 93}, language = {en} } @misc{KammererKuepper, author = {Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {Optimized protocol for induction of cytochrome P450 enzymes 1A2 and 3A4 in human primary-like hepatocyte cell strain HepaFH3 to study in vitro toxicology}, series = {Clinical Hemorheology and Microcirculation}, volume = {70}, journal = {Clinical Hemorheology and Microcirculation}, number = {4}, issn = {1386-0291}, doi = {10.3233/CH-189321}, pages = {563 -- 571}, language = {en} } @misc{SteinbrechtKoenigSchmidtkeetal., author = {Steinbrecht, Susanne and K{\"o}nig, Rosalie and Schmidtke, Kai-Uwe and Herzog, Natalie and Scheibner, Katrin and Kr{\"u}ger-Genge, Anne and Jung, Friedrich and Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {Metabolic activity testing can underestimate acute drug cytotoxicity as revealed by HepG2 cell clones overexpressing cytochrome P450 2C19 and 3A4}, series = {Toxicology}, volume = {412}, journal = {Toxicology}, issn = {0300-483X}, doi = {10.1016/j.tox.2018.11.008}, pages = {37 -- 47}, language = {en} } @misc{KruegerGengeBrauneWalteretal., author = {Kr{\"u}ger-Genge, Anne and Braune, Steffen and Walter, Maria and Kratz, Karl and K{\"u}pper, Jan-Heiner and Krengel, M. and Lendlein, Andreas and Jung, Friedrich}, title = {Influence of surface treatments of poly(n-butyl acrylate) networks on fibroblasts adhesion, morphology and viability}, series = {Clinical Hemorheology and Microcirculation}, volume = {69}, journal = {Clinical Hemorheology and Microcirculation}, number = {1-2}, issn = {1875-8622}, doi = {10.3233/CH-189130}, pages = {305 -- 316}, language = {en} } @misc{NowakKammererKuepper, author = {Nowak, Elisabeth and Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {ATP-based cell viability assay is superior to trypan blue exclusion and XTT assay in measuring cytotoxicity of anticancer drugs Taxol and Imatinib, and proteasome inhibitor MG-132 on human hepatoma cell line HepG2.}, series = {Clinical Hemorheology and Microcirculation}, volume = {69}, journal = {Clinical Hemorheology and Microcirculation}, number = {1-2}, issn = {1386-0291}, doi = {10.3233/CH-189120}, pages = {327 -- 336}, language = {en} } @misc{HofmanSorfVagiannisetal., author = {Hofman, Jakub and Sorf, Ales and Vagiannis, Dimitrios and Sucha, Simona and Novotna, Eva and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Ceckova, Martina and Staud, Frantisek}, title = {Interactions of Alectinib with Human ATP-Binding Cassette Drug Efflux Transporters and Cytochrome P450 Biotransformation Enzymes: Effect on Pharmacokinetic Multidrug Resistance}, series = {Drug Metabolism and Disposition}, volume = {47}, journal = {Drug Metabolism and Disposition}, number = {7}, issn = {1521-009X}, doi = {10.1124/dmd.119.086975}, pages = {699 -- 709}, language = {en} } @misc{SteinbrechtKammererKuepper, author = {Steinbrecht, Susanne and Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {HepG2 cells with recombinant cytochrome P450 enzyme overexpression: Their use and limitation as in vitro liver model}, series = {Journal of Cellular Biotechnology}, volume = {5}, journal = {Journal of Cellular Biotechnology}, number = {1}, issn = {2352-3697}, doi = {10.3233/JCB-189013}, pages = {55 -- 64}, language = {en} } @misc{HofmanSorfVagiannisetal., author = {Hofman, Jakub and Sorf, Ales and Vagiannis, Dimitrios and Sucha, Simona and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Chen, Si and Guo, Lei and Ceckova, Martina and Staud, Frantisek}, title = {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}, series = {Molecular Pharmaceutics}, volume = {16}, journal = {Molecular Pharmaceutics}, number = {11}, doi = {10.1021/acs.molpharmaceut.9b00361}, pages = {4436 -- 4450}, language = {en} } @misc{HailekaGeorgeSteinbrechtetal., author = {Haileka, Vanessa and George, Sandra and Steinbrecht, Susanne and Jung, Friedrich and Reinehr, R. and K{\"u}pper, Jan-Heiner}, title = {Colon cancer cells cultured under hyperosmotic conditions as in vitro model to investigate dehydration effects on cancer drug susceptibility}, series = {Clinical Hemorheology and Microcirculation}, volume = {73}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1875-8622}, doi = {10.3233/CH-199210}, pages = {169 -- 176}, language = {en} } @misc{SchulzKammererKuepper, author = {Schulz, Christian and Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {NADPH-cytochrome P450 reductase expression and enzymatic activity in primary-like human hepatocytes and HepG2 cells for in vitro biotransformation studies}, series = {Clinical Hemorheology and Microcirculation}, volume = {73}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1386-0291}, doi = {10.3233/CH-199226}, pages = {249 -- 260}, language = {en} } @misc{UhligGehreKammereretal., author = {Uhlig, Katja and Gehre, Christian P. and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Coleman, D. and P{\"u}schel, G. and Duschl, Claus}, title = {Real-time monitoring of oxygen consumption of hepatocytes in a microbioreactor}, series = {Toxicology Letters}, volume = {295}, journal = {Toxicology Letters}, number = {Supplement 1}, issn = {0378-4274}, doi = {10.1016/j.toxlet.2018.06.652}, pages = {S115}, language = {en} } @misc{SteinbrechtPfeiferHerzogetal., author = {Steinbrecht, Susanne and Pfeifer, Nadine and Herzog, Natalie and Katzenberger, Nadine and Schulz, Christian and Kammerer, Sarah and K{\"u}pper, Jan-Heiner}, title = {HepG2-1A2 C2 and C7: Lentivirus vector-mediated stable and functional overexpression of cytochrome P450 1A2 in human hepatoblastoma cells}, series = {Toxicology Letters}, volume = {319}, journal = {Toxicology Letters}, issn = {0378-4274}, doi = {10.1016/j.toxlet.2019.11.006}, pages = {155 -- 159}, abstract = {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.}, language = {en} } @misc{LauRangarajanKruegerGengeetal., author = {Lau, S. and Rangarajan, R. and Kr{\"u}ger-Genge, Anne and Braune, Steffen and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Lendlein, Andreas and Jung, Friedrich}, title = {Effects of acrolein in comparison to its prodrug cyclophosphamide on human primary endothelial cells in vitro}, series = {Toxicology in Vitro}, volume = {62}, journal = {Toxicology in Vitro}, issn = {0887-2333}, doi = {10.1016/j.tiv.2019.104685}, pages = {8}, abstract = {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.}, language = {en} } @misc{JungKruegerGengeWaldecketal., author = {Jung, Friedrich and Kr{\"u}ger-Genge, Anne and Waldeck, Peter and K{\"u}pper, Jan-Heiner}, title = {Spirulina platensis, a super food?}, series = {Journal of Cellular Biotechnology}, volume = {5}, journal = {Journal of Cellular Biotechnology}, number = {1}, issn = {2352-3689}, doi = {10.3233/JCB-189012}, pages = {43 -- 54}, abstract = {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.}, language = {en} } @misc{KruegerGengeJungKuepperetal., author = {Kr{\"u}ger-Genge, Anne and Jung, Friedrich and K{\"u}pper, Jan-Heiner and Lehmann, Christian and Franke, Ralf-Peter}, title = {Actin type and distribution in erythrocytes}, series = {Journal of Cellular Biotechnology}, volume = {3}, journal = {Journal of Cellular Biotechnology}, number = {2}, issn = {2352-3697}, doi = {10.3233/JCB-179014}, pages = {81 -- 83}, abstract = {Erythrocytes transport oxygen from the lungs to the tissues. The excess surface area together with the elasticity of the erythrocyte cell membrane provides the flexibility needed to pass through the microvasculature where the oxygen exchange occurs. Although the architecture of the red cell and its membrane-associated cytoskeletal network is known in general, the factors that control the characteristic shape change during echinocyte formation are poorly understood. In this short report we show that in echinocytes a completely reorganized membrane cytoskeleton with a box-like structure of actin filaments prevailed indicating the importance of the actin cytoskeleton during echinocyte formation.}, language = {en} } @misc{JungJungKruegerGengeetal., author = {Jung, Friedrich and Jung, Conrad H. G. and Kr{\"u}ger-Genge, Anne and Waldeck, Peter and K{\"u}pper, Jan-Heiner}, title = {Factors influencing the growth of Spirulina platensis in closed photobioreactors under CO₂ - O₂ conversion}, series = {Journal of Cellular Biotechnology}, volume = {5}, journal = {Journal of Cellular Biotechnology}, number = {2}, issn = {2352-3697}, doi = {10.3233/JCB-199004}, pages = {125 -- 134}, abstract = {Since there is growing interest throughout the world in photosynthetic microbes as a potential source of food or food supplements, an assessment of factors which influence the biomass obtained in bioreactors, protein contents and constituents is important. This work reviews the autotrophic cultivation conditions of Spirulina platensis especially the dependency on the strain, the composition of the nutrient solution, pH, temperature of the medium, light intensity and color as well as exposure rhythm, the flow rate and composition of the aerating gas mixture and the bubble size, the content of oxygen, CO₂ and HCO₃ in the medium and last but not least from the optical density of the spirulina suspension during growth.}, language = {en} } @misc{KruegerGengeJungHufertetal., author = {Kr{\"u}ger-Genge, Anne and Jung, Friedrich and Hufert, Frank and Jung, Ernst Michael and K{\"u}pper, Jan-Heiner and Storsberg, J.}, title = {Effects of gut microbial metabolite trimethylamine N-oxide (TMAO) on platelets and endothelial cells}, series = {Clinical Hemorheology and Microcirculation}, volume = {76}, journal = {Clinical Hemorheology and Microcirculation}, number = {2}, issn = {1875-8622}, doi = {10.3233/CH-209206}, pages = {309 -- 316}, abstract = {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.}, language = {en} } @misc{GehreFlechnerKammereretal., author = {Gehre, Christian P. and Flechner, Marie and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Coleman, Charles Dominic and P{\"u}schel, Gerhard Paul and Uhlig, Katja and Duschl, Claus}, title = {Real time monitoring of oxygen uptake of hepatocytes in a microreactor using optical microsensors}, series = {Scientific Reports}, volume = {10}, journal = {Scientific Reports}, issn = {2045-2322}, doi = {10.1038/s41598-020-70785-6}, abstract = {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.}, language = {en} } @misc{SchulteHubbertKuepperThomasetal., author = {Schulte-Hubbert, Ruth and K{\"u}pper, Jan-Heiner and Thomas, Adam D. and Schrenk, Dieter}, title = {Estragole: DNA adduct formation in primary rat hepatocytes and genotoxic potential in HepG2-CYP1A2 cells}, series = {Toxicology}, volume = {444}, journal = {Toxicology}, issn = {0300-483X}, doi = {10.1016/j.tox.2020.152566}, pages = {8}, abstract = {Estragole is a natural constituent in herbs and spices and in products thereof such as essential oils or herbal teas. After cytochrome P450-catalyzed hydroxylation and subsequent sulfation, estragole acts as a genotoxic hepatocarcinogen forming DNA adducts in rodent liver. Because of the genotoxic mode of action and the widespread occurrence in food and phytomedicines a refined risk assessment for estragole is needed. We analyzed the time- and concentration-dependent levels of the DNA adducts N2-(isoestragole-3'-yl)-2'-desoxyguanosine (E3′N2dG) and N6-(isoestragole-3'-yl)-desoxyadenosine (E3′N6dA), reported to be the major adducts formed in rat liver, in rat hepatocytes (pRH) in primary culture after incubation with estragole. DNA adduct levels were measured via UHPLC-ESI-MS/MS using stable isotope dilution analysis. Both adducts were formed in pRH and could already be quantified after an incubation time of 1 h (E3′N6dA at 10 μM, E3′N2dG at 1μM estragole). E3′N2dG, the main adduct at all incubation times and concentrations, could be detected at estragole concentrations < 0.1 μM after 24 h and < 0.5 μM after 48 h. Adduct levels were highest after 6 h and showed a downward trend at later time-points, possibly due to DNA repair and/or apoptosis. While the concentration-response characteristics of adduct formation were apparently linear over the whole concentration range, strong indication for marked hypo-linearity was obtained when the modeling was based on concentrations < 1 μM only. In the micronucleus assay no mutagenic potential of estragole was found in HepG2 cells whereas in HepG2-CYP1A2 cells 1 μM estragole led to a 3.2 fold and 300 μM to a 7.1 fold increase in micronuclei counts. Our findings suggest the existence of a 'practical threshold' dose for DNA adduct formation as an initiating key event of the carcinogenicity of estragole indicating that the default assumption of concentration-response-linearity is questionable, at least for the two major adducts studied here.}, language = {en} } @misc{RutzGaoKuepperetal., author = {Rutz, Lukas and Gao, Lan and K{\"u}pper, Jan-Heiner and Schrenk, Dieter}, title = {Structure-dependent genotoxic potencies of selected pyrrolizidine alkaloids in metabolically competent HepG2 cells}, series = {Archives of Toxicology}, volume = {94}, journal = {Archives of Toxicology}, number = {12}, issn = {0340-5761}, doi = {10.1007/s00204-020-02895-z}, pages = {4159 -- 4172}, abstract = {1,2-unsaturated pyrrolizidine alkaloids (PAs) are natural plant constituents comprising more than 600 different structures. A major source of human exposure is thought to be cross-contamination of food, feed and phytomedicines with PA plants. In humans, laboratory and farm animals, certain PAs exert pronounced liver toxicity and can induce malignant liver tumors in rodents. Here, we investigated the cytotoxicity and genotoxicity of eleven PAs belonging to different structural classes. Although all PAs were negative in the fluctuation Ames test in Salmonella, they were cytotoxic and induced micronuclei in human HepG2 hepatoblastoma cells over-expressing human cytochrome P450 3A4. Lasiocarpine and cyclic diesters except monocrotaline were the most potent congeners both in cytotoxicity and micronucleus assays with concentrations below 3 μM inducing a doubling in micronuclei counts. Other open di-esters and all monoesters exhibited weaker or much weaker geno- and cytotoxicity. The findings were in agreement with recently suggested interim Relative Potency (iREP) factors with the exceptions of europine and monocrotaline. A more detailed micronuclei analysis at low concentrations of lasiocarpine, retrorsine or senecionine indicated that pronounced hypolinearity of the concentration-response curves was evident for retrorsine and senecionine but not for lasiocarpine. Our findings show that the genotoxic and cytotoxic potencies of PAs in a human hepatic cell line vary in a structure-dependent manner. Both the low potency of monoesters and the shape of prototype concentration-response relationships warrant a substance- and structure-specific approach in the risk assessment of PAs.}, language = {en} } @misc{KuenzelRauschSchaefferetal., author = {K{\"u}nzel, Stephan R. and Rausch, Johanna S. E. and Sch{\"a}ffer, Charlotte and Hoffmann, Maximilian and K{\"u}nzel, Karolina and Klapproth, Erik and Kant, Theresa and Herzog, Natalie and K{\"u}pper, Jan-Heiner and Lorenz, Kristina and Dudek, Svenja and Emig, Ramona and Ravens, Ursula and Rog-Zielinska, Eva A. and Peyronnet, R{\´e}mi and El-Armouche, Ali}, title = {Modeling atrial fibrosis in vitro - Generation and characterization of a novel human atrial fibroblast cell line}, series = {FEBS Open Bio}, volume = {10}, journal = {FEBS Open Bio}, number = {7}, issn = {2211-5463}, doi = {10.1002/2211-5463.12896}, pages = {1210 -- 1218}, abstract = {Atrial fibrillation (AF) is regularly accompanied by cardiac fibrosis and concomitant heart failure. Due to the heterogeneous nature and complexity of fibrosis, the knowledge about the underlying mechanisms is limited, which prevents effective pharmacotherapy. A deeper understanding of cardiac fibroblasts is essential to meet this need. We previously described phenotypic and functional differences between atrial fibroblasts from patients in sinus rhythm and with AF. Herein, we established and characterized a novel human atrial fibroblast line, which displays typical fibroblast morphology and function comparable to primary cells but with improved proliferation capacity and low spontaneous myofibroblast differentiation. These traits make our model suitable for the study of fibrosis mechanisms and for drug screening aimed at developing effective antifibrotic pharmacotherapy.}, language = {en} } @misc{JungKriegerHufertetal., author = {Jung, Friedrich and Krieger, Volker and Hufert, Frank and K{\"u}pper, Jan-Heiner}, title = {How we should respond to the Coronavirus SARS-CoV-2 outbreak: A German perspective}, series = {Clinical Hemorheology and Microcirculation}, volume = {74}, journal = {Clinical Hemorheology and Microcirculation}, number = {4}, issn = {1875-8622}, doi = {10.3233/CH-209004}, pages = {363 -- 372}, abstract = {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.}, language = {en} } @misc{KuepperJungKriegeretal., author = {K{\"u}pper, Jan-Heiner and Jung, Friedrich and Krieger, Volker and Hufert, Frank}, title = {A comparison of mortality rates between European and Asian States}, series = {Clinical Hemorheology and Microcirculation}, volume = {75}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1875-8622}, doi = {10.3233/CH-209008}, pages = {3 -- 5}, language = {en} } @misc{JungKruegerGengeFrankeetal., author = {Jung, Friedrich and Kr{\"u}ger-Genge, Anne and Franke, Ralf-Peter and Hufert, Frank and K{\"u}pper, Jan-Heiner}, title = {COVID-19 and the endothelium}, series = {Clinical Hemorheology and Microcirculation}, volume = {75}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1875-8622}, doi = {10.3233/CH-209007}, pages = {7 -- 11}, abstract = {There is growing evidence that COVID-19 not only affects the lungs but beyond that the endothelial system. Recent studies showed that this can lead to microcirculatory impairments and in consequence to functional disorders of all inner organs. The combination of endothelial dysfunction with a generalized inflammatory state and complement elements may together contribute to the overall pro-coagulative state described in COVID-19 patients leading to venular as well as to arteriolar occlusions.}, language = {en} } @misc{JungKriegerHufertetal., author = {Jung, Friedrich and Krieger, Volker and Hufert, Frank and K{\"u}pper, Jan-Heiner}, title = {Herd immunity or suppression strategy to combat COVID-19}, series = {Clinical Hemorheology and Microcirculation}, volume = {75}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1875-8622}, doi = {10.3233/CH-209006}, pages = {13 -- 17}, abstract = {Some months ago, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out in Wuhan, China, and spread rapidly around the world. Some states, such as the Netherlands, Germany, Great Britain, Sweden and the USA initially focused on keeping the restrictions for economy and society as low as possible. The responsible authorities were of the opinion - and still are e.g. in Sweden - that it is sufficient enough to protect particularly vulnerable persons such as the elderly or people with pre-existing conditions. The idea behind this is that as soon as 60 to 70 percent of the population is infected with a pathogen, a so-called "herd immunity" has developed. However, the increasing numbers of deaths and modelling studies showed the expected overload of the hospitals. Therefore, most countries decided for a temporary lockdown with the exception of Sweden. Based on the number of the total population, three times more people died from COVID-19 in Sweden (2679 deaths per 10 million inhabitants) compared to Germany (6848 deaths per 80 million inhabitants). The comparison Sweden versus Taiwan is even worse because 1072 times more people died in Sweden based on the number of the population (6 deaths per 24 million inhabitants).}, language = {en} } @misc{SteinbrechtKiebistKoenigetal., author = {Steinbrecht, Susanne and Kiebist, Jan and K{\"o}nig, Rosalie and Thiessen, Markus and Schmidtke, Kai-Uwe and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Scheibner, Katrin}, title = {Synthesis of cyclophosphamide metabolites by a peroxygenase from Marasmius rotula for toxicological studies on human cancer cells}, series = {AMB Express}, volume = {10}, journal = {AMB Express}, issn = {2191-0855}, doi = {10.1186/s13568-020-01064-w}, pages = {13}, abstract = {Cyclophosphamide (CPA) represents a widely used anti-cancer prodrug that is converted by liver cytochrome P450 (CYP) enzymes into the primary metabolite 4-hydroxycyclophosphamide (4-OH-CPA), followed by non-enzymatic generation of the bioactive metabolites phosphoramide mustard and acrolein. The use of human drug metabolites as authentic standards to evaluate their toxicity is essential for drug development. However, the chemical synthesis of 4-OH-CPA is complex and leads to only low yields and undesired side products. In past years, fungal unspecific peroxygenases (UPOs) have raised to powerful biocatalysts. They can exert the identical selective oxyfunctionalization of organic compounds and drugs as known for CYP enzymes with hydrogen peroxide being used as sole cosubstrate. Herein, we report the efficient enzymatic hydroxylation of CPA using the unspecific peroxygenase from Marasmius rotula (MroUPO) in a simple reaction design. Depending on the conditions used the primary liver metabolite 4-OH-CPA, its tautomer aldophosphamide (APA) and the overoxidized product 4-ketocyclophosphamide (4-keto-CPA) could be obtained. Using a kinetically controlled approach 4-OH-CPA was isolated with a yield of 32\% (purity > 97.6\%). Two human cancer cell lines (HepG2 and MCF-7) were treated with purified 4-OH-CPA produced by MroUPO (4-OH-CPAUPO). 4-OH-CPAUPO-induced cytotoxicity as measured by a luminescent cell viability assay and its genotoxicity as measured by γH2AX foci formation was not significantly different to the commercially available standard. The high yield of 4-OH-CPAUPO and its biological activity demonstrate that UPOs can be efficiently used to produce CYP-specific drug metabolites for pharmacological assessment.}, language = {en} } @misc{VagiannisNovotnaSkarkaetal., author = {Vagiannis, Dimitrios and Novotna, Eva and Skarka, Adam and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Chen, Si and Guo, Lei and Staud, Frantisek and Hofman, Jakub}, title = {Ensartinib (X-396) Effectively Modulates Pharmacokinetic Resistance Mediated by ABCB1 and ABCG2 Drug Efflux Transporters and CYP3A4 Biotransformation Enzyme}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {4}, issn = {2072-6694}, doi = {10.3390/cancers12040813}, pages = {27}, abstract = {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.}, language = {en} } @misc{LauRangarajanKruegerGengeetal., author = {Lau, S. and Rangarajan, R. and Kr{\"u}ger-Genge, Anne and Braune, Steffen and K{\"u}pper, Jan-Heiner and Lendlein, Andreas and Jung, Friedrich}, title = {Age-related morphology and function of human arterial endothelial cells}, series = {Clinical Hemorheology and Microcirculation}, volume = {74}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1875-8622}, doi = {10.3233/CH-199238}, pages = {93 -- 107}, abstract = {Endothelialization of cardiovascular implants is regarded as a promising strategy for long-term compatibility. While umbilical vein endothelial cells are typically applied in research, human arterial endothelial cells (HAEC) from elderly donors would be the obvious source for autologous cellularization strategies. In our approach, HAEC from 16 donors of varying age (16-63 years) were divided into two groups (<30 years and >30 years) and analyzed regarding morphology, viability, proliferation, function and senescence status. No age-related differences were found regarding morphology, viability, density, prostacyclin and nitrite secretion or collagen and laminin production. However, the metabolic activity was slightly decreased (p = 0.0374) and the membrane integrity marginally impaired (p = 0.0404) in cells from older donors. Two out of three senescence assays detected more senescence markers in cells from older donors. According to the assays applied here, HAEC from young and elderly donors up to the age of 63 years could be judged equally suitable for autologous cellularization strategies. However, this finding should be regarded with caution due to the extremely large variability between individual donors. Further studies comprising a larger sample size are necessary to investigate this issue more thoroughly.}, language = {en} } @misc{KruegerGengeSteinbrechtJungetal., author = {Kr{\"u}ger-Genge, Anne and Steinbrecht, Susanne and Jung, Conrad H. G. and Westphal, Sophia and Kl{\"o}pzig, Stefanie and Waldeck, Peter and K{\"u}pper, Jan-Heiner and Storsberg, J. and Jung, Friedrich}, title = {Arthrospira platensis accelerates the formation of an endothelial cell monolayer and protects against endothelial cell detachment after bacterial contamination}, series = {Clinical Hemorheology and Microcirculation}, volume = {78}, journal = {Clinical Hemorheology and Microcirculation}, number = {2}, issn = {1386-0291}, doi = {10.3233/CH-201096}, pages = {151 -- 161}, abstract = {Within the last years a comprehensive number of scientific studies demonstrated beneficial effect of Arthropira platensis (AP) as dietary supplement due to a high content of proteins, minerals and vitamins. Positive effects like promoting the immune system, reducing inflammation and an anti-oxidant capacity are reported. In this study, the effect of an aqueous AP extract on primary human venous endothelial cells (HUVEC) was investigated. In addition, the effect of AP on HUVEC treated with a bacterial toxin (lipopolysaccharide, LPA), inducing an activation of HUVEC and cellular detachment, was analyzed. Depending on the concentration of AP extract a significantly accelerated formation of an endothelial cell monolayer was observed. Furthermore, the detachment of HUVEC after LPA addition was dramatically reduced by AP. In conclusion, the data are promising and indicatory for an application of Arthrospira platensis in the clinical field.}, language = {en} } @misc{SchulzKruegerGengeLendleinetal., author = {Schulz, Christian and Kr{\"u}ger-Genge, Anne and Lendlein, Andreas and K{\"u}pper, Jan-Heiner and Jung, Friedrich}, title = {Potential Effects of Nonadherent on Adherent Human Umbilical Venous Endothelial Cells in Cell Culture}, series = {International Journal of Molecular Science}, volume = {22}, journal = {International Journal of Molecular Science}, number = {3}, doi = {10.3390/ijms22031493}, pages = {15}, abstract = {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.}, language = {en} } @misc{GeburekRutzGaoetal., author = {Geburek, Ina and Rutz, Lukas and Gao, Lan and K{\"u}pper, Jan-Heiner and These, Anja and Schrenk, Dieter}, title = {The metabolic pattern of hepatotoxic pyrrolizidine alkaloids in liver cells}, series = {Chemical Research in Toxicology}, volume = {34}, journal = {Chemical Research in Toxicology}, number = {4}, doi = {10.1021/acs.chemrestox.0c00507}, pages = {1101 -- 1113}, abstract = {Contamination with 1,2-unsaturated pyrrolizidine alkaloids (PAs) is a serious problem for certain phytomedicines, foods, and animal feeds. Several of these PAs are genotoxic and carcinogenic, primarily in the liver, upon cytochrome P450 (CYP)-catalyzed activation into reactive (pyrrolic and pyrrole-like) metabolites. Here we investigated the metabolism of selected PAs (echimidine, europine, lasiocarpine, lycopsamine, retrorsine, and senecionine) in rat hepatocytes in primary culture and in human CYP3A4-transfected HepG2 cells. The open-chained diesters echimidine and lasiocarpine and the cyclic diester senecionine were extensively metabolized in rat hepatocytes into a broad spectrum of products released into the medium. A large portion of unidentified, possibly irreversibly bound, products remained in the cells while detectable amounts of reactive and other metabolites were found in the incubation media. In HepG2-CYP3A4 cells, lasiocarpine was more extensively metabolized than echimidine and senecionine which also gave rise to the release of pyrrolic metabolites. In human cells, no pyrrolic metabolites were detected in retrorsine or lycopsamine incubations, while no such metabolites were detected from europine in both cell types. Other types of metabolic changes comprised modifications such as side chain demethylation or oxygenation reactions like the formation of N-oxides. The latter, considered as a detoxification step, was a major pathway with cyclic diesters, was less distinctive for echimidine and lycopsamine and almost negligible for lasiocarpine and europine. Our data are in agreement with previously published cyto- and genotoxicity findings and suggests that the metabolic pattern may contribute substantially to the specific toxic potency of a certain congener. In addition, marked differences were found for certain congeners between rat hepatocytes and transfected human HepG2 cells, whereby a high level of bioactivation was found for lasiocarpine, whereas a very low level of bioactivation was observed for monoesters, in particular in human cells.}, language = {en} } @misc{JungWaldeckPetricketal., author = {Jung, Conrad H. G. and Waldeck, Peter and Petrick, Ingolf and Braune, Steffen and K{\"u}pper, Jan-Heiner and Jung, Friedrich}, title = {Bioreactor for the cultivation of Arthrospira platensis under controlled conditions}, series = {Journal of Cellular Biotechnology}, volume = {7}, journal = {Journal of Cellular Biotechnology}, number = {1}, doi = {10.3233/JCB-210032}, pages = {35 -- 40}, abstract = {A vertical flat-type bioreactor consisting of transparent polyethylene (food safe) was constructed, which is characterized by a flexible design and allows the adjustment of a light path of 1 cm - 8.5 cm and a working volume of 1.5 l - 4 l. To characterize the performance of the bioreactor, cultivation experiments were performed with the cyanobacterium Arthrospira platensis (AP). The growth was assessed continuously by monitoring optical density and intermittently by measuring the dry weight of the AP biomass. An on-line measurement technique for estimating biomass production rate in a photosynthetic microalgae culture was developed. The oxygen produced by AP in the culture medium was flushed out sparging using a mixture of air and CO2 (1\%). Factors which might influence the AP growth were monitored: pH, temperature, oxygen concentration and the filling level were corrected automatically to compensate evaporation losses. As an example, the huge influence of the light intensity on the AP growth was tested. The increase of the photon flux density of 15 to 1200μmol/(l · d) led to a 22-fold increase of the productivity and a 3.1-fold shorter doubling time. Using an online measurement technique - together with the control of the growth process via a wireless local area network (WLAN) router and virtual private network - allows monitoring the growth of Arthrospira platensis remotely.}, language = {en} } @misc{RahmanMoolaKuepper, author = {Rahman, Ateeq and Moola, Nyambe and K{\"u}pper, Jan-Heiner}, title = {Namibian algae species: A review of their distribution, medicinal uses and chemical constituents}, series = {Journal of Cellular Biotechnology}, volume = {6}, journal = {Journal of Cellular Biotechnology}, number = {2}, doi = {10.3233/JCB-209010}, pages = {139 -- 159}, abstract = {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.}, language = {en} } @misc{BrauneKuepperJung, author = {Braune, Steffen and K{\"u}pper, Jan-Heiner and Jung, Friedrich}, title = {Effect of Prostanoids on Human Platelet Function: An Overview}, series = {International Journal of Molecular Science}, volume = {21}, journal = {International Journal of Molecular Science}, number = {23}, doi = {10.3390/ijms21239020}, pages = {20}, abstract = {Prostanoids are bioactive lipid mediators and take part in many physiological and pathophysiological processes in practically every organ, tissue and cell, including the vascular, renal, gastrointestinal and reproductive systems. In this review, we focus on their influence on platelets, which are key elements in thrombosis and hemostasis. The function of platelets is influenced by mediators in the blood and the vascular wall. Activated platelets aggregate and release bioactive substances, thereby activating further neighbored platelets, which finally can lead to the formation of thrombi. Prostanoids regulate the function of blood platelets by both activating or inhibiting and so are involved in hemostasis. Each prostanoid has a unique activity profile and, thus, a specific profile of action. This article reviews the effects of the following prostanoids: prostaglandin-D2 (PGD2), prostaglandin-E1, -E2 and E3 (PGE1, PGE2, PGE3), prostaglandin F2α (PGF2α), prostacyclin (PGI2) and thromboxane-A2 (TXA2) on platelet activation and aggregation via their respective receptors.}, language = {en} } @misc{BrauneKruegerGengeKammereretal., author = {Braune, Steffen and Kr{\"u}ger-Genge, Anne and Kammerer, Sarah and Jung, Friedrich and K{\"u}pper, Jan-Heiner}, title = {Phycocyanin from Arthrospira platensis as Potential Anti-Cancer Drug: Review of In Vitro and In Vivo Studies}, series = {Life}, volume = {11}, journal = {Life}, number = {2}, doi = {10.3390/life11020091}, pages = {91}, language = {en} }