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 - Jung, Conrad H. G. A1 - Waldeck, Peter A1 - Petrick, Ingolf A1 - Akinwunmi, Mosunmol A1 - Braune, Steffen A1 - Jung, Friedrich A1 - Küpper, Jan-Heiner T1 - Light-induced changes in the morphology and fluorescence of Arthrospira platensis T2 - Clinical Hemorheology and Microcirculation N2 - The cyanobacterium Arthrospira platensis is a well-known source of bioactive substances. Growth and the generation of bioactive ingredients of Arthrospira platensis depend mainly on the quantity of light in a controlled environment. Photoinhibition is a time, nutrient, and light intensity-dependent decrease in photosynthetic efficiency. However, too strong illumination can induce two harmful effects: (1) photoinhibition as a reduction in photosynthetic rate and (2) photooxidation which can have lethal effects on the cells, and which can lead to total loss of the culture. The results of this microscopical study demonstrate, that under the procedures described and very high photon flux den-sities, not only a decrease in the photosynthetic efficiency but beyond, also destruction of Arthrospira platensis can occur. KW - Arthrospira platensis KW - light stress KW - photoinhibition KW - phototoxicity KW - morphology KW - fluorescence Y1 - 2023 UR - https://content.iospress.com/articles/journal-of-cellular-biotechnology/jcb239001 U6 - https://doi.org/10.3233/JCB-239001 SN - 1386-0291 VL - 9 IS - 1 SP - 71 EP - 77 ER - TY - GEN A1 - Rosellini, Matteo A1 - Schulze, Alicia A1 - Omer, Ejlal A. A1 - Ali, Nadeen T. A1 - Marini, Federico A1 - Küpper, Jan-Heiner A1 - Efferth, Thomas T1 - The effect of plastic-related compounds on transcriptome-wide gene expression on CYP2C19-overexpressing HepG2 cells T2 - Molecules N2 - In recent years, plastic and especially microplastic in the oceans have caused huge problems to marine flora and fauna. Recently, such particles have also been detected in blood, breast milk, and placenta, underlining their ability to enter the human body, presumably via the food chain and other yet-unknown mechanisms. In addition, plastic contains plasticizers, antioxidants, or lubricants, whose impact on human health is also under investigation. At the cellular level, the most important enzymes involved in the metabolism of xenobiotic compounds are the cytochrome P450 monooxygenases (CYPs). Despite their extensive characterization in the maintenance of cellular balance, their interactions with plastic and related products are unexplored. In this study, the possible interactions between several plastic-related compounds and one of the most important cytochromes, CYP2C19, were analyzed. By applying virtual compound screening and molecular docking to more than 1000 commercially available plastic-related compounds, we identified candidates that are likely to interact with this protein. A growth inhibition assay confirmed their cytotoxic activity on a CYP2C19-transfected hepatic cell line. Subsequently, we studied the effect of the selected compounds on the transcriptome-wide gene expression level by conducting RNA sequencing. Three candidate molecules were identified, i.e., 2,2′-methylene bis(6-tert-butyl-4-methylphenol), 1,1-bis(3,5-di-tert-butyl-2-hydroxyphenyl) ethane, and 2,2′-methylene bis(6-cyclohexyl-4-methylphenol)), which bound with a high affinity to CYP2C19 in silico. They exerted a profound cytotoxicity in vitro and interacted with several metabolic pathways, of which the ‘cholesterol biosynthesis process’ was the most affected. In addition, other affected pathways involved mitosis, DNA replication, and inflammation, suggesting an increase in hepatotoxicity. These results indicate that plastic-related compounds could damage the liver by affecting several molecular pathways. KW - cytotoxicity KW - ecotoxicity KW - hepatotoxicity KW - microplastic KW - RNA sequencing Y1 - 2023 UR - https://www.mdpi.com/1420-3049/28/16/5952 U6 - https://doi.org/10.3390/molecules28165952 SN - 1420-3049 VL - 28 IS - 16 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 - Nghinaunye, Theopolina A1 - Waldeck, Peter A1 - Jung, Conrad H. G. 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 - Jung, Conrad H. G. A1 - Nghinaunye, Theopolina A1 - Waldeck, Peter A1 - Braune, Steffen A1 - Petrick, Ingolf A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich T1 - Decarbonization of Arthrospira platensis production by using atmospheric CO2 as an exclusive carbon source: proof of principle T2 - International Journal of Environmental Science and Technology N2 - There is an urgent need to develop technologies for removing CO2 from the atmosphere to combat climate change. Microalgae and cyanobacteria, such as Arthrospira platensis (AP), have shown promise due to their high photoautotrophic biomass production. Conventional AP culture media are supplemented with high concentrations of NaHCO3 since AP utilizes as a carbon source. These culture conditions result in significant amounts of CO2 escaping into the atmosphere, instead of being sequestered during cultivation. Here, we investigated whether ambient air (0.042% CO2) can be used for growing AP in a culture medium lacking a fossil-based carbon source. AP was cultured in 2 L glass bioreactors containing: (1) Zarrouk medium with 16.8 g/L NaHCO3 and aeration with 0.236 vvm air with 2% CO2 (“NaHCO3/CO2-based”) to compensate carbon loss due to CO2 outgassing, and (2) Zarrouk medium without NaHCO3 and a gas flow with ambient air (0.926 vvm) as the only carbon source (“air-based”). The air-based production resulted in the biofixation of 3.78 gCO2/L during the linear growth phase. With NaHCO3/CO2-based production, a comparable amount of 3.42 gCO2/L was obtained while 659.12 g of CO2 was released into the atmosphere. Total protein, phycocyanin, chlorophyll-a, and carotenoids were present in similar or increased amounts in AP produced by the air-based method. We concluded that cultivation of AP with Zarrouk medium lacking NaHCO3 but using ambient air with atmospheric CO2 as the only carbon source is possible without reducing productivity. These results improve our understanding of how atmospheric CO2 can be reduced by culturing AP. KW - Arthrospira platensis KW - Atmospheric CO2 KW - Biomass production KW - Climate change KW - Carbon capturing KW - Decarbonization Y1 - 2023 UR - https://link.springer.com/article/10.1007/s13762-023-05215-x#citeas U6 - https://doi.org/10.1007/s13762-023-05215-x SN - 1735-2630 ER - TY - GEN A1 - Krüger-Genge, Anne A1 - Harb, Kudor A1 - Braune, Steffen A1 - Jung, Conrad H. G. A1 - Westphal, Sophia A1 - Bär, Stefanie A1 - Mauger, Olivia A1 - Küpper, Jan-Heiner A1 - Jung, Friedrich ED - Georgianos, Panagiotis T1 - Effects of arthrospira platensis on human Uumbilical vein endothelial cells T2 - Life N2 - Atherosclerosis is initiated by injury or damage to the vascular endothelial cell monolayer. Therefore, the early repair of the damaged vascular endothelium by a proliferation of neighbouring endothelial cells is important to prevent atherosclerosis and thrombotic events. Arthrospira platensis (AP) has been used as a dietary supplement, mainly due to its high content of vitamins, minerals, amino acids, and pigments such as chlorophylls, carotenoids, and phycocyanin, ingredients with antioxidant, anti-inflammatory, and anti-thrombotic properties. Therefore, in this prospective, placebo-controlled, data-driven, sample-size-estimated in vitro study, we tested whether an aqueous extract of AP at different concentrations (50, 100, and 200 µg/mL) had an effect on the different cellular parameters of human umbilical vein endothelial cells. Therefore, cell impedance measurement and cell proliferation were measured to investigate the monolayer formation. In addition, cell viability, integrity, and metabolism were analysed to evaluate singular cellular functions, especially the antithrombotic state. Furthermore, cell–cell and cell–substrate interactions were observed. The highest proliferation was achieved after the addition of 100 µg/mL. This was consistently confirmed by two independent optical experiments in cell cultures 48 h and 85 h after seeding and additionally by an indirect test. At this concentration, the activation or dysfunction of HUVECs was completely prevented, as confirmed by prostacyclin and interleukin-6 levels. In conclusion, in this study, AP induced a significant increase in HUVEC proliferation without inducing an inflammatory response but altered the hemostasiological balance in favour of prostacyclin over thromboxane, thereby creating an antithrombotic state. Thus, APE could be applied in the future as an accelerator of endothelial cell proliferation after, e.g., stent placement or atherosclerosis. KW - human umbilical vein endothelial cells KW - HUVEC Y1 - 2024 U6 - https://doi.org/10.3390/life14101253 SN - 2075-1729 VL - 14 IS - 10 PB - MDPI ER - TY - GEN A1 - Rosellini, Matteo A1 - Omer, Ejlal A. A1 - Schulze, Alicia A1 - Ali, Nadeen T. A1 - Boulos, Joelle C. A1 - Marini, Federico A1 - Küpper, Jan-Heiner A1 - Efferth, Thomas T1 - Impact of plastic-related compounds on the gene expression signature of HepG2 cells transfected with CYP3A4 T2 - Archives of Toxicology N2 - The presence of plastic and microplastic within the oceans as well as in marine flora and fauna have caused a multitude of problems that have been the topic of numerous investigations for many years. However, their impact on human health remains largely unknown. Such plastic and microplastic particles have been detected in blood and placenta, underlining their ability to enter the human body. Plastics also contain other compounds, such as plasticizers, antioxidants, or dyes, whose impact on human health is currently being studied. Critical enzymes within the metabolism of endogenous molecules, especially of xenobiotics, are the cytochrome P450 monooxygenases (CYPs). Although their importance in maintaining cellular balance has been confirmed, their interactions with plastics and related products are poorly understood. In this study, the possible relationship between different plastic-related compounds and CYP3A4 as one of the most important CYPs was analyzed using hepatic cells overexpressing this enzyme. Beginning with virtual compound screening and molecular docking of more than 1000 plastic-related compounds, several candidates were identified to interact with CYP3A4. In a second step, RNA-sequencing was used to study in detail the transcriptome-wide gene expression levels affected by the selected compounds. Three candidate molecules ((2,2′-methylenebis(6- tert -butyl-4-methylphenol), 1,1-bis(3,5-di- tert -butyl-2-hydroxyphenyl)ethane, and 2,2′-methylenebis(6-cyclohexyl-4-methylphenol)) had an excellent binding affinity to CYP3A4 in-silico as well as cytotoxic effects and interactions with several metabolic pathways in-vitro. We identified common pathways influenced by all three selected plastic-related compounds. In particular, the suppression of pathways related to mitosis and ‘DNA-templated DNA replication’ which were confirmed by cell cycle analysis and single-cell gel electrophoresis. Furthermore, several mis-regulated metabolic and inflammation-related pathways were identified, suggesting the induction of hepatotoxicity at different levels. These findings imply that these compounds may cause liver problems subsequently affecting the entire organism. KW - Cytotoxicity KW - Ecotoxicity KW - Environmental pollution KW - Hepatotoxicity KW - Marine pollution KW - Microplastic KW - RNA-sequencing KW - Biological Sciences Y1 - 2024 U6 - https://doi.org/10.1007/s00204-023-03648-4 SN - 0340-5761 SN - 1432-0738 VL - 98 IS - 2 SP - 525 EP - 536 PB - Springer Berlin Heidelberg ER - TY - GEN A1 - Schulz, Christian A1 - Stegen, Sarah A1 - Jung, Friedrich A1 - Küpper, Jan-Heiner ED - Lamb, David ED - Syed, Khajamohiddin T1 - Mono-CYP CHO model : a recombinant Chinese hamster ovary cell platform for investigating CYP-specific tamoxifen metabolism T2 - International journal of molecular sciences N2 - The metabolism of drugs and foreign substances in humans typically involves multiple enzymatic steps, particularly in phase-1 biotransformation in the liver, where various cytochrome P450 monooxygenases (CYPs) play crucial roles. This complexity can lead to a wide range of metabolites. Understanding the contributions of individual CYPs and their interactions within these intricate enzyme cascades can be challenging. We recently developed an in vitro biotransformation platform employing various Chinese Hamster Ovarian (CHO) cell clones. These clones express human cytochrome P450 oxidoreductase (CPR), and each is defined by a specific human CYP enzyme expression, thus exhibiting no detectable endogenous CYP enzyme activity (mono-CYP CHO platform). In this study, we investigated whether the mono-CYP CHO platform is a suitable tool for modeling complex drug metabolization reactions in vitro. Tamoxifen (TAM) was selected as a model substance due to its role as a prodrug widely used in breast cancer therapy, where its main active metabolite, endoxifen, arises from a two-step metabolism primarily involving the CYP system. Specifically, the combined activity of CYP3A4 and CYP2D6 is believed to be essential for efficient endoxifen production. However, the physiological metabolization pathway of TAM is more complex and interconnected, and the reasons for TAM’s therapeutic success and variability among patients are not yet fully understood. Analogous to our recently introduced mono-CYP3A4 CHO cells, we generated a CHO cell line expressing human CPR and CYP2D6, including analysis of CYP2D6 expression and specific activity. Comparative studies on the metabolization of TAM were performed with both mono-CYP CHO models individually and in co-culture with intact cells as well as with isolated microsomes. Supernatants were analyzed by HPLC to calculate individual CYP activity for each metabolite. All the picked mono-CYP2D6 clones expressed similar CYP2D6 protein amounts but showed different enzyme activities. Mono-CYP2D6 clone 18 was selected as the most suitable for TAM metabolization based on microsomal activity assays. TAM conversion with mono-CYP2D6 and -3A4 clones, as well as the combination of both, resulted in the formation of the expected main metabolites. Mono-CYP2D6 cells and microsomes produced the highest detected amounts of 4-hydroxytamoxifen and endoxifen, along with N -desmethyltamoxifen and small amounts of N , N -didesmethyltamoxifen. N -desmethyltamoxifen was the only TAM metabolite detected in notable quantities in mono-CYP3A4, while 4-hydroxytamoxifen and endoxifen were present only in trace amounts. In CYP2D6/3A4 co-culture and equal mixtures of both CYP microsomes, all metabolites were detected at concentrations around 50% of those in individual clones, indicating no significant synergistic effects. In conclusion, our mono-CYP CHO model confirmed the essential role of CYP2D6 in synthesizing the active TAM metabolite endoxifen and indicated that CYP2D6 is also involved in producing the by-metabolite N , N -didesmethyltamoxifen. The differences in metabolite spectra between the two mono-CYP models highlight the CYP specificity and sensitivity of our in vitro system. KW - Chinese hamster ovary cells KW - Mono-CYP CHO KW - Liver KW - Phase-1 biotransformation KW - Cytochrome P450 monooxygenase KW - CYP2D6 KW - Tamoxifen KW - Endoxifen KW - DDM-TAM Y1 - 2025 U6 - https://doi.org/10.3390/ijms26093992 SN - 1422-0067 VL - 26 IS - 9 SP - 1 EP - 24 PB - MDPI CY - Basel ER -