@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{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{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{VagiannisZhangBudagagaetal., author = {Vagiannis, Dimitrios and Zhang, Yu and Budagaga, Youssif and Novotna, Eva and Skarka, Adam and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Hofman, Jakub}, title = {Alisertib shows negligible potential for perpetrating pharmacokinetic drug-drug interactions on ABCB1, ABCG2 and cytochromes P450, but acts as dual-activity resistance modulator through the inhibition of ABCC1 transporter}, series = {Toxicology and Applied Pharmacology}, volume = {Vol. 434}, journal = {Toxicology and Applied Pharmacology}, issn = {0041-008X}, doi = {10.1016/j.taap.2021.115823}, pages = {13}, language = {en} } @misc{BrauneKruegerGengeKoehleretal., author = {Braune, Steffen and Kr{\"u}ger-Genge, Anne and K{\"o}hler, S. and K{\"u}pper, Jan-Heiner and Jung, Friedrich}, title = {Effects of Arthrospira platensis-derived substances on blood cells}, series = {Clinical Hemorheology and Microcirculation}, volume = {85(2023)}, journal = {Clinical Hemorheology and Microcirculation}, number = {3}, issn = {1875-8622}, doi = {10.3233/CH-229103}, pages = {315 -- 321}, language = {en} } @misc{JungNghinaunyeWaldecketal., author = {Jung, C. G. H. and Nghinaunye, Theopolina and Waldeck, Peter and Braune, Steffen and Petrick, Ingolf and K{\"u}pper, Jan-Heiner and Jung, Friedrich}, title = {Decarbonization of Arthrospira platensis production by using atmospheric CO2 as an exclusive carbon source: proof of principle}, series = {International Journal of Environmental Science and Technology}, journal = {International Journal of Environmental Science and Technology}, issn = {1735-2630}, doi = {10.1007/s13762-023-05215-x}, abstract = {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.}, language = {en} } @misc{HaasAckermannKuepperetal., author = {Haas, Manuel and Ackermann, Gabriel and K{\"u}pper, Jan-Heiner and Glatt, Hansruedi and Schrenk, Dieter and Fahrer, J{\"o}rg}, title = {OCT1-dependent uptake of structurally diverse pyrrolizidine alkaloids in human liver cells is crucial for their genotoxic and cytotoxic effects}, series = {Archives of Toxicology}, volume = {97}, journal = {Archives of Toxicology}, number = {12}, issn = {1432-0738}, doi = {10.1007/s00204-023-03591-4}, pages = {3259 -- 3271}, abstract = {Pyrrolizidine alkaloids (PAs) are important plant hepatotoxins, which occur as contaminants in plant-based foods, feeds and phytomedicines. Numerous studies demonstrated that the genotoxicity and cytotoxicity of PAs depend on their chemical structure, allowing for potency ranking and grouping. Organic cation transporter-1 (OCT1) was previously shown to be involved in the cellular uptake of the cyclic PA diesters monocrotaline, retrorsine and senescionine. However, little is known about the structure-dependent transport of PAs. Therefore, we investigated the impact of OCT1 on the uptake and toxicity of three structurally diverse PAs (heliotrine, lasiocarpine and riddelliine) differing in their degree and type of esterification in metabolically competent human liver cell models and hamster fibroblasts. Human HepG2-CYP3A4 liver cells were exposed to the respective PA in the presence or absence of the OCT1-inhibitors D-THP and quinidine, revealing a strongly attenuated cytotoxicity upon OCT1 inhibition. The same experiments were repeated in V79-CYP3A4 hamster fibroblasts, confirming that OCT1 inhibition prevents the cytotoxic effects of all tested PAs. Interestingly, OCT1 protein levels were much lower in V79-CYP3A4 than in HepG2-CYP3A4 cells, which correlated with their lower susceptibility to PA-induced cytotoxicity. The cytoprotective effect of OCT1 inhibiton was also demonstrated in primary human hepatocytes following PA exposure. Our experiments further showed that the genotoxic effects triggered by the three PAs are blocked by OCT1 inhibition as evidenced by strongly reduced γH2AX and p53 levels. Consistently, inhibition of OCT1-mediated uptake suppressed the activation of the DNA damage response (DDR) as revealed by decreased phosphorylation of checkpoint kinases upon PA treatment. In conclusion, we demonstrated that PAs, independent of their degree of esterification, are substrates for OCT1-mediated uptake into human liver cells. We further provided evidence that OCT1 inhibition prevents PA-triggered genotoxicity, DDR activation and subsequent cytotoxicity. These findings highlight the crucial role of OCT1 together with CYP3A4-dependent metabolic activation for PA toxicity.}, language = {en} } @misc{JungWaldeckPetricketal., author = {Jung, Conrad H. G. and Waldeck, Peter and Petrick, Ingolf and Akinwunmi, Mosunmol and Braune, Steffen and Jung, Friedrich and K{\"u}pper, Jan-Heiner}, title = {Light-induced changes in the morphology and fluorescence of Arthrospira platensis}, series = {Clinical Hemorheology and Microcirculation}, volume = {9}, journal = {Clinical Hemorheology and Microcirculation}, number = {1}, issn = {1386-0291}, doi = {10.3233/JCB-239001}, pages = {71 -- 77}, abstract = {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.}, language = {en} }