@article{WienekeNeuschaeferRubeBodeetal.2009, author = {Wieneke, Nadine and Neuschaefer-Rube, Frank and Bode, L. M. and Kuna, Manuela and Andres, Jesus and Carnevali Junior, Luiz Carlos and Hirsch-Ernst, Karen I. and P{\"u}schel, Gerhard Paul}, title = {Synergistic acceleration of thyroid hormone degradation by phenobarbital and the PPAR alpha agonist WY14643 in rat hepatocytes}, issn = {0041-008X}, doi = {10.1016/j.taap.2009.07.014}, year = {2009}, abstract = {Energy balance is maintained by controlling both energy intake and energy expenditure. Thyroid hormones play a crucial role in regulating energy expenditure. Their levels are adjusted by a tight feed back-control led regulation of thyroid hormone production/incretion and by their hepatic metabolism. Thyroid hormone degradation has previously been shown to be enhanced by treatment with phenobarbital or other antiepileptic drugs due to a CAR-dependent induction of phase 11 enzymes of xenobiotic metabolism. We have recently shown, that PPAR alpha agonists synergize with phenobarbital to induce another prototypical CAR target gene, CYP2B1. Therefore, it was tested whether a PPAR alpha agonist could enhance the phenobarbital-dependent acceleration of thyroid hormone elimination. In primary cultures of rat hepatocytes the apparent half-life of T3 was reduced after induction with a combination of phenobarbital and the PPARa agonist WY14643 to a larger extent than after induction with either Compound alone. The synergistic reduction of the half-life could be attributed to a synergistic induction of CAR and the CAR target genes that code for enzymes and transporters involved in the hepatic elimination of T3, such as OATP1A1, OATP1A3, UGT1A3 and UCT1A10. The PPAR alpha-dependent CAR induction and the subsequent induction of T3-eliminating enzymes might be of physiological significance for the fasting- incluced reduction in energy expenditure by fatty acids as natural PPARa ligands. The synergism of the PPAR alpha agonist WY14643 and phenobarbital in inducing thyroid hormone breakdown might serve as a paradigm for the synergistic disruption of endocrine control by other combinations of xenobiotics.}, language = {en} } @article{WienekeHirschErnstKunaetal.2007, author = {Wieneke, Nadine and Hirsch-Ernst, Karen I. and Kuna, Manuela and Kersten, Sander and P{\"u}schel, Gerhard Paul}, title = {PPARalpha-dependent induction of the energy homeostasis-regulating nuclear}, issn = {0014-5793}, year = {2007}, abstract = {A tight hormonal control of energy homeostasis is of pivotal relevance for animals. Recent evidence suggests an involvement of the nuclear receptor NR1i3 (CAR). Fasting induces CAR by largely unknown mechanisms and CAR-deficient mice are defective in fasting adaptation. In rat hepatocytes CAR was induced by WY14643, a PPARalpha-agonist. A DR1 motif in the CAR promoter was necessary and sufficient for this control. The PPARalpha-dependent increase in CAR potentiated the phenobarbital-induced transcription of the prototypical CAR-dependent gene CYP2B1. Since free fatty acids are natural ligands for PPARalpha, a fasting-induced increase in free fatty acids might induce CAR. In accordance with this hypothesis, CAR induction by fasting was abrogated in PPARalpha-deficient mice.}, language = {en} } @misc{WatanabePueschelGardemannetal.1994, author = {Watanabe, Yuji and P{\"u}schel, Gerhard Paul and Gardemann, Andreas and Jungermann, Kurt}, title = {Presinusoidal and proximal intrasinusoidal confluence of hepatic artery and portal vein in rat liver : functional evidence by orthograde and retrograde bivascular perfusion}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16702}, year = {1994}, abstract = {The site of confluence of the artery and the portal vein in the liver still appears to be controversial. Anatomical studies suggested a presinusoidal or an intrasinusoidal confluence in the first, second or even final third of the sinusoids. The objective of this investigation was to study the problem with functional biochemical techniques. Rat livers were perfused through the hepatic artery and simultaneously either in the orthograde direction from the portal vein to the hepatic vein or in the retrograde direction from the hepatic vein to the portal vein. Arterial how was linearly dependent on arterial pressure between 70 cm H2O and 120 cm H2O at a constant portal or hepatovenous pressure of 18 cm H2O. An arterial pressure of 100 cm H2O was required for the maintenance of a homogeneous orthograde perfusion of the whole parenchyma and of a physiologic ratio of arterial to portal how of about 1:3. Glucagon was infused either through the artery or the portal vein and hepatic vein, respectively, to a submaximally effective ''calculated'' sinusoidal concentration after mixing of 0.1 nmol/L. During orthograde perfusions, arterial and portal glucagon caused the same increases in glucose output. Yet during retrograde perfusions, hepatovenous glucagon elicited metabolic alterations equal to those in orthograde perfusions, whereas arterial glucagon effected changes strongly reduced to between 10\% and 50\%. Arterially infused trypan blue was distributed homogeneously in the parenchyma during orthograde perfusions, whereas it reached clearly smaller areas of parenchyma during retrograde perfusions. Finally, arterially applied acridine orange was taken up by all periportal hepatocytes in the proximal half of the acinus during orthograde perfusions but only by a much smaller portion of periportal cells in the proximal third of the acinus during retrograde perfusions. These findings suggest that in rat liver, the hepatic artery and the portal vein mix before and within the first third of the sinusoids, rather than in the middle or even last third.}, language = {en} } @article{vonLoeffelholzLieskeNeuschaeferRubeetal.2017, author = {von Loeffelholz, Christian and Lieske, Stefanie and Neuschaefer-Rube, Frank and Willmes, Diana M. and Raschzok, Nathanael and Sauer, Igor M. and K{\"o}nig, J{\"o}rg and Fromm, Martin F. and Horn, Paul and Chatzigeorgiou, Antonios and Pathe-Neuschaefer-Rube, Andrea and Jordan, Jens and Pfeiffer, Andreas F. H. and Mingrone, Geltrude and Bornstein, Stefan R. and Stroehle, Peter and Harms, Christoph and Wunderlich, F. Thomas and Helfand, Stephen L. and Bernier, Michel and de Cabo, Rafael and Shulman, Gerald I. and Chavakis, Triantafyllos and P{\"u}schel, Gerhard Paul and Birkenfeld, Andreas L.}, title = {The human longevity gene homolog INDY and interleukin-6 interact in hepatic lipid metabolism}, series = {Hepatology}, volume = {66}, journal = {Hepatology}, number = {2}, publisher = {Wiley}, address = {Hoboken}, issn = {0270-9139}, doi = {10.1002/hep.29089}, pages = {616 -- 630}, year = {2017}, abstract = {Reduced expression of the Indy ("I am Not Dead, Yet") gene in lower organisms promotes longevity in a manner akin to caloric restriction. Deletion of the mammalian homolog of Indy (mIndy, Slc13a5) encoding for a plasma membrane-associated citrate transporter expressed highly in the liver, protects mice from high-fat diet-induced and aging-induced obesity and hepatic fat accumulation through a mechanism resembling caloric restriction. We studied a possible role of mIndy in human hepatic fat metabolism. In obese, insulin-resistant patients with nonalcoholic fatty liver disease, hepatic mIndy expression was increased and mIndy expression was also independently associated with hepatic steatosis. In nonhuman primates, a 2-year high-fat, high-sucrose diet increased hepatic mIndy expression. Liver microarray analysis showed that high mIndy expression was associated with pathways involved in hepatic lipid metabolism and immunological processes. Interleukin-6 (IL-6) was identified as a regulator of mIndy by binding to its cognate receptor. Studies in human primary hepatocytes confirmed that IL-6 markedly induced mIndy transcription through the IL-6 receptor and activation of the transcription factor signal transducer and activator of transcription 3, and a putative start site of the human mIndy promoter was determined. Activation of the IL-6-signal transducer and activator of transcription 3 pathway stimulated mIndy expression, enhanced cytoplasmic citrate influx, and augmented hepatic lipogenesis in vivo. In contrast, deletion of mIndy completely prevented the stimulating effect of IL-6 on citrate uptake and reduced hepatic lipogenesis. These data show that mIndy is increased in liver of obese humans and nonhuman primates with NALFD. Moreover, our data identify mIndy as a target gene of IL-6 and determine novel functions of IL-6 through mINDY. Conclusion: Targeting human mINDY may have therapeutic potential in obese patients with nonalcoholic fatty liver disease. German Clinical Trials Register: DRKS00005450.}, language = {en} } @misc{UhligGehreKammereretal.2018, author = {Uhlig, Katja and Gehre, Christian P. and Kammerer, Sarah and K{\"u}pper, Jan-Heiner and Coleman, Charles Dominic and P{\"u}schel, Gerhard Paul and Duschl, Claus}, title = {Real-time monitoring of oxygen consumption of hepatocytes in a microbioreactor}, series = {Toxicology letters}, volume = {295}, journal = {Toxicology letters}, publisher = {Elsevier}, address = {Clare}, issn = {0378-4274}, doi = {10.1016/j.toxlet.2018.06.652}, pages = {S115 -- S115}, year = {2018}, language = {en} } @article{SprussHenkelKanurietal.2012, author = {Spruss, Astrid and Henkel, Janin and Kanuri, Giridhar and Blank, Daniela and P{\"u}schel, Gerhard Paul and Bischoff, Stephan C. and Bergheim, Ina}, title = {Female mice are more susceptible to nonalcoholic fatty liver disease sex-specific regulation of the hepatic AMP-Activated protein Kinase-Plasminogen activator inhibitor 1 cascade, but not the hepatic endotoxin response}, series = {Molecular medicine}, volume = {18}, journal = {Molecular medicine}, number = {9}, publisher = {Feinstein Inst. for Medical Research}, address = {Manhasset}, issn = {1076-1551}, doi = {10.2119/molmed.2012.00223}, pages = {1346 -- 1355}, year = {2012}, abstract = {As significant differences between sexes were found in the susceptibility to alcoholic liver disease in human and animal models, it was the aim of the present study to investigate whether female mice also are more susceptible to the development of nonalcoholic fatty liver disease (NAFLD). Male and female C57BL/6J mice were fed either water or 30\% fructose solution ad libitum for 16 wks. Liver damage was evaluated by histological scoring. Portal endotoxin levels and markers of Kupffer cell activation and insulin resistance, plasminogen activator inhibitor 1 (PAI-1) and phosphorylated adenosine monophosphate-activated protein kinase (pAMPK) were measured in the liver. Adiponectin mRNA expression was determined in adipose tissue. Hepatic steatosis was almost similar between male and female mice; however, inflammation was markedly more pronounced in livers of female mice. Portal endotoxin levels, hepatic levels of myeloid differentiation primary response gene (88) (MyD88) protein and of 4-hydroxynonenal protein adducts were elevated in animals with NAFLD regardless of sex. Expression of insulin receptor substrate 1 and 2 was decreased to a similar extent in livers of male and female mice with NAFLD. The less pronounced susceptibility to liver damage in male mice was associated with a superinduction of hepatic pAMPK in these mice whereas, in livers of female mice with NAFLD, PAI-1 was markedly induced. Expression of adiponectin in visceral fat was significantly lower in female mice with NAFLD but unchanged in male mice compared with respective controls. In conclusion, our data suggest that the sex-specific differences in the susceptibility to NAFLD are associated with differences in the regulation of the adiponectin-AMPK-PAI-1 signaling cascade. Online address: http://www.molmed.Org doi: 10.2119/molmed.2012.00223}, language = {en} } @unpublished{SeelaenderLavianoBusquetsetal.2015, author = {Seelaender, Marilia and Laviano, A. and Busquets, S. and P{\"u}schel, Gerhard Paul and Margaria, T. and Batista Jr., Miguel Luiz}, title = {Inflammation in Cachexia}, series = {Mediators of inflammation}, journal = {Mediators of inflammation}, publisher = {Hindawi Publishing Corp.}, address = {New York}, issn = {0962-9351}, doi = {10.1155/2015/536954}, pages = {2}, year = {2015}, language = {en} } @misc{SchaeferKakularamReischetal.2022, author = {Sch{\"a}fer, Marj{\"a}nn Helena and Kakularam, Kumar Reddy and Reisch, Florian and Rothe, Michael and Stehling, Sabine and Heydeck, Dagmar and P{\"u}schel, Gerhard Paul and Kuhn, Hartmut}, title = {Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1295}, issn = {1866-8372}, doi = {10.25932/publishup-57649}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-576491}, pages = {22}, year = {2022}, abstract = {Mammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional Alox genes and the encoded enzymes share a high degree of amino acid conservation with their human orthologs. There are, however, functional differences between mouse and human ALOX orthologs. Human ALOX15B oxygenates arachidonic acid exclusively to its 15-hydroperoxy derivative (15S-HpETE), whereas 8S-HpETE is dominantly formed by mouse Alox15b. The structural basis for this functional difference has been explored and in vitro mutagenesis humanized the reaction specificity of the mouse enzyme. To explore whether this mutagenesis strategy may also humanize the reaction specificity of mouse Alox15b in vivo, we created Alox15b knock-in mice expressing the arachidonic acid 15-lipoxygenating Tyr603Asp+His604Val double mutant instead of the 8-lipoxygenating wildtype enzyme. These mice are fertile, display slightly modified plasma oxylipidomes and develop normally up to an age of 24 weeks. At later developmental stages, male Alox15b-KI mice gain significantly less body weight than outbred wildtype controls, but this effect was not observed for female individuals. To explore the possible reasons for the observed gender-specific growth arrest, we determined the basic hematological parameters and found that aged male Alox15b-KI mice exhibited significantly attenuated red blood cell parameters (erythrocyte counts, hematocrit, hemoglobin). Here again, these differences were not observed in female individuals. These data suggest that humanization of the reaction specificity of mouse Alox15b impairs the functionality of the hematopoietic system in males, which is paralleled by a premature growth arrest.}, language = {en} } @article{SchaeferKakularamReischetal.2022, author = {Sch{\"a}fer, Marj{\"a}nn Helena and Kakularam, Kumar Reddy and Reisch, Florian and Rothe, Michael and Stehling, Sabine and Heydeck, Dagmar and P{\"u}schel, Gerhard Paul and Kuhn, Hartmut}, title = {Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging}, series = {Biomedicines}, volume = {10}, journal = {Biomedicines}, edition = {6}, publisher = {MDPI}, address = {Basel, Schweiz}, issn = {2227-9059}, doi = {10.3390/biomedicines10061379}, pages = {1 -- 22}, year = {2022}, abstract = {Mammalian arachidonic acid lipoxygenases (ALOXs) have been implicated in cell differentiation and in the pathogenesis of inflammation. The mouse genome involves seven functional Alox genes and the encoded enzymes share a high degree of amino acid conservation with their human orthologs. There are, however, functional differences between mouse and human ALOX orthologs. Human ALOX15B oxygenates arachidonic acid exclusively to its 15-hydroperoxy derivative (15S-HpETE), whereas 8S-HpETE is dominantly formed by mouse Alox15b. The structural basis for this functional difference has been explored and in vitro mutagenesis humanized the reaction specificity of the mouse enzyme. To explore whether this mutagenesis strategy may also humanize the reaction specificity of mouse Alox15b in vivo, we created Alox15b knock-in mice expressing the arachidonic acid 15-lipoxygenating Tyr603Asp+His604Val double mutant instead of the 8-lipoxygenating wildtype enzyme. These mice are fertile, display slightly modified plasma oxylipidomes and develop normally up to an age of 24 weeks. At later developmental stages, male Alox15b-KI mice gain significantly less body weight than outbred wildtype controls, but this effect was not observed for female individuals. To explore the possible reasons for the observed gender-specific growth arrest, we determined the basic hematological parameters and found that aged male Alox15b-KI mice exhibited significantly attenuated red blood cell parameters (erythrocyte counts, hematocrit, hemoglobin). Here again, these differences were not observed in female individuals. These data suggest that humanization of the reaction specificity of mouse Alox15b impairs the functionality of the hematopoietic system in males, which is paralleled by a premature growth arrest.}, language = {en} } @article{SchraplauScheweNeuschaeferRubeetal.2015, author = {Schraplau, Anne and Schewe, Bettina and Neusch{\"a}fer-Rube, Frank and Ringel, Sebastian and Neuber, Corinna and Kleuser, Burkhard and P{\"u}schel, Gerhard Paul}, title = {Enhanced thyroid hormone breakdown in hepatocytes by mutual induction of the constitutive androstane receptor (CAR, NR1I3) and arylhydrocarbon receptor by benzo[a]pyrene and phenobarbital}, series = {Toxicology}, volume = {328}, journal = {Toxicology}, publisher = {Elsevier}, address = {Clare}, issn = {0300-483X}, doi = {10.1016/j.tox.2014.12.004}, pages = {21 -- 28}, year = {2015}, abstract = {Xenobiotics may interfere with the hypothalamic-pituitary-thyroid endocrine axis by inducing enzymes that inactivate thyroid hormones and thereby reduce the metabolic rate. This induction results from an activation of xeno-sensing nuclear receptors. The current study shows that benzo[a]pyrene, a frequent contaminant of processed food and activator of the arylhydrocarbon receptor (AhR) activated the promoter and induced the transcription of the nuclear receptor constitutive androstane receptor (CAR, NR1I3) in rat hepatocytes. Likewise, phenobarbital induced the AhR transcription. This mutual induction of the nuclear receptors enhanced the phenobarbital-dependent induction of the prototypic CAR target gene Cyp2b1 as well as the AhR-dependent induction of UDP-glucuronosyltransferases. In both cases, the induction by the combination of both xenobiotics was more than the sum of the induction by either substance alone. By inducing the AhR, phenobarbital enhanced the benzo[a]pyrene-dependent reduction of thyroid hormone half-life and the benzo[a]pyrene-dependent increase in the rate of thyroid hormone glucuronide formation in hepatocyte cultures. CAR ligands might thus augment the endocrine disrupting potential of AhR activators by an induction of the AhR. (C) 2014 Elsevier Ireland Ltd. All rights reserved.}, language = {en} } @article{SchieferdeckerPestelPuescheletal.1999, author = {Schieferdecker, Henrike L. and Pestel, Sabine and P{\"u}schel, Gerhard Paul and G{\"o}tze, Otto}, title = {Increase by anaphylatoxin C5a of glucose output in perfused rat liver via prostanoids derived from nonparenchymal cells : direct action of prostaglandins and indirect action of thromboxane A(2) on hepatocytes}, year = {1999}, abstract = {In the perfused rat liver the anaphylatoxin C5a enhanced glucose output, reduced flow, and elevated prostanoid overflow. Because hepatocytes (HCs) do not express C5a receptors, the metabolic C5a actions must be indirect, mediated by e.g. prostanoids from Kupffer cells (KCs) and hepatic stellate cells (HSCs), which possess C5a receptors. Surprisingly, the metabolic C5a effects were not only impaired by the prostanoid synthesis inhibitor, indomethacin, but also by the thromboxane A(2) (TXA(2)) receptor antagonist, daltroban, even though HCs do not express TXA(2) receptors. TXA(2) did not induce prostaglandin (PG) or an unknown factor release from KCs or sinusoidal endothelial cells (SECs), which express TXA(2) receptors, because (1) daltroban did neither influence the C5a-induced release of prostanoids from cultured KCs nor the C5a-dependent activation of glycogen phosphorylase in KC/HC cocultures and because (2) the TXA(2) analog, U46619, failed to stimulate prostanoid release from cultured KCs or SECs or to activate glycogen phosphorylase in KC/HC or SEC/HC cocultures. In the perfused liver, Ca(2+)-deprivation inhibited not only flow reduction but also glucose output elicited by C5a to similar extents as daltroban. Similarly, in the absence of extracellular Ca(2+), flow reduction and glucose output induced by U46619 were almost completely prevented, whereas glucose output induced by the directly acting PGF(2alpha) was only slightly lowered. Thus, in the perfused rat liver PGs released after C5a- stimulation from KCs and HSCs directly activated glycogen phosphorylase in HCs, and TXA(2) enhanced glucose output indirectly mainly by causing hypoxia as a result of flow reduction.}, language = {en} } @misc{SchenkeSchjeidePuescheletal.2020, author = {Schenke, Maren and Schjeide, Brit-Maren and P{\"u}schel, Gerhard Paul and Seeger, Bettina}, title = {Analysis of motor neurons differentiated from human induced pluripotent stem cells for the use in cell-based Botulinum neurotoxin activity assays}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1083}, issn = {1866-8372}, doi = {10.25932/publishup-47207}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-472071}, pages = {22}, year = {2020}, abstract = {Botulinum neurotoxins (BoNTs) are potent neurotoxins produced by bacteria, which inhibit neurotransmitter release, specifically in their physiological target known as motor neurons (MNs). For the potency assessment of BoNTs produced for treatment in traditional and aesthetic medicine, the mouse lethality assay is still used by the majority of manufacturers, which is ethically questionable in terms of the 3Rs principle. In this study, MNs were differentiated from human induced pluripotent stem cells based on three published protocols. The resulting cell populations were analyzed for their MN yield and their suitability for the potency assessment of BoNTs. MNs produce specific gangliosides and synaptic proteins, which are bound by BoNTs in order to be taken up by receptor-mediated endocytosis, which is followed by cleavage of specific soluble N-ethylmaleimide-sensitive-factor attachment receptor (SNARE) proteins required for neurotransmitter release. The presence of receptors and substrates for all BoNT serotypes was demonstrated in MNs generated in vitro. In particular, the MN differentiation protocol based on Du et al. yielded high numbers of MNs in a short amount of time with high expression of BoNT receptors and targets. The resulting cells are more sensitive to BoNT/A1 than the commonly used neuroblastoma cell line SiMa. MNs are, therefore, an ideal tool for being combined with already established detection methods.}, language = {en} } @article{SchenkeSchjeidePuescheletal.2020, author = {Schenke, Maren and Schjeide, Brit-Maren and P{\"u}schel, Gerhard Paul and Seeger, Bettina}, title = {Analysis of motor neurons differentiated from human induced pluripotent stem cells for the use in cell-based Botulinum neurotoxin activity assays}, series = {Toxins}, volume = {12}, journal = {Toxins}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2072-6651}, doi = {10.3390/toxins12050276}, pages = {20}, year = {2020}, abstract = {Botulinum neurotoxins (BoNTs) are potent neurotoxins produced by bacteria, which inhibit neurotransmitter release, specifically in their physiological target known as motor neurons (MNs). For the potency assessment of BoNTs produced for treatment in traditional and aesthetic medicine, the mouse lethality assay is still used by the majority of manufacturers, which is ethically questionable in terms of the 3Rs principle. In this study, MNs were differentiated from human induced pluripotent stem cells based on three published protocols. The resulting cell populations were analyzed for their MN yield and their suitability for the potency assessment of BoNTs. MNs produce specific gangliosides and synaptic proteins, which are bound by BoNTs in order to be taken up by receptor-mediated endocytosis, which is followed by cleavage of specific soluble N-ethylmaleimide-sensitive-factor attachment receptor (SNARE) proteins required for neurotransmitter release. The presence of receptors and substrates for all BoNT serotypes was demonstrated in MNs generated in vitro. In particular, the MN differentiation protocol based on Du et al. yielded high numbers of MNs in a short amount of time with high expression of BoNT receptors and targets. The resulting cells are more sensitive to BoNT/A1 than the commonly used neuroblastoma cell line SiMa. MNs are, therefore, an ideal tool for being combined with already established detection methods.}, language = {en} } @inproceedings{SchenkeSchjeidePuescheletal.2021, author = {Schenke, Maren and Schjeide, Brit-Maren and P{\"u}schel, Gerhard Paul and Seeger, Bettina}, title = {Serotype-specific sensitivity to Botulinum neurotoxins of iPSC-derived motor neurons}, series = {Naunyn-Schmiedeberg's archives of pharmacology}, volume = {394}, booktitle = {Naunyn-Schmiedeberg's archives of pharmacology}, number = {Suppl. 1}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {0028-1298}, doi = {10.1007/s00210-021-02066-6}, pages = {S4 -- S4}, year = {2021}, language = {en} } @article{RehwaldNeuschaeferRubeDeVriesetal.1999, author = {Rehwald, Matthias and Neusch{\"a}fer-Rube, Frank and DeVries, Christa and P{\"u}schel, Gerhard Paul}, title = {Possible role for ligand binding of histidine 81 in the second transmembrane domain of the rat prostaglandin F2alpha receptor}, year = {1999}, abstract = {For the five principal prostanoids PGD2, PGE2, PGF2alpha, prostacyclin and thromboxane A2 eight receptors have been identified that belong to the family of G-protein-coupled receptors. They display an overall homology of merely 30\%. However, single amino acids in the transmembrane domains such as an Arg in the seventh transmembrane domain are highly conserved. This Arg has been identified as part of the ligand binding pocket. It interacts with the carboxyl group of the prostanoid. The aim of the current study was to analyze the potential role in ligand binding of His-81 in the second transmembrane domain of the rat PGF2alpha receptor, which is conserved among all PGF2alpha receptors from different species. Molecular modeling suggested that this residue is located in close proximity to the ligand binding pocket Arg 291 in the 7th transmembrane domain. The His81 (H) was exchanged by site-directed mutagenesis to Gln (Q), Asp (D), Arg (R), Ala (A) and Gly (G). The receptor molecules were N-terminally extended by a Flag epitope for immunological detection. All mutant proteins were expressed at levels between 50\% and 80\% of the wild type construct. The H81Q and H81D receptor bound PGF2alpha with 2-fold and 25-fold lower affinity, respectively, than the wild type receptor. Membranes of cells expressing the H81R, H81A or H81G mutants did not bind significant amounts of PGF2alpha. Wild type receptor and H81Q showed a shallow pH optimum for PGF2alpha binding around pH 5.5 with almost no reduction of binding at higher pH. In contrast the H81D mutant bound PGF2alpha with a sharp optimum at pH 4.5, a pH at which the Asp side chain is partially undissociated and may serve as a hydrogen bond donor as do His and Gln at higher pH values. The data indicate that the His-81 in the second transmembrane domain of the PGF2alpha receptor in concert with Arg-291 in the seventh transmembrane domain may be involved in ligand binding, most likely not by ionic interaction with the prostaglandin's carboxyl group but rather as a hydrogen bond donor.}, language = {en} } @misc{PueschelOppermannNeuschaeferRubeetal.1991, author = {P{\"u}schel, Gerhard Paul and Oppermann, Martin and Neusch{\"a}fer-Rube, Frank and G{\"o}tze, Otto and Jungermann, Kurt}, title = {Differential effects of human anaphylatoxin C3a on glucose output and flow in rat liver during orthograde and retrograde perfusion : the periportal scavenger cell hypothesis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16747}, year = {1991}, abstract = {1) During orthograde perfusion of rat liver human anaphylatoxin C3a caused an increase in glucose and lactate output and reduction of flow. These effects could be enhanced nearly twofold by co-infusion of the carboxypeptidase inhibitor MERGETPA, which reduced inactivation of C3a to C3adesArg. 2) During retrograde perfusion C3a caused a two- to threefold larger increase in glucose and lactate output and reduction of flow than in orthograde perfusions. These actions tended to be slightly enhanced by MERGETPA. 3) The elimination of C3a plus C3adesArg immunoreactivity during a single liver passage was around 67\%, irrespective of the perfusion direction and the presence of the carboxypeptidase inhibitor MERGETPA; however, less C3adesArg and more intact C3a appeared in the perfusate in the presence of MERGETPA in orthograde and retrogade perfusions It is concluded that rat liver inactivated human anaphylatoxin C3a by conversion to C3adesArg and moreover eliminated it by an additional process. The inactivation to C3adesArg seemed to be located predominantly in the proximal periportal region of the liver sinusoid, since C3a was less effective in orthograde perfusions, when C3a first passed the proximal periportal region before reaching the predominant mass of parenchyma as its site of action, than in retrograde perfusions, when it first passed the perivenous area. These data may be evidence for a periportal scavenger mechanism, by which the liver protects itself from systemically released mediators of inflammation that interfere with the local regulation of liver metabolism and hemodynamics.}, language = {en} } @misc{PueschelOppermannMuscholetal.1989, author = {P{\"u}schel, Gerhard Paul and Oppermann, Martin and Muschol, Waldemar and G{\"o}tze, Otto and Jungermann, Kurt}, title = {Increase of glucose and lactate output and decrease of flow by human anaphylatoxin C3a but not C5a in perfused rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16733}, year = {1989}, abstract = {The complement fragments C3a and C5a were purified from zymosan-activated human serum by column chromatographic procedures after the bulk of the proteins had been removed by acidic polyethylene glycol precipitation. In the isolated in situ perfused rat liver C3a increased glucose and lactate output and reduced flow. Its effects were enhanced in the presence of the carboxypeptidase inhibitor DL-mercaptomethyl-3-guanidinoethylthio-propanoic acid (MERGETPA) and abolished by preincubation of the anaphylatoxin with carboxypeptidase B or with Fab fragments of an anti-C3a monoclonal antibody. The C3a effects were partially inhibited by the thromboxane antagonist BM13505. C5a had no effect. It is concluded that locally but not systemically produced C3a may play an important role in the regulation of local metabolism and hemodynamics during inflammatory processes in the liver.}, language = {en} } @misc{PueschelNathJungermann1987, author = {P{\"u}schel, Gerhard Paul and Nath, Annegret and Jungermann, Kurt}, title = {Increase of urate formation by stimulation of sympathetic hepatic nerves, circulating noradrenaline and glucagon inthe perfused rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16728}, year = {1987}, abstract = {In the isolated rat liver perfused in situ stimulation of the nerve bundles around the portal vein and the hepatic artery caused an increase of urate formation that was inhibited by the α1-blocker prazosine and the xanthine oxidase inhibitor allopurinol. Moreover, nerve stimulation increased glucose and lactate output and decreased perfusion flow. Infusion of noradrenaline had similar effects. Compared to nerve stimulation infusion of glucagon led to a less pronounced increase of urate formation and a twice as large increase in glucose output but a decrease in lactate release without affecting the flow rate. Insulin had no effect on any of the parameters studied.}, language = {en} } @misc{PueschelMiuraNeuschaeferRubeetal.1993, author = {P{\"u}schel, Gerhard Paul and Miura, Hisayuki and Neusch{\"a}fer-Rube, Frank and Jungermann, Kurt}, title = {Inhibition by the protein kinase C activator 4β-phorbol 12-myristate 13-acetate of the prostaglandin F₂α-mediated and noradrenaline-mediated but not glucagon-mediated activation of glycogenolysis in rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45889}, year = {1993}, abstract = {In perfused rat livers, infusion of prostaglandin F₂α (PGF₂α) or noradrenaline increased glucose and lactate output and reduced flow. Glucagon increased glucose output and decreased lactate output without influence on flow. Infusion of phorbol 13-myristate 14-acetate (PMA) for 20 min prior to these stimuli strongly inhibited the metabolic and hemodynamic effects of noradrenaline, reduced the metabolic actions of PGF₂α but did not alter the effects of glucagon. In isolated rat hepatocytes PGF₂α, noradrenaline and glucagon activated glycogen phosphorylase but only PGF₂α and noradrenaline increased intracellular inositol 1,4,5-1risphosphalc (InsP₃). The noradrenaline- or PGF₂α-elicited activation of glycogen phosphorylase and increase in InsP₃ were largely reduced after preincubation of the cells for 10 min with PMA, whereas the glucagon-mediated enzyme activation was not affected. In contra\t to PMA, the phorbol ester 4a-phorbol 13,14-didecanoate. which does not activate protein kinase C, did not attenuate the PGF₂α- and noradrenaline-elicited stimulation of glucose output, glycogen phosphorylase and InsP, formation. Stimulation of InsP₃ formation by AlF₄⁻, which activates phospholipase C independently of the receptor, was not attenuated by prior incubation with PMA. Plasma membranes purified from isolated hepatocytes had both a high-capacity, low-affinity and a low-capacity, high-affinity binding site for PGF₂α. The Kd of the high-capacity, low-affinity binding site was close to the concentration of PGF₂α that increased glycogen phosphorylase activity halfmaximally. Binding to the high-capacity, low-affinity binding site was enhanced by guanosine 5'- 0-(3-thio)triphosphate (GTP[S]). This high-capacity, low-affinity site might thus represent the receptor. The Bmax and Kd of the high-capacity site, as well as the enhancement by GTP[S] of PGF₂α binding to this site, remained unaffected by PMA pretreatment. It is concluded that, in hepatocytes, activation of protein kinase C by PMA interrupted the InsP₃-mediated signal pathway from PGF₂α via a PGF₂α receptor and phospholipase C to glycogen phosphorylase at a point distal of the receptor prior to phospholipase C.}, language = {en} } @misc{PueschelMentleinHeymann1982, author = {P{\"u}schel, Gerhard Paul and Mentlein, Rolf and Heymann, Eberhard}, title = {Isolation and characterization of Dipeptidyl Peptidase IV from human placenta}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45875}, year = {1982}, abstract = {Human placenta is surprisingly rich in post-proline dipeptidyl peptidase activity. Among various cell fractions, microsomes have the highest specific activity. A homogeneous enzyme preparation is obtained in a six-step purification procedure. The final preparation appears homogeneous upon dodecyl sulfate electrophoresis, but analytical isoelectric focussing reveals various active bands with isoelectric points in the range of pH 3 - 4. The enzyme is a glycoprotein containing about 30\% carbohydrate. Treatment with neuraminidase lowers the isoelectric points but does not reduce the heterogeneity of the band pattern. The subunit molecular weight is 120000 as estimated by dodecyl sulfate electrophoresis, whereas Mr of the native enzyme is > 200000, as can be concluded from gel filtration experiments. The purified dipeptidyl peptidase cleaves various synthetic and natural peptides, including substance P, kentsin, casomorphin and a synthetic renin inhibitor. In general, the specificity of the placenta peptidase is similar to that of post-proline dipeptidyl peptidase from other sources. Phenylalanylprolyl-P-naphthylamide (Km = 0.02 mM, I/ = 92 Ujmg) is the best substrate among various synthetic peptide derivatives. Only peptides with a free N-terminal amino group and proline, hydroxyproline, or alanine in position 2 of the N-terminal sequence are cieaved. However, X-Pro-Pro- . . . structures, e. g. as in bradykinin, are not attacked. 1 mM bis-(6nitrophenyI)phosphate or 1 mM diisopropylfluorophosphate completely inactivate the peptidase within 30 min at 30°C (pH 8). The peptidase is also completely inhibited by 1 mM Zn²⁺ and by other heavy metals.}, language = {en} }