@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} } @article{Pueschel2004, author = {P{\"u}schel, Gerhard Paul}, title = {Control of hepatocyte metabolism by sympathetic and parasympathetic hepatic nerves}, year = {2004}, abstract = {More than any other organ, the liver contributes to maintaining metabolic equilibrium of the body, most importantly of glucose homeostasis. It can store or release large quantities of glucose according to changing demands. This homeostasis is controlled by circulating hormones and direct innervation of the liver by autonomous hepatic nerves. Sympathetic hepatic nerves can increase hepatic glucose output; they appear, however, to contribute little to the stimulation of hepatic glucose output under physiological conditions. Parasympathetic hepatic nerves potentiate the insulin-dependent hepatic glucose extraction when a portal glucose sensor detects prandial glucose delivery from the gut. In addition, they might coordinate the hepatic and extrahepatic glucose utilization to prevent hypoglycemia and, at the same time, warrant efficient disposal of excess glucose.}, language = {en} } @article{PatheNeuschaeferRubeNeuschaeferRubePueschel2004, author = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul}, title = {G protein coupling control by the ERC-motif in the proximal part of the second intracellular loop and the C- terminal domain of the human prostaglandin F-2A receptor (FP receptor)}, issn = {0028-1298}, year = {2004}, language = {en} } @article{NeuschaeferRubeHermosillaKunaetal.2004, author = {Neusch{\"a}fer-Rube, Frank and Hermosilla, Ricardo and Kuna, Manuela and Pathe-Neuschaefer-Rube, Andrea and P{\"u}schel, Gerhard Paul}, title = {Agonist-induced desensitization of rat prostaglandin EP3 receptor isoforms}, issn = {0028-1298}, year = {2004}, language = {en} } @article{CamargodosReisRiccardiTeixeiraRibeiroetal.2015, author = {Camargo, Rodolfo Gonzalez and dos Reis Riccardi, Daniela Mendes and Teixeira Ribeiro, Henrique Quintas and Carnevali Junior, Luiz Carlos and de Matos-Neto, Emidio Marques and Enjiu, Lucas and Neves, Rodrigo Xavier and Carola Correia Lima, Joanna Darck and Figueredo, Raquel Galvao and Martins de Alcantara, Paulo Sergio and Maximiano, Linda and Otoch, Jose and Batista Jr., Miguel Luiz and P{\"u}schel, Gerhard Paul and Seelaender, Marilia}, title = {NF-kappa Bp65 and Expression of Its Pro-Inflammatory Target Genes Are Upregulated in the Subcutaneous Adipose Tissue of Cachectic Cancer Patients}, series = {Nutrients}, volume = {7}, journal = {Nutrients}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2072-6643}, doi = {10.3390/nu7064465}, pages = {4465 -- 4479}, year = {2015}, abstract = {Cancer cachexia, of which the most notable symptom is severe and rapid weight loss, is present in the majority of patients with advanced cancer. Inflammatory mediators play an important role in the development of cachexia, envisaged as a chronic inflammatory syndrome. The white adipose tissue (WAT) is one of the first compartments affected in cancer cachexia and suffers a high rate of lipolysis. It secretes several cytokines capable of directly regulating intermediate metabolism. A common pathway in the regulation of the expression of pro-inflammatory cytokines in WAT is the activation of the nuclear transcription factor kappa-B (NF-B). We have examined the gene expression of the subunits NF-Bp65 and NF-Bp50, as well as NF-Bp65 and NF-Bp50 binding, the gene expression of pro-inflammatory mediators under NF-B control (IL-1, IL-6, INF-, TNF-, MCP-1), and its inhibitory protein, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IB-). The observational study involved 35 patients (control group, n = 12 and cancer group, n = 23, further divided into cachectic and non-cachectic). NF-Bp65 and its target genes expression (TNF-, IL-1, MCP-1 and IB-) were significantly higher in cachectic cancer patients. Moreover, NF-Bp65 gene expression correlated positively with the expression of its target genes. The results strongly suggest that the NF-B pathway plays a role in the promotion of WAT inflammation during cachexia.}, language = {en} } @article{HenkelFredeSchanzeetal.2012, author = {Henkel, Janin and Frede, Katja and Schanze, Nancy and Vogel, Heike and Sch{\"u}rmann, Annette and Spruß, Astrid and Bergheim, Ina and P{\"u}schel, Gerhard Paul}, title = {Stimulation of fat accumulation in hepatocytes by PGE(2)-dependent repression of hepatic lipolysis, beta-oxidation and VLDL-synthesis}, series = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, volume = {92}, journal = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, number = {11}, publisher = {Nature Publ. Group}, address = {New York}, issn = {0023-6837}, doi = {10.1038/labinvest.2012.128}, pages = {1597 -- 1606}, year = {2012}, abstract = {Hepatic steatosis is recognized as hepatic presentation of the metabolic syndrome. Hyperinsulinaemia, which shifts fatty acid oxidation to de novo lipogenesis and lipid storage in the liver, appears to be a principal elicitor particularly in the early stages of disease development. The impact of PGE(2), which has previously been shown to attenuate insulin signaling and hence might reduce insulin-dependent lipid accumulation, on insulin-induced steatosis of hepatocytes was studied. The PGE(2)-generating capacity was enhanced in various obese mouse models by the induction of cyclooxygenase 2 and microsomal prostaglandin E-synthases (mPGES1, mPGES2). PGE(2) attenuated the insulin-dependent induction of SREBP-1c and its target genes glucokinase and fatty acid synthase. Nevertheless, PGE(2) enhanced incorporation of glucose into hepatic triglycerides synergistically with insulin. This was most likely due to a combination of a PGE(2)-dependent repression of (1) the key lipolytic enzyme adipose triglyceride lipase, (2) carnitine-palmitoyltransferase 1, a key regulator of mitochondrial beta-oxidation, and (3) microsomal transfer protein, as well as (4) apolipoprotein B, key components of the VLDL synthesis. Repression of PGC1 alpha, a common upstream regulator of these genes, was identified as a possible cause. In support of this hypothesis, overexpression of PGC1 alpha completely blunted the PGE(2)-dependent fat accumulation. PGE(2) enhanced lipid accumulation synergistically with insulin, despite attenuating insulin signaling and might thus contribute to the development of hepatic steatosis. Induction of enzymes involved in PGE(2) synthesis in in vivo models of obesity imply a potential role of prostanoids in the development of NAFLD and NASH. Laboratory Investigation (2012) 92, 1597-1606; doi:10.1038/labinvest.2012.128; published online 10 September 2012}, language = {en} } @article{NeuschaeferRubeSchraplauScheweetal.2015, author = {Neuschaefer-Rube, Frank and Schraplau, Anne and Schewe, Bettina and Lieske, Stefanie and Kruetzfeldt, Julia-Mignon and Ringel, Sebastian and Henkela, Janin and Birkenfeld, Andreas L. and P{\"u}schel, Gerhard Paul}, title = {Arylhydrocarbon receptor-dependent mIndy (SIc13a5) induction as possible contributor to benzo[a]pyrene-induced lipid accumulation in hepatocytes}, series = {Toxicology}, volume = {337}, journal = {Toxicology}, publisher = {Elsevier}, address = {Clare}, issn = {0300-483X}, doi = {10.1016/j.tox.2015.08.007}, pages = {1 -- 9}, year = {2015}, abstract = {Non-alcoholic fatty liver disease is a growing problem in industrialized and developing countries. Hepatic lipid accumulation is the result of an imbalance between fatty acid uptake, fatty acid de novo synthesis, beta-oxidation and secretion of triglyceride-rich lipoproteins from the hepatocyte. A central regulator of hepatic lipid metabolism is cytosolic citrate that can either be derived from the mitochondrium or be taken up from the blood via the plasma membrane sodium citrate transporter NaCT, the product of the mammalian INDY gene (SLC13A5). mINDY ablation protects against diet-induced steatosis whereas mINDY expression is increased in patients with hepatic steatosis. Diet-induced hepatic steatosis is also enhanced by activation of the arylhyrocarbon receptor (AhR) both in humans and animal models. Therefore, the hypothesis was tested whether the mINDY gene might be a target of the AhR. In accordance with such a hypothesis, the AhR activator benzo[a]pyrene induced the mINDY expression in primary cultures of rat hepatocytes in an AhR-dependent manner. This induction resulted in an increased citrate uptake and citrate incorporation into lipids which probably was further enhanced by the benzo[a]pyrene-dependent induction of key enzymes of fatty acid synthesis. A potential AhR binding site was identified in the mINDY promoter that appears to be conserved in the human promoter. Elimination or mutation of this site largely abolished the activation of the mINDY promoter by benzo[a]pyrene. This study thus identified the mINDY as an AhR target gene. AhR-dependent induction of the mINDY gene might contribute to the development of hepatic steatosis. (C) 2015 Elsevier Ireland Ltd. All rights reserved.}, language = {en} } @article{HesseJaschkeKanzleiteretal.2012, author = {Hesse, Deike and Jaschke, Alexander and Kanzleiter, Timo and Witte, Nicole and Augustin, Robert and Hommel, Angela and P{\"u}schel, Gerhard Paul and Petzke, Klaus-J{\"u}rgen and Joost, Hans-Georg and Schupp, Michael and Sch{\"u}rmann, Annette}, title = {GTPase ARFRP1 is essential for normal hepatic glycogen storage and insulin-like growth factor 1 secretion}, series = {Molecular and cellular biology}, volume = {32}, journal = {Molecular and cellular biology}, number = {21}, publisher = {American Society for Microbiology}, address = {Washington}, issn = {0270-7306}, doi = {10.1128/MCB.00522-12}, pages = {4363 -- 4374}, year = {2012}, abstract = {The GTPase ADP-ribosylation factor-related protein 1 (ARFRP1) is located at the trans-Golgi compartment and regulates the recruitment of Arf-like 1 (ARL1) and its effector golgin-245 to this compartment. Here, we show that liver-specific knockout of Arfrp1 in the mouse (Arfrp1(liv-/-)) resulted in early growth retardation, which was associated with reduced hepatic insulin-like growth factor 1 (IGF1) secretion. Accordingly, suppression of Arfrp1 in primary hepatocytes resulted in a significant reduction of IGF1 release. However, the hepatic secretion of IGF-binding protein 2 (IGFBP2) was not affected in the absence of ARFRP1. In addition, Arfrp1(liv-/-) mice exhibited decreased glucose transport into the liver, leading to a 50\% reduction of glycogen stores as well as a marked retardation of glycogen storage after fasting and refeeding. These abnormalities in glucose metabolism were attributable to reduced protein levels and intracellular retention of the glucose transporter GLUT2 in Arfrp1(liv-/-) livers. As a consequence of impaired glucose uptake into the liver, the expression levels of carbohydrate response element binding protein (ChREBP), a transcription factor regulated by glucose concentration, and its target genes (glucokinase and pyruvate kinase) were markedly reduced. Our data indicate that ARFRP1 in the liver is involved in the regulation of IGF1 secretion and GLUT2 sorting and is thereby essential for normal growth and glycogen storage.}, 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} } @article{HenkelGaertnerDornetal.2011, author = {Henkel, Janin and G{\"a}rtner, Daniela and Dorn, Christoph and Hellerbrand, Claus and Schanze, Nancy and Elz, Sheila R. and P{\"u}schel, Gerhard Paul}, title = {Oncostatin M produced in Kupffer cells in response to PGE(2) possible contributor to hepatic insulin resistance and steatosis}, series = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, volume = {91}, journal = {Laboratory investigation : the basic and translational pathology research journal ; an official journal of the United States and Canadian Academy of Pathology}, number = {7}, publisher = {Nature Publ. Group}, address = {New York}, issn = {0023-6837}, doi = {10.1038/labinvest.2011.47}, pages = {1107 -- 1117}, year = {2011}, abstract = {Hepatic insulin resistance is a major contributor to hyperglycemia in metabolic syndrome and type II diabetes. It is caused in part by the low-grade inflammation that accompanies both diseases, leading to elevated local and circulating levels of cytokines and cyclooxygenase (COX) products such as prostaglandin E-2 (PGE(2)). In a recent study, PGE(2) produced in Kupffer cells attenuated insulin-dependent glucose utilization by interrupting the intracellular signal chain downstream of the insulin receptor in hepatocytes. In addition to directly affecting insulin signaling in hepatocytes, PGE(2) in the liver might affect insulin resistance by modulating cytokine production in non-parenchymal cells. In accordance with this hypothesis, PGE(2) stimulated oncostatin M (OSM) production by Kupffer cells. OSM in turn attenuated insulin-dependent Akt activation and, as a downstream target, glucokinase induction in hepatocytes, most likely by inducing suppressor of cytokine signaling 3 (SOCS3). In addition, it inhibited the expression of key enzymes of hepatic lipid metabolism. COX-2 and OSM mRNA were induced early in the course of the development of non-alcoholic steatohepatitis (NASH) in mice. Thus, induction of OSM production in Kupffer cells by an autocrine PGE(2)-dependent feed-forward loop may be an additional, thus far unrecognized, mechanism contributing to hepatic insulin resistance and the development of NASH.}, language = {en} } @article{NeuschaeferRubeLieskeKunaetal.2014, author = {Neuschaefer-Rube, Frank and Lieske, Stefanie and Kuna, Manuela and Henkel, Janin and Perry, Rachel J. and Erion, Derek M. and Pesta, Dominik and Willmes, Diana M. and Brachs, Sebastian and von Loeffelholz, Christian and Tolkachov, Alexander and Schupp, Michael and Pathe-Neuschaefer-Rube, Andrea and Pfeiffer, Andreas F. H. and Shulman, Gerald I. and P{\"u}schel, Gerhard Paul and Birkenfeld, Andreas L.}, title = {The mammalian INDY homolog is induced by CREB in a rat model of type 2 diabetes}, series = {Diabetes : a journal of the American Diabetes Association}, volume = {63}, journal = {Diabetes : a journal of the American Diabetes Association}, number = {3}, publisher = {American Diabetes Association}, address = {Alexandria}, issn = {0012-1797}, pages = {1048 -- 1057}, year = {2014}, language = {en} } @inproceedings{HenkelCamargoSchanzeetal.2014, author = {Henkel, Janine and Camargo, Rodolfo Gonzalez and Schanze, Nancy and P{\"u}schel, Gerhard Paul}, title = {The vicious circle of prostaglandin- and cytokine-dependent hepatic insulin resistance: a key role of prostaglandin E2}, series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, volume = {57}, booktitle = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, publisher = {Springer}, address = {New York}, issn = {0012-186X}, pages = {S241 -- S242}, year = {2014}, language = {en} } @misc{HenkelColemanMacGregorofInneregnySchraplauetal.2018, author = {Henkel, Janin and Coleman Mac Gregor of Inneregny, Charles Dominic and Schraplau, Anne and J{\"o}hrens, Korinna and Weiss, Thomas Siegfried and Jonas, Wenke and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {483}, issn = {1866-8372}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420879}, pages = {11}, year = {2018}, abstract = {In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.}, language = {en} } @article{HocherHaumannRahnenfuehreretal.2016, author = {Hocher, Berthold and Haumann, Hannah and Rahnenf{\"u}hrer, Jan and Reichetzeder, Christoph and Kalk, Philipp and Pfab, Thiemo and Tsuprykov, Oleg and Winter, Stefan and Hofmann, Ute and Li, Jian and P{\"u}schel, Gerhard Paul and Lang, Florian and Schuppan, Detlef and Schwab, Matthias and Schaeffeler, Elke}, title = {Maternal eNOS deficiency determines a fatty liver phenotype of the offspring in a sex dependent manner}, series = {Epigenetics : the official journal of the DNA Methylation Society}, volume = {11}, journal = {Epigenetics : the official journal of the DNA Methylation Society}, publisher = {Routledge, Taylor \& Francis Group}, address = {Philadelphia}, issn = {1559-2294}, doi = {10.1080/15592294.2016.1184800}, pages = {539 -- 552}, year = {2016}, abstract = {Maternal environmental factors can impact on the phenotype of the offspring via the induction of epigenetic adaptive mechanisms. The advanced fetal programming hypothesis proposes that maternal genetic variants may influence the offspring's phenotype indirectly via epigenetic modification, despite the absence of a primary genetic defect. To test this hypothesis, heterozygous female eNOS knockout mice and wild type mice were bred with male wild type mice. We then assessed the impact of maternal eNOS deficiency on the liver phenotype of wild type offspring. Birth weight of male wild type offspring born to female heterozygous eNOS knockout mice was reduced compared to offspring of wild type mice. Moreover, the offspring displayed a sex specific liver phenotype, with an increased liver weight, due to steatosis. This was accompanied by sex specific differences in expression and DNA methylation of distinct genes. Liver global DNA methylation was significantly enhanced in both male and female offspring. Also, hepatic parameters of carbohydrate metabolism were reduced in male and female offspring. In addition, male mice displayed reductions in various amino acids in the liver. Maternal genetic alterations, such as partial deletion of the eNOS gene, can affect liver metabolism of wild type offspring without transmission of the intrinsic defect. This occurs in a sex specific way, with more detrimental effects in females. This finding demonstrates that a maternal genetic defect can epigenetically alter the phenotype of the offspring, without inheritance of the defect itself. Importantly, these acquired epigenetic phenotypic changes can persist into adulthood.}, language = {en} } @article{HenkelColemanMacGregorofInneregnySchraplauetal.2018, author = {Henkel, Janin and Coleman Mac Gregor of Inneregny, Charles Dominic and Schraplau, Anne and J{\"o}hrens, Korinna and Weiss, Thomas Siegfried and Jonas, Wenke and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model}, series = {Scientific Reports}, journal = {Scientific Reports}, number = {8}, publisher = {Nature Research}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-34633-y}, pages = {1 -- 11}, year = {2018}, abstract = {In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.}, language = {en} } @article{ManowskyCamargoKippetal.2016, author = {Manowsky, Julia and Camargo, Rodolfo Gonzalez and Kipp, Anna Patricia and Henkel, Janin and P{\"u}schel, Gerhard Paul}, title = {Insulin-induced cytokine production in macrophages causes insulin resistance in hepatocytes}, series = {American journal of physiology : Endocrinology and metabolism}, volume = {310}, journal = {American journal of physiology : Endocrinology and metabolism}, publisher = {American Chemical Society}, address = {Bethesda}, issn = {0193-1849}, doi = {10.1152/ajpendo.00427.2015}, pages = {E938 -- E946}, year = {2016}, abstract = {Overweight and obesity are associated with hyperinsulinemia, insulin resistance, and a low-grade inflammation. Although hyperinsulinemia is generally thought to result from an attempt of the beta-cell to compensate for insulin resistance, there is evidence that hyperinsulinaemia itself may contribute to the development of insulin resistance and possibly the low-grade inflammation. To test this hypothesis, U937 macrophages were exposed to insulin. In these cells, insulin induced expression of the proinflammatory cytokines IL-1 beta, IL-8, CCL2, and OSM. The insulin-elicited induction of IL-1 beta was independent of the presence of endotoxin and most likely mediated by an insulin-dependent activation of NF-kappa B. Supernatants of the insulin-treated U937 macrophages rendered primary cultures of rat hepatocytes insulin resistant; they attenuated the insulin-dependent induction of glucokinase by 50\%. The cytokines contained in the supernatants of insulin-treated U937 macrophages activated ERK1/2 and IKK beta, resulting in an inhibitory serine phosphorylation of the insulin receptor substrate. In addition, STAT3 was activated and SOCS3 induced, further contributing to the interruption of the insulin receptor signal chain in hepatocytes. These results indicate that hyperinsulinemia per se might contribute to the low-grade inflammation prevailing in overweight and obese patients and thereby promote the development of insulin resistance particularly in the liver, because the insulin concentration in the portal circulation is much higher than in all other tissues.}, 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} } @article{HenkelColemanSchraplauetal.2017, author = {Henkel, Janin and Coleman, Charles Dominic and Schraplau, Anne and J{\"o}hrens, Korinna and Weber, Daniela and Castro, Jose Pedro and Hugo, Martin and Schulz, Tim Julius and Kr{\"a}mer, Stephanie and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Induction of Steatohepatitis (NASH) with Insulin Resistance in Wild-type B6 Mice by a Western-type Diet Containing Soybean Oil and Cholesterol}, series = {Molecular medicine}, volume = {23}, journal = {Molecular medicine}, publisher = {Feinstein Inst. for Medical Research}, address = {Manhasset}, issn = {1076-1551}, doi = {10.2119/molmed.2016.00203}, pages = {70 -- 82}, year = {2017}, abstract = {Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are hepatic manifestations of the metabolic syndrome. Many currently used animal models of NAFLD/NASH lack clinical features of either NASH or metabolic syndrome such as hepatic inflammation and fibrosis (e.g., high-fat diets) or overweight and insulin resistance (e.g., methionine-choline-deficient diets), or they are based on monogenetic defects (e.g., ob/ob mice). In the current study, a Western-type diet containing soybean oil with high n-6-PUFA and 0.75\% cholesterol (SOD + Cho) induced steatosis, inflammation and fibrosis accompanied by hepatic lipid peroxidation and oxidative stress in livers of C57BL/6-mice, which in addition showed increased weight gain and insulin resistance, thus displaying a phenotype closely resembling all clinical features of NASH in patients with metabolic syndrome. In striking contrast, a soybean oil-containing Western-type diet without cholesterol (SOD) induced only mild steatosis but not hepatic inflammation, fibrosis, weight gain or insulin resistance. Another high-fat diet, mainly consisting of lard and supplemented with fructose in drinking water (LAD + Fru), resulted in more prominent weight gain, insulin resistance and hepatic steatosis than SOD + Cho, but livers were devoid of inflammation and fibrosis. Although both LAD + Fru-and SOD + Cho-fed animals had high plasma cholesterol, liver cholesterol was elevated only in SOD + Cho animals. Cholesterol induced expression of chemotactic and inflammatory cytokines in cultured Kupffer cells and rendered hepatocytes more susceptible to apoptosis. In summary, dietary cholesterol in the SOD + Cho diet may trigger hepatic inflammation and fibrosis. SOD + Cho-fed animals may be a useful disease model displaying many clinical features of patients with the metabolic syndrome and NASH.}, language = {en} } @article{KnebelNeebZahnetal.2018, author = {Knebel, Constanze and Neeb, Jannika and Zahn, Elisabeth and Schmidt, Flavia and Carazo, Alejandro and Holas, Ondej and Pavek, Petr and P{\"u}schel, Gerhard Paul and Zanger, Ulrich M. and S{\"u}ssmuth, Roderich and Lampen, Alfonso and Marx-Stoelting, Philip and Braeuning, Albert}, title = {Unexpected Effects of Propiconazole, Tebuconazole, and Their Mixture on the Receptors CAR and PXR in Human Liver Cells}, series = {Toxicological sciences}, volume = {163}, journal = {Toxicological sciences}, number = {1}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1096-6080}, doi = {10.1093/toxsci/kfy026}, pages = {170 -- 181}, year = {2018}, abstract = {Analyzing mixture toxicity requires an in-depth understanding of the mechanisms of action of its individual components. Substances with the same target organ, same toxic effect and same mode of action (MoA) are believed to cause additive effects, whereas substances with different MoAs are assumed to act independently. Here, we tested 2 triazole fungicides, propiconazole, and tebuconazole (Te), for individual and combined effects on liver toxicity-related endpoints. Both triazoles are proposed to belong to the same cumulative assessment group and are therefore thought to display similar and additive behavior. Our data show that Te is an antagonist of the constitutive androstane receptor (CAR) in rats and humans, while propiconazole is an agonist of this receptor. Both substances activate the pregnane X-receptor (PXR) and further induce mRNA expression of CYP3A4. CYP3A4 enzyme activity, however, is inhibited by propiconazole. For common targets of PXR and CAR, the activation of PXR by Te overrides CAR inhibition. In summary, propiconazole and Te affect different hepatotoxicity-relevant cellular targets and, depending on the individual endpoint analyzed, act via similar or dissimilar mechanisms. The use of molecular data based on research in human cell systems extends the picture to refine cumulative assessment group grouping and substantially contributes to the understanding of mixture effects of chemicals in biological systems.}, language = {en} } @article{NeuschaeferRubePatheNeuschaeferRubePueschel2022, author = {Neusch{\"a}fer-Rube, Frank and Pathe-Neusch{\"a}fer-Rube, Andrea and P{\"u}schel, Gerhard Paul}, title = {Discrimination of the activity of low-affinity wild-type and high-affinity mutant recombinant BoNT/B by a SIMA cell-based reporter release assay}, series = {Toxins}, volume = {14}, journal = {Toxins}, edition = {1}, publisher = {MDPI}, address = {Basel, Schweiz}, issn = {2072-6651}, doi = {10.3390/toxins14010065}, pages = {1 -- 11}, year = {2022}, abstract = {Botulinum neurotoxin (BoNT) is used for the treatment of a number of ailments. The activity of the toxin that is isolated from bacterial cultures is frequently tested in the mouse lethality assay. Apart from the ethical concerns inherent to this assay, species-specific differences in the affinity for different BoNT serotypes give rise to activity results that differ from the activity in humans. Thus, BoNT/B is more active in mice than in humans. The current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-Gluc) was inhibited by clostridial and recombinant BoNT/A to the same extent, whereas both clostridial and recombinant BoNT/B inhibited the release to a lesser extent and only at much higher concentrations, reflecting the low activity of BoNT/B in humans. By contrast, the genetically modified BoNT/B-MY, which has increased affinity for human synaptotagmin, and the BoNT/B protein receptor inhibited luciferase release effectively and with an EC50 comparable to recombinant BoNT/A. This was due to an enhanced uptake into the reporter cells of BoNT/B-MY in comparison to the recombinant wild-type toxin. Thus, the SIMA-hPOMC1-26-Gluc cell assay is a versatile tool to determine the activity of different BoNT serotypes providing human-relevant dose-response data.}, language = {en} } @article{NeuschaeferRubePatheNeuschaeferRubeHippenstieletal.2018, author = {Neusch{\"a}fer-Rube, Frank and Pathe-Neusch{\"a}fer-Rube, Andrea and Hippenstiel, Stefan and P{\"u}schel, Gerhard Paul}, title = {PGE(2) enhanced TNF alpha-mediated IL-8 induction in monocytic cell lines and PBMC}, series = {Cytokine}, volume = {113}, journal = {Cytokine}, publisher = {Elsevier}, address = {London}, issn = {1043-4666}, doi = {10.1016/j.cyto.2018.06.020}, pages = {105 -- 116}, year = {2018}, abstract = {Background \& purpose: Recent studies suggested a role of prostaglandin E-2 (PGE(2)) in the expression of the chemokine IL-8 by monocytes. The function of EP4 receptor for TNF alpha-induced IL-8 expression was studied in monocytic cell lines. Experimental approach: IL-8 mRNA and protein induction as well as IL-8 promoter activity and transcription factor activation were assessed in monocytic cell lines, primary blood mononuclear cells (PBMC) and transgenic HEK293 cells expressing the EP4 receptor. Key results: In monocytic cell lines THP-1, MonoMac and U937 PGE(2) had only a marginal impact on IL-8 induction but strongly enhanced TNFa-induced IL-8 mRNA and protein synthesis. Similarly, in PBMC IL-8 mRNA induction was larger by simultaneous stimulation with TNF alpha and PGE(2) than by either stimulus alone. The EP4 receptor subtype was the most abundant EP receptor in all three cell lines and in PBMC. Stimulation of THP-1 cells with an EP4 specific agonist enhanced TNF alpha-induced IL-8 mRNA and protein formation to the same extent as PGE(2). In HEK293 cells expressing EP4, but not in wild type HEK293 cells lacking EP4, PGE(2) enhanced TNFainduced IL-8 protein and mRNA synthesis. In THP-1 cells, the enhancement of TNF alpha-mediated IL-8 mRNA induction by PGE(2) was mimicked by a PICA-activator. Furthermore in these cells PGE(2) induced expression of transcription factor C/EBPS, enhanced NF-KB activation by TNFa and inhibited TNF alpha-mediated AP-1 activation. PGE(2) and TNF alpha synergistically activated transcription factor CREB, induced C/EBPS expression and enhanced the activity of an IL-8 promoter fragment containing-223 bp upstream of the transcription start site. Conclusions and implications: These findings suggest that a combined stimulation of TNF alpha and PGE(2)/EP4 signal chains in monocytic cells leads to maximal IL-8 promoter activity, as well as IL-8 mRNA and protein induction, by activating the PICA/CREB/C/EB1313 as well as NF-kappa B signal chains.}, language = {en} } @article{HenkelColemanSchraplauetal.2018, author = {Henkel, Janin and Coleman, Charles Dominic and Schraplau, Anne and Joehrens, Korinna and Weiss, Thomas Siegfried and Jonas, Wenke and Sch{\"u}rmann, Annette and P{\"u}schel, Gerhard Paul}, title = {Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model}, series = {Scientific reports}, volume = {8}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-34633-y}, pages = {11}, year = {2018}, abstract = {In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E-2 (PGE(2)), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE(2) synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE(2) concentration that was completely abrogated in mPGES-1-deficient mice. PGE(2) is known to inhibit TNF-alpha synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-alpha expression. Due to the impaired PGE(2) production, TNF-alpha expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-alpha resulted in an enhanced IL-1 beta production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE(2) production by mPGES-1 ablation enhanced the TNF-alpha-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.}, language = {en} } @article{PatheNeuschaeferRubeNeuschaeferRubePueschel2021, author = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul}, title = {Cell-based reporter release assay to determine the activity of calcium-dependent neurotoxins and neuroactive pharmaceuticals}, series = {Toxins / Molecular Diversity Preservation International (MDPI)}, volume = {13}, journal = {Toxins / Molecular Diversity Preservation International (MDPI)}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2072-6651}, doi = {10.3390/toxins13040247}, pages = {13}, year = {2021}, abstract = {The suitability of a newly developed cell-based functional assay was tested for the detection of the activity of a range of neurotoxins and neuroactive pharmaceuticals which act by stimulation or inhibition of calcium-dependent neurotransmitter release. In this functional assay, a reporter enzyme is released concomitantly with the neurotransmitter from neurosecretory vesicles. The current study showed that the release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) can be stimulated by a carbachol-mediated activation of the Gq-coupled muscarinic-acetylcholine receptor and by the Ca2+-channel forming spider toxin α-latrotoxin. Carbachol-stimulated luciferase release was completely inhibited by the muscarinic acetylcholine receptor antagonist atropine and α-latrotoxin-mediated release by the Ca2+-chelator EGTA, demonstrating the specificity of luciferase-release stimulation. SIMA-hPOMC1-26-GLuc cells express mainly L- and N-type and to a lesser extent T-type VGCC on the mRNA and protein level. In accordance with the expression profile a depolarization-stimulated luciferase release by a high K+-buffer was effectively and dose-dependently inhibited by L-type VGCC inhibitors and to a lesser extent by N-type and T-type inhibitors. P/Q- and R-type inhibitors did not affect the K+-stimulated luciferase release. In summary, the newly established cell-based assay may represent a versatile tool to analyze the biological efficiency of a range of neurotoxins and neuroactive pharmaceuticals which mediate their activity by the modulation of calcium-dependent neurotransmitter release.}, language = {en} } @misc{PatheNeuschaeferRubeNeuschaeferRubePueschel2021, author = {Pathe-Neusch{\"a}fer-Rube, Andrea and Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul}, title = {Cell-based reporter release assay to determine the activity of calcium-dependent neurotoxins and neuroactive pharmaceuticals}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1139}, issn = {1866-8372}, doi = {10.25932/publishup-50322}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-503225}, pages = {15}, year = {2021}, abstract = {The suitability of a newly developed cell-based functional assay was tested for the detection of the activity of a range of neurotoxins and neuroactive pharmaceuticals which act by stimulation or inhibition of calcium-dependent neurotransmitter release. In this functional assay, a reporter enzyme is released concomitantly with the neurotransmitter from neurosecretory vesicles. The current study showed that the release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-GLuc cells) can be stimulated by a carbachol-mediated activation of the Gq-coupled muscarinic-acetylcholine receptor and by the Ca2+-channel forming spider toxin α-latrotoxin. Carbachol-stimulated luciferase release was completely inhibited by the muscarinic acetylcholine receptor antagonist atropine and α-latrotoxin-mediated release by the Ca2+-chelator EGTA, demonstrating the specificity of luciferase-release stimulation. SIMA-hPOMC1-26-GLuc cells express mainly L- and N-type and to a lesser extent T-type VGCC on the mRNA and protein level. In accordance with the expression profile a depolarization-stimulated luciferase release by a high K+-buffer was effectively and dose-dependently inhibited by L-type VGCC inhibitors and to a lesser extent by N-type and T-type inhibitors. P/Q- and R-type inhibitors did not affect the K+-stimulated luciferase release. In summary, the newly established cell-based assay may represent a versatile tool to analyze the biological efficiency of a range of neurotoxins and neuroactive pharmaceuticals which mediate their activity by the modulation of calcium-dependent neurotransmitter release.}, language = {en} } @misc{PueschelHespelingOppermannetal.1993, author = {P{\"u}schel, Gerhard Paul and Hespeling, Ursula and Oppermann, Martin and Dieter, Peter}, title = {Increase in prostanoid formation in rat liver macrophages (Kupffer cells) by human anaphylatoxin C3a}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16716}, year = {1993}, abstract = {Human anaphylatoxin C3a increases glycogenolysis in perfused rat liver. This action is inhibited by prostanoid synthesis inhibitors and prostanoid antagonists. Because prostanoids but not anaphylatoxin C3a can increase glycogenolysis in hepatocytes, it has been proposed that prostanoid formation in nonparenchymal cells represents an important step in the C3a-dependent increase in hepatic glycogenolysis. This study shows that (a) human anaphylatoxin C3a (0.1 to 10 mug/ml) dose-dependently increased prostaglandin D2, thromboxane B, and prostaglandin F2alpha formation in rat liver macrophages (Kupffer cells); (b) the C3a-mediated increase in prostanoid formation was maximal after 2 min and showed tachyphylaxis; and (c) the C3a-elicited prostanoid formation could be inhibited specifically by preincubation of C3a with carboxypeptidase B to remove the essential C-terminal arginine or by preincubation of C3a with Fab fragments of a neutralizing monoclonal antibody. These data support the hypothesis that the C3a-dependent activation of hepatic glycogenolysis is mediated by way of a C3a-induced prostanoid production in Kupffer cells.}, 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{PueschelChrist1994, author = {P{\"u}schel, Gerhard Paul and Christ, Bruno}, title = {Inhibition by PGE₂ of glucagon-induced increase in phosphoenolpyruvate carboxykinase mRNA and acceleration of mRNA degradation in cultured rat hepatocytes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45792}, year = {1994}, abstract = {In cultured rat hepatocytes the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK) is known to be induced by glucagon via an elevation of cAMP. Prostaglandin E₂ has been shown to antagonize the glucagon-activated cAMP formation, glycogen phosphorylase activity and glucose output in hepatocytes. It was the purpose of the current investigation to study the potential of PGE₂ to inhibit the glucagon-induced expression of PCK on the level of mRNA and enzyme activity. PCK mRNA and enzyme activity were increased by 0.1 nM glucagon to a maximum after 2 h and 4 h, respectively. This increase was completely inhibited if 10 μM PGE2 was added concomitantly with glucagon. This inhibition by PGE₂ of glucagon-induced PCK activity was abolished by pertussis toxin treatment. When added at the maximum of PCK mRNA at 2 h, PGE₂ accelerated the decay of mRNA and reduced enzyme activity. This effect was not reversed by pertussis toxin treatment. Since in liver PGE₂ is derived from Kupffer cells, which play a key role in the local inflammatory response, the present data imply that during inflammation PGE₂ may reduce the hepatic gluconeogenic capacity via a Gᵢ-linked signal chain.}, 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{NeuschaeferRubePueschelJungermann1993, author = {Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul and Jungermann, Kurt}, title = {Characterization of prostaglandin-F₂α-binding sites on rat hepatocyte plasma membranes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45863}, year = {1993}, abstract = {Prostaglandin (PG)F₂α has previously been shown to increase glucose output from perfused livers and isolated hepatocytes, where it stimulated glycogen phosphorylase via an inositol-trisphosphatedependent signal pathway. In this study, PGF₂α binding sites on hepatocyte plasma membranes, that might represent the putative receptor, were characterized. Binding studies could not be performed with intact hepatocytes, because PGF₂α accumulated within the cells even at 4°C. The intracellular accumulation was an order of magnitude higher than binding to plasma membranes. Purified hepatocyte plasma membranes had a high-affinity/low-capacity and a low-affinity/highcapacity binding'site for PGF₂α. The respective binding constants for the high-affinity site were Kd = 3 nM and Bmax = 6 fmol/mg membrane protein, and for the low-affinity site Kd = 426 nM and Bmax = 245 fmol/mg membrane protein. Specific PGF₂α binding to the low-affinity site, but not to the high-affinity site, could be enhanced most potently by GTP[γS] followed by GDP[ϐS] and GTP, but not by ATP[γS] or GMP. PGF₂α competed most potently with [³H]PGF₂α for specific binding to hepatocyte plasma membranes, followed by PGD₂ and PGE₂. Since the low-affinity PGF₂α-binding site had a Kd in the concentration range in which PG had previously been shown to be half-maximally active, and since this binding site showed a sensitivity to GTP, it is concluded that it might represent the receptor involved in the PGF₂α signal chain in hepatocytes. A biological function of the high-affinity site is currently not known.}, language = {en} } @misc{PueschelKirchnerSchroederetal.1993, author = {P{\"u}schel, Gerhard Paul and Kirchner, C. and Schr{\"o}der, A. and Jungermann, Kurt}, title = {Glycogenolytic and antiglycogenolytic prostaglandin E₂ actions in rat hepatocytes are mediated via different signalling pathways}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45853}, year = {1993}, abstract = {Prostaglandin E₂ has been reported both to stimulate glycogen-phosphorylase activity (glycogenolytic effect) and to inhibit the glucagon-stimulated glycogen-phosphorylase activity (antiglycogenolytic effect) in rat hepatocytes. It was the purpose of this study to resolve this apparent contradiction and to characterize the signalling pathways and receptor subtypes involved in the opposing prostaglandin E₂ actions. Prostaglandin E₂ (10 μM) increased glucose output, glycogen-phosphorylase activity and inositol trisphosphate formation in hepatocyte cell culture andor suspension. In the same systems, prostaglandin E₂ decreased the glucagon-stimulated (1 nM) glycogen-phosphorylase activity and cAMP formation. The signalling pathway leading to the glycogenolytic effect of PGE₂ was interrupted by incubation of the hepatocytes with 4P-phorbol 12-myristate 13-acetate (100 nM) for 10 min, while the antiglycogenolytic effect of prostaglandin E₂ was not attenuated. The signalling pathway leading to the antiglycogenolytic effect of prostaglandin E₂ was interrupted by an incubation of cultured hepatocytes with pertussis toxin (100 ng/ml) for 18 h, whereas the glycogenolytic effect of prostaglandin E₂ was enhanced. The EP₁/EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Sulproston had a stronger glycogenolytic potency than the EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Misoprostol. The antiglycogenolytic potency of both agonists was equal. It is concluded that the glycogenolytic and the antiglycogenolytic effects of prostaglandin E₂ are mediated via different signalling pathways in hepatocytes possibly involving EP₁ and EP₃ prostaglandin E₂ receptors, respectively.}, language = {en} } @misc{HespelingPueschelJungermannetal.1995, author = {Hespeling, Ursula and P{\"u}schel, Gerhard Paul and Jungermann, Kurt and G{\"o}tze, Otto and Zwirner, J{\"o}rg}, title = {Stimulation of glycogen phosphorylase in rat hepatocytes via prostanoid release from Kupffer cells by recombinant rat anaphylatoxin C5a but not by native human C5a in hepatocyte/Kupffer cell co-cultures}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45909}, year = {1995}, abstract = {Human anaphylatoxin C3a had previously been shown to increase glycogenolysis in perfused rat liver and prostanoid formation in rat liver macrophages. Surprisingly, human C5a, which in other systems elicited stronger responses than C3a, did not increase glycogenolysis in perfused rat liver. Species incompatibilities within the experimental system had been supposed to be the reason. The current study supports this hypothesis: (1) In rat liver macrophages that had been maintained in primary culture for 72 h recombinant rat anaphylatoxin C5a in concentrations between 0.1 and 10 pg/ml increased the formation of thromboxane A₂, prostaglandin D₂, E₂ and F₂α6- to 12-fold over basal within 10 min. In contrast, human anaphylatoxin C5a did not increase prostanoid formation in rat Kupffer cells. (2) The increase in prostanoid formation by recombinant rat C5a was specific. It was inhibited by a neutralizing monoclonal antibody. (3) In co-cultures of rat hepatocytes and rat Kupffer cells but not in hepatocyte mono-cultures recombinant rat C5a increased glycogen phosphorylase activity 3-fold over basal. This effect was inhibited by incubation of the co-cultures with 500 μM acetylsalicyclic acid. Thus, C5a generated either locally in the liver or systemically e.g. in the course of sepsis, may increase hepatic glycogenolysis by a prostanoid-mediated intercellular communication between Kupffer cells and hepatocytes.}, language = {en} } @misc{NeuschaeferRubeDeVriesHaeneckeetal.1994, author = {Neusch{\"a}fer-Rube, Frank and DeVries, Christa and H{\"a}necke, Kristina and Jungermann, Kurt and P{\"u}schel, Gerhard Paul}, title = {Molecular cloning and expression of a prostaglandin E₂ receptor of the EP₃ϐ subtype from rat hepatocytes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45830}, year = {1994}, abstract = {Rat hepatocytes have previously been reported to possess prostaglandin E₂ receptors of the EP₃-type (EP₃-receptors) that inhibit glucagonstimulated glycogenolysis by decreasing cAMP. Here, the isolation of a functional EP₃ϐ receptor cDNA clone from a rat hepatocyte cDNA library is reported. This clone can be translated into a 362-amino-acid protein, that displays over 95\% homology to the EP₃ϐ receptor from mouse mastocytoma. The amino- and carboxy-terminal region of the protein are least conserved. Transiently transfected HEK 293 cells expressed a single binding site for PGE₂ with an apparent Kd of 15 nM. PGE₂ > PGF₂α > PGD₂ competed for [³H]PGE₂ binding sites as did the EP₃ receptor agonists M\&B 28767 = sulprostone > misoprostol but not the EP₁ receptor antagonist SC 19220. In stably transfected CHO cells M\&B 28767 > sulprostone = PGE₂ > misoprostol > PGF₂α inhibited the forskolin-elicited cAMP formation. Thus, the characteristics of the EP₃ϐ receptor of rat hepatocytes closely resemble those of the EP₃ϐ receptor of mouse mastocytoma.}, language = {en} } @misc{HenkelBuchheimDieckowCastroetal.2019, author = {Henkel, Janin and Buchheim-Dieckow, Katja and Castro, Jos{\´e} Pedro and Laeger, Thomas and Wardelmann, Kristina and Kleinridders, Andr{\´e} and J{\"o}hrens, Korinna and P{\"u}schel, Gerhard Paul}, title = {Reduced Oxidative Stress and Enhanced FGF21 Formation in Livers of Endurance-Exercised Rats with Diet-Induced NASH}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {807}, issn = {1866-8372}, doi = {10.25932/publishup-44238}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-442384}, pages = {17}, year = {2019}, abstract = {Non-alcoholic fatty liver diseases (NAFLD) including the severe form with steatohepatitis (NASH) are highly prevalent ailments to which no approved pharmacological treatment exists. Dietary intervention aiming at 10\% weight reduction is efficient but fails due to low compliance. Increase in physical activity is an alternative that improved NAFLD even in the absence of weight reduction. The underlying mechanisms are unclear and cannot be studied in humans. Here, a rat NAFLD model was developed that reproduces many facets of the diet-induced NAFLD in humans. The impact of endurance exercise was studied in this model. Male Wistar rats received control chow or a NASH-inducing diet rich in fat, cholesterol, and fructose. Both diet groups were subdivided into a sedentary and an endurance exercise group. Animals receiving the NASH-inducing diet gained more body weight, got glucose intolerant and developed a liver pathology with steatosis, hepatocyte hypertrophy, inflammation and fibrosis typical of NAFLD or NASH. Contrary to expectations, endurance exercise did not improve the NASH activity score and even enhanced hepatic inflammation. However, endurance exercise attenuated the hepatic cholesterol overload and the ensuing severe oxidative stress. In addition, exercise improved glucose tolerance possibly in part by induction of hepatic FGF21 production.}, language = {en} } @article{HenkelBuchheimDieckowCastroetal.2019, author = {Henkel, Janin and Buchheim-Dieckow, Katja and Castro, Jos{\´e} Pedro and Laeger, Thomas and Wardelmann, Kristina and Kleinridders, Andr{\´e} and J{\"o}hrens, Korinna and P{\"u}schel, Gerhard Paul}, title = {Reduced Oxidative Stress and Enhanced FGF21 Formation in Livers of Endurance-Exercised Rats with Diet-Induced NASH}, series = {Nutrients}, volume = {11}, journal = {Nutrients}, number = {11}, publisher = {MDPI}, address = {Basel}, issn = {2072-6643}, doi = {10.3390/nu11112709}, pages = {15}, year = {2019}, abstract = {Non-alcoholic fatty liver diseases (NAFLD) including the severe form with steatohepatitis (NASH) are highly prevalent ailments to which no approved pharmacological treatment exists. Dietary intervention aiming at 10\% weight reduction is efficient but fails due to low compliance. Increase in physical activity is an alternative that improved NAFLD even in the absence of weight reduction. The underlying mechanisms are unclear and cannot be studied in humans. Here, a rat NAFLD model was developed that reproduces many facets of the diet-induced NAFLD in humans. The impact of endurance exercise was studied in this model. Male Wistar rats received control chow or a NASH-inducing diet rich in fat, cholesterol, and fructose. Both diet groups were subdivided into a sedentary and an endurance exercise group. Animals receiving the NASH-inducing diet gained more body weight, got glucose intolerant and developed a liver pathology with steatosis, hepatocyte hypertrophy, inflammation and fibrosis typical of NAFLD or NASH. Contrary to expectations, endurance exercise did not improve the NASH activity score and even enhanced hepatic inflammation. However, endurance exercise attenuated the hepatic cholesterol overload and the ensuing severe oxidative stress. In addition, exercise improved glucose tolerance possibly in part by induction of hepatic FGF21 production.}, language = {en} } @article{GehreFlechnerKammereretal.2020, author = {Gehre, Christian 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}, number = {1}, publisher = {Macmillan Publishers Limited, part of Springer Nature}, address = {[London]}, issn = {2045-2322}, doi = {10.1038/s41598-020-70785-6}, pages = {12}, year = {2020}, 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{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} } @misc{NeuschaeferRubePatheNeuschaeferRubePueschel2022, author = {Neusch{\"a}fer-Rube, Frank and Pathe-Neusch{\"a}fer-Rube, Andrea and P{\"u}schel, Gerhard Paul}, title = {Discrimination of the Activity of Low-Affinity Wild-Type and High-Affinity Mutant Recombinant BoNT/B by a SIMA Cell-Based Reporter Release Assay}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8372}, doi = {10.25932/publishup-55803}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-558032}, pages = {1 -- 11}, year = {2022}, abstract = {Botulinum neurotoxin (BoNT) is used for the treatment of a number of ailments. The activity of the toxin that is isolated from bacterial cultures is frequently tested in the mouse lethality assay. Apart from the ethical concerns inherent to this assay, species-specific differences in the affinity for different BoNT serotypes give rise to activity results that differ from the activity in humans. Thus, BoNT/B is more active in mice than in humans. The current study shows that the stimulus-dependent release of a luciferase from a differentiated human neuroblastoma-based reporter cell line (SIMA-hPOMC1-26-Gluc) was inhibited by clostridial and recombinant BoNT/A to the same extent, whereas both clostridial and recombinant BoNT/B inhibited the release to a lesser extent and only at much higher concentrations, reflecting the low activity of BoNT/B in humans. By contrast, the genetically modified BoNT/B-MY, which has increased affinity for human synaptotagmin, and the BoNT/B protein receptor inhibited luciferase release effectively and with an EC50 comparable to recombinant BoNT/A. This was due to an enhanced uptake into the reporter cells of BoNT/B-MY in comparison to the recombinant wild-type toxin. Thus, the SIMA-hPOMC1-26-Gluc cell assay is a versatile tool to determine the activity of different BoNT serotypes providing human-relevant dose-response data.}, language = {en} } @misc{MichaudSchjeideSchenkeSeegeretal.2022, author = {Michaud Schjeide, Brit-Maren and Schenke, Maren and Seeger, Bettina and P{\"u}schel, Gerhard Paul}, title = {Validation of a Novel Double Control Quantitative Copy Number PCR Method to Quantify Off-Target Transgene Integration after CRISPR-Induced DNA Modification}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-8372}, doi = {10.25932/publishup-56175}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-561755}, pages = {1 -- 14}, year = {2022}, abstract = {In order to improve a recently established cell-based assay to assess the potency of botulinum neurotoxin, neuroblastoma-derived SiMa cells and induced pluripotent stem-cells (iPSC) were modified to incorporate the coding sequence of a reporter luciferase into a genetic safe harbor utilizing CRISPR/Cas9. A novel method, the double-control quantitative copy number PCR (dc-qcnPCR), was developed to detect off-target integrations of donor DNA. The donor DNA insertion success rate and targeted insertion success rate were analyzed in clones of each cell type. The dc-qcnPCR reliably quantified the copy number in both cell lines. The probability of incorrect donor DNA integration was significantly increased in SiMa cells in comparison to the iPSCs. This can possibly be explained by the lower bundled relative gene expression of a number of double-strand repair genes (BRCA1, DNA2, EXO1, MCPH1, MRE11, and RAD51) in SiMa clones than in iPSC clones. The dc-qcnPCR offers an efficient and cost-effective method to detect off-target CRISPR/Cas9-induced donor DNA integrations.}, language = {en} } @misc{PueschelKlauderHenkelOberlaender, author = {P{\"u}schel, Gerhard Paul and Klauder, Julia and Henkel-Oberl{\"a}nder, Janin}, title = {Macrophages, Low-Grade Inflammation, Insulin Resistance and Hyperinsulinemia: A Mutual Ambiguous Relationship in the Development of Metabolic Diseases}, 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 = {1279}, issn = {1866-8372}, doi = {10.25932/publishup-57010}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-570106}, pages = {1 -- 30}, abstract = {Metabolic derangement with poor glycemic control accompanying overweight and obesity is associated with chronic low-grade inflammation and hyperinsulinemia. Macrophages, which present a very heterogeneous population of cells, play a key role in the maintenance of normal tissue homeostasis, but functional alterations in the resident macrophage pool as well as newly recruited monocyte-derived macrophages are important drivers in the development of low-grade inflammation. While metabolic dysfunction, insulin resistance and tissue damage may trigger or advance pro-inflammatory responses in macrophages, the inflammation itself contributes to the development of insulin resistance and the resulting hyperinsulinemia. Macrophages express insulin receptors whose downstream signaling networks share a number of knots with the signaling pathways of pattern recognition and cytokine receptors, which shape macrophage polarity. The shared knots allow insulin to enhance or attenuate both pro-inflammatory and anti-inflammatory macrophage responses. This supposedly physiological function may be impaired by hyperinsulinemia or insulin resistance in macrophages. This review discusses the mutual ambiguous relationship of low-grade inflammation, insulin resistance, hyperinsulinemia and the insulin-dependent modulation of macrophage activity with a focus on adipose tissue and liver.}, language = {en} } @article{HenkelAlfineSainetal.2018, author = {Henkel, Janin and Alfine, Eugenia and Sa{\´i}n, Juliana and J{\"o}hrens, Korinna and Weber, Daniela and Castro, Jos{\´e} Pedro and K{\"o}nig, Jeannette and Stuhlmann, Christin and Vahrenbrink, Madita and Jonas, Wenke and Kleinridders, Andr{\´e} and P{\"u}schel, Gerhard Paul}, title = {Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol}, series = {Nutrients}, volume = {10}, journal = {Nutrients}, number = {9}, publisher = {Molecular Diversity Preservation International (MDPI)}, address = {Basel}, issn = {2072-6643}, doi = {10.3390/nu10091326}, pages = {1 -- 17}, year = {2018}, abstract = {While the impact of dietary cholesterol on the progression of atherosclerosis has probably been overestimated, increasing evidence suggests that dietary cholesterol might favor the transition from blunt steatosis to non-alcoholic steatohepatitis (NASH), especially in combination with high fat diets. It is poorly understood how cholesterol alone or in combination with other dietary lipid components contributes to the development of lipotoxicity. The current study demonstrated that liver damage caused by dietary cholesterol in mice was strongly enhanced by a high fat diet containing soybean oil-derived ω6-poly-unsaturated fatty acids (ω6-PUFA), but not by a lard-based high fat diet containing mainly saturated fatty acids. In contrast to the lard-based diet the soybean oil-based diet augmented cholesterol accumulation in hepatocytes, presumably by impairing cholesterol-eliminating pathways. The soybean oil-based diet enhanced cholesterol-induced mitochondrial damage and amplified the ensuing oxidative stress, probably by peroxidation of poly-unsaturated fatty acids. This resulted in hepatocyte death, recruitment of inflammatory cells, and fibrosis, and caused a transition from steatosis to NASH, doubling the NASH activity score. Thus, the recommendation to reduce cholesterol intake, in particular in diets rich in ω6-PUFA, although not necessary to reduce the risk of atherosclerosis, might be sensible for patients suffering from non-alcoholic fatty liver disease.}, language = {en} } @misc{HenkelAlfineSainetal.2018, author = {Henkel, Janin and Alfine, Eugenia and Sa{\´i}n, Juliana and J{\"o}hrens, Korinna and Weber, Daniela and Castro, Jos{\´e} Pedro and K{\"o}nig, Jeannette and Stuhlmann, Christin and Vahrenbrink, Madita and Jonas, Wenke and Kleinridders, Andr{\´e} and P{\"u}schel, Gerhard Paul}, title = {Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol}, series = {Nutrients}, journal = {Nutrients}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419773}, pages = {17}, year = {2018}, abstract = {While the impact of dietary cholesterol on the progression of atherosclerosis has probably been overestimated, increasing evidence suggests that dietary cholesterol might favor the transition from blunt steatosis to non-alcoholic steatohepatitis (NASH), especially in combination with high fat diets. It is poorly understood how cholesterol alone or in combination with other dietary lipid components contributes to the development of lipotoxicity. The current study demonstrated that liver damage caused by dietary cholesterol in mice was strongly enhanced by a high fat diet containing soybean oil-derived ω6-poly-unsaturated fatty acids (ω6-PUFA), but not by a lard-based high fat diet containing mainly saturated fatty acids. In contrast to the lard-based diet the soybean oil-based diet augmented cholesterol accumulation in hepatocytes, presumably by impairing cholesterol-eliminating pathways. The soybean oil-based diet enhanced cholesterol-induced mitochondrial damage and amplified the ensuing oxidative stress, probably by peroxidation of poly-unsaturated fatty acids. This resulted in hepatocyte death, recruitment of inflammatory cells, and fibrosis, and caused a transition from steatosis to NASH, doubling the NASH activity score. Thus, the recommendation to reduce cholesterol intake, in particular in diets rich in ω6-PUFA, although not necessary to reduce the risk of atherosclerosis, might be sensible for patients suffering from non-alcoholic fatty liver disease.}, 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} } @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{HenkelKlauderStatzetal.2021, author = {Henkel, Janin and Klauder, Julia and Statz, Meike and Wohlenberg, Anne-Sophie and Kuipers, Sonja and Vahrenbrink, Madita and P{\"u}schel, Gerhard Paul}, title = {Enhanced Palmitate-Induced Interleukin-8 Formation in Human Macrophages by Insulin or Prostaglandin E-2}, series = {Biomedicines}, volume = {9}, journal = {Biomedicines}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2227-9059}, doi = {10.3390/biomedicines9050449}, pages = {10}, year = {2021}, abstract = {Macrophages in pathologically expanded dysfunctional white adipose tissue are exposed to a mix of potential modulators of inflammatory response, including fatty acids released from insulin-resistant adipocytes, increased levels of insulin produced to compensate insulin resistance, and prostaglandin E-2 (PGE(2)) released from activated macrophages. The current study addressed the question of how palmitate might interact with insulin or PGE(2) to induce the formation of the chemotactic pro-inflammatory cytokine interleukin-8 (IL-8). Human THP-1 cells were differentiated into macrophages. In these macrophages, palmitate induced IL-8 formation. Insulin enhanced the induction of IL-8 formation by palmitate as well as the palmitate-dependent stimulation of PGE(2) synthesis. PGE(2) in turn elicited IL-8 formation on its own and enhanced the induction of IL-8 release by palmitate, most likely by activating the EP4 receptor. Since IL-8 causes insulin resistance and fosters inflammation, the increase in palmitate-induced IL-8 formation that is caused by hyperinsulinemia and locally produced PGE(2) in chronically inflamed adipose tissue might favor disease progression in a vicious feed-forward cycle.}, language = {en} } @article{FayyazHenkelJaptoketal.2014, author = {Fayyaz, Susann and Henkel, Janin and Japtok, Lukasz and Kr{\"a}mer, Stephanie and Damm, Georg and Seehofer, Daniel and P{\"u}schel, Gerhard Paul and Kleuser, Burkhard}, title = {Involvement of sphingosine 1-phosphate in palmitate-induced insulin resistance of hepatocytes via the S1P(2) receptor subtype}, series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, volume = {57}, journal = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, number = {2}, publisher = {Springer}, address = {New York}, issn = {0012-186X}, doi = {10.1007/s00125-013-3123-6}, pages = {373 -- 382}, year = {2014}, abstract = {Enhanced plasma levels of NEFA have been shown to induce hepatic insulin resistance, which contributes to the development of type 2 diabetes. Indeed, sphingolipids can be formed via a de novo pathway from the saturated fatty acid palmitate and the amino acid serine. Besides ceramides, sphingosine 1-phosphate (S1P) has been identified as a major bioactive lipid mediator. Therefore, our aim was to investigate the generation and function of S1P in hepatic insulin resistance. The incorporation of palmitate into sphingolipids was performed by rapid-resolution liquid chromatography-MS/MS in primary human and rat hepatocytes. The influence of S1P and the involvement of S1P receptors in hepatic insulin resistance was examined in human and rat hepatocytes, as well as in New Zealand obese (NZO) mice. Palmitate induced an impressive formation of extra- and intracellular S1P in rat and human hepatocytes. An elevation of hepatic S1P levels was observed in NZO mice fed a high-fat diet. Once generated, S1P was able, similarly to palmitate, to counteract insulin signalling. The inhibitory effect of S1P was abolished in the presence of the S1P(2) receptor antagonist JTE-013 both in vitro and in vivo. In agreement with this, the immunomodulator FTY720-phosphate, which binds to all S1P receptors except S1P(2), was not able to inhibit insulin signalling. These data indicate that palmitate is metabolised by hepatocytes to S1P, which acts via stimulation of the S1P(2) receptor to impair insulin signalling. In particular, S1P(2) inhibition could be considered as a novel therapeutic target for the treatment of insulin resistance.}, language = {en} } @misc{PueschelJungermann1994, author = {P{\"u}schel, Gerhard Paul and Jungermann, Kurt}, title = {Integration of function in the hepatic acinus : intercellular communication in neural and humoral control of liver metabolism}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51279}, year = {1994}, abstract = {Content: Architecture of the liver acinus Functional zonation of the liver acinus Topological organization of metabollc regulation in the acinus Topological organization of defense and organ structure regulation in the acinus}, language = {de} } @misc{GardemannPueschelJungermann1992, author = {Gardemann, Andreas and P{\"u}schel, Gerhard Paul and Jungermann, Kurt}, title = {Nervous control of liver metabolism and hemodynamics}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51346}, year = {1992}, abstract = {Content: Anatomy of hepatic innervation In vivo studies on the role of hepatic nerves Effects of hepatic nerves in isolated perfused liver Mechanism of action of sympathetic hepatic nerves}, 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} }