@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{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}
}
@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{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}
}