TY - GEN A1 - Wardelmann, Kristina A1 - Rath, Michaela A1 - Castro, José Pedro A1 - Blümel, Sabine A1 - Schell, Mareike A1 - Hauffe, Robert A1 - Schumacher, Fabian A1 - Flore, Tanina A1 - Ritter, Katrin A1 - Wernitz, Andreas A1 - Hosoi, Toru A1 - Ozawa, Koichiro A1 - Kleuser, Burkhard A1 - Weiß, Jürgen A1 - Schürmann, Annette A1 - Kleinridders, André T1 - Central acting Hsp10 regulates mitochondrial function, fatty acid metabolism and insulin sensitivity in the hypothalamus T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Mitochondria are critical for hypothalamic function and regulators of metabolism. Hypothalamic mitochondrial dysfunction with decreased mitochondrial chaperone expression is present in type 2 diabetes (T2D). Recently, we demonstrated that a dysregulated mitochondrial stress response (MSR) with reduced chaperone expression in the hypothalamus is an early event in obesity development due to insufficient insulin signaling. Although insulin activates this response and improves metabolism, the metabolic impact of one of its members, the mitochondrial chaperone heat shock protein 10 (Hsp10), is unknown. Thus, we hypothesized that a reduction of Hsp10 in hypothalamic neurons will impair mitochondrial function and impact brain insulin action. Therefore, we investigated the role of chaperone Hsp10 by introducing a lentiviral-mediated Hsp10 knockdown (KD) in the hypothalamic cell line CLU-183 and in the arcuate nucleus (ARC) of C57BL/6N male mice. We analyzed mitochondrial function and insulin signaling utilizing qPCR, Western blot, XF96 Analyzer, immunohistochemistry, and microscopy techniques. We show that Hsp10 expression is reduced in T2D mice brains and regulated by leptin in vitro. Hsp10 KD in hypothalamic cells induced mitochondrial dysfunction with altered fatty acid metabolism and increased mitochondria-specific oxidative stress resulting in neuronal insulin resistance. Consequently, the reduction of Hsp10 in the ARC of C57BL/6N mice caused hypothalamic insulin resistance with acute liver insulin resistance. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1165 KW - brain insulin signaling KW - mitochondria KW - oxidative stress KW - fatty acid metabolism Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-522985 SN - 1866-8372 IS - 5 ER - TY - JOUR A1 - Wardelmann, Kristina A1 - Rath, Michaela A1 - Castro, José Pedro A1 - Blümel, Sabine A1 - Schell, Mareike A1 - Hauffe, Robert A1 - Schumacher, Fabian A1 - Flore, Tanina A1 - Ritter, Katrin A1 - Wernitz, Andreas A1 - Hosoi, Toru A1 - Ozawa, Koichiro A1 - Kleuser, Burkhard A1 - Weiß, Jürgen A1 - Schürmann, Annette A1 - Kleinridders, André T1 - Central acting Hsp10 regulates mitochondrial function, fatty acid metabolism and insulin sensitivity in the hypothalamus JF - Antioxidants N2 - Mitochondria are critical for hypothalamic function and regulators of metabolism. Hypothalamic mitochondrial dysfunction with decreased mitochondrial chaperone expression is present in type 2 diabetes (T2D). Recently, we demonstrated that a dysregulated mitochondrial stress response (MSR) with reduced chaperone expression in the hypothalamus is an early event in obesity development due to insufficient insulin signaling. Although insulin activates this response and improves metabolism, the metabolic impact of one of its members, the mitochondrial chaperone heat shock protein 10 (Hsp10), is unknown. Thus, we hypothesized that a reduction of Hsp10 in hypothalamic neurons will impair mitochondrial function and impact brain insulin action. Therefore, we investigated the role of chaperone Hsp10 by introducing a lentiviral-mediated Hsp10 knockdown (KD) in the hypothalamic cell line CLU-183 and in the arcuate nucleus (ARC) of C57BL/6N male mice. We analyzed mitochondrial function and insulin signaling utilizing qPCR, Western blot, XF96 Analyzer, immunohistochemistry, and microscopy techniques. We show that Hsp10 expression is reduced in T2D mice brains and regulated by leptin in vitro. Hsp10 KD in hypothalamic cells induced mitochondrial dysfunction with altered fatty acid metabolism and increased mitochondria-specific oxidative stress resulting in neuronal insulin resistance. Consequently, the reduction of Hsp10 in the ARC of C57BL/6N mice caused hypothalamic insulin resistance with acute liver insulin resistance. KW - brain insulin signaling KW - mitochondria KW - oxidative stress KW - fatty acid metabolism Y1 - 2021 U6 - https://doi.org/10.3390/antiox10050711 SN - 2076-3921 VL - 10 IS - 5 PB - MDPI CY - Basel ER - TY - GEN A1 - Henkel, Janin A1 - Buchheim-Dieckow, Katja A1 - Castro, José Pedro A1 - Laeger, Thomas A1 - Wardelmann, Kristina A1 - Kleinridders, André A1 - Jöhrens, Korinna A1 - Püschel, Gerhard Paul T1 - Reduced Oxidative Stress and Enhanced FGF21 Formation in Livers of Endurance-Exercised Rats with Diet-Induced NASH T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 807 KW - NAFLD KW - NASH KW - endurance exercise KW - FGF21 KW - glucose intolerance KW - cholesterol KW - oxidative stress Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-442384 SN - 1866-8372 IS - 807 ER - TY - JOUR A1 - Henkel, Janin A1 - Buchheim-Dieckow, Katja A1 - Castro, José Pedro A1 - Laeger, Thomas A1 - Wardelmann, Kristina A1 - Kleinridders, André A1 - Jöhrens, Korinna A1 - Püschel, Gerhard Paul T1 - Reduced Oxidative Stress and Enhanced FGF21 Formation in Livers of Endurance-Exercised Rats with Diet-Induced NASH JF - Nutrients N2 - 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. KW - NAFLD KW - NASH KW - endurance exercise KW - FGF21 KW - glucose intolerance KW - cholesterol KW - oxidative stress Y1 - 2019 U6 - https://doi.org/10.3390/nu11112709 SN - 2072-6643 VL - 11 IS - 11 PB - MDPI CY - Basel ER - TY - JOUR A1 - Henkel, Janin A1 - Alfine, Eugenia A1 - Saín, Juliana A1 - Jöhrens, Korinna A1 - Weber, Daniela A1 - Castro, José Pedro A1 - König, Jeannette A1 - Stuhlmann, Christin A1 - Vahrenbrink, Madita A1 - Jonas, Wenke A1 - Kleinridders, André A1 - Püschel, Gerhard Paul T1 - Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol JF - Nutrients N2 - 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. KW - non-alcoholic fatty liver disease (NAFLD) KW - NASH KW - cholesterol KW - PUFA KW - inflammation KW - oxidative stress Y1 - 2018 U6 - https://doi.org/10.3390/nu10091326 SN - 2072-6643 VL - 10 IS - 9 SP - 1 EP - 17 PB - Molecular Diversity Preservation International (MDPI) CY - Basel ER - TY - GEN A1 - Henkel, Janin A1 - Alfine, Eugenia A1 - Saín, Juliana A1 - Jöhrens, Korinna A1 - Weber, Daniela A1 - Castro, José Pedro A1 - König, Jeannette A1 - Stuhlmann, Christin A1 - Vahrenbrink, Madita A1 - Jonas, Wenke A1 - Kleinridders, André A1 - Püschel, Gerhard Paul T1 - Soybean Oil-Derived Poly-Unsaturated Fatty Acids Enhance Liver Damage in NAFLD Induced by Dietary Cholesterol T2 - Nutrients N2 - 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 479 KW - non-alcoholic fatty liver disease (NAFLD) KW - NASH KW - cholesterol KW - PUFA KW - inflammation KW - oxidative stress Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419773 ER -