TY - JOUR A1 - Rohn, Isabelle A1 - Raschke, Stefanie A1 - Aschner, Michael A1 - Tuck, Simon A1 - Kuehnelt, Doris A1 - Kipp, Anna Patricia A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Treatment of caenorhabditis elegans with small selenium species enhances antioxidant defense systems JF - Molecular nutrition & food research : bioactivity, chemistry, immunology, microbiology, safety, technology N2 - ScopeSmall selenium (Se) species play a key role in Se metabolism and act as dietary sources of the essential trace element. However, they are redox-active and trigger pro- and antioxidant responses. As health outcomes are strongly species-dependent, species-specific characteristics of Se compounds are tested in vivo. Methods and resultsIn the model organism Caenorhabditis elegans (C. elegans), immediate and sustained effects of selenite, selenomethionine (SeMet), and Se-methylselenocysteine (MeSeCys) are studied regarding their bioavailability, incorporation into proteins, as well as modulation of the cellular redox status. While all tested Se compounds are bioavailable, only SeMet persistently accumulates and is non-specifically incorporated into proteins. However, the protection toward chemically-induced formation of reactive species is independent of the applied Se compound. Increased thioredoxin reductase (TXNRD) activity and changes in mRNA expression levels of antioxidant proteins indicate the activation of cellular defense mechanisms. However, in txnrd-1 deletion mutants, no protective effects of the Se species are observed anymore, which is also reflected by differential gene expression data. ConclusionSe species protect against chemically-induced reactive species formation. The identified immediate and sustained systemic effects of Se species give rise to speculations on possible benefits facing subsequent periods of inadequate Se intake. KW - antioxidant defense systems KW - caenorhabditis elegans KW - selenium KW - oxidative stress KW - selenoproteins Y1 - 2019 U6 - https://doi.org/10.1002/mnfr.201801304 SN - 1613-4125 SN - 1613-4133 VL - 63 IS - 9 PB - Wiley CY - Hoboken 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 - JOUR A1 - Ijomone, Omamuyovwi M. A1 - Iroegbu, Joy D. A1 - Morcillo, Patricia A1 - Ayodele, Akinyemi J. A1 - Ijomone, Olayemi K. A1 - Bornhorst, Julia A1 - Schwerdtle, Tanja A1 - Aschner, Michael T1 - Sex-dependent metal accumulation and immunoexpression of Hsp70 and Nrf2 in rats' brain following manganese exposure JF - Environmental toxicology N2 - Manganese (Mn), although important for multiple cellular processes, has posed environmental health concerns due to its neurotoxic effects. In recent years, there have been extensive studies on the mechanism of Mn-induced neuropathology, as well as the sex-dependent vulnerability to its neurotoxic effects. Nonetheless, cellular mechanisms influenced by sex differences in susceptibility to Mn have yet to be adequately characterized. Since oxidative stress is a key mechanism of Mn neurotoxicity, here, we have probed Hsp70 and Nrf2 proteins to investigate the sex-dependent changes following exposure to Mn. Male and female rats were administered intraperitoneal injections of MnCl2 (10 mg/kg and 25 mg/kg) 48 hourly for a total of eight injections (15 days). We evaluated changes in body weight, as well as Mn accumulation, Nrf2 and Hsp70 expression across four brain regions; striatum, cortex, hippocampus and cerebellum in both sexes. Our results showed sex-specific changes in body-weight, specifically in males but not in females. Additionally, we noted sex-dependent accumulation of Mn in the brain, as well as in expression levels of Nrf2 and Hsp70 proteins. These findings revealed sex-dependent susceptibility to Mn-induced neurotoxicity corresponding to differential Mn accumulation, and expression of Hsp70 and Nrf2 across several brain regions. KW - brain KW - female KW - male KW - manganese KW - oxidative stress Y1 - 2022 U6 - https://doi.org/10.1002/tox.23583 SN - 1520-4081 SN - 1522-7278 VL - 37 IS - 9 SP - 2167 EP - 2177 PB - Wiley CY - New York, NY 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 - Schäfer, Marjänn Helena A1 - Kakularam, Kumar Reddy A1 - Reisch, Florian A1 - Rothe, Michael A1 - Stehling, Sabine A1 - Heydeck, Dagmar A1 - Püschel, Gerhard Paul A1 - Kuhn, Hartmut T1 - Male Knock-in Mice Expressing an Arachidonic Acid Lipoxygenase 15B (Alox15B) with Humanized Reaction Specificity Are Prematurely Growth Arrested When Aging JF - Biomedicines N2 - 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. KW - eicosanoids KW - lipid peroxidation KW - oxidative stress KW - polyenoic fatty acids KW - erythropoiesis Y1 - 2022 U6 - https://doi.org/10.3390/biomedicines10061379 SN - 2227-9059 VL - 10 SP - 1 EP - 22 PB - MDPI CY - Basel, Schweiz ET - 6 ER - TY - JOUR A1 - Chaykovska, Lyubov A1 - Alter, Markus L. A1 - von Websky, Karoline A1 - Hohmann, Margarete A1 - Tsuprykov, Oleg A1 - Reichetzeder, Christoph A1 - Kutil, Barbara A1 - Kraft, Robin A1 - Klein, Thomas A1 - Hocher, Berthold T1 - Effects of telmisartan and linagliptin when used in combination on blood pressure and oxidative stress in rats with 2-kidney-1-clip hypertension JF - Journal of hypertension N2 - Objective:To investigate the effects of linagliptin alone and in combination with the angiotensin II receptor blocker (ARB), telmisartan on blood pressure (BP), kidney function, heart morphology and oxidative stress in rats with renovascular hypertension.Methods:Fifty-seven male Wistar rats underwent unilateral surgical stenosis of the renal artery [2-kidney-1-clip (2k1c) method]. Animals were randomly divided into four treatment groups (n=14-18 per group) receiving: telmisartan (10mg/kg per day in drinking water), linagliptin (89ppm in chow), combination (linagliptin 89ppm+telmisartan 10mg/kg per day) or placebo. An additional group of 12 rats underwent sham surgery. BP was measured one week after surgery. Hypertensive animals entered a 16-week dosing period. BP was measured 2, 4, 8, 12 and 16 weeks after the initiation of treatment. Blood and urine were tested for assessment of kidney function and oxidative stress 6, 10, 14 and 18 weeks after surgery. Blood and urine sampling and organ harvesting were finally performed.Results:Renal stenosis caused an increase in meanSD systolic BP as compared with the sham group (157.7 +/- 29.3 vs. 106.2 +/- 20.5mmHg, respectively; P<0.001). Telmisartan alone and in combination with linagliptin, normalized SBP (111.1 +/- 24.3mmHg and 100.4 +/- 13.9mmHg, respectively; P<0.001 vs. placebo). Telmisartan alone and in combination with linagliptin significantly prevented cardiac hypertrophy, measured by heart weight and myocyte diameter. Renal function measured by cystatin C was not affected by 2k1c surgery. Telmisartan significantly increased plasma concentration of cystatin C. 2k1c surgery initiated fibrosis in both kidneys. Telmisartan promoted further fibrotic changes in the clipped kidney, as measured by protein expression of Col1a1 and histology for interstitial fibrosis and glomerulosclerosis. In non-clipped kidneys, telmisartan demonstrated antifibrotic properties, reducing Col1a1 protein expression. Plasma levels of oxidized low-density lipoprotein were higher in the placebo-treated 2k1c rats as compared to sham-operated animals. The increase was abolished by linagliptin alone (P=0.03 vs. placebo) and in combination with telmisartan (P=0.02 vs. placebo). Combination therapy also significantly reduced plasma concentration of carbonyl proteins (P=0.04 vs. placebo).Conclusion:Inhibition of type 4 dipeptidyl peptidase with linagliptin did not counter BP-lowering effects of ARB in 2k1c rats. Linagliptin reduced lipid and protein oxidation in 2k1c rats, and this effect was BP-independent. KW - 2k1c renovascular hypertension KW - blood pressure KW - DPP4 inhibition KW - linagliptin KW - oxidative stress Y1 - 2013 U6 - https://doi.org/10.1097/HJH.0b013e3283649b4d SN - 0263-6352 SN - 1473-5598 VL - 31 IS - 11 SP - 2290 EP - 2299 PB - Lippincott Williams & Wilkins CY - Philadelphia 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 -