@article{SchwiebsThomasKleuseretal.2017,
  author    = {Schwiebs, Anja and Thomas, Dominique Jeanette and Kleuser, Burkhard and Pfeilschifter, Josef and Radeke, Heinfried H.},
  title     = {Nuclear translocation of SGPP-1 and decrease of SGPL-1 activity contribute to sphingolipid rheostat regulation of inflammatory dendritic cells},
  series = {Mediators of inflammation},
  journal   = {Mediators of inflammation},
  publisher = {Hindawi Publishing Corp.},
  address   = {London},
  issn      = {0962-9351},
  doi       = {10.1155/2017/5187368},
  pages     = {10},
  year      = {2017},
  abstract  = {A balanced sphingolipid rheostat is indispensable for dendritic cell function and survival and thus initiation of an immune response. Sphingolipid levels are dynamically maintained by the action of sphingolipid enzymes of which sphingosine kinases, S1P phosphatases (SGPP-1/2) and S1P lyase (SGPL-1), are pivotal in the balance of S1P and sphingosine levels. In this study, we present that SGPP-1 and SGPL-1 are regulated in inflammatory dendritic cells and contribute to S1P fate. TLR-dependent activation caused SGPL-1 protein downregulation with subsequent decrease of enzymatic activity by two-thirds. In parallel, confocal fluorescence microscopy revealed that endogenous SGPP-1 was expressed in nuclei of naive dendritic cells and was translocated into the cytoplasmatic compartment upon inflammatory stimulation resulting in dephosphorylation of S1P. Mass spectrometric determination showed that a part of the resulting sphingosine was released from the cell, increasing extracellular levels. Another route of diminishing intracellular S1P was possibly taken by its export via ATP-binding cassette transporter C1 which was upregulated in array analysis, while the S1P transporter, spinster homolog 2, was not relevant in dendritic cells. These investigations newly describe the sequential expression and localization of the endogenous S1P regulators SGPP-1 and SGPL-1 and highlight their contribution to the sphingolipid rheostat in inflammation.},
  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{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}
}
@article{BorremansBusslerSaguTchewonpietal.2020,
  author    = {Borremans, An and Bußler, Sara and Sagu Tchewonpi, Sorel and Rawel, Harshadrai Manilal and Schl{\"u}ter, Oliver K. and Leen, Van Campenhout},
  title     = {Effect of blanching plus fermentation on selected functional properties of mealworm (Tenebrio molitor) powders},
  series = {Foods : open access journal},
  volume    = {9},
  journal   = {Foods : open access journal},
  number    = {7},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2304-8158},
  doi       = {10.3390/foods9070917},
  pages     = {17},
  year      = {2020},
  abstract  = {The aim of this study was to determine the effect of blanching followed by fermentation of mealworms (Tenebrio molitor) with commercial meat starter cultures on the functional properties of powders produced from the larvae. Full fat and defatted powder samples were prepared from non-fermented and fermented mealworm pastes. Then the crude protein, crude fat, and dry matter contents, pH, bulk density, colour, water and oil binding capacity, foaming capacity and stability, emulsion capacity and stability, protein solubility, quantity of free amino groups, and protein composition of the powders were evaluated. Regardless of the starter culture used, the blanching plus fermentation process reduced the crude and soluble protein contents of the full fat powders and in general impaired their water and oil binding, foaming, and emulsifying properties. Defatting of the powders improved most functional properties studied. The o-phthaldialdehyde assay revealed that the amount of free amino groups was higher in the fermented powders while sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that the soluble proteins of the fermented powders were composed of molecules of lower molecular mass compared to non-fermented powders. As molecular sizes of the soluble proteins decreased, it was clear that the protein structure was also modified by the fermentation process, which in turn led to changes in functional properties. In general, it was concluded that fermentation of mealworms with blanching as a pre-treatment does not contribute to the functional properties studied in this work. Nevertheless, the results confirmed that the properties of non-fermented powders are comparable to other food protein sources.},
  language  = {en}
}
@article{HenkelOberlaenderKlauderStatzetal.2021,
  author    = {Henkel-Oberl{\"a}nder, Janin and Klauder, Julia and Statz, Meike and Wohlenberg, Anne-Sophie and Kuipers, Sonja and Vahrenbrink, Madita and P{\"u}schel, Gerhard},
  title     = {Enhanced Palmitate-Induced Interleukin-8 Formation in Human Macrophages by Insulin or Prostaglandin E₂},
  series = {Biomedicines : open access journal},
  volume    = {9},
  journal   = {Biomedicines : open access journal},
  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 E₂ (PGE₂) released from activated macrophages. The current study addressed the question of how palmitate might interact with insulin or PGE₂ 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 PGE₂ synthesis. PGE₂ 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 PGE₂ in chronically inflamed adipose tissue might favor disease progression in a vicious feed-forward cycle.},
  language  = {en}
}
@article{RauschBrockmeyerSchwerdtle2021,
  author    = {Rausch, Ann-Kristin and Brockmeyer, Robert and Schwerdtle, Tanja},
  title     = {Development, validation, and application of a multi-method for the determination of mycotoxins, plant growth regulators, tropane alkaloids, and pesticides in cereals by two-dimensional liquid chromatography tandem mass spectrometry},
  series = {Analytical \& bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica},
  volume    = {413},
  journal   = {Analytical \& bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica},
  number    = {11},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1618-2650},
  doi       = {10.1007/s00216-021-03239-1},
  pages     = {3041 -- 3054},
  year      = {2021},
  abstract  = {Mycotoxins and pesticides regularly co-occur in agricultural products worldwide. Thus, humans can be exposed to both toxic contaminants and pesticides simultaneously, and multi-methods assessing the occurrence of various food contaminants and residues in a single method are necessary. A two-dimensional high performance liquid chromatography tandem mass spectrometry method for the analysis of 40 (modified) mycotoxins, two plant growth regulators, two tropane alkaloids, and 334 pesticides in cereals was developed. After an acetonitrile/water/formic acid (79:20:1, v/v/v) multi-analyte extraction procedure, extracts were injected into the two-dimensional setup, and an online clean-up was performed. The method was validated according to Commission Decision (EC) no. 657/2002 and document N° SANTE/12682/2019. Good linearity (R2 > 0.96), recovery data between 70-120\%, repeatability and reproducibility values < 20\%, and expanded measurement uncertainties < 50\% were obtained for a wide range of analytes, including very polar substances like deoxynivalenol-3-glucoside and methamidophos. However, results for fumonisins, zearalenone-14,16-disulfate, acid-labile pesticides, and carbamates were unsatisfying. Limits of quantification meeting maximum (residue) limits were achieved for most analytes. Matrix effects varied highly (-85 to +1574\%) and were mainly observed for analytes eluting in the first dimension and early-eluting analytes in the second dimension. The application of the method demonstrated the co-occurrence of different types of cereals with 28 toxins and pesticides. Overall, 86\% of the samples showed positive findings with at least one mycotoxin, plant growth regulator, or pesticide.},
  language  = {en}
}
@article{GohlkeManciniGarciaCarrizoetal.2021,
  author    = {Gohlke, Sabrina and Mancini, Carola and Garcia-Carrizo, Francisco and Schulz, Tim J.},
  title     = {Loss of the ciliary gene Bbs4 results in defective thermogenesis due to metabolic inefficiency and impaired lipid metabolism},
  series = {The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology},
  volume    = {35},
  journal   = {The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology},
  number    = {11},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1530-6860},
  doi       = {10.1096/fj.202100772RR},
  pages     = {13},
  year      = {2021},
  abstract  = {Adipose tissue is central to the regulation of energy balance. While white adipose tissue (WAT) is responsible for triglyceride storage, brown adipose tissue specializes in energy expenditure. Deterioration of brown adipocyte function contributes to the development of metabolic complications like obesity and diabetes. These disorders are also leading symptoms of the Bardet-Biedl syndrome (BBS), a hereditary disorder in humans which is caused by dysfunctions of the primary cilium and which therefore belongs to the group of ciliopathies. The cilium is a hair-like organelle involved in cellular signal transduction. The BBSome, a supercomplex of several Bbs gene products, localizes to the basal body of cilia and is thought to be involved in protein sorting to and from the ciliary membrane. The effects of a functional BBSome on energy metabolism and lipid mobilization in brown and white adipocytes were tested in whole-body Bbs4 knockout mice that were subjected to metabolic challenges. Chronic cold exposure reveals cold-intolerance of knockout mice but also ameliorates the markers of metabolic pathology detected in knockouts prior to cold. Hepatic triglyceride content is markedly reduced in knockout mice while circulating lipids are elevated, altogether suggesting that defective lipid metabolism in adipose tissue creates increased demand for systemic lipid mobilization to meet energetic demands of reduced body temperatures. These findings taken together suggest that Bbs4 is essential for the regulation of adipose tissue lipid metabolism, representing a potential target to treat metabolic disorders.},
  language  = {en}
}
@article{WittStibollerRaschkeetal.2021,
  author    = {Witt, Barbara and Stiboller, Michael and Raschke, Stefanie and Friese, Sharleen and Ebert, Franziska and Schwerdtle, Tanja},
  title     = {Characterizing effects of excess copper levels in a human astrocytic cell line with focus on oxidative stress markers},
  series = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS},
  volume    = {65},
  journal   = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements, GMS},
  publisher = {Elsevier},
  address   = {M{\"u}nchen},
  issn      = {1878-3252},
  doi       = {10.1016/j.jtemb.2021.126711},
  pages     = {9},
  year      = {2021},
  abstract  = {Background: Being an essential trace element, copper is involved in diverse physiological processes. However, excess levels might lead to adverse effects. Disrupted copper homeostasis, particularly in the brain, has been associated with human diseases including the neurodegenerative disorders Wilson and Alzheimer?s disease. In this context, astrocytes play an important role in the regulation of the copper homeostasis in the brain and likely in the prevention against neuronal toxicity, consequently pointing them out as a potential target for the neurotoxicity of copper. Major toxic mechanisms are discussed to be directed against mitochondria probably via oxidative stress. However, the toxic potential and mode of action of copper in astrocytes is poorly understood, so far. Methods: In this study, excess copper levels affecting human astrocytic cell model and their involvement in the neurotoxic mode of action of copper, as well as, effects on the homeostasis of other trace elements (Mn, Fe, Ca and Mg) were investigated. Results: Copper induced substantial cytotoxic effects in the human astrocytic cell line following 48 h incubation (EC30: 250 ?M) and affected mitochondrial function, as observed via reduction of mitochondrial membrane potential and increased ROS production, likely originating from mitochondria. Moreover, cellular GSH metabolism was altered as well. Interestingly, not only cellular copper levels were affected, but also the homeostasis of other elements (Ca, Fe and Mn) were disrupted. Conclusion: One potential toxic mode of action of copper seems to be effects on the mitochondria along with induction of oxidative stress in the human astrocytic cell model. Moreover, excess copper levels seem to interact with the homeostasis of other essential elements such as Ca, Fe and Mn. Disrupted element homeostasis might also contribute to the induction of oxidative stress, likely involved in the onset and progression of neurodegenerative disorders. These insights in the toxic mechanisms will help to develop ideas and approaches for therapeutic strategies against copper-mediated diseases.},
  language  = {en}
}
@article{WittSchaumloeffelSchwerdtle2020,
  author    = {Witt, Barbara and Schauml{\"o}ffel, Dirk and Schwerdtle, Tanja},
  title     = {Subcellular Localization of Copper},
  series = {International Journal of Molecular Sciences},
  volume    = {21},
  journal   = {International Journal of Molecular Sciences},
  number    = {7},
  publisher = {Molecular Diversity Preservation International},
  address   = {Basel},
  issn      = {1422-0067},
  doi       = {10.3390/ijms21072341},
  pages     = {25},
  year      = {2020},
  abstract  = {As an essential trace element, copper plays a pivotal role in physiological body functions. In fact, dysregulated copper homeostasis has been clearly linked to neurological disorders including Wilson and Alzheimer's disease. Such neurodegenerative diseases are associated with progressive loss of neurons and thus impaired brain functions. However, the underlying mechanisms are not fully understood. Characterization of the element species and their subcellular localization is of great importance to uncover cellular mechanisms. Recent research activities focus on the question of how copper contributes to the pathological findings. Cellular bioimaging of copper is an essential key to accomplish this objective. Besides information on the spatial distribution and chemical properties of copper, other essential trace elements can be localized in parallel. Highly sensitive and high spatial resolution techniques such as LA-ICP-MS, TEM-EDS, S-XRF and NanoSIMS are required for elemental mapping on subcellular level. This review summarizes state-of-the-art techniques in the field of bioimaging. Their strengths and limitations will be discussed with particular focus on potential applications for the elucidation of copper-related diseases. Based on such investigations, further information on cellular processes and mechanisms can be derived under physiological and pathological conditions. Bioimaging studies might enable the clarification of the role of copper in the context of neurodegenerative diseases and provide an important basis to develop therapeutic strategies for reduction or even prevention of copper-related disorders and their pathological consequences.},
  language  = {en}
}
@article{KluthStadionGottmannetal.2019,
  author    = {Kluth, Oliver and Stadion, Mandy and Gottmann, Pascal and Aga-Barfknecht, Heja and J{\"a}hnert, Markus and Scherneck, Stephan and Vogel, Heike and Krus, Ulrika and Seelig, Anett and Ling, Charlotte and Gerdes, Jantje and Sch{\"u}rmann, Annette},
  title     = {Decreased expression of cilia genes in pancreatic islets as a risk factor for type 2 diabetes in mice and humans},
  series = {Cell reports},
  volume    = {26},
  journal   = {Cell reports},
  number    = {11},
  publisher = {Cell Press},
  address   = {Maryland Heights},
  issn      = {2211-1247},
  doi       = {10.1016/j.celrep.2019.02.056},
  pages     = {3027 -- 3036},
  year      = {2019},
  abstract  = {An insufficient adaptive beta-cell compensation is a hallmark of type 2 diabetes (T2D). Primary cilia function as versatile sensory antennae regulating various cellular processes, but their role on compensatory beta-cell replication has not been examined. Here, we identify a significant enrichment of downregulated, cilia-annotated genes in pancreatic islets of diabetes-prone NZO mice as compared with diabetes-resistant B6-ob/ob mice. Among 327 differentially expressed mouse cilia genes, 81 human orthologs are also affected in islets of diabetic donors. Islets of nondiabetic mice and humans show a substantial overlap of upregulated cilia genes that are linked to cell-cycle progression. The shRNA-mediated suppression of KIF3A, essential for ciliogenesis, impairs division of MINE beta cells as well as in dispersed primary mouse and human islet cells, as shown by decreased BrdU incorporation. These findings demonstrate the substantial role of cilia-gene regulation on islet function and T2D risk.},
  language  = {en}
}
@article{KnocheLisecSchwerdtleetal.2022,
  author    = {Knoche, Lisa and Lisec, Jan and Schwerdtle, Tanja and Koch, Matthias},
  title     = {LC-HRMS-Based identification of transformation products of the drug salinomycin generated by electrochemistry and liver microsome},
  series = {Antibiotics},
  volume    = {11},
  journal   = {Antibiotics},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-6382},
  doi       = {10.3390/antibiotics11020155},
  pages     = {12},
  year      = {2022},
  abstract  = {The drug salinomycin (SAL) is a polyether antibiotic and used in veterinary medicine as coccidiostat and growth promoter. Recently, SAL was suggested as a potential anticancer drug. However, transformation products (TPs) resulting from metabolic and environmental degradation of SAL are incompletely known and structural information is missing. In this study, we therefore systematically investigated the formation and identification of SAL derived TPs using electrochemistry (EC) in an electrochemical reactor and rat and human liver microsome incubation (RLM and HLM) as TP generating methods. Liquid chromatography (LC) coupled to high-resolution mass spectrometry (HRMS) was applied to determine accurate masses in a suspected target analysis to identify TPs and to deduce occurring modification reactions of derived TPs. A total of 14 new, structurally different TPs were found (two EC-TPs, five RLM-TPs, and 11 HLM-TPs). The main modification reactions are decarbonylation for EC-TPs and oxidation (hydroxylation) for RLM/HLM-TPs. Of particular interest are potassium-based TPs identified after liver microsome incubation because these might have been overlooked or declared as oxidated sodium adducts in previous, non-HRMS-based studies due to the small mass difference between K and O + Na of 21 mDa. The MS fragmentation pattern of TPs was used to predict the position of identified modifications in the SAL molecule. The obtained knowledge regarding transformation reactions and novel TPs of SAL will contribute to elucidate SAL-metabolites with regards to structural prediction.},
  language  = {en}
}
@article{AgaBarfknechtSoultoukisStadionetal.2022,
  author    = {Aga-Barfknecht, Heja and Soultoukis, George A. and Stadion, Mandy and Garcia-Carrizo, Francisco and J{\"a}hnert, Markus and Gottmann, Pascal and Vogel, Heike and Schulz, Tim Julius and Sch{\"u}rmann, Annette},
  title     = {Distinct adipogenic and fibrogenic differentiation capacities of mesenchymal stromal cells from pancreas and white adipose tissue},
  series = {International journal of molecular sciences},
  volume    = {23},
  journal   = {International journal of molecular sciences},
  number    = {4},
  publisher = {Molecular Diversity Preservation International},
  address   = {Basel},
  issn      = {1422-0067},
  doi       = {10.3390/ijms23042108},
  pages     = {21},
  year      = {2022},
  abstract  = {Pancreatic steatosis associates with beta-cell failure and may participate in the development of type-2-diabetes. Our previous studies have shown that diabetes-susceptible mice accumulate more adipocytes in the pancreas than diabetes-resistant mice. In addition, we have demonstrated that the co-culture of pancreatic islets and adipocytes affect insulin secretion. The aim of this current study was to elucidate if and to what extent pancreas-resident mesenchymal stromal cells (MSCs) with adipogenic progenitor potential differ from the corresponding stromal-type cells of the inguinal white adipose tissue (iWAT). miRNA (miRNome) and mRNA expression (transcriptome) analyses of MSCs isolated by flow cytometry of both tissues revealed 121 differentially expressed miRNAs and 1227 differentially expressed genes (DEGs). Target prediction analysis estimated 510 DEGs to be regulated by 58 differentially expressed miRNAs. Pathway analyses of DEGs and miRNA target genes showed unique transcriptional and miRNA signatures in pancreas (pMSCs) and iWAT MSCs (iwatMSCs), for instance fibrogenic and adipogenic differentiation, respectively. Accordingly, iwatMSCs revealed a higher adipogenic lineage commitment, whereas pMSCs showed an elevated fibrogenesis. As a low degree of adipogenesis was also observed in pMSCs of diabetes-susceptible mice, we conclude that the development of pancreatic steatosis has to be induced by other factors not related to cell-autonomous transcriptomic changes and miRNA-based signals.},
  language  = {en}
}
@article{SaguTchewonpiHuschekWaldbachBragaetal.2022,
  author    = {Sagu Tchewonpi, Sorel and Huschek, Gerd and Waldbach Braga, Tess and Rackiewicz, Michal and Homann, Thomas and Rawel, Harshadrai Manilal},
  title     = {Design of Experiment (DoE) for Optimization of HPLC Conditions for the Simultaneous Fractionation of Seven α-Amylase/Trypsin Inhibitors from Wheat (Triticum aestivum L.)},
  series = {Processes : open access journal},
  volume    = {10},
  journal   = {Processes : open access journal},
  edition   = {2},
  publisher = {MDPI},
  address   = {Basel, Schweiz},
  issn      = {2227-9717},
  doi       = {10.3390/pr10020259},
  pages     = {1 -- 18},
  year      = {2022},
  abstract  = {Wheat alpha-amylase/trypsin inhibitors remain a subject of interest considering the latest findings showing their implication in wheat-related non-celiac sensitivity (NCWS). Understanding their functions in such a disorder is still unclear and for further study, the need for pure ATI molecules is one of the limiting problems. In this work, a simplified approach based on the successive fractionation of ATI extracts by reverse phase and ion exchange chromatography was developed. ATIs were first extracted from wheat flour using a combination of Tris buffer and chloroform/methanol methods. The separation of the extracts on a C18 column generated two main fractions of interest F1 and F2. The response surface methodology with the Doehlert design allowed optimizing the operating parameters of the strong anion exchange chromatography. Finally, the seven major wheat ATIs namely P01083, P17314, P16850, P01085, P16851, P16159, and P83207 were recovered with purity levels (according to the targeted LC-MS/MS analysis) of 98.2 ± 0.7; 98.1 ± 0.8; 97.9 ± 0.5; 95.1 ± 0.8; 98.3 ± 0.4; 96.9 ± 0.5, and 96.2 ± 0.4\%, respectively. MALDI-TOF-MS analysis revealed single peaks in each of the pure fractions and the mass analysis yielded deviations of 0.4, 1.9, 0.1, 0.2, 0.2, 0.9, and 0.1\% between the theoretical and the determined masses of P01083, P17314, P16850, P01085, P16851, P16159, and P83207, respectively. Overall, the study allowed establishing an efficient purification process of the most important wheat ATIs. This paves the way for further in-depth investigation of the ATIs to gain more knowledge related to their involvement in NCWS disease and to allow the absolute quantification in wheat samples.},
  language  = {en}
}
@article{XiongStibollerGlabonjatetal.2020,
  author    = {Xiong, Chan and Stiboller, Michael and Glabonjat, Ronald A. and Rieger, Jaqueline and Paton, Lhiam and Francesconi, Kevin A.},
  title     = {Transport of arsenolipids to the milk of a nursing mother after consuming salmon fish},
  series = {Journal of trace elements in medicine and biology},
  volume    = {61},
  journal   = {Journal of trace elements in medicine and biology},
  publisher = {Elsevier},
  address   = {M{\"u}nchen},
  issn      = {0946-672X},
  doi       = {10.1016/j.jtemb.2020.126502},
  pages     = {6},
  year      = {2020},
  abstract  = {Objective: We address two questions relevant to infants' exposure to potentially toxic arsenolipids, namely, are the arsenolipids naturally present in fish transported intact to a mother's milk, and what is the efficiency of this transport. Methods: We investigated the transport of arsenolipids and other arsenic species present in fish to mother's milk by analyzing the milk of a single nursing mother at 15 sampling times over a 3-day period after she had consumed a meal of salmon. Total arsenic values were obtained by elemental mass spectrometry, and arsenic species were measured by HPLC coupled to both elemental and molecular mass spectrometry. Results: Total arsenic increased from background levels (0.1 mu g As kg(-1)) to a peak value of 1.72 lig As kg(-1) eight hours after the fish meal. The pattern for arsenolipids was similar to that of total arsenic, increasing from undetectable background levels (< 0.01 mu g As kg(-1)) to a peak after eight hours of 0.45 mu g As kg(-1). Most of the remaining total arsenic in the milk was accounted for by arsenobetaine. The major arsenolipids in the salmon were arsenic hydrocarbons (AsHCs; 55 \% of total arsenolipids), and these compounds were also the dominant arsenolipids in the milk where they contributed over 90 \% of the total arsenolipids. Conclusions: Our study has shown that ca 2-3 \% of arsenic hydrocarbons, natural constituents of fish, can be directly transferred unchanged to the milk of a nursing mother. In view of the potential neurotoxicity of AsHCs, the effects of these compounds on the brain developmental stage of infants need to be investigated.},
  language  = {en}
}
@article{StepanovskaZivkovicEnzmannetal.2020,
  author    = {Stepanovska, Bisera and Zivkovic, Aleksandra and Enzmann, Gaby and Tietz, Silvia and Homann, Thomas and Kleuser, Burkhard and Engelhardt, Britta and Stark, Holger and Huwiler, Andrea},
  title     = {Morpholino analogues of fingolimod as novel and selective S1P1 ligands with in vivo efficacy in a mouse model of experimental antigen-induced encephalomyelitis},
  series = {International journal of molecular sciences},
  volume    = {21},
  journal   = {International journal of molecular sciences},
  number    = {18},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1422-0067},
  doi       = {10.3390/ijms21186463},
  pages     = {17},
  year      = {2020},
  abstract  = {Multiple sclerosis (MS) is a chronic, inflammatory, autoimmune disease of the central nervous system (CNS) which is associated with lower life expectancy and disability. The experimental antigen-induced encephalomyelitis (EAE) in mice is a useful animal model of MS, which allows exploring the etiopathogenetic mechanisms and testing novel potential therapeutic drugs. A new therapeutic paradigm for the treatment of MS was introduced in 2010 through the sphingosine 1-phosphate (S1P) analogue fingolimod (FTY720, Gilenya(R)), which acts as a functional S1P(1) antagonist on T lymphocytes to deplete these cells from the blood. In this study, we synthesized two novel structures, ST-1893 and ST-1894, which are derived from fingolimod and chemically feature a morpholine ring in the polar head group. These compounds showed a selective S1P(1) activation profile and a sustained S1P(1) internalization in cultures of S1P(1)-overexpressing Chinese hamster ovary (CHO)-K1 cells, consistent with a functional antagonism. In vivo, both compounds induced a profound lymphopenia in mice. Finally, these substances showed efficacy in the EAE model, where they reduced clinical symptoms of the disease, and, on the molecular level, they reduced the T-cell infiltration and several inflammatory mediators in the brain and spinal cord. In summary, these data suggest that S1P(1)-selective compounds may have an advantage over fingolimod and siponimod, not only in MS but also in other autoimmune diseases.},
  language  = {en}
}
@article{NaserKadowSchumacheretal.2021,
  author    = {Naser, Eyad and Kadow, Stephanie and Schumacher, Fabian and Mohamed, Zainelabdeen H. and Kappe, Christian and Hessler, Gabriele and Pollmeier, Barbara and Kleuser, Burkhard and Arenz, Christoph and Becker, Katrin Anne and Gulbins, Erich and Carpinteiro, Alexander},
  title     = {Characterization of the small molecule ARC39},
  series = {Journal of Lipid Research},
  volume    = {61},
  journal   = {Journal of Lipid Research},
  number    = {6},
  publisher = {American Society for Biochemistry and Molecular Biology},
  address   = {Bethesda},
  issn      = {1539-7262},
  doi       = {10.1194/jlr.RA120000682},
  pages     = {896 -- 910},
  year      = {2021},
  abstract  = {Inhibition of acid sphingomyelinase (ASM), a lysosomal enzyme that catalyzes the hydrolysis of sphingomyelin into ceramide and phosphorylcholine, may serve as an investigational tool or a therapeutic intervention to control many diseases. Specific ASM inhibitors are currently not sufficiently characterized. Here, we found that 1-aminodecylidene bis-phosphonic acid (ARC39) specifically and efficiently (>90\%) inhibits both lysosomal and secretory ASM in vitro. Results from investigating sphingomyelin phosphodiesterase 1 (SMPD1/Smpd1) mRNA and ASM protein levels suggested that ARC39 directly inhibits ASM's catalytic activity in cultured cells, a mechanism that differs from that of functional inhibitors of ASM. We further provide evidence that ARC39 dose- and time-dependently inhibits lysosomal ASM in intact cells, and we show that ARC39 also reduces platelet- and ASM-promoted adhesion of tumor cells. The observed toxicity of ARC39 is low at concentrations relevant for ASM inhibition in vitro, and it does not strongly alter the lysosomal compartment or induce phospholipidosis in vitro. When applied intraperitoneally in vivo, even subtoxic high doses administered short-term induced sphingomyelin accumulation only locally in the peritoneal lavage without significant accumulation in plasma, liver, spleen, or brain. These findings require further investigation with other possible chemical modifications. In conclusion, our results indicate that ARC39 potently and selectively inhibits ASM in vitro and highlight the need for developing compounds that can reach tissue concentrations sufficient for ASM inhibition in vivo.},
  language  = {en}
}
@article{LangBohnBhatetal.2020,
  author    = {Lang, Judith and Bohn, Patrick and Bhat, Hilal and Jastrow, Holger and Walkenfort, Bernd and Cansiz, Feyza and Fink, Julian and Bauer, Michael and Schumacher, Fabian and Kleuser, Burkhard and Lang, Karl S.},
  title     = {Acid ceramidase of macrophages traps herpes simplex virus in multivesicular bodies and protects from severe disease},
  series = {Nature Communications},
  volume    = {11},
  journal   = {Nature Communications},
  number    = {1},
  publisher = {Nature Publishing Group UK},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/s41467-020-15072-8},
  pages     = {1 -- 15},
  year      = {2020},
  abstract  = {Macrophages have important protective functions during infection with herpes simplex virus type 1 (HSV-1). However, molecular mechanisms that restrict viral propagation and protect from severe disease are unclear. Here we show that macrophages take up HSV-1 via endocytosis and transport the virions into multivesicular bodies (MVBs). In MVBs, acid ceramidase (aCDase) converts ceramide into sphingosine and increases the formation of sphingosine-rich intraluminal vesicles (ILVs). Once HSV-1 particles reach MVBs, sphingosine-rich ILVs bind to HSV-1 particles, which restricts fusion with the limiting endosomal membrane and prevents cellular infection. Lack of aCDase in macrophage cultures or in Asah1(-/-) mice results in replication of HSV-1 and Asah1(-/-) mice die soon after systemic or intravaginal inoculation. The treatment of macrophages with sphingosine enhancing compounds blocks HSV-1 propagation, suggesting a therapeutic potential of this pathway. In conclusion, aCDase loads ILVs with sphingosine, which prevents HSV-1 capsids from penetrating into the cytosol.},
  language  = {en}
}
@article{FredeSchreinerBaldermann2019,
  author    = {Frede, Katja and Schreiner, Monika and Baldermann, Susanne},
  title     = {Light quality-induced changes of carotenoid composition in pak choi Brassica rapa ssp. chinensis},
  volume    = {193},
  publisher = {Elsevier},
  address   = {Lausanne},
  issn      = {1011-1344},
  doi       = {10.1016/j.jphotobiol.2019.02.001},
  pages     = {18 -- 30},
  year      = {2019},
  abstract  = {Carotenoids as part of the photosystems are crucial for their assembly, light-harvesting, and photoprotection. Light of different wavelengths impacts the composition and structure of photosystems, thus offering the possibility to influence the carotenoid concentrations and composition in photosystems by illumination with specific narrow-banded light spectra. Key components involved in the regulation of gene transcription are still poorly characterized, particularly in leafy vegetables as compared to model plants. In particular, the effect of different light qualities and its connection to redox control mechanisms, which also determine the photosystem composition and structure, is not yet well understood. Furthermore, light quality effects are species-dependent, and thus, increase the need to perform research on individual vegetable species such as pak choi Brassica rapa ssp. chinensis. Here, we investigated the carotenoid concentrations and composition of pak choi sprouts grown for 6 days under blue, red, or white light emitting diodes (LEDs) as light source. After 6 days, the total carotenoid content was the highest under white and slightly reduced under blue or red LEDs. Blue, red, and white light differently affected the carotenoid composition mainly due to variations of the beta-carotene content which could be correlated to changes in the transcript levels of beta-carotene hydroxylase 1 (beta-OHASE1). Further investigations implied a redox controlled gene expression of beta-OHASE1. In addition, transcription factors related to light signaling and the circadian clock differed in their transcriptional abundance after exposure to blue and red light. RNA-Seq analysis also revealed increased transcript levels of genes encoding the outer antenna complex of photosystem II under red compared to blue light, indicating an adjustment of the photosystems to the different light qualities which possibly contributed to the alternations in the carotenoid content and composition.},
  language  = {en}
}
@article{OdongoSchlotzBaldermannetal.2018,
  author    = {Odongo, Grace Akinyi and Schlotz, Nina and Baldermann, Susanne and Neugart, Susanne and Ngwene, Benard and Schreiner, Monika and Lamy, Evelyn},
  title     = {Effects of Amaranthus cruentus L. on aflatoxin B1- and oxidative stress-induced DNA damage in human liver (HepG2) cells},
  series = {Food bioscience},
  volume    = {26},
  journal   = {Food bioscience},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2212-4292},
  doi       = {10.1016/j.fbio.2018.09.006},
  pages     = {42 -- 48},
  year      = {2018},
  abstract  = {Amaranth is presently an underutilized crop despite its high content of micronutrients/bioactive phytochemicals and its capacity to thrive in harsh environmental condition. The present study aimed at determining the health benefits of Amaranthus cruentus L. in terms of protection against DNA damage induced by the mycotoxin aflatoxin B1 (AFB1) and oxidative stress using comet assay. The antioxidant potential was further investigated using electron paramagnetic resonance spectroscopy (EPR) and an ARE/Nrf2 reporter gene assay in vitro in a human liver model using the HepG2 cell line. Ethanolic extracts from fresh leaves grown under controlled conditions were used and additionally analyzed for their phytochemical content using liquid chromatography-mass spectrometry (LC-MS). The extracts inhibited both AFB1- and oxidative stress-induced DNA damage in a concentration dependent way with a maximum effect of 57\% and 81\%, respectively. Oxidative stress triggered using ferrous sulfate was blocked by up to 38\% (EPR); the potential to induce antioxidant enzymes using ARE/Nrf2-mediated gene expression was also confirmed. Based on these in vitro findings, further studies on the health-protecting effects of A. cruentus are encouraged to fully explore its health promoting potential and provide the scientific basis for encouraging its cultivation and consumption.},
  language  = {en}
}
@article{OlayideLargeStridhetal.2020,
  author    = {Olayide, Priscilla and Large, Annabel and Stridh, Linnea and Rabbi, Ismail and Baldermann, Susanne and Stavolone, Livia and Alexandersson, Erik},
  title     = {Gene expression and metabolite profiling of thirteen Nigerian cassava landraces to elucidate starch and carotenoid composition},
  series = {Agronomy},
  volume    = {10},
  journal   = {Agronomy},
  number    = {3},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4395},
  doi       = {10.3390/agronomy10030424},
  pages     = {1 -- 16},
  year      = {2020},
  abstract  = {The prevalence of vitamin A deficiency in sub-Saharan Africa necessitates effective approaches to improve provitamin A content of major staple crops. Cassava holds much promise for food security in sub-Saharan Africa, but a negative correlation between beta-carotene, a provitamin A carotenoid, and dry matter content has been reported, which poses a challenge to cassava biofortification by conventional breeding. To identify suitable material for genetic transformation in tissue culture with the overall aim to increase beta-carotene and maintain starch content as well as better understand carotenoid composition, root and leaf tissues from thirteen field-grown cassava landraces were analyzed for agronomic traits, carotenoid, chlorophyll, and starch content. The expression of five genes related to carotenoid biosynthesis were determined in selected landraces. Analysis revealed a weak negative correlation between starch and beta-carotene content, whereas there was a strong positive correlation between root yield and many carotenoids including beta-carotene. Carotenoid synthesis genes were expressed in both white and yellow cassava roots, but phytoene synthase 2 (PSY2), lycopene-epsilon-cyclase (LCY epsilon), and beta-carotenoid hydroxylase (CHY beta) expression were generally higher in yellow roots. This study identified lines with reasonably high content of starch and beta-carotene that could be candidates for biofortification by further breeding or plant biotechnological means.},
  language  = {en}
}
@article{WetzelScholtkaSchumacheretal.2021,
  author    = {Wetzel, Alexandra Nicole and Scholtka, Bettina and Schumacher, Fabian and Rawel, Harshadrai Manilal and Geisend{\"o}rfer, Birte and Kleuser, Burkhard},
  title     = {Epigenetic DNA methylation of EBI3 modulates human interleukin-35 formation via NFkB signaling},
  series = {International journal of molecular sciences},
  volume    = {22},
  journal   = {International journal of molecular sciences},
  number    = {10},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1422-0067},
  doi       = {10.3390/ijms22105329},
  pages     = {21},
  year      = {2021},
  abstract  = {Ulcerative colitis (UC), a severe chronic disease with unclear etiology that is associated with increased risk for colorectal cancer, is accompanied by dysregulation of cytokines. Epstein-Barr virus-induced gene 3 (EBI3) encodes a subunit in the unique heterodimeric IL-12 cytokine family of either pro- or anti-inflammatory function. After having recently demonstrated that upregulation of EBI3 by histone acetylation alleviates disease symptoms in a dextran sulfate sodium (DSS)-treated mouse model of chronic colitis, we now aimed to examine a possible further epigenetic regulation of EBI3 by DNA methylation under inflammatory conditions. Treatment with the DNA methyltransferase inhibitor (DNMTi) decitabine (DAC) and TNF alpha led to synergistic upregulation of EBI3 in human colon epithelial cells (HCEC). Use of different signaling pathway inhibitors indicated NF kappa B signaling was necessary and proportional to the synergistic EBI3 induction. MALDI-TOF/MS and HPLC-ESIMS/MS analysis of DAC/TNF alpha-treated HCEC identified IL-12p35 as the most probable binding partner to form a functional protein. EBI3/IL-12p35 heterodimers (IL-35) induce their own gene upregulation, something that was indeed observed in HCEC cultured with media from previously DAC/TNF alpha-treated HCEC. These results suggest that under inflammatory and demethylating conditions the upregulation of EBI3 results in the formation of anti-inflammatory IL-35, which might be considered as a therapeutic target in colitis.},
  language  = {en}
}
@article{ShiXieQietal.2019,
  author    = {Shi, Jiang and Xie, Dongchao and Qi, Dandan and Peng, Qunhua and Chen, Zongmao and Schreiner, Monika and Lin, Zhi and Baldermann, Susanne},
  title     = {Methyl jasmonate-induced changes of flavor profiles during the processing of Green, Oolong, and Black Tea},
  series = {Frontiers in plant science},
  volume    = {10},
  journal   = {Frontiers in plant science},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-462X},
  doi       = {10.3389/fpls.2019.00781},
  pages     = {13},
  year      = {2019},
  abstract  = {Tea aroma is one of the most important factors affecting the character and quality of tea. Here we describe the practical application of methyl jasmonate (MeJA) to improve the aroma quality of teas. The changes of selected metabolites during crucial tea processing steps, namely, withering, fixing and rolling, and fermentation, were analyzed. MeJA treatment of tea leaves (12, 24, 48, and 168 h) greatly promotes the aroma quality of green, oolong, and black tea products when comparing with untreated ones (0 h) and as confirmed by sensory evaluation. MeJA modulates the aroma profiles before, during, and after processing. Benzyl alcohol, benzaldehyde, 2-phenylethyl alcohol, phenylacetaldehyde, and trans-2-hexenal increased 1.07- to 3-fold in MeJA-treated fresh leaves and the first two maintained at a higher level in black tea and the last two in green tea. This correlates with a decrease in aromatic amino acids by more than twofold indicating a direct relation to tryptophan- and phenylalanine-derived volatiles. MeJA-treated oolong tea was characterized by a more pleasant aroma. Especially the terpenoids linalool and oxides, geraniol, and carvenol increased by more than twofold.},
  language  = {en}
}
@article{YadavDreherAthmeretal.2019,
  author    = {Yadav, Heena and Dreher, Doroth{\´e}e and Athmer, Benedikt and Porzel, Andrea and Gavrin, Aleksandr and Baldermann, Susanne and Tissier, Alain and Hause, Bettina},
  title     = {Medicago TERPENE SYNTHASE 10 is involved in defense against an oomycete root pathogen},
  series = {Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants},
  volume    = {180},
  journal   = {Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants},
  number    = {3},
  publisher = {American Society of Plant Physiologists},
  address   = {Rockville},
  issn      = {0032-0889},
  doi       = {10.1104/pp.19.00278},
  pages     = {1598 -- 1613},
  year      = {2019},
  abstract  = {In nature, plants interact with numerous beneficial or pathogenic soil-borne microorganisms. Plants have developed various defense strategies to expel pathogenic microbes, some of which function soon after pathogen infection. We used Medicago truncatula and its oomycete pathogen Aphanomyces euteiches to elucidate early responses of the infected root. A. euteiches causes root rot disease in legumes and is a limiting factor in legume production. Transcript profiling of seedlings and adult plant roots inoculated with A. euteiches zoospores for 2 h revealed specific upregulation of a gene encoding a putative sesquiterpene synthase (M. truncatula TERPENE SYNTHASE 10 [MtTPS10]) in both developmental stages. MtTPS10 was specifically expressed in roots upon oomycete infection. Heterologous expression of MtTPS10 in yeast led to production of a blend of sesquiterpenes and sesquiterpene alcohols, with NMR identifying a major peak corresponding to himalachol. Moreover, plants carrying a tobacco (Nicotiana tabacum) retrotransposon Tnt1 insertion in MtTPS10 lacked the emission of sesquiterpenes upon A. euteiches infection, supporting the assumption that the identified gene encodes a multiproduct sesquiterpene synthase. Mttps10 plants and plants with reduced MtTPS10 transcript levels created by expression of an MtTPS10-artificial microRNA in roots were more susceptible to A. euteiches infection than were the corresponding wild-type plants and roots transformed with the empty vector, respectively. Sesquiterpenes produced by expression of MtTPS10 in yeast also inhibited mycelial growth and A. euteiches zoospore germination. These data suggest that sesquiterpene production in roots by MtTPS10 plays a previously unrecognized role in the defense response of M. truncatula against A. euteiches.},
  language  = {en}
}
@article{JonasKluthHelmsetal.2022,
  author    = {Jonas, Wenke and Kluth, Oliver and Helms, Anett and Voss, Sarah and Jahnert, Markus and Gottmann, Pascal and Speckmann, Thilo and Knebel, Birgit and Chadt, Alexandra and Al-Hasani, Hadi and Sch{\"u}rmann, Annette and Vogel, Heike},
  title     = {Identification of novel genes involved in hyperglycemia in mice},
  series = {International journal of molecular sciences},
  volume    = {23},
  journal   = {International journal of molecular sciences},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1661-6596},
  doi       = {10.3390/ijms23063205},
  pages     = {13},
  year      = {2022},
  abstract  = {Current attempts to prevent and manage type 2 diabetes have been moderately effective, and a better understanding of the molecular roots of this complex disease is important to develop more successful and precise treatment options. Recently, we initiated the collective diabetes cross, where four mouse inbred strains differing in their diabetes susceptibility were crossed with the obese and diabetes-prone NZO strain and identified the quantitative trait loci (QTL) Nidd13/NZO, a genomic region on chromosome 13 that correlates with hyperglycemia in NZO allele carriers compared to B6 controls. Subsequent analysis of the critical region, harboring 644 genes, included expression studies in pancreatic islets of congenic Nidd13/NZO mice, integration of single-cell data from parental NZO and B6 islets as well as haplotype analysis. Finally, of the five genes (Acot12, S100z, Ankrd55, Rnf180, and Iqgap2) within the polymorphic haplotype block that are differently expressed in islets of B6 compared to NZO mice, we identified the calcium-binding protein S100z gene to affect islet cell proliferation as well as apoptosis when overexpressed in MINE cells. In summary, we define S100z as the most striking gene to be causal for the diabetes QTL Nidd13/NZO by affecting beta-cell proliferation and apoptosis. Thus, S100z is an entirely novel diabetes gene regulating islet cell function.},
  language  = {en}
}
@article{FayyazJaptokSchumacheretal.2017,
  author    = {Fayyaz, Susann and Japtok, Lukasz and Schumacher, Fabian and Wigger, Dominik and Schulz, Tim Julius and Haubold, Kathrin and Gulbins, Erich and V{\"o}ller, Heinz and Kleuser, Burkhard},
  title     = {Lysophosphatidic acid inhibits insulin signaling in primary rat hepatocytes via the LPA(3) receptor subtype and is increased in obesity},
  series = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology},
  volume    = {43},
  journal   = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology},
  publisher = {Karger},
  address   = {Basel},
  issn      = {1015-8987},
  doi       = {10.1159/000480470},
  pages     = {445 -- 456},
  year      = {2017},
  abstract  = {Background/Aims: Obesity is a main risk factor for the development of hepatic insulin resistance and it is accompanied by adipocyte hypertrophy and an elevated expression of different adipokines such as autotaxin (ATX). ATX converts lysophosphatidylcholine to lysophosphatidic acid (LPA) and acts as the main producer of extracellular LPA. This bioactive lipid regulates a broad range of physiological and pathological responses by activation of LPA receptors (LPA1-6). Methods: The activation of phosphatidylinositide 3-kinases (PI3K) signaling (Akt and GSK-3ß) was analyzed via western blotting in primary rat hepatocytes. Incorporation of glucose into glycogen was measured by using radio labeled glucose. Real-time PCR analysis and pharmacological modulation of LPA receptors were performed. Human plasma LPA levels of obese (BMI > 30, n = 18) and normal weight individuals (BMI 18.5-25, n = 14) were analyzed by liquid chromatography tandem-mass spectrometry (LC-MS/MS). Results: Pretreatment of primary hepatocytes with LPA resulted in an inhibition of insulin-mediated Gck expression, PI3K activation and glycogen synthesis. Pharmacological approaches revealed that the LPA3-receptor subtype is responsible for the inhibitory effect of LPA on insulin signaling. Moreover, human plasma LPA concentrations (16: 0 LPA) of obese participants (BMI > 30) are significantly elevated in comparison to normal weight individuals (BMI 18.5-25). Conclusion: LPA is able to interrupt insulin signaling in primary rat hepatocytes via the LPA3 receptor subtype. Moreover, the bioactive lipid LPA (16: 0) is increased in obesity.},
  language  = {en}
}
@article{WiggerSchumacherSchneiderSchauliesetal.2021,
  author    = {Wigger, Dominik and Schumacher, Fabian and Schneider-Schaulies, Sibylle and Kleuser, Burkhard},
  title     = {Sphingosine 1-phosphate metabolism and insulin signaling},
  series = {Cellular signalling},
  volume    = {82},
  journal   = {Cellular signalling},
  publisher = {Elsevier Science},
  address   = {Amsterdam [u.a.]},
  issn      = {0898-6568},
  doi       = {10.1016/j.cellsig.2021.109959},
  pages     = {16},
  year      = {2021},
  abstract  = {Insulin is the main anabolic hormone secreted by 13-cells of the pancreas stimulating the assimilation and storage of glucose in muscle and fat cells. It modulates the postprandial balance of carbohydrates, lipids and proteins via enhancing lipogenesis, glycogen and protein synthesis and suppressing glucose generation and its release from the liver. Resistance to insulin is a severe metabolic disorder related to a diminished response of peripheral tissues to the insulin action and signaling. This leads to a disturbed glucose homeostasis that precedes the onset of type 2 diabetes (T2D), a disease reaching epidemic proportions. A large number of studies reported an association between elevated circulating fatty acids and the development of insulin resistance. The increased fatty acid lipid flux results in the accumulation of lipid droplets in a variety of tissues. However, lipid intermediates such as diacylglycerols and ceramides are also formed in response to elevated fatty acid levels. These bioactive lipids have been associated with the pathogenesis of insulin resistance. More recently, sphingosine 1-phosphate (S1P), another bioactive sphingolipid derivative, has also been shown to increase in T2D and obesity. Although many studies propose a protective role of S1P metabolism on insulin signaling in peripheral tissues, other studies suggest a causal role of S1P on insulin resistance. In this review, we critically summarize the current state of knowledge of S1P metabolism and its modulating role on insulin resistance. A particular emphasis is placed on S1P and insulin signaling in hepatocytes, skeletal muscle cells, adipocytes and pancreatic 13-cells. In particular, modulation of receptors and enzymes that regulate S1P metabolism can be considered as a new therapeutic option for the treatment of insulin resistance and T2D.},
  language  = {en}
}
@article{ZoicasSchumacherKleuseretal.2020,
  author    = {Zoicas, Iulia and Schumacher, Fabian and Kleuser, Burkhard and Reichel, Martin and Gulbins, Erich and Fejtova, Anna and Kornhuber, Johannes and Rhein, Cosima},
  title     = {The forebrain-specific overexpression of acid sphingomyelinase induces depressive-like symptoms in mice},
  series = {Cells},
  volume    = {9},
  journal   = {Cells},
  number    = {5},
  publisher = {MDPI},
  address   = {Basel},
  pages     = {12},
  year      = {2020},
  abstract  = {Human and murine studies identified the lysosomal enzyme acid sphingomyelinase (ASM) as a target for antidepressant therapy and revealed its role in the pathophysiology of major depression. In this study, we generated a mouse model with overexpression of Asm (Asm-tg(fb)) that is restricted to the forebrain to rule out any systemic effects of Asm overexpression on depressive-like symptoms. The increase in Asm activity was higher in male Asm-tg(fb) mice than in female Asm-tg(fb) mice due to the breeding strategy, which allows for the generation of wild-type littermates as appropriate controls. Asm overexpression in the forebrain of male mice resulted in a depressive-like phenotype, whereas in female mice, Asm overexpression resulted in a social anxiogenic-like phenotype. Ceramides in male Asm-tg(fb) mice were elevated specifically in the dorsal hippocampus. mRNA expression analyses indicated that the increase in Asm activity affected other ceramide-generating pathways, which might help to balance ceramide levels in cortical brain regions. This forebrain-specific mouse model offers a novel tool for dissecting the molecular mechanisms that play a role in the pathophysiology of major depression.},
  language  = {en}
}
@article{WiggerGulbinsKleuseretal.2019,
  author    = {Wigger, Dominik and Gulbins, Erich and Kleuser, Burkhard and Schumacher, Fabian},
  title     = {Monitoring the Sphingolipid de novo Synthesis by Stable-Isotope Labeling and Liquid Chromatography-Mass Spectrometry},
  series = {Frontiers in Cell and Developmental Biology},
  volume    = {7},
  journal   = {Frontiers in Cell and Developmental Biology},
  publisher = {Frontiers Media},
  address   = {Lausanne},
  issn      = {2296-634X},
  doi       = {10.3389/fcell.2019.00210},
  pages     = {16},
  year      = {2019},
  abstract  = {Sphingolipids are a class of lipids that share a sphingoid base backbone. They exert various effects in eukaryotes, ranging from structural roles in plasma membranes to cellular signaling. De novo sphingolipid synthesis takes place in the endoplasmic reticulum (ER), where the condensation of the activated C₁₆ fatty acid palmitoyl-CoA and the amino acid L-serine is catalyzed by serine palmitoyltransferase (SPT). The product, 3-ketosphinganine, is then converted into more complex sphingolipids by additional ER-bound enzymes, resulting in the formation of ceramides. Since sphingolipid homeostasis is crucial to numerous cellular functions, improved assessment of sphingolipid metabolism will be key to better understanding several human diseases. To date, no assay exists capable of monitoring de novo synthesis sphingolipid in its entirety. Here, we have established a cell-free assay utilizing rat liver microsomes containing all the enzymes necessary for bottom-up synthesis of ceramides. Following lipid extraction, we were able to track the different intermediates of the sphingolipid metabolism pathway, namely 3-ketosphinganine, sphinganine, dihydroceramide, and ceramide. This was achieved by chromatographic separation of sphingolipid metabolites followed by detection of their accurate mass and characteristic fragmentations through high-resolution mass spectrometry and tandem-mass spectrometry. We were able to distinguish, unequivocally, between de novo synthesized sphingolipids and intrinsic species, inevitably present in the microsome preparations, through the addition of stable isotope-labeled palmitate-d₃ and L-serine-d₃. To the best of our knowledge, this is the first demonstration of a method monitoring the entirety of ER-associated sphingolipid biosynthesis. Proof-of-concept data was provided by modulating the levels of supplied cofactors (e.g., NADPH) or the addition of specific enzyme inhibitors (e.g., fumonisin B₁). The presented microsomal assay may serve as a useful tool for monitoring alterations in sphingolipid de novo synthesis in cells or tissues. Additionally, our methodology may be used for metabolism studies of atypical substrates - naturally occurring or chemically tailored - as well as novel inhibitors of enzymes involved in sphingolipid de novo synthesis.},
  language  = {en}
}
@article{FrombachUnbehauenKurniasihetal.2019,
  author    = {Frombach, Janna and Unbehauen, Michael and Kurniasih, Indah N. and Schumacher, Fabian and Volz, Pierre and Hadam, Sabrina and Rancan, Fiorenza and Blume-Peytavi, Ulrike and Kleuser, Burkhard and Haag, Rainer and Alexiev, Ulrike and Vogt, Annika},
  title     = {Core-multishell nanocarriers enhance drug penetration and reach keratinocytes and antigen-presenting cells in intact human skin},
  series = {Journal of controlled release},
  volume    = {299},
  journal   = {Journal of controlled release},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0168-3659},
  doi       = {10.1016/j.jconrel.2019.02.028},
  pages     = {138 -- 148},
  year      = {2019},
  abstract  = {In reconstructed skin and diffusion cell studies, core-multishell nanocarriers (CMS-NC) showed great potential for drug delivery across the skin barrier. Herein, we investigated penetration, release of dexamethasone (DXM), in excised full-thickness human skin with special focus on hair follicles (HF). Four hours and 16 h after topical application of clinically relevant dosages of 10 mu g DXM/cm(2) skin encapsulated in CMS-NC (12 nm diameter, 5.8\% loading), presence of DXM in the tissue as assessed by fluorescence microscopy of anti-DXM-stained tissue sections as well as ELISA and HPLC-MS/MS in tissue extracts was enhanced compared to standard LAW-creme but lower compared to DXM aqueous/alcoholic solution. Such enhanced penetration compared to conventional cremes offers high potential for topical therapies, as recurrent applications of corticosteroid solutions face limitations with regard to tolerability and fast drainage. The findings encourage more detailed investigations on where and how the nanocarrier and drug dissociate within the skin and what other factors, e.g. thermodynamic activity, influence the penetration of this formulations. Microscopic studies on the spatial distribution within the skin revealed accumulation in HF and furrows accompanied by limited cellular uptake assessed by flow cytometry (up to 9\% of total epidermal cells). FLIM clearly visualized the presence of CMS-NC in the viable epidermis and dermis. When exposed in situ a fraction of up to 25\% CD1a(+) cells were found within the epidermal CMS-NC+ population compared to approximately 3\% CD1a(+)/CMS-NC+ cells after in vitro exposure in short-term cultures of epidermal cell suspensions. The latter reflects the natural percentage of Langerhans cells (LC) in epidermis suspensions and indicated that CMS-NC were not preferentially internalized by one cell type. The increased CMS-NC+ LC proportion after exposure within the tissue is in accordance with the strategic suprabasal LC-localization. More specifically we postulate that the extensive dendrite meshwork, their position around HF orifices and their capacity to modulate tight junctions facilitated a preferential uptake of CMS-NC by LC within the skin. This newly identified aspect of CMS-NC penetration underlines the potential of CMS-NC for dermatotherapy and encourages further investigations of CMS-NC for the delivery of other molecule classes for which intracellular delivery is even more crucial.},
  language  = {en}
}
@article{WiesnerReinholdBarknowitzFlorianetal.2019,
  author    = {Wiesner-Reinhold, Melanie and Barknowitz, Gitte and Florian, Simone and Mewis, Inga and Schumacher, Fabian and Schreiner, Monika and Glatt, Hansruedi},
  title     = {1-Methoxy-3-indolylmethyl DNA adducts in six tissues, and blood protein adducts, in mice under pak choi diet: time course and persistence},
  series = {Archives of toxicology : official journal of EUROTOX},
  volume    = {93},
  journal   = {Archives of toxicology : official journal of EUROTOX},
  number    = {6},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0340-5761},
  doi       = {10.1007/s00204-019-02452-3},
  pages     = {1515 -- 1527},
  year      = {2019},
  abstract  = {We previously showed that purified 1-methoxy-3-indolylmethyl (1-MIM) glucosinolate, a secondary plant metabolite in Brassica species, is mutagenic in various in vitro systems and forms DNA and protein adducts in mouse models. In the present study, we administered 1-MIM glucosinolate in a natural matrix to mice, by feeding a diet containing pak choi powder and extract. Groups of animals were killed after 1, 2, 4 and 8 days of pak choi diet, directly or, in the case of the 8-day treatment, after 0, 8 and 16 days of recovery with pak choi-free diet. DNA adducts [N-2-(1-MIM)-dG, N-6-(1-MIM)-dA] in six tissues, as well as protein adducts [tau N-(1-MIM)-His] in serum albumin (SA) and hemoglobin (Hb) were determined using UPLC-MS/MS with isotopically labeled internal standards. None of the samples from the 12 control animals under standard diet contained any 1-MIM adducts. All groups receiving pak choi diet showed DNA adducts in all six tissues (exception: lung of mice treated for a single day) as well as SA and Hb adducts. During the feeding period, all adduct levels continuously increased until day 8 (in the jejunum until day 4). During the 14-day recovery period, N-2-(1-MIM)-dG in liver, kidney, lung, jejunum, cecum and colon decreased to 52, 41, 59, 11, 7 and 2\%, respectively, of the peak level. The time course of N-6-(1-MIM)-dA was similar. Immunohistochemical analyses indicated that cell turnover is a major mechanism of DNA adduct elimination in the intestine. In the same recovery period, protein adducts decreased more rapidly in SA than in Hb, to 0.7 and 37\%, respectively, of the peak level, consistent with the differential turnover of these proteins. In conclusion, the pak choi diet lead to the formation of high levels of adducts in mice. Cell and protein turnover was a major mechanism of adduct elimination, at least in gut and blood.},
  language  = {en}
}
@article{RancanVolkmannGiulbudagianetal.2019,
  author    = {Rancan, Fiorenza and Volkmann, Hildburg and Giulbudagian, Michael and Schumacher, Fabian and Stanko, Jessica Isolde and Kleuser, Burkhard and Blume-Peytavi, Ulrike and Calderon, Marcelo and Vogt, Annika},
  title     = {Dermal Delivery of the High-Molecular-Weight Drug Tacrolimus by Means of Polyglycerol-Based Nanogels},
  series = {Pharmaceutics : Molecular Diversity Preservation International},
  volume    = {11},
  journal   = {Pharmaceutics : Molecular Diversity Preservation International},
  number    = {8},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1999-4923},
  doi       = {10.3390/pharmaceutics11080394},
  pages     = {14},
  year      = {2019},
  abstract  = {Polyglycerol-based thermoresponsive nanogels (tNGs) have been shown to have excellent skin hydration properties and to be valuable delivery systems for sustained release of drugs into skin. In this study, we compared the skin penetration of tacrolimus formulated in tNGs with a commercial 0.1\% tacrolimus ointment. The penetration of the drug was investigated in ex vivo abdominal and breast skin, while different methods for skin barrier disruption were investigated to improve skin permeability or simulate inflammatory conditions with compromised skin barrier. The amount of penetrated tacrolimus was measured in skin extracts by liquid chromatography tandem-mass spectrometry (LC-MS/MS), whereas the inflammatory markers IL-6 and IL-8 were detected by enzyme-linked immunosorbent assay (ELISA). Higher amounts of tacrolimus penetrated in breast as compared to abdominal skin or in barrier-disrupted as compared to intact skin, confirming that the stratum corneum is the main barrier for tacrolimus skin penetration. The anti-proliferative effect of the penetrated drug was measured in skin tissue/Jurkat cells co-cultures. Interestingly, tNGs exhibited similar anti-proliferative effects as the 0.1\% tacrolimus ointment. We conclude that polyglycerol-based nanogels represent an interesting alternative to paraffin-based formulations for the treatment of inflammatory skin conditions.},
  language  = {en}
}
@article{LaegerCastanoMartinezWernoetal.2018,
  author    = {Laeger, Thomas and Castano-Martinez, Teresa and Werno, Martin W. and Japtok, Lukasz and Baumeier, Christian and Jonas, Wenke and Kleuser, Burkhard and Sch{\"u}rmann, Annette},
  title     = {Dietary carbohydrates impair the protective effect of protein restriction against diabetes in NZO mice used as a model of type 2 diabetes},
  series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  volume    = {61},
  journal   = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  number    = {6},
  publisher = {Springer},
  address   = {New York},
  issn      = {0012-186X},
  doi       = {10.1007/s00125-018-4595-1},
  pages     = {1459 -- 1469},
  year      = {2018},
  abstract  = {Aims/hypothesis Low-protein diets are well known to improve glucose tolerance and increase energy expenditure. Increases in circulating fibroblast growth factor 21 (FGF21) have been implicated as a potential underlying mechanism. Methods We aimed to test whether low-protein diets in the context of a high-carbohydrate or high-fat regimen would also protect against type 2 diabetes in New Zealand Obese (NZO) mice used as a model of polygenetic obesity and type 2 diabetes. Mice were placed on high-fat diets that provided protein at control (16 kJ\%; CON) or low (4 kJ\%; low-protein/high-carbohydrate [LP/HC] or low-protein/high-fat [LP/HF]) levels. Results Protein restriction prevented the onset of hyperglycaemia and beta cell loss despite increased food intake and fat mass. The effect was seen only under conditions of a lower carbohydrate/fat ratio (LP/HF). When the carbohydrate/fat ratio was high (LP/HC), mice developed type 2 diabetes despite the robustly elevated hepatic FGF21 secretion and increased energy expenditure. Conclusion/interpretation Prevention of type 2 diabetes through protein restriction, without lowering food intake and body fat mass, is compromised by high dietary carbohydrates. Increased FGF21 levels and elevated energy expenditure do not protect against hyperglycaemia and type 2 diabetes per se.},
  language  = {en}
}
@article{McVeyKimTabuchietal.2017,
  author    = {McVey, Mark J. and Kim, Michael and Tabuchi, Arata and Srbely, Victoria and Japtok, Lukasz and Arenz, Christoph and Rotstein, Ori and Kleuser, Burkhard and Semple, John W. and Kuebler, Wolfgang M.},
  title     = {Acid sphingomyelinase mediates murine acute lung injury following transfusion of aged platelets},
  series = {American journal of physiology : Lung cellular and molecular physiology},
  volume    = {312},
  journal   = {American journal of physiology : Lung cellular and molecular physiology},
  number    = {5},
  publisher = {American Physiological Society},
  address   = {Bethesda},
  issn      = {1040-0605},
  doi       = {10.1152/ajplung.00317.2016},
  pages     = {625 -- 637},
  year      = {2017},
  abstract  = {Pulmonary complications from stored blood products are the leading cause of mortality related to transfusion. Transfusion-related acute lung injury is mediated by antibodies or bioactive mediators, yet underlying mechanisms are incompletely understood. Sphingolipids such as ceramide regulate lung injury, and their composition changes as a function of time in stored blood. Here, we tested the hypothesis that aged platelets may induce lung injury via a sphingolipid-mediated mechanism. To assess this hypothesis, a two-hit mouse model was devised. Recipient mice were treated with 2 mg/kg intraperitoneal lipopolysaccharide (priming) 2 h before transfusion of 10 ml/kg stored (1-5 days) platelets treated with or without addition of acid sphingomyelinase inhibitor ARC39 or platelets from acid sphingomyelinase-deficient mice, which both reduce ceramide formation. Transfused mice were examined for signs of pulmonary neutrophil accumulation, endothelial barrier dysfunction, and histological evidence of lung injury. Sphingolipid profiles in stored platelets were analyzed by mass spectrophotometry. Transfusion of aged platelets into primed mice induced characteristic features of lung injury, which increased in severity as a function of storage time. Ceramide accumulated in platelets during storage, but this was attenuated by ARC39 or in acid sphingomyelinase-deficient platelets. Compared with wild-type platelets, transfusion of ARC39-treated or acid sphingomyelinase-deficient aged platelets alleviated lung injury. Aged platelets elicit lung injury in primed recipient mice, which can be alleviated by pharmacological inhibition or genetic deletion of acid sphingomyelinase. Interventions targeting sphingolipid formation represent a promising strategy to increase the safety and longevity of stored blood products.},
  language  = {en}
}
@article{BernacchioniGhiniCencettietal.2017,
  author    = {Bernacchioni, Caterina and Ghini, Veronica and Cencetti, Francesca and Japtok, Lukasz and Donati, Chiara and Bruni, Paola and Turano, Paola},
  title     = {NMR metabolomics highlights sphingosine kinase-1 as a new molecular switch in the orchestration of aberrant metabolic phenotype in cancer cells},
  series = {Molecular oncology / Federation of European Biochemical Societies},
  volume    = {11},
  journal   = {Molecular oncology / Federation of European Biochemical Societies},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1878-0261},
  doi       = {10.1002/1878-0261.12048},
  pages     = {517 -- 533},
  year      = {2017},
  abstract  = {Strong experimental evidence in animal and cellular models supports a pivotal role of sphingosine kinase-1 (SK1) in oncogenesis. In many human cancers, SK1 levels are upregulated and these increases are linked to poor prognosis in patients. Here, by employing untargeted NMR- based metabolomic profiling combined with functional validations, we report the crucial role of SK1 in the metabolic shift known as the Warburg effect in A2780 ovarian cancer cells. Indeed, expression of SK1 induced a high glycolytic rate, characterized by increased levels of lactate along with increased expression of the proton/monocarboxylate symporter MCT1, and decreased oxidative metabolism, associated with the accumulation of intermediates of the tricarboxylic acid cycle and reduction in CO2 production. Additionally, SK1-expressing cells displayed a significant increase in glucose uptake paralleled by GLUT3 transporter upregulation. The role of SK1 is not limited to the induction of aerobic glycolysis, affecting metabolic pathways that appear to support the biosynthesis of macromolecules. These findings highlight the role of SK1 signaling axis in cancer metabolic reprogramming, pointing out innovative strategies for cancer therapies.},
  language  = {en}
}
@article{HoehnJerniganJaptoketal.2017,
  author    = {Hoehn, Richard S. and Jernigan, Peter L. and Japtok, Lukasz and Chang, Alex L. and Midura, Emily F. and Caldwell, Charles C. and Kleuser, Burkhard and Lentsch, Alex B. and Edwards, Michael J. and Gulbins, Erich and Pritts, Timothy A.},
  title     = {Acid sphingomyelinase inhibition in stored erythrocytes reduces transfusion-associated lung inflammation},
  series = {Annals of surgery : a monthly review of surgical science and practice},
  volume    = {265},
  journal   = {Annals of surgery : a monthly review of surgical science and practice},
  number    = {1},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {0003-4932},
  doi       = {10.1097/SLA.0000000000001648},
  pages     = {218 -- 226},
  year      = {2017},
  abstract  = {Objective: We aimed to identify the role of the enzyme acid sphingomyelinase in the aging of stored units of packed red blood cells (pRBCs) and subsequent lung inflammation after transfusion. Summary Background Data: Large volume pRBC transfusions are associated with multiple adverse clinical sequelae, including lung inflammation. Microparticles are formed in stored pRBCs over time and have been shown to contribute to lung inflammation after transfusion. Methods: Human and murine pRBCs were stored with or without amitriptyline, a functional inhibitor of acid sphingomyelinase, or obtained from acid sphingomyelinase-deficient mice, and lung inflammation was studied in mice receiving transfusions of pRBCs and microparticles isolated from these units. Results: Acid sphingomyelinase activity in pRBCs was associated with the formation of ceramide and the release of microparticles. Treatment of pRBCs with amitriptyline inhibited acid sphingomyelinase activity, ceramide accumulation, and microparticle production during pRBC storage. Transfusion of aged pRBCs or microparticles isolated from aged blood into mice caused lung inflammation. This was attenuated after transfusion of pRBCs treated with amitriptyline or from acid sphingomyelinase-deficient mice. Conclusions: Acid sphingomyelinase inhibition in stored pRBCs offers a novel mechanism for improving the quality of stored blood.},
  language  = {en}
}
@article{FolkessonVorkapicGulbinsetal.2017,
  author    = {Folkesson, Maggie and Vorkapic, Emina and Gulbins, Erich and Japtok, Lukasz and Kleuser, Burkhard and Welander, Martin and L{\"a}nne, Toste and W{\aa}gs{\"a}ter, Dick},
  title     = {Inflammatory cells, ceramides, and expression of proteases in perivascular adipose tissue adjacent to human abdominal aortic aneurysms},
  series = {Journal of vascular surgery},
  volume    = {65},
  journal   = {Journal of vascular surgery},
  number    = {4},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0741-5214},
  doi       = {10.1016/j.jvs.2015.12.056},
  pages     = {1171 -- 1179},
  year      = {2017},
  abstract  = {Background: Abdominal aortic aneurysm (AAA) is a deadly irreversible weakening and distension of the abdominal aortic wall. The pathogenesis of AAA remains poorly understood. Investigation into the physical and molecular characteristics of perivascular adipose tissue (PVAT) adjacent to AAA has not been done before and is the purpose of this study. Methods and Results: Human aortae, periaortic PVAT, and fat surrounding peripheral arteries were collected from patients undergoing elective surgical repair of AAA. Control aortas were obtained from recently deceased healthy organ donors with no known arterial disease. Aorta and PVAT was found in AAA to larger extent compared with control aortas. Immunohistochemistry revealed neutrophils, macrophages, mast cells, and T-cells surrounding necrotic adipocytes. Gene expression analysis showed that neutrophils, mast cells, and T-cells were found to be increased in PVAT compared with AAA as well as cathepsin K and S. The concentration of ceramides in PVAT was determined using mass spectrometry and correlated with content of T-cells in the PVAT. Conclusions: Our results suggest a role for abnormal necrotic, inflamed, proteolytic adipose tissue to the adjacent aneurysmal aortic wall in ongoing vascular damage.},
  language  = {en}
}
@article{DwiPutraReichetzederHasanetal.2020,
  author    = {Dwi Putra, Sulistyo Emantoko and Reichetzeder, Christoph and Hasan, Ahmed Abdallah Abdalrahman Mohamed and Slowinski, Torsten and Chu, Chang and Kr{\"a}mer, Bernhard K. and Kleuser, Burkhard and Hocher, Berthold},
  title     = {Being born large for gestational age is associated with increased global placental DNA methylation},
  series = {Scientific Reports},
  volume    = {10},
  journal   = {Scientific Reports},
  number    = {1},
  publisher = {Springer Nature},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-020-57725-0},
  pages     = {1 -- 10},
  year      = {2020},
  abstract  = {Being born small (SGA) or large for gestational age (LGA) is associated with adverse birth outcomes and metabolic diseases in later life of the offspring. It is known that aberrations in growth during gestation are related to altered placental function. Placental function is regulated by epigenetic mechanisms such as DNA methylation. Several studies in recent years have demonstrated associations between altered patterns of DNA methylation and adverse birth outcomes. However, larger studies that reliably investigated global DNA methylation are lacking. The aim of this study was to characterize global placental DNA methylation in relationship to size for gestational age. Global DNA methylation was assessed in 1023 placental samples by LC-MS/MS. LGA offspring displayed significantly higher global placental DNA methylation compared to appropriate for gestational age (AGA; p<0.001). ANCOVA analyses adjusted for known factors impacting on DNA methylation demonstrated an independent association between placental global DNA methylation and LGA births (p<0.001). Tertile stratification according to global placental DNA methylation levels revealed a significantly higher frequency of LGA births in the third tertile. Furthermore, a multiple logistic regression analysis corrected for known factors influencing birth weight highlighted an independent positive association between global placental DNA methylation and the frequency of LGA births (p=0.001).},
  language  = {en}
}
@article{KlausIgualGilOst2021,
  author    = {Klaus, Susanne and Igual Gil, Carla and Ost, Mario},
  title     = {Regulation of diurnal energy balance by mitokines},
  series = {Cellular and molecular life sciences : CMLS},
  volume    = {78},
  journal   = {Cellular and molecular life sciences : CMLS},
  number    = {7},
  publisher = {Springer International Publishing AG},
  address   = {Cham (ZG)},
  issn      = {1420-682X},
  doi       = {10.1007/s00018-020-03748-9},
  pages     = {3369 -- 3384},
  year      = {2021},
  abstract  = {The mammalian system of energy balance regulation is intrinsically rhythmic with diurnal oscillations of behavioral and metabolic traits according to the 24 h day/night cycle, driven by cellular circadian clocks and synchronized by environmental or internal cues such as metabolites and hormones associated with feeding rhythms. Mitochondria are crucial organelles for cellular energy generation and their biology is largely under the control of the circadian system. Whether mitochondrial status might also feed-back on the circadian system, possibly via mitokines that are induced by mitochondrial stress as endocrine-acting molecules, remains poorly understood. Here, we describe our current understanding of the diurnal regulation of systemic energy balance, with focus on fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15), two well-known endocrine-acting metabolic mediators. FGF21 shows a diurnal oscillation and directly affects the output of the brain master clock. Moreover, recent data demonstrated that mitochondrial stress-induced GDF15 promotes a day-time restricted anorexia and systemic metabolic remodeling as shown in UCP1-transgenic mice, where both FGF21 and GDF15 are induced as myomitokines. In this mouse model of slightly uncoupled skeletal muscle mitochondria GDF15 proved responsible for an increased metabolic flexibility and a number of beneficial metabolic adaptations. However, the molecular mechanisms underlying energy balance regulation by mitokines are just starting to emerge, and more data on diurnal patterns in mouse and man are required. This will open new perspectives into the diurnal nature of mitokines and action both in health and disease.},
  language  = {en}
}
@article{McNultyGoupilAlbaradoetal.2020,
  author    = {McNulty, Margaret A. and Goupil, Brad A. and Albarado, Diana C. and Casta{\~n}o-Martinez, Teresa and Ambrosi, Thomas H. and Puh, Spela and Schulz, Tim Julius and Sch{\"u}rmann, Annette and Morrison, Christopher D. and Laeger, Thomas},
  title     = {FGF21, not GCN2, influences bone morphology due to dietary protein restrictions},
  series = {Bone Reports},
  volume    = {12},
  journal   = {Bone Reports},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2352-1872},
  doi       = {10.1016/j.bonr.2019.100241},
  pages     = {1 -- 10},
  year      = {2020},
  abstract  = {Background: Dietary protein restriction is emerging as an alternative approach to treat obesity and glucose intolerance because it markedly increases plasma fibroblast growth factor 21 (FGF21) concentrations. Similarly, dietary restriction of methionine is known to mimic metabolic effects of energy and protein restriction with FGF21 as a required mechanism. However, dietary protein has been shown to be required for normal bone growth, though there is conflicting evidence as to the influence of dietary protein restriction on bone remodeling. The purpose of the current study was to evaluate the effect of dietary protein and methionine restriction on bone in lean and obese mice, and clarify whether FGF21 and general control nonderepressible 2 (GCN2) kinase, that are part of a novel endocrine pathway implicated in the detection of protein restriction, influence the effect of dietary protein restriction on bone. Methods: Adult wild-type (WT) or Fgf21 KO mice were fed a normal protein (18 kcal\%; CON) or low protein (4 kcal\%; LP) diet for 2 or 27 weeks. In addition, adult WT or Gcn2 KO mice were fed a CON or LP diet for 27 weeks. Young New Zealand obese (NZO) mice were placed on high-fat diets that provided protein at control (16 kcal\%; CON), low levels (4 kcal\%) in a high-carbohydrate (LP/HC) or high-fat (LP/HF) regimen, or on high-fat diets (protein, 16 kcal\%) that provided methionine at control (0.86\%; CON-MR) or low levels (0.17\%; MR) for up to 9 weeks. Long bones from the hind limbs of these mice were collected and evaluated with micro-computed tomography (mu CT) for changes in trabecular and cortical architecture and mass. Results: In WT mice the 27-week LP diet significantly reduced cortical bone, and this effect was enhanced by deletion of Fgf21 but not Gcn2. This decrease in bone did not appear after 2 weeks on the LP diet. In addition, Fgf21 KO mice had significantly less bone than their WT counterparts. In obese NZO mice dietary protein and methionine restriction altered bone architecture. The changes were mediated by FGF21 due to methionine restriction in the presence of cystine, which did not increase plasma FGF21 levels and did not affect bone architecture. Conclusions: This study provides direct evidence of a reduction in bone following long-term dietary protein restriction in a mouse model, effects that appear to be mediated by FGF21.},
  language  = {en}
}
@article{SchjeideSchenkeSeegeretal.2022,
  author    = {Schjeide, Brit-Maren and Schenke, Maren and Seeger, Bettina and P{\"u}schel, Gerhard},
  title     = {Validation of a novel double control quantitative copy number PCR method to quantify off-target transgene integration after CRISPR-induced DNA modification},
  series = {Methods and protocols : M\&Ps},
  volume    = {5},
  journal   = {Methods and protocols : M\&Ps},
  number    = {3},
  publisher = {MDPI},
  address   = {Basel, Schweiz},
  issn      = {2409-9279},
  doi       = {10.3390/mps5030043},
  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}
}
@article{RundHeylmannSeiwertetal.2019,
  author    = {Rund, Katharina M. and Heylmann, Daniel and Seiwert, Nina and Wecklein, Sabine and Oger, Camille and Galano, Jean-Marie and Durand, Thierry and Chen, Rongjun and G{\"u}ler, Faikah and Fahrer, J{\"o}rg and Bornhorst, Julia and Schebb, Nils Helge},
  title     = {Formation of trans-epoxy fatty acids correlates with formation of isoprostanes and could serve as biomarker of oxidative stress},
  series = {Prostaglandins \& Other Lipid Mediators},
  volume    = {144},
  journal   = {Prostaglandins \& Other Lipid Mediators},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {1098-8823},
  doi       = {10.1016/j.prostaglandins.2019.04.004},
  pages     = {10},
  year      = {2019},
  abstract  = {In mammals, epoxy-polyunsaturated fatty acids (epoxy-PUFA) are enzymatically formed from naturally occurring all-cis PUFA by cytochrome P450 monooxygenases leading to the generation of cis-epoxy-PUFA (mixture of R,S- and S,R-enantiomers). In addition, also non-enzymatic chemical peroxidation gives rise to epoxy-PUFA leading to both, cis- and trans-epoxy-PUFA (mixture of R,R- and S,S-enantiomers). Here, we investigated for the first time trans-epoxy-PUFA and the trans/cis-epoxy-PUFA ratio as potential new biomarker of lipid peroxidation. Their formation was analyzed in correlation with the formation of isoprostanes (IsoP), which are commonly used as biomarkers of oxidative stress. Five oxidative stress models were investigated including incubations of three human cell lines as well as the in vivo model Caenorhabditis elegans with tert-butyl hydroperoxide (t-BOOH) and analysis of murine kidney tissue after renal ischemia reperfusion injury (IRI). A comprehensive set of IsoP and epoxy-PUFA derived from biologically relevant PUFA (ARA, EPA and DHA) was simultaneously quantified by LC-ESI(-)-MS/MS. Following renal IRI only a moderate increase in the kidney levels of IsoP and no relevant change in the trans/cis-epoxy-PUFA ratio was observed. In all investigated cell lines (HCT-116, HepG2 and Caki-2) as well as C. elegans a dose dependent increase of both, IsoP and the trans/cis-epoxy-PUFA ratio in response to the applied t-BOOH was observed. The different cell lines showed a distinct time dependent pattern consistent for both classes of autoxidatively formed oxylipins. Clear and highly significant correlations of the trans/cisepoxy-PUFA ratios with the IsoP levels were found in all investigated cell lines and C. elegans. Based on this, we suggest the trans/cis-epoxy-PUFA ratio as potential new biomarker of oxidative stress, which warrants further investigation.},
  language  = {en}
}
@article{RohnKroepflBornhorstetal.2019,
  author    = {Rohn, Isabelle and Kroepfl, Nina and Bornhorst, Julia and K{\"u}hnelt, Doris and Schwerdtle, Tanja},
  title     = {Side-directed transfer and presystemic metabolism of selenoneine in a human intestinal barrier model},
  series = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  volume    = {63},
  journal   = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology},
  number    = {12},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1613-4125},
  doi       = {10.1002/mnfr.201900080},
  pages     = {11},
  year      = {2019},
  abstract  = {Scope: Selenoneine, a recently discovered selenium (Se) species mainly present in marine fish, is the Se analogue of ergothioneine, a sulfur-containing purported antioxidant. Although similar properties have been proposed for selenoneine, data on its relevance to human health are yet scarce. Here, the transfer and presystemic metabolism of selenoneine in an in vitro model of the human intestinal barrier are investigated. Methods and results: Selenoneine and the reference species Se-methylselenocysteine (MeSeCys) and selenite are applied to the Caco-2 intestinal barrier model. Selenoneine is transferred in higher amounts, but with similar kinetics as selenite, while MeSeCys shows the highest permeability. In contrast to the reference species, transfer of selenoneine is directed toward the blood side. Cellular Se contents demonstrate that selenoneine is efficiently taken up by Caco-2 cells. Moreover, HPLC/MS-based Se speciation studies reveal a partial metabolism to Se-methylselenoneine, a metabolite previously detected in human blood and urine. Conclusions: Selenoneine is likely to pass the intestinal barrier via transcellular, carrier-mediated transport, is highly bioavailable to Caco-2 cells and undergoes metabolic transformations. Therefore, further studies are needed to elucidate its possible health effects and to characterize the metabolism of selenoneine in humans.},
  language  = {en}
}
@article{BaeslerKoppPohletal.2019,
  author    = {Baesler, Jessica and Kopp, Johannes Florian and Pohl, Gabriele and Aschner, Michael and Haase, Hajo and Schwerdtle, Tanja and Bornhorst, Julia},
  title     = {Zn homeostasis in genetic models of Parkinson's disease in Caenorhabditis elegans},
  series = {Journal of Trace Elements in Medicine and Biology},
  volume    = {55},
  journal   = {Journal of Trace Elements in Medicine and Biology},
  publisher = {Elsevier},
  address   = {M{\"u}nchen},
  doi       = {10.1016/j.jtemb.2019.05.005},
  pages     = {44 -- 49},
  year      = {2019},
  abstract  = {While the underlying mechanisms of Parkinson's disease (PD) are still insufficiently studied, a complex interaction between genetic and environmental factors is emphasized. Nevertheless, the role of the essential trace element zinc (Zn) in this regard remains controversial. In this study we altered Zn balance within PD models of the versatile model organism Caenorhabditis elegans (C. elegans) in order to examine whether a genetic predisposition in selected genes with relevance for PD affects Zn homeostasis. Protein-bound and labile Zn species act in various areas, such as enzymatic catalysis, protein stabilization pathways and cell signaling. Therefore, total Zn and labile Zn were quantitatively determined in living nematodes as individual biomarkers of Zn uptake and bioavailability with inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) or a multi-well method using the fluorescent probe ZinPyr-1. Young and middle-aged deletion mutants of catp-6 and pdr-1, which are orthologues of mammalian ATP13A2 (PARK9) and parkin (PARK2), showed altered Zn homeostasis following Zn exposure compared to wildtype worms. Furthermore, age-specific differences in Zn uptake were observed in wildtype worms for total as well as labile Zn species. These data emphasize the importance of differentiation between Zn species as meaningful biomarkers of Zn uptake as well as the need for further studies investigating the role of dysregulated Zn homeostasis in the etiology of PD.},
  language  = {en}
}
@article{Wardelmann2019,
  author    = {Wardelmann, Kristina},
  title     = {Hormonal regulation of neuronal mitochondrial unfolded protein response and its impact on metabolism},
  pages     = {108},
  year      = {2019},
  abstract  = {The hypothalamus is the main brain area of central regulation of whole body metabolism through impacting food intake and energy expenditure. For the complex regulation, high amounts of energy are needed and mainly provided by mitochondria. Hence, mitochondrial function is crucial for cell homeostasis and modulates central insulin sensitivity. Thus, mitochondrial dysfunction is associated with insulin resistance in the brain and therefore is involved in the pathogenesis of type-2 diabetes (T2D). Mitochondrial health and protein homeostasis is propagated by mitochondrial stress responses like e.g. mitochondrial unfolded protein response (UPRmt). Therefore, studies regarding the regulation of mitochondrial homeostasis are crucial for understanding its effects on the central nervous system (CNS) for the progression of metabolic and nutrition-dependent disorders. One main aim of this thesis was to investigate the metabolic regulation of mitochondrial stress responsiveness in the hypothalamus. The observed results showed that functional ERK-dependent insulin signaling is needed for regulation of mitochondrial stress response (MSR) genes and positively impacted the metabolism by controlling mitochondrial proteostasis without affecting mitochondrial biogenesis. To further explore the role of MSR genes for brain cell homeostasis and its consequences for the metabolism, one of the key players - the mitochondrial chaperone heat shock protein 10 (Hsp10) - was studied in detail. Hsp10 expression was decreased in insulin-resistant, hyperglycemic db/db mice brains along with increased protein oxidation. Leptin, another key hormone in regulating metabolism, was able to induce Hsp10 in neurons. Appropriately, lentiviral-mediated knock down (KD) of Hsp10 introduced into hypothalamic CLU-183 cells induced mitochondrial dysfunction, altered mitochondrial dynamics and increased contact sites between mitochondria and endoplasmic reticulum (ER). In addition, Hsp10 KD caused cellular insulin resistance along with increasing oxidative stress specifically in mitochondrial fraction. Interestingly, acute Hsp10 KD in the arcuate nucleus of the hypothalamus in C57BL/6N male mice did not change body weight or food intake, but it increased plasma leptin concentrations suggesting an effect on global leptin signaling. It increased hepatic markers of gluconeogenesis and hepatic insulin resistance along with features of low-grade inflammation. Long-term studies of hypothalamic Hsp10 KD mice revealed unaltered systemic insulin sensitivity. The demonstrated increase in markers of hepatic gluconeogenesis of acute Hsp10 KD was still exhibited after 13 weeks, but insulin resistance in the liver was no longer observed. In conclusion, hypothalamic insulin action regulates MSR and ensures proper mitochondrial function which positively affects metabolism. In addition, hypothalamic Hsp10 acts as a modulator of both insulin and leptin signaling and is identified as pivotal for the regulation of central mitochondrial function as well as insulin sensitivity in the brain and it impacts liver function. It may present a regulator of brain-liver crosstalk influencing hepatic gluconeogenesis and insulin sensitivity through a novel regulatory signaling mechanism.},
  language  = {en}
}
@article{ChristakoudiTsilidisMulleretal.2020,
  author    = {Christakoudi, Sofa and Tsilidis, Konstantinos K. and Muller, David C. and Freisling, Heinz and Weiderpass, Elisabete and Overvad, Kim and S{\"o}derberg, Stefan and H{\"a}ggstr{\"o}m, Christel and Pischon, Tobias and Dahm, Christina C. and Zhang, Jie and Tj{\o}nneland, Anne and Schulze, Matthias Bernd},
  title     = {A Body Shape Index (ABSI) achieves better mortality risk stratification than alternative indices of abdominal obesity: results from a large European cohort},
  series = {Scientific Reports},
  volume    = {10},
  journal   = {Scientific Reports},
  number    = {1},
  publisher = {Springer Nature},
  address   = {Berlin},
  pages     = {15},
  year      = {2020},
  abstract  = {Abdominal and general adiposity are independently associated with mortality, but there is no consensus on how best to assess abdominal adiposity. We compared the ability of alternative waist indices to complement body mass index (BMI) when assessing all-cause mortality. We used data from 352,985 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) and Cox proportional hazards models adjusted for other risk factors. During a mean follow-up of 16.1 years, 38,178 participants died. Combining in one model BMI and a strongly correlated waist index altered the association patterns with mortality, to a predominantly negative association for BMI and a stronger positive association for the waist index, while combining BMI with the uncorrelated A Body Shape Index (ABSI) preserved the association patterns. Sex-specific cohort-wide quartiles of waist indices correlated with BMI could not separate high-risk from low-risk individuals within underweight (BMI<18.5 kg/m(2)) or obese (BMI30 kg/m(2)) categories, while the highest quartile of ABSI separated 18-39\% of the individuals within each BMI category, which had 22-55\% higher risk of death. In conclusion, only a waist index independent of BMI by design, such as ABSI, complements BMI and enables efficient risk stratification, which could facilitate personalisation of screening, treatment and monitoring.},
  language  = {en}
}
@article{CastroFernandoReegetal.2019,
  author    = {Castro, Jose Pedro and Fernando, Raquel and Reeg, Sandra and Meinl, Walter and Almeida, Henrique and Grune, Tilman},
  title     = {Non-enzymatic cleavage of Hsp90 by oxidative stress leads to actin aggregate formation},
  series = {Redox Biology},
  volume    = {21},
  journal   = {Redox Biology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2213-2317},
  doi       = {10.1016/j.redox.2019.101108},
  pages     = {10},
  year      = {2019},
  abstract  = {Aging is accompanied by the accumulation of oxidized proteins. To remove them, cells employ the proteasomal and autophagy-lysosomal systems; however, if the clearance rate is inferior to its formation, protein aggregates form as a hallmark of proteostasis loss. In cells, during stress conditions, actin aggregates accumulate leading to impaired proliferation and reduced proteasomal activity, as observed in cellular senescence. The heat shock protein 90 (Hsp90) is a molecular chaperone that binds and protects the proteasome from oxidative inactivation. We hypothesized that in oxidative stress conditions a malfunction of Hsp90 occurs resulting in the aforementioned protein aggregates. Here, we demonstrate that upon oxidative stress Hsp90 loses its function in a highly specific non-enzymatic iron-catalyzed oxidation event and its breakdown product, a cleaved form of Hsp90 (Hsp90cl), acquires a new function in mediating the accumulation of actin aggregates. Moreover, the prevention of Hsp90 cleavage reduces oxidized actin accumulation, whereas transfection of the cleaved form of Hsp90 leads to an enhanced accumulation of oxidized actin. This indicates a clear role of the Hsp90cl in the aggregation of oxidized proteins.},
  language  = {en}
}
@article{RaupbachOttKoenigetal.2020,
  author    = {Raupbach, Jana and Ott, Christiane and K{\"o}nig, Jeannette and Grune, Tilman},
  title     = {Proteasomal degradation of glycated proteins depends on substrate unfolding: Preferred degradation of moderately modified myoglobin},
  series = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  volume    = {152},
  journal   = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0891-5849},
  doi       = {10.1016/j.freeradbiomed.2019.11.024},
  pages     = {516 -- 524},
  year      = {2020},
  abstract  = {The Maillard reaction generates protein modifications which can accumulate during hyperglycemia or aging and may have inflammatory consequences. The proteasome is one of the major intracellular systems involved in the proteolytic degradation of modified proteins but its role in the degradation of glycated proteins is scarcely studied. In this study, chemical and structural changes of glycated myoglobin were analyzed and its degradation by 20S proteasome was studied. Myoglobin was incubated with physiological (5-10 mM), moderate (50-100 mM) and severe levels (300 mM) of glucose or methylglyoxal (MGO, 50 mM). Glycation increased myoglobin's fluorescence and surface hydrophobicity. Severe glycation generated crosslinked proteins as shown by gel electrophoresis. The concentration of advanced glycation endproducts (AGEs) N-epsilon-carboxymethyl lysine (CML), N-epsilon-carboxyethyl lysine (CEL), methylglyoxal-derived hydroimidazolone-1 (MG-H1), pentosidine and pyrraline was analyzed after enzymatic hydrolysis followed by UPLC-MS/MS. Higher concentrations of glucose increased all analyzed AGEs and incubation with MGO led to a pronounced increase of CEL and MG-H1. The binding of the heme group to apo-myoglobin was decreased with increasing glycation indicating the loss of tertiary protein structure. Proteasomal degradation of modified myoglobin compared to native myoglobin depends on the degree of glycation: physiological conditions decreased proteasomal degradation whereas moderate glycation increased degradation. Severe glycation again decreased proteolytic cleavage which might be due to crosslinking of protein monomers. The activity of the proteasomal subunit beta 5 is influenced by the presence of glycated myoglobin. In conclusion, the role of the proteasome in the degradation of glycated proteins is highly dependent on the level of glycation and consequent protein unfolding.},
  language  = {en}
}
@article{WiedmerJungCastroetal.2020,
  author    = {Wiedmer, Petra and Jung, Tobias and Castro, Jose Pedro and Pomatto, Laura C. D. and Sun, Patrick Y. and Davies, Kelvin J. A. and Grune, Tilman},
  title     = {Sarcopenia},
  series = {Ageing research reviews : ARR},
  volume    = {65},
  journal   = {Ageing research reviews : ARR},
  publisher = {Elsevier},
  address   = {Clare},
  issn      = {1568-1637},
  doi       = {10.1016/j.arr.2020.101200},
  pages     = {17},
  year      = {2020},
  abstract  = {Sarcopenia represents a muscle-wasting syndrome characterized by progressive and generalized degenerative loss of skeletal muscle mass, quality, and strength occurring during normal aging. Sarcopenia patients are mainly suffering from the loss in muscle strength and are faced with mobility disorders reducing their quality of life and are, therefore, at higher risk for morbidity (falls, bone fracture, metabolic diseases) and mortality. <br /> Several molecular mechanisms have been described as causes for sarcopenia that refer to very different levels of muscle physiology. These mechanisms cover e. g. function of hormones (e. g. IGF-1 and Insulin), muscle fiber composition and neuromuscular drive, myo-satellite cell potential to differentiate and proliferate, inflammatory pathways as well as intracellular mechanisms in the processes of proteostasis and mitochondrial function. <br /> In this review, we describe sarcopenia as a muscle-wasting syndrome distinct from other atrophic diseases and summarize the current view on molecular causes of sarcopenia development as well as open questions provoking further research efforts for establishing efficient lifestyle and therapeutic interventions.},
  language  = {en}
}
@article{SchibornSchulze2022,
  author    = {Schiborn, Catarina and Schulze, Matthias Bernd},
  title     = {Precision prognostics for the development of complications in diabetes},
  series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  journal   = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  publisher = {Springer},
  address   = {New York},
  issn      = {0012-186X},
  doi       = {10.1007/s00125-022-05731-4},
  pages     = {16},
  year      = {2022},
  abstract  = {Individuals with diabetes face higher risks for macro- and microvascular complications than their non-diabetic counterparts. The concept of precision medicine in diabetes aims to optimise treatment decisions for individual patients to reduce the risk of major diabetic complications, including cardiovascular outcomes, retinopathy, nephropathy, neuropathy and overall mortality. In this context, prognostic models can be used to estimate an individual's risk for relevant complications based on individual risk profiles. This review aims to place the concept of prediction modelling into the context of precision prognostics. As opposed to identification of diabetes subsets, the development of prediction models, including the selection of predictors based on their longitudinal association with the outcome of interest and their discriminatory ability, allows estimation of an individual's absolute risk of complications. As a consequence, such models provide information about potential patient subgroups and their treatment needs. This review provides insight into the methodological issues specifically related to the development and validation of prediction models for diabetes complications. We summarise existing prediction models for macro- and microvascular complications, commonly included predictors, and examples of available validation studies. The review also discusses the potential of non-classical risk markers and omics-based predictors. Finally, it gives insight into the requirements and challenges related to the clinical applications and implementation of developed predictions models to optimise medical decision making.},
  language  = {en}
}
@article{WittenbecherKuxhausBoeingetal.2019,
  author    = {Wittenbecher, Clemens and Kuxhaus, Olga and Boeing, Heiner and Stefan, Norbert and Schulze, Matthias Bernd},
  title     = {Associations of short stature and components of height with incidence of type 2 diabetes},
  series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  volume    = {62},
  journal   = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)},
  number    = {12},
  publisher = {Springer},
  address   = {New York},
  issn      = {0012-186X},
  doi       = {10.1007/s00125-019-04978-8},
  pages     = {2211 -- 2221},
  year      = {2019},
  abstract  = {Aims/hypothesis This study aimed to evaluate associations of height as well as components of height (sitting height and leg length) with risk of type 2 diabetes and to explore to what extent associations are explainable by liver fat and cardiometabolic risk markers. Methods A case-cohort study within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study comprising 26,437 participants who provided blood samples was designed. We randomly selected a subcohort of 2500 individuals (2029 diabetes-free at baseline and with anamnestic, anthropometrical and metabolic data for analysis). Of the 820 incident diabetes cases identified in the full cohort during 7 years of follow-up, 698 remained for analyses after similar exclusions. Results After adjustment for age, potential lifestyle confounders, education and waist circumference, greater height was related to lower diabetes risk (HR per 10 cm, men 0.59 [95\% CI 0.47, 0.75] and women 0.67 [0.51, 0.88], respectively). Leg length was related to lower risk among men and women, but only among men if adjusted for total height. Adjustment for liver fat and triacylglycerols, adiponectin and C-reactive protein substantially attenuated associations between height and diabetes risk, particularly among women. Conclusions/interpretation We observed inverse associations between height and risk of type 2 diabetes, which was largely related to leg length among men. The inverse associations may be partly driven by lower liver fat content and a more favourable cardiometabolic profile.},
  language  = {en}
}