241 results on '"Schäffler A"'
Search Results
2. CTRP-3 Regulates NOD1-mediated Inflammation and NOD1 Expression in Adipocytes and Adipose Tissue
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Andreas Schmid, Andreas Schäffler, and Thomas Karrasch
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0301 basic medicine ,Lipopolysaccharides ,Male ,Chemokine ,NOD1 ,THP-1 Cells ,Immunology ,Subcutaneous Fat ,Adipose tissue ,Adipokine ,030209 endocrinology & metabolism ,Inflammation ,macrophage ,peptidoglycan ,Intra-Abdominal Fat ,adipocyte ,Proinflammatory cytokine ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Adipokines ,Adipocyte ,3T3-L1 Cells ,Nod1 Signaling Adaptor Protein ,medicine ,Adipocytes ,Immunology and Allergy ,Animals ,Humans ,Mice, Knockout ,biology ,Systemic Inflammatory Response Syndrome ,Cell biology ,adipose tissue ,body regions ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,chemistry ,biology.protein ,Cytokines ,Cytokine secretion ,Tumor necrosis factor alpha ,Original Article ,medicine.symptom ,Inflammation Mediators ,C1q/TNF-related protein-3 ,Signal Transduction - Abstract
The anti-inflammatory adipokine CTRP-3 might affect innate immune reactions such as NOD1. The impact of CTRP-3 on NOD1-mediated inflammation in adipocytes and monocytic cells as well as on NOD1 expression was investigated. Murine 3T3-L1 pre-adipocytes and adipocytes as well as human THP-1 monocyte-like cells were co-stimulated with the synthetic NOD1 agonist Tri-DAP and recombinant CTRP-3. Gonadal adipose tissue and primary adipocytes were obtained from a murine model carrying a knockout (KO) of CTRP-3 in adipocytes but not in stroma-vascular cells. Wildtype mice with lipopolysaccharide (LPS)-induced elevated NOD1 expression were treated with CTRP-3. Secreted inflammatory cytokines in cell supernatants were measured by ELISA and mRNA levels were quantified by RT-PCR. Pro-inflammatory chemokine and cytokine secretion (MCP-1, RANTES, TNFα) was induced by NOD1 activation in adipocytes and monocyte-like cells, and MCP-1 and RANTES release was effectively inhibited by pre-incubation of cells with CTRP-3. CTRP-3 also antagonized LPS-triggered induction of NOD1 gene expression in murine adipose tissue, whereas adipocyte CTRP-3 deficiency upregulated NOD1 expression in adipose tissue. CTRP-3 is an effective antagonist of peptidoglycan-induced, NOD1-mediated inflammation and of LPS-induced NOD1 expression. Since basal NOD1 expression is increased by adipocyte CTRP-3 deficiency, there have to be also inflammation-independent mechanisms of NOD1 expression regulation by CTRP-3.
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- 2021
3. Succession of Dung-Inhabiting Beetles and Flies Reflects the Succession of Dung-Emitted Volatile Compounds
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Martin Konvicka, Irmgard Schäffler, Stefan Dötterl, Frantisek Xaver Jiri Sladecek, and Simon T. Segar
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0106 biological sciences ,Entomology ,Ecology ,media_common.quotation_subject ,fungi ,food and beverages ,General Medicine ,Insect ,Ecological succession ,Biology ,01 natural sciences ,Biochemistry ,Decomposer ,010602 entomology ,chemistry.chemical_compound ,Habitat ,chemistry ,Carrion ,Dimethyl trisulfide ,Cow dung ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany ,media_common - Abstract
Chemical cues, such as volatile organic compounds (VOCs), are often essential for insects to locate food. Relative to the volume of studies on the role of VOCs in insect-plant relationships, the role of VOCs emitted by dung and carrion in mediating the behavior of insect decomposers is understudied. Such relationships may provide a mechanistic understanding of the temporal axis of community assembly processes in decomposing insect communities. We focused on the temporal succession of volatiles released by cow dung pats and the potential influence on dung-inhabiting insects. Using gas chromatography/mass spectrometry we identified and quantified VOCs released from dung 1-h, and 1, 2 3, 5, and 7 d-old. We then related changes in VOCs to successional patterns of dung-inhabiting beetles and flies. We detected 54 VOCs which could be assigned to two successional groups, with chemical turnover in dung changing around day 2. The early successional group consisted primarily of aliphatic alcohols and phenols, and the late one of aliphatic esters, nitrogen- and sulfur-bearing compounds. Flies were predominately associated with the early successional group, mainly with 1-butanol. Beetles were associated predominately with the late-successional group, mainly with dimethyl trisulfide. This association between insect and chemical successional patterns supports the idea that habitat filtering drives the community assembly of dung-inhabiting insects on an aging resource. Moreover, the affinity of both insect groups to specific VOC groups provides a mechanistic explanation for the predictability of successional patterns found in dung-inhabiting insect communities.
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- 2021
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4. Regulation of CAMP (cathelicidin antimicrobial peptide) expression in adipocytes by TLR 2 and 4
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Thomas Karrasch, Andreas Schmid, Alexandra Höpfinger, and Andreas Schäffler
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Lipopolysaccharides ,Male ,STAT3 Transcription Factor ,lcsh:Immunologic diseases. Allergy ,0301 basic medicine ,MAPK/ERK pathway ,LPS ,Immunology ,Adipose tissue ,Microbiology ,Cell Line ,Lipopeptides ,Mice ,Phosphatidylinositol 3-Kinases ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Cathelicidins ,Toll-like receptor ,Adipocyte ,Gene expression ,Adipocytes ,Animals ,cathelicidin antimicrobial peptide ,Gonads ,Molecular Biology ,Sex Characteristics ,Chemistry ,Original Articles ,Cell Biology ,Toll-Like Receptor 2 ,adipose tissue ,Cell biology ,Toll-Like Receptor 4 ,TLR2 ,MALP-2 ,030104 developmental biology ,Infectious Diseases ,Gene Expression Regulation ,TLR4 ,Female ,Signal transduction ,lcsh:RC581-607 ,Signal Transduction ,030215 immunology - Abstract
Recent data argue for a pro-inflammatory role of CAMP (cathelicidin antimicrobial peptide) in adipocytes and adipose tissue (AT) and for regulatory circuits involving TLRs. In order to investigate regulatory effects of TLR2 and TLR4, 3T3-L1 adipocytes were stimulated with TLR2 agonistic lipopeptide MALP-2 and with TLR4 agonist LPS in presence or absence of signal transduction inhibitors. CAMP gene expression was analysed by quantitative real-time PCR in adipocytes and in murine AT compartments and cellular subfractions. CAMP expression was higher in gonadal than in subcutaneous AT and there was a gender-specific effect with higher levels in males. Adipocytes had higher CAMP expression than the stroma-vascular cell (SVC) fraction. MALP-2 up-regulated CAMP expression significantly, mediated by STAT3 and PI3K and potentially (non-significant trend) by NF-κB and MAPK, but not by raf-activated MEK-1/-2. Moreover, LPS proved to act as a potent inducer of CAMP via NF-κB, PI3K and STAT3, whereas specific inhibition of MAPK and MEK-1/-2 had no effect. In conclusion, activation of TLR2 and TLR4 by classical ligands up-regulates adipocyte CAMP expression involving classical signal transduction elements. These might represent future drug targets for pharmacological modulation of CAMP expression in adipocytes, especially in the context of metabolic and infectious diseases.
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- 2021
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5. Serum Levels and Adipose Tissue Gene Expression of Cathelicidin Antimicrobial Peptide (CAMP) in Obesity and During Weight Loss
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Marissa Patz, Alexandra Hochberg, Andreas Schäffler, Thomas Karrasch, and Andreas Schmid
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0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Cathelicidin antimicrobial peptide ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,bariatric surgery ,Clinical Biochemistry ,Adipokine ,Adipose tissue ,030209 endocrinology & metabolism ,Biology ,adipocyte ,Biochemistry ,Cohort Studies ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Endocrinology ,Downregulation and upregulation ,Cathelicidins ,Internal medicine ,Adipocyte ,Gene expression ,Weight Loss ,medicine ,Adipocytes ,Animals ,Humans ,Longitudinal Studies ,Obesity ,Innate immune system ,Endocrine Care ,Insulin ,Biochemistry (medical) ,General Medicine ,Metabolism ,Middle Aged ,adipose tissue ,Obesity, Morbid ,030104 developmental biology ,chemistry ,NIH 3T3 Cells ,diet ,Antimicrobial Cationic Peptides - Abstract
CAMP (Cathelicidin antimicrobial peptide) is synthesized and secreted by adipocytes and involved in adipose tissue (AT) innate immune response and host defense of subcutaneous AT against Gram positive bacteria. Data on the regulation of CAMP in obesity and during weight loss are scarce and reference values do not exist. Serum CAMP levels (ELISA) and AT gene expression levels (quantitative real time PCR) were investigated in two large and longitudinal (12 months) cohorts of severely obese patients undergoing either a low calorie diet (LCD; n=79) or bariatric surgery (BS; n=156). The impact of metabolic factors on CAMP expression in vitro was investigated in differentiated 3T3-L1 adipocytes. CAMP serum levels significantly increased after BS but not during LCD. Females had lower CAMP serum levels and lower gene expression levels in subcutaneous AT. CAMP was positively correlated to unfavorable metabolic factors/adipokines and negatively to favorable factors/adipokines. CAMP gene expression was higher in subcutaneous than in visceral AT but serum CAMP levels were not correlated to levels of AT gene expression. While certain bile acids upregulated CAMP expression in vitro, high glucose/insulin as well as GLP-1 had an inhibitory effect. There exist gender-specific and AT compartment-specific effects on the regulation of CAMP gene expression. Weight loss induced by BS (but not by LCD) upregulated CAMP serum levels suggesting the involvement of weight loss-independent mechanisms in CAMP regulation such as bile acids, incretins and metabolic factors. CAMP might represent an adipokine at the interface between metabolism and innate immune response.
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- 2021
6. Moisture Absorption and Desorption in an Ionomer-Based Encapsulant: A Type of Self-Breathing Encapsulant for CIGS Thin-Film PV Modules
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Tobias Repmann, Miao Yang, Raymund Schäffler, and Kay Orgassa
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Environmental Engineering ,Materials science ,General Computer Science ,Materials Science (miscellaneous) ,General Chemical Engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,Cu(In,Ga)Se2 photovoltaic module ,01 natural sciences ,chemistry.chemical_compound ,Encapsulant ,Desorption ,Relative humidity ,Moisture absorption and desorption ,Composite material ,Thin film ,Ionomer ,Moisture ,General Engineering ,Humidity ,021001 nanoscience & nanotechnology ,Equilibrium moisture content ,Copper indium gallium selenide solar cells ,0104 chemical sciences ,chemistry ,lcsh:TA1-2040 ,0210 nano-technology ,lcsh:Engineering (General). Civil engineering (General) - Abstract
As an alternative to conventional encapsulation concepts for a double glass photovoltaic (PV) module, we introduce an innovative ionomer-based multi-layer encapsulant, by which the application of additional edge sealing to prevent moisture penetration is not required. The spontaneous moisture absorption and desorption of this encapsulant and its raw materials, poly (ethylene-co-acrylic acid) and an ionomer, are analyzed under different climatic conditions in this work. The relative air humidity is thermodynamically the driving force for these inverse processes and determines the corresponding equilibrium moisture content (EMC). Higher air humidity results in a larger EMC. The homogenization of the absorbed water molecules is a diffusion-controlled process, in which temperature plays a dominant role. Nevertheless, the diffusion coefficient at a higher temperature is still relatively low. Hence, under normal climatic conditions for the application of PV modules, we believe that the investigated ionomer-based encapsulant can “breathe” the humidity: During the day, when there is higher relative humidity, it “inhales” (absorbs) moisture and restrains it within the outer edge of the module; then at night, when there is a lower relative humidity, it “exhales” (desorbs) the moisture. In this way, the encapsulant protects the cell from moisture ingress.
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- 2020
7. Honeybee Pollinators Use Visual and Floral Scent Cues to Find Apple (Malus domestica) Flowers
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Stefan Dötterl, Guaraci Duran Cordeiro, Irmgard Schäffler, and Melanie Rachersberger
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0106 biological sciences ,Attractiveness ,Malus ,010401 analytical chemistry ,Olfactory cues ,General Chemistry ,Biology ,biology.organism_classification ,01 natural sciences ,Attraction ,0104 chemical sciences ,Crop ,chemistry.chemical_compound ,Linalool ,chemistry ,Pollinator ,Floral scent ,Botany ,General Agricultural and Biological Sciences ,010606 plant biology & botany - Abstract
Apple flowers of most varieties require pollinator-mediated cross-pollination. However, little is known about the cues used by pollinators to find the flowers. We used bioassays to investigate the importance of visual and olfactory cues for the attraction of honeybee pollinators to apple flowers. Chemical-analytical and electrophysiological approaches were used to determine floral scents and investigate antennal responses of honeybees to scents from flowering twigs. Bioassays showed that visual and olfactory cues were equally important for the attraction of honeybees to apple flowers. Floral scents were dominated by aromatic components, mainly benzyl alcohol, and the antennae of honeybees responded to a large number of components, among them to benzyl alcohol, linalool, and indole. Our study aims to better understand how this important fruit crop communicates with its main pollinators. This knowledge might be used to improve the attractiveness of apple flowers to pollinators to optimize fruit sets.
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- 2019
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8. On the State and Stability of Fuel Cell Catalyst Inks
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Shalmali Bapat, Michael Schäffler, Christopher Giehl, Volker Peinecke, Sebastian Kohsakowski, and Doris Segets
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chemistry.chemical_classification ,Materials science ,General Chemical Engineering ,Sonication ,Chemie ,Proton exchange membrane fuel cell ,Polymer ,Electrolyte ,Catalysis ,Membrane ,Maschinenbau ,Chemical engineering ,chemistry ,Mechanics of Materials ,Coated membrane ,Dispersion (chemistry) - Abstract
Catalyst layers (CL), as an active component of the catalyst coated membrane (CCM), form the heart of the proton electrolyte membrane fuel cell (PEMFC). For optimum performance of the fuel cell, obtaining suitable structural and functional characteristics for the CL is crucial. Direct tuning of the microstructure and morphology of the CL is non-trivial; hence catalyst inks as CL precursors need to be modulated, which are then applied onto a membrane to form the CCM. Obtaining favorable dispersion characteristics forms an important prerequisite in engineering catalyst inks for large scale manufacturing. In order to facilitate a knowledge-based approach for developing fuel cell inks, this work introduces new tools and methods to study both the dispersion state and stability characteristics, simultaneously. Catalyst inks were prepared using different processing methods, which include stirring and ultrasonication. The proposed tools are used to characterize and elucidate the effects of the processing method. Structural characterization of the dispersed particles and their assemblages was carried out by means of transmission electron microscopy. Analytical centrifugation (AC) was used to study the state and stability of the inks. Herein, we introduce new concepts, S score, and stability trajectory, for a time-resolved assessment of inks in their native state using AC. The findings were validated and rationalized using transmittograms as a direct visualization technique. The flowability of inks was investigated by rheological measurements. It was found that probe sonication only up to an optimum amplitude leads to a highly stable colloidal ink.
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- 2021
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9. Loss of Mucosal p32/gC1qR/HABP1 Triggers Energy Deficiency and Impairs Goblet Cell Differentiation in Ulcerative Colitis
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Dominik Bettenworth, Anne G. Savitt, Annika Raschdorf, Berhane Ghebrehiwet, Annika Sünderhauf, Stefanie Derer, Holger Schäffler, Ellinor I.B. Peerschke, Kerstin Skibbe, Misa Hirose, Heidi Schlichting, Maren Hicken, Christian Sina, Saleh M. Ibrahim, Mohab Ragab, Arne Bokemeyer, and Sven Perner
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0301 basic medicine ,Male ,Colon ,Cellular differentiation ,Crypt ,RC799-869 ,Oxidative phosphorylation ,Inflammatory bowel disease ,Pathogenesis ,Mitochondrial Proteins ,03 medical and health sciences ,Mice ,0302 clinical medicine ,medicine ,Tumor Cells, Cultured ,Gene silencing ,Animals ,Humans ,C1QBP ,Mucus Barrier ,Goblet cell ,Hepatology ,Chemistry ,Inflammatory Bowel Disease ,Gastroenterology ,Cell Differentiation ,Diseases of the digestive system. Gastroenterology ,respiratory system ,medicine.disease ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Mitochondrial respiratory chain ,Editorial ,Cancer research ,030211 gastroenterology & hepatology ,Colitis, Ulcerative ,Goblet Cells ,Carrier Proteins ,Mitochondrial Function - Abstract
Background & Aims Cell differentiation in the colonic crypt is driven by a metabolic switch from glycolysis to mitochondrial oxidation. Mitochondrial and goblet cell dysfunction have been attributed to the pathology of ulcerative colitis (UC). We hypothesized that p32/gC1qR/HABP1, which critically maintains oxidative phosphorylation, is involved in goblet cell differentiation and hence in the pathogenesis of UC. Methods Ex vivo, goblet cell differentiation in relation to p32 expression and mitochondrial function was studied in tissue biopsies from UC patients versus controls. Functional studies were performed in goblet cell-like HT29-MTX cells in vitro. Mitochondrial respiratory chain complex V-deficient, ATP8 mutant mice were utilized as a confirmatory model. Nutritional intervention studies were performed in C57BL/6 mice. Results In UC patients in remission, colonic goblet cell differentiation was significantly decreased compared to controls in a p32-dependent manner. Plasma/serum L-lactate and colonic pAMPK level were increased, pointing at high glycolytic activity and energy deficiency. Consistently, p32 silencing in mucus-secreting HT29-MTX cells abolished butyrate-induced differentiation and induced a shift towards glycolysis. In ATP8 mutant mice, colonic p32 expression correlated with loss of differentiated goblet cells, resulting in a thinner mucus layer. Conversely, feeding mice an isocaloric glucose-free, high-protein diet increased mucosal energy supply that promoted colonic p32 level, goblet cell differentiation and mucus production. Conclusion We here describe a new molecular mechanism linking mucosal energy deficiency in UC to impaired, p32-dependent goblet cell differentiation that may be therapeutically prevented by nutritional intervention.
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- 2020
10. Loss of p32 triggers energy deficiency and impairs goblet cell differentiation in ulcerative colitis
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Dominik Bettenworth, Arne Bokemeyer, Kerstin Skibbe, Ellinor I.B. Peerschke, Heidi Schlichting, Annika Raschdorf, Mohab Ragab, Misa Hirose, Sven Perner, Anne G. Savitt, Holger Schäffler, Berhane Ghebrehiwet, Maren Hicken, Stefanie Derer, Christian Sina, Saleh M. Ibrahim, and Annika Sünderhauf
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Goblet cell ,medicine.medical_specialty ,Chemistry ,Cellular differentiation ,Crypt ,Oxidative phosphorylation ,body regions ,Pathogenesis ,medicine.anatomical_structure ,Mitochondrial respiratory chain ,Endocrinology ,Internal medicine ,medicine ,Gene silencing ,Glycolysis - Abstract
Cell differentiation in the colonic crypt is driven by a metabolic switch from glycolysis to mitochondrial oxidation. Mitochondrial and goblet cell (GC) dysfunction have been attributed to the pathology of ulcerative colitis (UC). We hypothesized that p32/gC1qR/HABP1, which critically maintains oxidative phosphorylation, is involved in GC differentiation and hence in the pathogenesis of UC. In UC patients in remission, colonic GC differentiation was significantly decreased compared to controls in a p32-dependent manner. Plasma/serum lactate and colonic pAMPK level were increased, pointing at high glycolytic activity and energy deficiency. Consistently, p32 silencing in mucus-secreting HT29-MTX cells abolished butyrate-induced differentiation and induced a shift towards glycolysis. In mitochondrial respiratory chain complex V-deficient mice, colonic p32 expression correlated with loss of differentiated GCs, resulting in a thinner mucus layer. Conversely, feeding mice an isocaloric glucose-free, high-protein diet increased mucosal energy supply that promoted colonic p32 level, GC differentiation and mucus production. We here describe a new molecular mechanism linking mucosal energy deficiency in UC to impaired p32-dependent GC differentiation that may be therapeutically prevented by nutritional intervention.
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- 2020
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11. Glucocorticoids dexamethasone and prednisolone suppress fibroblast growth factor 23 (FGF23)
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Michael Föller, Jörg Strotmann, Martina Feger, Franz Ewendt, Philipp Glosse, Holger Schäffler, Gabriele I. Stangl, and Daniela Kempe-Teufel
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Fibroblast growth factor 23 ,Male ,medicine.medical_specialty ,Calcitriol ,Prednisolone ,030232 urology & nephrology ,Parathyroid hormone ,Phosphate ,urologic and male genital diseases ,Bone and Bones ,Dexamethasone ,Phosphates ,03 medical and health sciences ,Paracrine signalling ,Mice ,0302 clinical medicine ,Receptors, Glucocorticoid ,Internal medicine ,Cell Line, Tumor ,Drug Discovery ,medicine ,Animals ,Glucocorticoids ,Genetics (clinical) ,030304 developmental biology ,Inflammation ,0303 health sciences ,αKlotho ,Osteoblasts ,Chemistry ,Rats ,Fibroblast Growth Factors ,Mice, Inbred C57BL ,stomatognathic diseases ,Fibroblast Growth Factor-23 ,Mifepristone ,Renal Elimination ,Endocrinology ,Molecular Medicine ,1,25(OH)2D3 ,Female ,Original Article ,Renal phosphate excretion ,Glucocorticoid ,medicine.drug ,Hormone ,Signal Transduction - Abstract
Abstract Fibroblast growth factor 23 (FGF23) is a hormone mainly secreted by bone cells. Its most prominent effects are the regulation of renal phosphate reabsorption and calcitriol (active vitamin D, 1,25(OH)2D3) formation, effects dependent on its co-receptor αKlotho. Besides these actions, further paracrine and endocrine effects exist. The production of FGF23 is regulated by 1,25(OH)2D3, parathyroid hormone, dietary phosphate intake, iron status, as well as inflammation. Glucocorticoids are hormones with anti-inflammatory properties and are, therefore, widely used for acute and chronic inflammatory diseases, autoimmune disorders, and malignancies. The present study explored whether glucocorticoids influence the production of FGF23 in vitro as well as in mice. Fgf23 transcription was analyzed by semi-quantitative real-time PCR. Serum concentrations of FGF23 and 1,25(OH)2D3 were measured by ELISA. Urinary phosphate and Ca2+ excretion were determined in metabolic cages. As a result, in UMR106 rat osteoblast-like cells and in MC3T3-E1 cells, both, dexamethasone and prednisolone, downregulated Fgf23 transcription and FGF23 protein synthesis. Dexamethasone increased Dmp1 and Phex (encoding FGF23-regulating genes) as well as Nfkbia (encoding NFκB inhibitor IκBα) transcription in UMR106 cells. In mice, a single injection of dexamethasone or prednisolone was followed by a significant decrease of serum C-terminal and intact FGF23 concentration and bone Fgf23 mRNA expression within 12 h. These effects were paralleled by increased renal phosphate excretion and enhanced 1,25(OH)2D3 formation. We conclude that a single glucocorticoid treatment strongly downregulates the FGF23 plasma concentration. Key messages Glucocorticoids dexamethasone and prednisolone suppress the formation of bone-derived hormone fibroblast growth factor 23 (FGF23) in vitro. The effect is accompanied by an upregulation of Dmp1, Phex, and IκBα, negative regulators of FGF23, in UMR106 osteoblast-like cells. Glucocorticoid receptor antagonist RU-486 attenuates the effect of dexamethasone on FGF23, Dmp1, and Phex. In mice, a single glucocorticoid dose suppresses FGF23 and enhances 1,25(OH)2D3 (active vitamin D).
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- 2020
12. Polymer grafted graphitic carbon nitrides as precursors for reinforced lubricant hydrogels
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Florian Rummel, Baris Kumru, Bernhard V. K. J. Schmidt, Michael Schäffler, Valerio Molinari, and Markus Hilgart
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chemistry.chemical_classification ,Toughness ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Graphitic carbon nitride ,Bioengineering ,02 engineering and technology ,Polymer ,Nitride ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,chemistry.chemical_compound ,Lubricity ,chemistry ,Chemical engineering ,Self-healing hydrogels ,Lubricant ,0210 nano-technology ,Prepolymer - Abstract
Hydrogels constitute an important class of polymeric materials, mainly due to their promising applications in the biomedical field. Particularly, mechanical properties are a limiting factor for applications, and reinforcement and improved wear resistance are major directions in current research. In here, graphitic carbon nitride (g-CN)-based hydrogels are presented. The hydrogels are formed in a two-step procedure. In the first step, a prepolymer is synthesized that leads to a significantly improved g-CN dispersibility and stability of g-CN dispersions. Hence, the g-CN content in the final hydrogels can be increased to obtain tough hydrogels. More importantly, hydrogels from charged monomers can be formed as well, which leads to lubricant properties. As such, the investigated route opens up new opportunities to fabricate functional hydrogels with significant toughness, compressibility and lubricity.
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- 2019
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13. NOD2- and disease-specific gene expression profiles of peripheral blood mononuclear cells from Crohn’s disease patients
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Nicole Gittel, Sarah Rohde, Robert Jaster, Hannes Hollborn, Georg Lamprecht, Astrid Huth, Dirk Koczan, Maria Rohde, Änne Glass, and Holger Schäffler
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0301 basic medicine ,Disease specific ,Crohn’s disease ,Lysozyme ,CLEC5A ,Disease ,Peripheral blood mononuclear cell ,NOD2 ,03 medical and health sciences ,chemistry.chemical_compound ,Gene expression ,Medicine ,Crohn's disease ,business.industry ,Gastroenterology ,General Medicine ,Basic Study ,medicine.disease ,digestive system diseases ,030104 developmental biology ,chemistry ,Peripheral blood mononuclear cells ,Immunology ,business - Abstract
AIM To investigate disease-specific gene expression profiles of peripheral blood mononuclear cells (PBMCs) from Crohn’s disease (CD) patients in clinical remission. METHODS Patients with CD in clinical remission or with very low disease activity according to the Crohn’s disease activity index were genotyped regarding nucleotide-binding oligomerization domain 2 (NOD2), and PBMCs from wild-type (WT)-NOD2 patients, patients with homozygous or heterozygous NOD2 mutations and healthy donors were isolated for further analysis. The cells were cultured with vitamin D, peptidoglycan (PGN) and lipopolysaccharide (LPS) for defined periods of time before RNA was isolated and subjected to microarray analysis using Clariom S assays and quantitative real-time PCR. NOD2- and disease-specific gene expression profiles were evaluated with repeated measure ANOVA by a general linear model. RESULTS Employing microarray assays, a total of 267 genes were identified that were significantly up- or downregulated in PBMCs of WT-NOD2 patients, compared to healthy donors after challenge with vitamin D and/or a combination of LPS and PGN (P < 0.05; threshold: ≥ 2-fold change). For further analysis by real-time PCR, genes with known impact on inflammation and immunity were selected that fulfilled predefined expression criteria. In a larger cohort of patients and controls, a disease-associated expression pattern, with higher transcript levels in vitamin D-treated PBMCs from patients, was observed for three of these genes, CLEC5A (P < 0.030), lysozyme (LYZ; P < 0.047) and TREM1 (P < 0.023). Six genes were found to be expressed in a NOD2-dependent manner (CD101, P < 0.002; CLEC5A, P < 0.020; CXCL5, P < 0.009; IL-24, P < 0.044; ITGB2, P < 0.041; LYZ, P < 0.042). Interestingly, the highest transcript levels were observed in patients with heterozygous NOD2 mutations. CONCLUSION Our data identify CLEC5A and LYZ as CD- and NOD2-associated genes of PBMCs and encourage further studies on their pathomechanistic roles.
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- 2018
14. The adipokine C1q/TNF-related protein-3 (CTRP-3) inhibits Toll-like receptor (TLR)-induced expression of Cathelicidin antimicrobial peptide (CAMP) in adipocytes
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Alexandra Höpfinger, Andreas Schmid, Andreas Schäffler, and Thomas Karrasch
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Lipopolysaccharides ,Male ,Immunology ,Adipokine ,Adipose tissue ,Biology ,Models, Biological ,Biochemistry ,Mice ,chemistry.chemical_compound ,Adipokines ,3T3-L1 Cells ,Adipocyte ,Adipocytes ,Animals ,Immunology and Allergy ,Receptor ,Molecular Biology ,Mice, Knockout ,Toll-like receptor ,Toll-Like Receptors ,Hematology ,Systemic Inflammatory Response Syndrome ,Cell biology ,Mice, Inbred C57BL ,Disease Models, Animal ,TLR2 ,Adipose Tissue ,Gene Expression Regulation ,chemistry ,TLR3 ,TLR4 ,Transcriptome ,Antimicrobial Peptides - Abstract
Background and aim CAMP (Cathelicidin antimicrobial peptide) expression in adipocytes is regulated by Toll-like receptor (TLR) agonists. Secreted adipokines such as CTRP-3 have been suggested to participate in innate immune signaling in adipose tissue (AT). This study investigates whether TLR-induced CAMP expression in adipocytes is antagonized by CTRP-3. Methods 3T3-L1 adipocytes were co-stimulated with TLR agonists (LPS, MALP-2, Pam3CSK4, pI:C) and recombinant CTRP-3. In a SIRS model, C57BL/6 wild-type mice were intraperitoneally (ip) injected with recombinant CTRP-3 prior to LPS. CAMP expression was analyzed by real-time PCR in AT of wild-type mice and in AT and primary adipocytes from transgenic mice lacking adipocyte CTRP-3 expression. Comparative transcriptome analysis by RNA seq. was applied in CTRP-3 KO adipocytes. Results In vitro, CTRP-3 antagonized TLR4- and TLR1/2-induced CAMP expression in adipocytes whereas TLR3- and TLR2/6-mediated induction of CAMP was not affected. in vivo, application of exogenous CTRP-3 dose-dependently antagonized LPS-induced CAMP expression in intra-abdominal AT. CAMP expression in total AT and in primary adipocytes of subcutaneous and intra-abdominal AT did not differ between wild-type mice and transgenic mice lacking adipocyte CTRP-3 expression. Conclusions The study suggests a hypothetical role of CAMP in host defense not only against Gram-positive bacteria sensed by TLR1/2 and TLR2/6 but also against Gram-negative bacteria sensed by TLR4 and potentially against viruses sensed by TLR3. The machinery of TLR-mediated pro-inflammatory activation of the CAMP gene in adipocytes seems to be partly modulated by secreted adipokines belonging to the growing family of C1q/TNF-related proteins such as CTRP-3.
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- 2021
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15. Helium neutral beam injection into ASDEX Upgrade
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D. Rittich, Christian Hopf, J. Schäffler, J. Thalhammer, and ASDEX Upgrade Team, Max Planck Institute for Plasma Physics, Max Planck Society
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Jet (fluid) ,Materials science ,Mechanical Engineering ,Nuclear engineering ,chemistry.chemical_element ,Plasma ,Injector ,7. Clean energy ,01 natural sciences ,Neutral beam injection ,010305 fluids & plasmas ,law.invention ,Nuclear Energy and Engineering ,ASDEX Upgrade ,chemistry ,Getter ,law ,0103 physical sciences ,General Materials Science ,Atomic physics ,010306 general physics ,Beam (structure) ,Helium ,Civil and Structural Engineering - Abstract
ASDEX Upgrade's (AUG) neutral beam injection (NBI) system is primarily designed for deuterium injection and delivers 20 MW heating power from two injectors with four beams each at 60 and 93 keV, respectively. As opposed to the cryo pumps of the JET NBI, the Ti getter pumps of the AUG NBI with a pumping speed of 3 × 10 6 l/s for hydrogen do not pump helium at all, leaving only the conventional pumping system with 3 l/s for He. This imposes constraints on the possible operation in helium. In order to prepare for AUG He plasma campaigns, serious trials to operate the AUG NBI with He began in 2014. It was found that despite the lack of high speed pumping up to two beams per injector could be operated simultaneously at reduced feed gas flow without particular restrictions on the beam-on time. For injector 1 the power per beam was limited to 550 kW at 40 keV by the required filament current in its arc sources, while for injector 2 the limitation came from the bending magnet's power supply that restricted the beam energy to 68 keV and the NBI power to 730 kW per beam. Thus the maximum available NBI heating power in He amounts to 2.6 MW for 10 s, the maximum discharge duration of AUG. Helium neutral beam injection into plasma was first tried out in 2014 for two discharges. In 2015 a dedicated He campaign used He NBI in a total of 44 discharges. As He is almost not pumped in the injectors the neutral gas flow into the torus is comparable with the total He gas puff.
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- 2017
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16. Interpopulation variation in pollinators and floral scent of the lady’s-slipper orchid Cypripedium calceolus L
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Herbert Braunschmid, Stefan Dötterl, Daniele Birtele, Bernadette Mükisch, Thomas Rupp, Pietro Zito, and Irmgard Schäffler
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0106 biological sciences ,Nomada ,Andrena ,Cypripedium calceolus ,Ecology ,biology ,biology.organism_classification ,medicine.disease_cause ,010603 evolutionary biology ,01 natural sciences ,Lasioglossum ,Electroantennography ,chemistry.chemical_compound ,Linalool ,chemistry ,Pollinator ,Insect Science ,Pollen ,Botany ,medicine ,Agronomy and Crop Science ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany - Abstract
Floral scent is a key mediator in many plant–pollinator interactions. It is known to vary not only among plant species, but also within species among populations. However, there is a big gap in our knowledge of whether such variability is the result of divergent selective pressures exerted by a variable pollinator climate or alternative scenarios (e.g., genetic drift). Cypripedium calceolus is a Eurasian deceptive lady’s-slipper orchid pollinated by bees. It is found from near sea level to altitudes of 2500 m. We asked whether pollinator climate and floral scents vary in a concerted manner among different altitudes. Floral scents of four populations in the Limestone Alps were collected by dynamic headspace and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Flower visitors and pollinators (the subset of visitors with pollen loads) were collected and identified. Preliminary coupled gas chromatographic and electroantennographic measurements with floral scents and pollinators revealed biologically active components. More than 70 compounds were detected in the scent samples, mainly aliphatics, terpenoids, and aromatics. Although several compounds were found in all samples, and all samples were dominated by linalool and octyl acetate, scents differed among populations. Similarly, there were strong differences in flower visitor spectra among populations with most abundant flower visitors being bees and syrphid flies at low and high altitudes, respectively. Pollinator climate differed also among populations; however, independent of altitude, most pollinators were bees of Lasioglossum, Andrena, and Nomada. Only few syrphids acted as pollinators and this is the first record of flies as pollinators in C. calceolus. The electrophysiological tests showed that bees and syrphid flies sensed many of the compounds released by the flowers, among them linalool and octyl acetate. Overall, we found that both floral scent and visitor/pollinator climate differ among populations. We discuss whether interpopulation variation in scent is a result of pollinator-mediated selection.
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- 2017
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17. Crystal Structure of a Variant PAM2 Motif of LARP4B Bound to the MLLE Domain of PABPC1
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C. Schneider, Jann Patrick Pelz, Katrin Schäffler, Clemens Grimm, and Utz Fischer
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Models, Molecular ,Amino Acid Motifs ,lcsh:QR1-502 ,PAM2 ,Crystallography, X-Ray ,Poly(A)-Binding Protein I ,Biochemistry ,DNA-binding protein ,lcsh:Microbiology ,Article ,03 medical and health sciences ,0302 clinical medicine ,Protein Domains ,PABPC1 ,Transcription (biology) ,Poly(A)-binding protein ,Humans ,Translation factor ,Molecular Biology ,Cells, Cultured ,030304 developmental biology ,0303 health sciences ,Messenger RNA ,PABC1 ,biology ,Poly(A) binding protein ,Chemistry ,Binding protein ,MLLE domain ,PAM2w ,Cell biology ,HEK293 Cells ,RNA Recognition Motif Proteins ,Ribonucleoproteins ,Cytoplasm ,ddc:540 ,biology.protein ,030217 neurology & neurosurgery ,PABP ,Protein Binding - Abstract
Eukaryotic cells determine the protein output of their genetic program by regulating mRNA transcription, localization, translation and turnover rates. This regulation is accomplished by an ensemble of RNA-binding proteins (RBPs) that bind to any given mRNA, thus forming mRNPs. Poly(A) binding proteins (PABPs) are prominent members of virtually all mRNPs that possess poly(A) tails. They serve as multifunctional scaffolds, allowing the recruitment of diverse factors containing a poly(A)-interacting motif (PAM) into mRNPs. We present the crystal structure of the variant PAM motif (termed PAM2w) in the N-terminal part of the positive translation factor LARP4B, which binds to the MLLE domain of the poly(A) binding protein C1 cytoplasmic 1 (PABPC1). The structural analysis, along with mutational studies in vitro and in vivo, uncovered a new mode of interaction between PAM2 motifs and MLLE domains.
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- 2020
18. Teduglutide Promotes Epithelial Tight Junction Pore Function in Murine Short Bowel Syndrome to Alleviate Intestinal Insufficiency
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Maria Witte, Georg Lamprecht, Johannes Reiner, Peggy Berlin, Karen Bannert, Brigitte Vollmar, Jakob Wobar, Holger Schäffler, Manuela Bastian, and Robert Jaster
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Short Bowel Syndrome ,medicine.medical_specialty ,Physiology ,Nod2 Signaling Adaptor Protein ,Teduglutide ,Intestinal absorption ,Tight Junctions ,chemistry.chemical_compound ,Mice ,Gastrointestinal Agents ,Internal medicine ,medicine ,Glucagon-Like Peptide 2 ,Animals ,Intestinal Mucosa ,Barrier function ,Mice, Inbred ICR ,Ussing chamber ,Tight junction ,Chemistry ,Gastroenterology ,Short bowel syndrome ,medicine.disease ,Small intestine ,Disease Models, Animal ,Endocrinology ,medicine.anatomical_structure ,Intestinal Absorption ,Paracellular transport ,Peptides - Abstract
In short bowel syndrome, epithelial surface loss results in impaired nutrient absorption and may lead to intestinal insufficiency or intestinal failure. Nucleotide oligomerization domain 2 (Nod2) dysfunction predisposes to the development of intestinal failure after intestinal resection and is associated with intestinal barrier defects. Epithelial barrier function is crucial for intestinal absorption and for intestinal adaptation in the short bowel situation. The aim of the study was to characterize the effects of the GLP-2 analogue Teduglutide in the small intestine in the presence and absence of Nod2 in a mouse model of short bowel syndrome. Mice underwent 40% ICR and were thereafter treated with Teduglutide versus vehicle injections. Survival, body weight, stool water, and sodium content and plasma aldosterone concentrations were determined. Intestinal and kidney tissue was examined with light and fluorescence microscopy, Ussing chamber studies and quantitative PCR in wild type and transgenic mice. Teduglutide reduced intestinal failure incidence in Nod2 k.o. mice. In wt mice, Teduglutide attenuated intestinal insufficiency as indicated by reduced body weight loss and lower plasma aldosterone concentrations, lower stool water content, and lower stool sodium losses. Teduglutide treatment was associated with enhanced epithelial paracellular pore function and enhanced claudin-10 expression in tight junctions in the villus tips, where it colocalized with sodium–glucose cotransporter 1 (SGLT-1), which mediates Na-coupled glucose transport. In the SBS situation, Teduglutide not only maximizes small intestinal mucosal hypertrophy but also partially restores small intestinal epithelial function through an altered distribution of claudin-10, facilitating sodium recirculation for Na-coupled glucose transport and water absorption.
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- 2019
19. Influence of Molybdenum Back Contact on the PID Effect for Cu(In,Ga)Se2 Solar Cell
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Wolfram Hempel, Dennis Mücke, Artan Ferati, Oliver Salomon, R. Schäffler, Gunar Kaune, Oliver Kiowski, Erwin Lotter, Anja Schneikart, Maximilian Becker, Thomas Walter, Ricardo Vidal Lorbada, Wolfram Witte, and Birgit Schröppel
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Materials science ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Substrate (electronics) ,Photovoltaic power generation ,Potential induced degradation ,7. Clean energy ,01 natural sciences ,law.invention ,photovoltaic ,Depletion region ,law ,0103 physical sciences ,Materials Chemistry ,EBIC-Verfahren ,sodium ,010302 applied physics ,GDOES ,Sodium ,Doping ,PID ,Surfaces and Interfaces ,CIGS ,021001 nanoscience & nanotechnology ,stability PV ,Copper indium gallium selenide solar cells ,Cathode ,CIGS-Solarzelle ,Surfaces, Coatings and Films ,Natrium ,EBIC ,chemistry ,Molybdenum ,Photovoltaic power systems ,Energías Renovables ,Fotovoltaik ,CV ,ddc:620 ,0210 nano-technology ,Layer (electronics) - Abstract
The authors investigated the effect of an applied high voltage (1 kV) across the thickness of a soda-lime glass substrate of Cu(In,Ga)Se2 (CIGS) thin-film solar cells. Two types of CIGS cells were tested, differing only in the deposition process of the molybdenum (Mo) back contact. Whilst one cell type was susceptible to potential induced degradation (PID), the other exhibited highly increased stability against PID. PID occurs for PID-susceptible cells after the transfer of a certain amount of charge through the soda-lime glass substrate when the Mo back contact of the cell operates as a cathode (negatively biased versus backside of the substrate). Capacitance&ndash, voltage and electron-beam-induced current measurements showed an enlarged space charge region expanding to the Mo back contact and a lowered doping density by a negative potential for PID-susceptible cells. Glow discharge optical emission spectroscopy (GDOES) revealed an accumulation of sodium (Na) in the solution-grown CdS buffer layer and a segregation on the surface of the ZnO:Al window layer for higher charges for PID-susceptible cells. Cells with increased PID immunity did not show an increase of Na for charges up to around 9 mC/cm², We demonstrate that it is possible to improve the PID stability of CIGS solar cells by modification of the molybdenum back contact.
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- 2019
20. Distinct Roles of Cuticular Aldehydes as Pheromonal Cues in Two Cotesia Parasitoids
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Ted C. J. Turlings, Hao Xu, Thomas Degen, Stefan Dötterl, Guoxin Zhou, Irmgard Schäffler, and Li Chen
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Male ,Nonanal ,Zoology ,Biochemistry ,Gas Chromatography-Mass Spectrometry ,Parasitoid ,chemistry.chemical_compound ,Sexual Behavior, Animal ,Animals ,Mating ,Sex Attractants ,Ecology, Evolution, Behavior and Systematics ,Aldehydes ,Volatile Organic Compounds ,biology ,fungi ,General Medicine ,biology.organism_classification ,Cotesia glomerata ,Attraction ,Hymenoptera ,chemistry ,Cotesia ,Sex pheromone ,Pheromone ,Female ,Cues - Abstract
Cuticular compounds (CCs) that cover the surface of insects primarily serve as protection against entomopathogens, harmful substances, and desiccation. However, CCs may also have secondary signaling functions. By studying the role of CCs in intraspecific interactions, we may advance our understanding of the evolution of pheromonal communication in insects. We previously found that the gregarious parasitoid, Cotesia glomerata (L.), uses heptanal as a repellent pheromone to help avoid mate competition among sibling males, whereas another cuticular aldehyde, nonanal, is part of the female-produced attractive sex pheromone. Here, we show that the same aldehydes have different pheromonal functions in a related solitary parasitoid, Cotesia marginiventris (Cresson). Heptanal enhances the attractiveness of the female’s sex pheromone, whereas nonanal does not affect a female’s attractiveness. Hence, these common aldehydes are differentially used by the two Cotesia species to mediate, synergistically, the attractiveness of the main constituents of their respective sex pheromones. The specificity of the complete sex pheromone blend is apparently regulated by two specific, less volatile compounds, which evoke strong electroantennographic (EAG) responses. This is the first demonstration that volatile CCs have evolved distinct pheromonal functions to aid divergent mating strategies in closely related species. We discuss the possibility that additional compounds are involved in attraction and that, like the aldehydes, they are likely oxidative products of unsaturated cuticular hydrocarbons.
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- 2019
21. Characterization and ex vivo expansion of rare in situ cytokine secreting T cell populations from tumor tissue and blood of oral squamous cell carcinoma patients
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Petra Hoffmann, Irina Fink, Rüdiger Eder, Birgitta Ott-Rötzer, Heiko Smetak, Torsten E. Reichert, Katharina Schäffler, Slava Stamova, Philipp Beckhove, and Gerrit Spanier
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Adult ,Male ,0301 basic medicine ,medicine.medical_treatment ,T cell ,Immunology ,Cell Separation ,CD8-Positive T-Lymphocytes ,Interferon-gamma ,03 medical and health sciences ,Lymphocytes, Tumor-Infiltrating ,0302 clinical medicine ,Cancer immunotherapy ,Antigens, Neoplasm ,medicine ,Humans ,Immunology and Allergy ,Cells, Cultured ,Aged ,Cell Proliferation ,Squamous Cell Carcinoma of Head and Neck ,Tumor Necrosis Factor-alpha ,Chemistry ,T-Lymphocytes, Helper-Inducer ,Immunotherapy ,Middle Aged ,Phenotype ,030104 developmental biology ,medicine.anatomical_structure ,Cytokine ,Cell culture ,Cancer research ,Female ,Mouth Neoplasms ,Immunologic Memory ,Memory T cell ,CD8 ,Ex vivo ,030215 immunology - Abstract
Rare subpopulations of tumor antigen-reactive memory T cells, which actively secrete type-1 effector cytokines, particularly TNF-α in situ, possess anti-tumor activity and prognostic relevance. These cells are relevant for cancer immunotherapy; however, their low frequencies make them difficult to study and novel protocols for their culture and expansion ex vivo are needed. Here, we studied the presence of T cells secreting type-1 cytokines (Cy+T cells) in the blood and tumors of 24 patients with oral squamous cell carcinomas (OSCC) and explored possibilities for their isolation and expansion. More than 90% of OSCC patients contained enriched numbers Cy+T cells in the blood and tumors compared to healthy donors in which these were hardly detectable. The majority of TNF-α+T cells were CD4+ T helper cells while IFN-γ+TIL were predominantly CD8+. Cy+T helper cells in the blood were early-differentiated memory T cells while Cy+TIL and Cy+CD8+T cells showed advanced-differentiated memory T cell phenotypes. We explored different conditions for their in vitro culture and found that Cy+T cells can be efficiently expanded in vitro to similar levels as Cy-T cells and after expansion maintained their TNF-α secreting capacity. However, for optimal expansion they required specific culture conditions to support the maintenance of stem-like and central memory T cell phenotype. In conclusion, we show that Cy+T cells are enriched in OSCC patients and report a novel cell culture protocol optimized to specifically expand and functionally maintain these cells for further functional characterization or for their exploitation in immunotherapy of OSCC.
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- 2021
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22. CTRP-3 is permeable to the blood-brain barrier and is not regulated by glucose or lipidsin vivo
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Andreas Schäffler, Thomas Karrasch, Martin Berghoff, Alexandra Hochberg, and Andreas Schmid
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Adult ,Male ,0301 basic medicine ,medicine.medical_specialty ,Cell Membrane Permeability ,Adolescent ,Clinical Biochemistry ,Adipokine ,Adipose tissue ,030209 endocrinology & metabolism ,Stimulation ,Biology ,Blood–brain barrier ,Biochemistry ,Cohort Studies ,Mice ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Cerebrospinal fluid ,3T3-L1 Cells ,Adipocyte ,Internal medicine ,Adipocytes ,medicine ,Animals ,Humans ,Glucose tolerance test ,medicine.diagnostic_test ,General Medicine ,Middle Aged ,Lipids ,Glucose ,030104 developmental biology ,medicine.anatomical_structure ,Endocrinology ,Postprandial ,Gene Expression Regulation ,chemistry ,Blood-Brain Barrier ,Case-Control Studies ,Tumor Necrosis Factors ,Female ,Biomarkers - Abstract
Background C1q/TNF-related protein-3 (CTRP-3) represents a novel anti-inflammatory and anti-diabetic adipokine secreted by adipose tissue. The physiological and postprandial regulation of CTRP-3 remains obscure and it is not known whether CTRP-3 is permeable to the brain Aim The postprandial regulation of CTRP-3 during an oral glucose tolerance test (n=100) and an oral lipid tolerance test (n=100) in humans was investigated. Moreover, CTRP-3 concentrations were measured in paired serum and cerebrospinal fluid (CSF) samples of patients (n=270) undergoing neurological evaluation. The expression of CTRP-3 mRNA was investigated in adipocytes upon stimulation with glucose, sex hormones and a broad panel of fatty acids Material and methods Serum and CSF CTRP-3 concentrations were measured by ELISA. 3T3-L1 adipocytes were used for stimulation experiments. CTRP-3 mRNA expression was quantified by using real-time PCR analysis Results CTRP-3 is present in human cerebrospinal fluid with a mean CSF/serum ratio of 110 + 64 x 10-3. CTRP-3 is not regulated postprandially by carbohydrates or lipids in the healthy state. Females have slightly higher levels of CTRP-3 when compared to males. A significant and positive correlation of CTRP-3 to LDL cholesterol serum levels is reproducible in several cohorts and deserves further mechanistic investigation. Whereas glucose concentrations do not influence CTRP-3 mRNA expression in 3T3-L1 adipocytes in vitro, fatty acids differentially modulate CTRP-3 expression Conclusions The novel adipokine CTRP-3 is detectable in human cerebrospinal fluid (proof of principle). Due to its blood-brain-barrier permeability, CTRP-3 represents a novel putative candidate for a physiological regulator molecule affecting central nervous functions. This article is protected by copyright. All rights reserved.
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- 2017
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23. Innate Immunity of Adipose Tissue in Rodent Models of Local and SystemicStaphylococcus aureusInfection
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Miriam Thomalla, Thomas Karrasch, Andreas Schmid, Jutta Schlegel, Bernd Salzberger, Frank Hanses, and Andreas Schäffler
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0301 basic medicine ,Innate immune system ,Article Subject ,Adipose tissue macrophages ,Immunology ,Adipose tissue ,Cell Biology ,Biology ,Systemic inflammation ,medicine.disease_cause ,Proinflammatory cytokine ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,TLR2 ,030104 developmental biology ,chemistry ,Staphylococcus aureus ,Adipocyte ,lcsh:Pathology ,medicine ,medicine.symptom ,lcsh:RB1-214 - Abstract
Background. The role of adipose tissue in systemic inflammation during bacterial infection is unclear. Effects ofStaphylococcus aureusinfection on adipocytes in rodent models of experimental endocarditis and peritonitis, the impact ofS. aureusinfection on gene expression in epididymal and subcutaneous adipose tissue, and effects ofS. aureusinfection on the toll-like receptor-2- (TLR2-) cathelicidin pathway in vivo and in vitro were investigated.Material and methods.The rat model of catheter-inducedS. aureusendocarditis and the mouse model ofS. aureus-induced peritonitis were used for infection experiments, gene expression profiling in adipose tissue, and measurement of cytokines. 3T3-L1 adipocytes were analyzed for expression of the TLR2-cathelicidin pathway.Results. Upon systemic bacterial infection byS. aureus, there is a shift from anti- to proinflammatory cytokines in serum and in adipose tissue gene expression. The TLR2-cathelicidin pathway is increasingly expressed during adipocyte differentiation in vitro and is induced upon stimulation by synthetic lipopeptides.Conclusions. Systemic infection by Gram-positive bacteria induces proinflammatory transformation of adipose tissue sites distinct from infection sites, documented on the levels of gene expression and secreted mediators. The TLR2-cathelicidine pathway is expressed and highly inducible in adipocytes in vitro. Lipopeptides are important immune-modulators of adipocytes in both gene expression and protein secretion.
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- 2017
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24. Role of progranulin in adipose tissue innate immunity
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Andreas Schmid, Alexandra Hochberg, Thomas Karrasch, Jonas Gehl, Frank Hanses, Andreas Schäffler, Anja Franziska Kreiß, Miriam Thomalla, and Marissa Patz
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0301 basic medicine ,Lipopolysaccharides ,Male ,Adipose tissue ,Biochemistry ,chemistry.chemical_compound ,Mice ,Phosphatidylinositol 3-Kinases ,0302 clinical medicine ,Progranulins ,Adipocyte ,Gene expression ,Adipocytes ,Immunology and Allergy ,Insulin ,Testosterone ,Phosphoinositide-3 Kinase Inhibitors ,Toll-like receptor ,Adipogenesis ,Estradiol ,Fatty Acids ,Toll-Like Receptors ,NF-kappa B ,Hematology ,Staphylococcal Infections ,Adipose Tissue ,030220 oncology & carcinogenesis ,Tumor necrosis factor alpha ,Female ,medicine.symptom ,medicine.medical_specialty ,Immunology ,Adipokine ,Inflammation ,Biology ,Peritonitis ,Bile Acids and Salts ,03 medical and health sciences ,Internal medicine ,mental disorders ,medicine ,Animals ,Molecular Biology ,Interleukin-6 ,Tumor Necrosis Factor-alpha ,Immunity, Innate ,Mice, Inbred C57BL ,TLR2 ,030104 developmental biology ,Endocrinology ,Glucose ,chemistry ,Gene Expression Regulation - Abstract
Regulation of progranulin in adipocytes and its role in inflammation is poorly understood. Aim: (i) to investigate regulation of progranulin in adipocyte differentiation and adipose tissue compartments, (ii) to address progranulin expression in two murine (C57BL/6) models of inflammation. Results: Progranulin expression was induced during adipocyte differentiation. Neither estradiol nor testosterone or metabolic stimuli such as glucose and insulin modified progranulin synthesis. Fatty acids, bile acids and incretins GLP-1 and GIP-1 exerted potent and differential effects on progranulin secretion. LPS, TNF and IL6 significantly increased progranulin secretion. TLR9 agonists decreased and TLR1/2, TLR3, TLR5, and TLR2/6 ligands increased progranulin expression. TLR3-mediated progranulin induction was abrogated by inhibitors of NF-κB and PI3K pathways. Progranulin expression between murine epididymal and subcutaneous adipose tissue did not differ in total adipose tissue, in isolated adipocytes or in the stromal-vascular cell fraction (SVC). However, SVC expressed significantly higher levels of progranulin than adipocytes at all sites. In adipocytes, female mice had significantly higher progranulin expression at all sites. An intra-peritoneal LPS challenge in mice did not affect adipose tissue progranulin expression, whereas peritoneal infection by S. aureus increased progranulin expression after 24 h. Conclusions: There are relevant sex-, site- and cell-specific effects on progranulin gene expression that is induced during adipocyte differentiation and modulated by various inflammatory and metabolic factors. Most importantly, ligands for TLR1/2 and TLR2/6 (recognizing S. aureus) in vitro and infection by S. aureus in vivo induce progranulin expression suggesting a role of adipocytes in protection against infection by gram-positive bacteria.
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- 2019
25. Quantitative biokinetics over a 28day period of freshly generated, pristine, 20 nm titanium dioxide nanoparticle aerosols in healthy adult rats after a single two-hour inhalation exposure
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Wolfgang G. Kreyling, Uwe Holzwarth, Carsten Schleh, Stephanie Hirn, Alexander Wenk, Martin Schäffler, Nadine Haberl, Manuela Semmler-Behnke, and Neil Gibson
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Time Factors ,Health, Toxicology and Mutagenesis ,02 engineering and technology ,Toxicology ,Rats, Inbred WKY ,Silver nanoparticle ,chemistry.chemical_compound ,Spark ignition generated titanium dioxide nanoparticle aerosols ,Tissue Distribution ,Lung ,Dissolution ,Titanium ,Inhalation exposure ,Inhalation Exposure ,0303 health sciences ,Inhalation ,Chemistry ,Re-entrainment from interstitium back to lung epithelium for clearance towards the larynx ,General Medicine ,021001 nanoscience & nanotechnology ,Translocation across air-blood-barrier ,3. Good health ,Characterization of physicochemical particle properties ,medicine.anatomical_structure ,Organ Specificity ,Intratracheal inhalation of freshly generated aerosols ,Female ,Accumulation in secondary organs and tissues ,0210 nano-technology ,Nanoparticle relocation into the interstitium ,Spark Ignition Generated Titanium Dioxide Nanoparticle Aerosols ,Characterization Of Physicochemical Particle Properties ,Intratracheal Inhalation Of Freshly Generated Aerosols ,Translocation Across Air-blood-barrier ,Accumulation In Secondary Organs ,Bronchoalveolar Lavage Fluid ,Metabolic Clearance Rate ,lcsh:Industrial hygiene. Industrial welfare ,Respiratory Mucosa ,Excretion ,03 medical and health sciences ,lcsh:RA1190-1270 ,medicine ,Animals ,Particle Size ,030304 developmental biology ,lcsh:Toxicology. Poisons ,Aerosols ,Research ,Radiochemistry ,Small intestine ,Rats ,Titanium dioxide ,Nanoparticles ,Long-term alveolar macrophage-mediated nanoparticle clearance ,lcsh:HD7260-7780.8 - Abstract
There is a steadily increasing quantity of silver nanoparticles (AgNP) produced for numerous industrial, medicinal and private purposes, leading to an increased risk of inhalation exposure for both professionals and consumers. Particle inhalation can result in inflammatory and allergic responses, and there are concerns about other negative health effects from either acute or chronic low-dose exposure. To study the fate of inhaled AgNP, healthy adult rats were exposed to 1½-hour intra-tracheal inhalations of pristine 105Ag-radiolabeled, 20 nm AgNP aerosols (with mean doses across all rats of each exposure group of deposited NP-mass and NP-number being 13.5 ± 3.6 μg, 7.9 ± 3.2•1011, respectively). At five time-points (0.75 h, 4 h, 24 h, 7d, 28d) post-exposure (p.e.), a complete balance of the [105Ag]AgNP fate and its degradation products were quantified in organs, tissues, carcass, lavage and body fluids, including excretions. Rapid dissolution of [105Ag]Ag-ions from the [105Ag]AgNP surface was apparent together with both fast particulate airway clearance and long-term particulate clearance from the alveolar region to the larynx. The results are compatible with evidence from the literature that the released [105Ag]Ag-ions precipitate rapidly to low-solubility [105Ag]Ag-salts in the ion-rich epithelial lining lung fluid (ELF) and blood. Based on the existing literature, the degradation products rapidly translocate across the air-blood-barrier (ABB) into the blood and are eliminated via the liver and gall-bladder into the small intestine for fecal excretion. The pathway of [105Ag]Ag-salt precipitates was compatible with auxiliary biokinetics studies at 24 h and 7 days after either intravenous injection or intratracheal or oral instillation of [110mAg]AgNO3 solutions in sentinel groups of rats. However, dissolution of [105Ag]Ag-ions appeared not to be complete after a few hours or days but continued over two weeks p.e. This was due to the additional formation of salt layers on the [105Ag]AgNP surface that mediate and prolonge the dissolution process. The concurrent clearance of persistent cores of [105Ag]AgNP and [105Ag]Ag-salt precipitates results in the elimination of a fraction > 0.8 (per ILD) after one week, each particulate Ag-species accounting for about half of this. After 28 days p.e. the cleared fraction rises marginally to 0.94 while 2/3 of the remaining [105Ag]AgNP are retained in the lungs and 1/3 in secondary organs and tissues with an unknown partition of the Ag species involved. However, making use of our previous biokinetics studies of poorly soluble [195Au]AuNP of the same size and under identical experimental and exposure conditions (Kreyling et al., ACS Nano 2018), the kinetics of the ABB-translocation of [105Ag]Ag-salt precipitates was estimated to reach a fractional maximum of 0.12 at day 3 p.e. and became undetectable 16 days p.e. Hence, persistent cores of [105Ag]AgNP were cleared throughout the study period. Urinary [105Ag]Ag excretion is minimal, finally accumulating to 0.016. The biokinetics of inhaled [105Ag]AgNP is relatively complex since the dissolving [105Ag]Ag-ions (a) form salt layers on the [105Ag]AgNP surface which retard dissolution and (b) the [105Ag]Ag-ions released from the [105Ag]AgNP surface form poorly-soluble precipitates of [105Ag]Ag-salts in ELF. Therefore, hardly any [105Ag]Ag-ion clearance occurs from the lungs but instead [105Ag]AgNP and nano-sized precipitated [105Ag]Ag-salt are cleared via the larynx into GIT and, in addition, via blood, liver, gall bladder into GIT with one common excretional pathway via feces out of the body.
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- 2019
26. Evidence of an anti-inflammatory toll-like receptor 9 (TLR 9) pathway in adipocytes
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Elena Neumann, Thomas Karrasch, Petra Ina Pfefferle, Miriam Thomalla, Ulf Müller-Ladner, Andreas Schäffler, and Andreas Schmid
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0301 basic medicine ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Adipose tissue ,Adipokine ,Gene Expression ,chemical and pharmacologic phenomena ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Endocrinology ,immune system diseases ,Internal medicine ,Adipocyte ,3T3-L1 Cells ,parasitic diseases ,medicine ,Adipocytes ,Animals ,Humans ,Adiponectin secretion ,Resistin ,Obesity ,Receptor ,Cells, Cultured ,Inflammation ,Gene knockdown ,Adiponectin ,Chemistry ,hemic and immune systems ,Cell Differentiation ,030104 developmental biology ,Adipose Tissue ,Oligodeoxyribonucleotides ,030220 oncology & carcinogenesis ,Toll-Like Receptor 9 ,RNA Interference ,Signal Transduction - Abstract
Adipocytes express various pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and actively participate in anti-bacterial and anti-viral host defence. Obesity is associated with adipose tissue PRR expression. The potential role of Toll-like receptor 9 (TLR9) in adipocytes has not yet been investigated. Here, we evaluated TLR9 expression during adipocyte differentiation (AD) of 3T3-L1 adipocytes, in primary murine adipocytes and in different murine and human adipose tissue depots by real-time PCR, immunocytochemistry and immunohistochemistry. TLR9 expression was inhibited using specific siRNA-mediated knockdown, and TLR9 signaling was induced using specific class A, B and C agonistic CpG-oligodeoxynucleotide (ODN) treatment vs ODN controls in 3T3-L1 adipocytes and in primary murine adipocytes from Tlr9wt/wt vs Tlr9−/− mice. We found that TLR9 gene expression is induced during AD and that TLR9 protein is expressed in murine gonadal and human visceral adipocytes. AD depends on intact TLR9 expression. Tlr9−/− mice demonstrate significantly reduced adiponectin serum levels, while siRNA-mediated TLR9 knockdown led to reduced adiponectin mRNA expression in adipocytes. TLR9 ligands (CpG-ODNs) inhibit pro-inflammatory resistin secretion in mature 3T3-L1 adipocytes. Tlr9−/− as compared to Tlr9wt/wt adipocytes exhibit increased resistin and MCP1 secretion and reduced adiponectin secretion into cell culture supernatants, while TLR9 ligands (ODNs) show differential effects in Tlr9−/− vs Tlr9wt/wt primary murine adipocytes. TLR9 expression is significantly increased in visceral compared to subcutaneous adipose tissue depots in non-diabetic obese patients and correlates with systemic resistin levels in a compartment-specific manner. Thus, adipocytic TLR9 is a putative, new protective factor during (obesity-associated) adipose tissue inflammation.
- Published
- 2018
27. Evidence of functional bile acid signaling pathways in adipocytes
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Thomas Karrasch, Jutta Schlegel, Miriam Thomalla, Andreas Schmid, and Andreas Schäffler
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0301 basic medicine ,Adult ,Lipopolysaccharides ,Male ,medicine.medical_specialty ,medicine.drug_class ,Lipolysis ,Adipocytes, White ,Glycocholic acid ,Adipose tissue ,Receptors, Cytoplasmic and Nuclear ,030209 endocrinology & metabolism ,Biochemistry ,Receptors, G-Protein-Coupled ,Bile Acids and Salts ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Endocrinology ,Adipokines ,Internal medicine ,Adipocyte ,3T3-L1 Cells ,medicine ,Animals ,Humans ,Receptor, Fibroblast Growth Factor, Type 1 ,Molecular Biology ,ATP Binding Cassette Transporter, Subfamily B, Member 11 ,Cells, Cultured ,Adiponectin ,Bile acid ,Chemistry ,Deoxycholic acid ,Cell Differentiation ,G protein-coupled bile acid receptor ,030104 developmental biology ,Gene Expression Regulation ,Female - Abstract
Background and aim Bile acids (BA) are increasingly recognized as pleiotropic and hormone-like signaling molecules with metabolic and endocrine functions. However, the role of BA in white adipocyte physiology remains somewhat obscure. It was the aim to investigate the BA receptors (FXR, TGR5) and FGFR1 (Fibroblast growth factor receptor 1) as well as Bsep (bile salt export pump) in white adipocytes and in murine and human adipose tissue (AT) and to investigate effects of different BA species in adipocyte physiology. Patients, material and methods Receptor mRNA expression was quantified by real-time PCR in mice, humans and during 3T3-L1 pre-adipocyte differentiation. Adipokines were measured by ELISA upon stimulation by several BA. Effects of BA on TNF- and LPS-induced MCP-1 secretion and lipolysis were analyzed. TNF-induced lipolysis was investigated by glycerol assay. Results The present data provide for the first time a detailed expression profile of FXR, TGR5, FGFR1, and Bsep during adipocyte differentiation and in murine and human AT. FGFR1 expression is upregulated in adipose tissue of LPS-injected animals. Several BA regulate secretion of adipokines such as adiponectin and resistin differentially. Importantly, TNF- and LPS-induced MCP-1 release from adipocytes as well as TNF-induced lipolysis can be antagonized by cholic acid (CA) and deoxycholic acid (DCA). Conclusions The present data provide evidence of functional BA signaling pathways in adipocytes and argue for certain MCP-1 related anti-inflammatory effects of BA in TNF- and LPS-induced inflammation, whereas pro-inflammatory resistin is induced by CA and glycocholic acid (GCA). Systemic bile acids might represent a hormonal network regulating white adipocyte physiology including lipolysis.
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- 2018
28. Regulation of natriuretic peptides postprandially in vivo and of their receptors in adipocytes by fatty acids in vitro
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Efthymia Arapogianni, Thomas Karrasch, Andreas Schmid, Jens Albrecht, Judith Brock, Maria Koukou, and Andreas Schäffler
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Adult ,Male ,medicine.medical_specialty ,medicine.drug_class ,Adipose tissue ,030209 endocrinology & metabolism ,Stimulation ,030204 cardiovascular system & hematology ,Biochemistry ,Cohort Studies ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Endocrinology ,Adipocyte ,Internal medicine ,3T3-L1 Cells ,medicine ,Natriuretic peptide ,Adipocytes ,Lipolysis ,Animals ,Humans ,Insulin ,RNA, Messenger ,Receptor ,Natriuretic Peptides ,Molecular Biology ,Glucose tolerance test ,medicine.diagnostic_test ,Fatty Acids ,Cell Differentiation ,Glucose Tolerance Test ,Postprandial Period ,Mice, Inbred C57BL ,Postprandial ,Glucose ,chemistry ,Adipose Tissue ,Gene Expression Regulation ,Female ,Receptors, Atrial Natriuretic Factor - Abstract
Background and aim Natriuretic peptides (NPs) and their receptors gain attention regarding adipocyte function. It was the aim to investigate the expression of natriuretic peptide receptors NPR-A, NPR-B and NPR-C during adipocyte differentiation (AD), upon stimulation with fatty acids (FA), and in murine and human adipose tissue depots (AT) of patients undergoing bariatric surgery (n = 44). Patients, material and methods The postprandial regulation of NT-proANP and NT-proBNP levels was measured by ELISA and was studied in two cohorts of healthy individuals undergoing an oral glucose tolerance test (OGTT) (n = 100) and an oral lipid tolerance test (OLTT) (n = 100). Adipocyte mRNA expression was investigated by quantitative real-time PCR. Results During AD, an early expression pattern could be described for NPR-C, a bimodal expression for NPR-B and a late expression pattern for NPR-A. NPR-A and NPR-B expression was high in epididymal and subcutaneous AT but low in peri-renal AT of mice. NPR-C showed a differential expression profile. FA stimulation caused a significant and differential regulation of NPRs in adipocytes. Serum NT-proANP and NT-proBNP concentrations did not change during OGTT, whereas NT-proANP significantly declined during OLTT. Basal NT-proANP and NT-proBNP concentrations were positively correlated with each other and with FGF-19 and FGF-21 levels. Conclusion Adipocytes and AT show a characteristic expression of NPRs. FA are able to regulate NPR expression differentially. There is a postprandial and negative regulation of serum NT-proANP concentrations after OLTT and of NPR-A after FA stimulation. Both effects could represent a novel hypothetical negative feedback mechanism on adipocyte lipolysis.
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- 2017
29. Short-term Regulation of Visfatin Release in vivo by Oral Lipid Ingestion and in vitro by Fatty Acid Stimulation
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Andreas Schmid, S Leszczak, I Ober, Thomas Karrasch, Andreas Schäffler, Andrea Kopp, J. Martin, and Margarita Bala
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Adult ,Blood Glucose ,Male ,medicine.medical_specialty ,Time Factors ,Adolescent ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Linoleic acid ,Adipose tissue ,Biology ,Palmitic acid ,Mice ,chemistry.chemical_compound ,Endocrinology ,3T3-L1 Cells ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Humans ,Insulin ,Palmitoleic acid ,Nicotinamide Phosphoribosyltransferase ,chemistry.chemical_classification ,C-Peptide ,Dose-Response Relationship, Drug ,Fatty Acids ,Fatty acid ,General Medicine ,Middle Aged ,Dietary Fats ,Oleic acid ,chemistry ,Cytokines ,Female ,Arachidonic acid - Abstract
Visfatin represents a new adipokine secreted by visceral adipose tissue and possibly regulating insulin sensitivity. Data on the regulation of visfatin are sparse and contradictory. Our study investigates the regulation of serum visfatin concentrations in healthy and non-diabetic subjects in response to the ingestion of a newly developed oral lipid solution (OLI) in vivo. Furthermore, the effects of a broad spectrum of fatty acids on adipocytic visfatin release were investigated in vitro. 100 (42 male and 58 female) healthy volunteers were included in the study. Anthropometric and laboratory parameters (lipoproteins, glucose, insulin, C-peptide) were measured after an overnight fast at 0 h and 2 h, 4 h, and 6 h after OLI. 3T3-L1 preadipocytes were differentiated into mature adipocytes and stimulated with increasing doses of 10 different fatty acids, and the release of visfatin into the supernatants was measured by ELISA. Serum triglycerides significantly rose after OLI. This was accompanied by a significant decrease of glucose, insulin and C-peptide. Serum visfatin levels significantly decreased after OLI. Fasting visfatin levels were negatively correlated with fasting glucose levels. Of the 5 saturated fatty acids tested, only palmitic acid exerted significant effects by strongly downregulating visfatin release by about 66%. The mono-unsaturated fatty acids palmitoleic acid and oleic acid exerted opposite effects decreasing/increasing visfatin release, respectively. Both of the poly-unsaturated fatty acids linoleic acid and arachidonic acid decreased visfatin release. Oral lipid ingestion is a physiological regulator of systemic visfatin release. Fatty acids differentially regulate visfatin release in vitro.
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- 2014
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30. 02.03 Influence of free fatty acids on osteoblasts and osteoclasts in rheumatic diseases
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Klaus W. Frommer, Elena Neumann, Markus Rickert, Ulf Müller-Ladner, Andreas Schäffler, Uwe Lange, Stefan Rehart, and Jürgen Steinmeyer
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musculoskeletal diseases ,030203 arthritis & rheumatology ,0301 basic medicine ,chemistry.chemical_classification ,medicine.medical_specialty ,Bone density ,biology ,business.industry ,Fatty acid ,Bone resorption ,Bone remodeling ,Proinflammatory cytokine ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Osteoclast ,RANKL ,Internal medicine ,biology.protein ,Osteocalcin ,Medicine ,business - Abstract
Background Increased amounts of visceral fat are often associated with lower bone density. Also, in obese patients an increased risk of osteoarthritis can be seen in non-weight bearing joints. Chronically elevated free fatty acid (FFA) levels as occurring in obesity may therefore also play a role in bone loss. We hence analysed if and how FFA influence cells of bone metabolism in rheumatic diseases. Methods Primary osteoblasts (OB) were isolated from cancellous bone of OA and RA patients undergoing knee joint surgery. Osteoclasts (OC) were differentiated from peripheral blood mononuclear cells (PBMC). OB and OC were stimulated with the saturated FFA palmitic acid (PA) and the unsaturated FFA linoleic acid (LA). Protein secretion was quantified by immunoassays, mRNA expression by real-time PCR. Mineralization activity was quantified using Alizarin Red S staining, differentiated OC were quantified by counting TRAP-positive multinuclear cells. Toll-like receptor (TLR) 4 and TLR2 were blocked by neutralising antibodies. Results Stimulation with PA or LA increased OB secretion of the proinflammatory cytokine IL6 (up to 9-fold ↑) and the chemokines IL-8 (up to 221-fold ↑), GRO-α (from below detection level to detectable levels) and MCP1 (up to 16-fold ↑). RANKL and OPG were not influenced by FFA on protein and mRNA level. In osteoblasts, activity (ALP/collagen type I) and differentiation markers (e.g. osteocalcin) as well as production of inorganic matrix were not altered by FFA stimulation. TLR4 but not TLR2 blockade significantly reduced PA-induced IL-8 secretion by OB. Secretion of IL-8 by RA OC was increased by FFA, while MMP-9 was reduced. The mRNA expression of osteoclast activity markers (CLCN7, CTSK, TCIRG) remained unchanged. However, the number of TRAP positive multinuclear cells formed from RA PBMC was decreased (by around 50%). Conclusions The pro-inflammatory effect of certain FFA on osteoblasts and osteoclasts may indirectly contribute to bone loss, while the reduction of mature OC after FFA stimulation suggests an inhibitory effect on bone resorption. In osteoblasts, FFA signalling is at least in part mediated by TLR4, but not by TLR2.
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- 2017
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31. Standardized ileal digestibility of amino acids in European soya bean and rapeseed products fed to growing pigs
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S Nenning, Rainer Mosenthin, Markus Wiltafsky, M Schäffler, C. Kaewtapee, Meike Eklund, and Pia Rosenfelder-Kuon
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0301 basic medicine ,Rapeseed ,Soya bean ,Swine ,Lysine ,03 medical and health sciences ,chemistry.chemical_compound ,Food Animals ,Ileum ,medicine ,Animals ,Food science ,Animal nutrition ,chemistry.chemical_classification ,Meal ,Methionine ,Cross-Over Studies ,Brassica rapa ,0402 animal and dairy science ,food and beverages ,04 agricultural and veterinary sciences ,Trypsin ,040201 dairy & animal science ,Animal Feed ,Amino acid ,Diet ,030104 developmental biology ,chemistry ,Animal Science and Zoology ,Animal Nutritional Physiological Phenomena ,Digestion ,Soybeans ,medicine.drug - Abstract
This study was conducted to determine the chemical composition and standardized ileal digestibility coefficients (SID) of crude protein (CP) and amino acids (AA) of European soya bean and rapeseed products in pigs. Six soya bean and two rapeseed products were used as the sole dietary source of CP and AA, including raw (FFSB) and roasted full-fat soya beans (FFSBRoasted ), soya bean (SBC) and rapeseed cake (RSC), and rapeseed meal (RSM) from Bavaria (Germany), soya bean meal (SBM) from the Danube region (Austria; SBMAustria ), a commercially available standard SBM (SBMStd ) and an imported genetically modified organism-free SBM (SBMGMO-free ). Eight ileal- cannulated pigs with an initial body weight of 32 ± 2 kg were allotted to a row-column design with eight diets and six periods of seven days each. Trypsin inhibitor activity (TIA) ranged from 1.8 in SBMStd to 24.5 mg/g DM in FFSB. The SID of CP and all AA in FFSBRoasted were greater than in FFSB, but lower when compared to SBC and SBMAustria (p < .05). The SID of CP and all AA (except glutamic acid) were not different between SBC and SBMAustria , but the SID of CP and all AA (except methionine) were greater (p < .05) in SBC than in SBMGMO-free . Furthermore, the SID of CP and most AA showed a quadratic response with decreasing TIA, and there exists a quadratic response in SID of CP and all AA with increasing lysine to CP ratio and neutral detergent insoluble nitrogen (p < .05). In conclusion, variation in chemical composition and SID of CP and AA was observed in different European soya bean and rapeseed products as influenced by differences in processing conditions. European SBC and SBMAustria can be used as alternative to imported SBMGMO-free and SBMStd in diets for growing pigs.
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- 2017
32. Colloidal Stability and Surface Chemistry Are Key Factors for the Composition of the Protein Corona of Inorganic Gold Nanoparticles
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Wolfgang G. Kreyling, Simon Ristig, Stefan Thalhammer, Martin Schäffler, Christian Pfeiffer, Matthias Epple, Jonas Hühn, Stefanie M. Hauck, Stephanie Hirn, Wolfgang J. Parak, Hakan Sarioglu, Pablo del Pino, Blair D Johnston, Nadine Haberl, and Manuela Semmler-Behnke
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endocrine system ,Chemie ,Nanoparticle ,Protein Corona ,02 engineering and technology ,Polyethylene glycol ,Conjugated system ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Biomaterials ,chemistry.chemical_compound ,Colloid ,chemistry ,Chemical engineering ,Colloidal gold ,Electrochemistry ,Surface modification ,Organic chemistry ,0210 nano-technology ,Citric acid - Abstract
To study the influence of colloidal stability on protein corona formation, gold nanoparticles are synthesized with five distinct surface modifications: coating with citric acid, bis(p-sulfonatophenyl)phenylphosphine dihydrate dipotassium salt, thiol-terminated methoxy-polyethylene glycol, dodecylamine-grafted poly(isobutylene-alt-maleic anhydride), and dodecylamine-grafted poly(isobutylene-alt-maleic anhydride) conjugated with polyethylene glycol. The nanoparticles are incubated with serum or bronchoalveolar lavage fluid from C57BL/6 mice (15 min or 24 h) to assess the effect of differential nanoparticle surface presentation on protein corona formation in the air–blood barrier exposure pathway. Proteomic quantification and nanoparticle size measurements are used to assess protein corona formation. We show that surface modification has a clear effect on the size and the composition of the protein corona that is related to the colloidal stability of the studied nanoparticles. Additionally, differences in the composition and size of the protein corona are shown between biological media and duration of exposure, indicating evolution of the corona through this exposure pathway. Consequently, a major determinant of protein corona formation is the colloidal stability of nanoparticles in biological media and chemical or environmental modification of the nanoparticles alters the surface presentation of the functional epitope in vivo. Therefore, the colloidal stability of nanoparticles has a decisive influence on nano–bio interactions.
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- 2017
33. Biodistribution of Inhaled Gold Nanoparticles in Mice and the Influence of Surfactant Protein D
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Neil Gibson, Stephanie Hirn, Wolfgang G. Kreyling, Uwe Holzwarth, Federica Simonelli, Carsten Schleh, Alexander Wenk, Martin Schäffler, and Winfried Möller
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Pulmonary and Respiratory Medicine ,Biodistribution ,Time Factors ,Metal Nanoparticles ,Pharmaceutical Science ,02 engineering and technology ,Pharmacology ,Mice ,03 medical and health sciences ,Drug Delivery Systems ,In vivo ,Administration, Inhalation ,Animals ,Tissue Distribution ,Pharmacology (medical) ,Pulmonary surfactant protein D ,Lung ,Aerosolization ,030304 developmental biology ,Aerosols ,0303 health sciences ,Inhalation ,Chemistry ,Surfactant protein D ,Pulmonary Surfactant-Associated Protein D ,021001 nanoscience & nanotechnology ,Mice, Inbred C57BL ,Mucociliary Clearance ,Colloidal gold ,Drug delivery ,Immunology ,Female ,Gold ,0210 nano-technology ,Bronchoalveolar Lavage Fluid - Abstract
The pulmonary route is very promising for drug delivery by inhalation. In this regard, nanoparticulate drug delivery systems are discussed, and one very promising nano carrier example is gold nanoparticles (Au NP). Directly after their deposition, inhaled Au NP come into contact with pulmonary surfactant protein D (SP-D). SP-D can agglomerate Au NP in vitro, and this may influence the clearance as well as the systemic translocation in vivo. The aim of the present study was to investigate the clearance and translocation of Au NP at a very early time point after inhalation, as well as the influence of SP-D.Aerosolized 20-nm radioactively labeled Au NP were inhaled by healthy adult female mice. One group of mice received dissolved 10 μg of SP-D by intratracheal instillation prior to the Au NP inhalation. After a 2-hr Au NP inhalation period, the mice were killed immediately, and the clearance and translocation to the blood stream were investigated.The highest amount of Au NP was associated with the lung tissue. In the bronchoalveolar lavage fluid (BALF), more Au NP remained free compared with the amount associated with the BALF cells. The amount of Au NP cleared by the mucociliary escalator was low, probably because of this very early time point. Instillation of SP-D prior to Au NP inhalation had no statistically significant effect on the biodistribution of the Au NP.Our data show that inhaled Au NP are retained in the mouse lungs and are translocated after a short time, and that SP-D has only a minor effect on Au NP translocation and clearance at a very early time point.
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- 2013
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34. Chemerin induces CCL2 and TLR4 in synovial fibroblasts of patients with rheumatoid arthritis and osteoarthritis
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Andreas Schäffler, Klaus W. Frommer, Christa Buechler, Elena Neumann, Ulf Müller-Ladner, Kristina Eisinger, Roland Walter, and Sabrina Bauer
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Male ,musculoskeletal diseases ,medicine.medical_specialty ,Chemokine ,Clinical Biochemistry ,Arthritis ,CMKLR1 ,Antibodies ,Pathology and Forensic Medicine ,Arthritis, Rheumatoid ,Cell Movement ,Internal medicine ,Synovitis ,Osteoarthritis ,Synovial Fluid ,medicine ,Humans ,Chemerin ,Synovial fluid ,RNA, Messenger ,Molecular Biology ,Cells, Cultured ,Chemokine CCL2 ,Cell Proliferation ,biology ,Fibroblast chemotaxis ,Chemistry ,Synovial Membrane ,Fibroblasts ,medicine.disease ,Up-Regulation ,Toll-Like Receptor 4 ,medicine.anatomical_structure ,Endocrinology ,Gene Expression Regulation ,biology.protein ,Intercellular Signaling Peptides and Proteins ,Receptors, Chemokine ,Chemokines ,Synovial membrane - Abstract
Introduction Chemerin stimulates migration of leukocytes to sites of inflammation and also increases inflammatory signaling in chondrocytes suggesting a function of chemerin in joint inflammation. Synovial fibroblasts (SF) are critically involved in synovitis and subsequent cartilage destruction. Here, we analyzed whether synovial fibroblasts express chemerin and its receptor CMKLR1. Further, the role of chemerin in synovial fibroblast chemotaxis, proliferation, insulin response and release of inflammatory proteins was studied. Methods Synovial tissue sections were labeled with chemerin antibody and chemerin was measured in synovial fluid by ELISA. Chemerin mRNA and protein as well as CMKLR1 expression were determined in SFs from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). Effects of chemerin on cytokines, chemokines and matrix metalloproteinases (MMP), and on proliferation, migration and insulin signaling were analyzed appropriately. Results SFs expressed CMKLR1 and chemerin mRNA, and chemerin protein was found in cell supernatants of synovial fibroblasts. Immunohistochemistry detected chemerin in synovial tissue predominantly localized within the lining layer. Chemerin was present in synovial fluids of RA, OA and psoriatic arthritis patients in similar concentrations. Chemerin neither increased IL-6 levels nor MMP-2 or − 9 activity in SFs. Also, it did not act as a chemoattractant for these cells. With respect to intracellular signaling, neither basal nor insulin-mediated phosphorylation of Akt was affected. However, chemerin significantly increased TLR4 mRNA and synthesis of CCL2 in SFs while CCL4 and − 5 were not altered. Cell proliferation of SFs, however, was modestly reduced by chemerin. Conclusions These data show that human SFs express both chemerin and its receptor. As chemerin enhanced expression of TLR4 and induced release of CCL2 in SFs, a role of this protein in innate immune system-associated joint inflammation is proposed.
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- 2012
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35. Additives for lubricants containing poly(tetrafluoroethylene). Part 1: Synthesis and rheological characterization
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D Lehmann, T Hoffmann, and M Schäffler
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Materials science ,Mechanical Engineering ,Fraction (chemistry) ,Surfaces and Interfaces ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Rheology ,Tetrafluoroethylene ,Irradiation ,Composite material ,Dispersion (chemistry) ,Phosphoric acid - Abstract
This article describes the synthesis of dispersions consisting of irradiated poly(tetrafluoroethylene) (PTFE) micropowder in an ester oil (Synative ES TMP 05) and presents their results of the characterization in terms of stability and rheology. The degree of PTFE micropowder in the dispersion was gradually increased from 10 wt% to 25 wt%. In addition, two additives based on phosphoric acid were used to study whether they are able to affect the properties of the dispersion with the lowest concentration of PTFE micropowder. The amount of irradiated PTFE micropowder affects the stability against separation. The dispersion with the lowest concentration of PTFE micropowder (10 wt%) showed the highest stability due to the pronounced high fine fraction of PTFE particles (Ø: 0.2–0.5 µm). On the other hand, the PTFE/oil dispersions with higher concentrations own a distinctive amount of greater particles (Ø: 0.3–3.0 µm), suggesting a negative influence on the stability of the dispersions. Nevertheless, these dispersions can stabilize themselves by these structures.
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- 2012
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36. Additives for lubricants containing poly(tetrafluoroethylene). Part 2: Tribological characterization
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T Hoffmann, D Lehmann, and M Schäffler
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Materials science ,Mechanical Engineering ,Surfaces and Interfaces ,Tribology ,Surfaces, Coatings and Films ,Characterization (materials science) ,Wear resistance ,chemistry.chemical_compound ,Chemical coupling ,chemistry ,Tetrafluoroethylene ,Composite material ,Coefficient of friction ,Dispersion (chemistry) ,Phosphoric acid - Abstract
This article describes the tribological characterization of dispersions consisting of irradiated poly(tetrafluoroethylene) (PTFE) micropowder (Zonyl® MP1100) and an ester oil (Synative ES TMP 05). A series of PTFE/oil dispersions were prepared with different amounts of PTFE micropowder (10–25 wt%) to study the influence of the PTFE in these dispersions on their tribological properties. The PTFE/oil dispersion with 10 wt% PTFE micropowder was additionally synthesized in the presence of two additives which are derived from phosphoric acid to study the influence on the tribological properties. In addition, a physical mixture of the ester oil and the PTFE micropowder was prepared to illustrate the impact of the chemical coupling reaction with regard to the tribological properties. A higher concentration of PTFE micropowder more clearly reduces the coefficient of friction in the ester oil. Low coefficient of friction and transition values from static to dynamic friction were observed. The resistance to wear was increased with the amount of PTFE micropowder in the dispersions and clearly reflects the difference between chemical coupling and physical mixture of the components.
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- 2012
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37. Adiponectin reduces connective tissue growth factor in human hepatocytes which is already induced in non-fibrotic non-alcoholic steatohepatitis
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Thomas S. Weiss, Roland Walter, Josef Wanninger, Markus Neumeier, T. Amann, Andreas Schäffler, Kristina Eisinger, Sabrina Bauer, Christa Buechler, Claus Hellerbrand, and Jürgen Schölmerich
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Male ,medicine.medical_specialty ,medicine.medical_treatment ,Primary Cell Culture ,Clinical Biochemistry ,Down-Regulation ,Adipokine ,Smad2 Protein ,Pathology and Forensic Medicine ,Fenofibrate ,Downregulation and upregulation ,Non-alcoholic Fatty Liver Disease ,Transforming Growth Factor beta ,Internal medicine ,medicine ,Humans ,PPAR alpha ,Smad3 Protein ,Phosphorylation ,Molecular Biology ,Adiponectin receptor 2 ,integumentary system ,Adiponectin ,Chemistry ,Anticholesteremic Agents ,Growth factor ,Connective Tissue Growth Factor ,medicine.disease ,Fatty Liver ,CTGF ,Pyrimidines ,Endocrinology ,Hepatocytes ,Female ,Steatohepatitis ,Signal Transduction ,Transforming growth factor - Abstract
Connective tissue growth factor (CTGF) is induced in liver fibrosis and enhances the activity of transforming growth factor β (TGFβ). Recently we have shown that the hepatoprotective adipokine adiponectin downregulates CTGF in primary human hepatocytes (PHH). In the current study, the mechanisms mediating suppression of CTGF by adiponectin and the well described downstream effector of adiponectin receptor 2 (AdipoR2), peroxisome proliferator activated receptor α (PPARα), were analyzed in more detail. Adiponectin downregulated CTGF mRNA and protein in primary human hepatocytes (PHH) and suppression was blocked by a PPARα antagonist indicating that AdipoR2 is involved. The PPARα agonists fenofibrate and WY14643 also reduced CTGF protein in these cells. Adiponectin further impaired TGFβ-mediated upregulation of CTGF. Phosphorylation of the TGFβ downstream effectors SMAD2 and –3 was reduced in PHH incubated with adiponectin or PPARα agonists suggesting that early steps in TGFβ signal transduction are impaired. CTGF and TGFβ mRNA levels were increased in human non-fibrotic non-alcoholic steatohepatitis (NASH), and here AdipoR2 expression was significantly reduced. Current data show that CTGF and TGFβ are already induced in non-fibrotic NASH and this may be partly explained by low adiponectin bioactivity which interferes with TGFβ signaling by reducing phosphorylation of SMAD2/3 and by downregulating CTGF.
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- 2011
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38. Nanoscale DNA Tetrahedra Improve Biomolecular Recognition on Patterned Surfaces
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Philipp D. Pollheimer, Andreas Ebner, Hermann J. Gruber, Robert Schlapak, Jürgen Danzberger, Peter Hinterdorfer, David J. Morgan, Stefan Howorka, David Armitage, and Friedrich Schäffler
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Nanostructure ,Materials science ,Oligonucleotide ,Nanotechnology ,Self-assembled monolayer ,Biosensing Techniques ,DNA ,General Chemistry ,Nanostructures ,Polyethylene Glycols ,Biomaterials ,chemistry.chemical_compound ,chemistry ,Colloidal gold ,Tetrahedron ,Molecule ,General Materials Science ,Biosensor ,Biotechnology - Abstract
The bottom-up approach of DNA nano-biotechnology can create biomaterials with defined properties relevant for a wide range of applications. This report describes nanoscale DNA tetrahedra that are beneficial to the field of biosensing and the targeted immobilization of biochemical receptors on substrate surfaces. The DNA nanostructures act as immobilization agents that are able to present individual molecules at a defined nanoscale distance to the solvent thereby improving biomolecular recognition of analytes. The tetrahedral display devices are self-assembled from four oligonucleotides. Three of the four tetrahedron vertices are equipped with disulfide groups to enable oriented binding to gold surfaces. The fourth vertex at the top of the bound tetrahedron presents the biomolecular receptor to the solvent. In assays testing the molecular accessibility via DNA hybridization and protein capturing, tetrahedron-tethered receptors outperformed conventional immobilization approaches with regard to specificity and amount of captured polypeptide by a factor of up to seven. The bottom-up strategy of creating DNA tetrahedrons is also compatible with the top-down route of nanopatterning of inorganic substrates, as demonstrated by the specific coating of micro- to nanoscale gold squares amid surrounding blank or poly(ethylene glycol)-passivated glass surfaces. DNA tetrahedra can create biofunctionalized surfaces of rationally designed properties that are of relevance in analytical chemistry, cell biology, and single-molecule biophysics.
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- 2011
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39. Intracellular Survival of Staphylococcus aureus in Adipocyte-Like Differentiated 3T3-L1 Cells Is Glucose Dependent and Alters Cytokine, Chemokine, and Adipokine Secretion
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Andrea Kopp, Margarita Bala, Werner Falk, Bernd Salzberger, Andreas Schäffler, Frank Hanses, and Christa Buechler
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Staphylococcus aureus ,medicine.medical_specialty ,medicine.medical_treatment ,Adipose tissue ,Adipokine ,Proinflammatory cytokine ,Mice ,chemistry.chemical_compound ,Endocrinology ,Adipokines ,3T3-L1 Cells ,Internal medicine ,Adipocyte ,Lipid droplet ,medicine ,Animals ,Insulin ,Adiponectin ,biology ,Cell Differentiation ,Insulin receptor ,Glucose ,chemistry ,biology.protein ,Cytokines ,Chemokines - Abstract
Although obesity and type 2 diabetes mellitus are associated with Gram-positive infections and a worse clinical outcome, it is unknown whether adipocytes can be infected by Gram-positive bacteria. Adipocyte-like differentiated 3T3-L1 cells and Staphylococcus aureus were used for infection experiments under normoglycemic (100 mg/dl) and hyperglycemic (450 mg/dl) conditions in the presence/absence of insulin (1 μm). Intracellular presence and survival of S. aureus was investigated quantitatively. Supernatant cytokines, chemokines, and adipokines were measured by ELISA. Lipid metabolism and cellular morphology of infected adipocytes were investigated by different techniques. The present study provides the proof of principle that adipocyte-like cells can be infected by S. aureus dose dependently for up to 5 d. Importantly, low bacterial inocula did not affect cell viability. Intracellular survival of S. aureus was glucose dependent but not insulin dependent, and insulin receptor expression and insulin receptor signaling were not altered. Infection increased macrophage chemoattractant protein-1, visfatin, and IL-6 secretion, whereas resistin and adiponectin were decreased. Infected adipocytes had higher intracellular triacylglycerol concentrations and larger lipid droplets because of a decreased lipolysis. Taken together, infection of adipocytes by S. aureus is glucose dependent, inhibits cellular lipolysis, and affects the secretion of immunomodulating adipokines differentially. Because cell viability is not affected during infection, adipose tissue might function as a host for chronic infection by bacteria-causing metabolic, proinflammatory, and prodiabetic disturbances.
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- 2011
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40. Adiponectin induces the transforming growth factor decoy receptor BAMBI in human hepatocytes
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Andreas Schäffler, Sabrina Bauer, Christa Buechler, Christoph Dorn, Claus Hellerbrand, Josef Wanninger, Thomas S. Weiss, Kristina Eisinger, Roland Walter, and Markus Neumeier
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Male ,medicine.medical_specialty ,medicine.medical_treatment ,Liver fibrosis ,Immunoblotting ,Biophysics ,Smad2 Protein ,Biochemistry ,Cholesterol, Dietary ,Mice ,Fatty liver disease ,Structural Biology ,Fibrosis ,Cell Line, Tumor ,Internal medicine ,Genetics ,medicine ,Animals ,Humans ,Hepatocyte ,Phosphorylation ,Transforming growth factor β ,Molecular Biology ,Cells, Cultured ,Aged ,Liver injury ,Adiponectin ,Reverse Transcriptase Polymerase Chain Reaction ,Chemistry ,Growth factor ,Fatty liver ,Membrane Proteins ,Hep G2 Cells ,Cell Biology ,Middle Aged ,medicine.disease ,Dietary Fats ,Fatty Liver ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Endocrinology ,Hepatocytes ,Female ,BAMBI ,Transforming growth factor - Abstract
Transforming growth factor (TGF) β is the central cytokine in fibrotic liver diseases. We analyzed whether hepatoprotective adiponectin directly interferes with TGFβ1 signaling in primary human hepatocytes (PHH). Adiponectin induces the TGFβ decoy receptor BMP-and activin-membrane-bound inhibitor (BAMBI) in PHH. Overexpression of BAMBI in hepatoma cells impairs TGFβ-mediated phosphorylation of SMAD2 and induction of connective tissue growth factor. BAMBI is lower in human fatty liver with a higher susceptibility to liver fibrosis and negatively correlates with BMI of the donors. Hepatic BAMBI is reduced in rodent models of liver inflammation and fibrosis. In summary, the current data show that hepatoprotective effects of adiponectin include induction of BAMBI which is reduced in human fatty liver and rodent models of metabolic liver injury.
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- 2011
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41. Elevated free fatty acids and impaired adiponectin bioactivity contribute to reduced SOD2 protein in monocytes of type 2 diabetes patients
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Josef Wanninger, S. Wurm, Charalampos Aslanidis, Margarita Bala, Markus Neumeier, Sabrina Bauer, Andrea Kopp, Christa Buechler, Johanna Weigert, and Andreas Schäffler
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Adult ,Male ,medicine.medical_specialty ,Antioxidant ,medicine.medical_treatment ,Clinical Biochemistry ,SOD2 ,Fatty Acids, Nonesterified ,Biology ,medicine.disease_cause ,Monocytes ,Body Mass Index ,Pathology and Forensic Medicine ,Superoxide dismutase ,Downregulation and upregulation ,Internal medicine ,Adipocytes ,medicine ,Humans ,skin and connective tissue diseases ,Molecular Biology ,Cells, Cultured ,Aged ,chemistry.chemical_classification ,Reactive oxygen species ,Dose-Response Relationship, Drug ,Adiponectin ,Superoxide Dismutase ,Monocyte ,nutritional and metabolic diseases ,Middle Aged ,Recombinant Proteins ,Endocrinology ,medicine.anatomical_structure ,Diabetes Mellitus, Type 2 ,chemistry ,Case-Control Studies ,cardiovascular system ,biology.protein ,Oxidative stress - Abstract
Type 2 diabetes (T2D) is characterized by increased oxidative stress contributing to the development of cardiovascular disease (CVD). Monocytes are critically important in the pathogenesis of CVD and antioxidant enzymes like superoxide dismutase (SOD2) protect these cells from excessive reactive oxygen species (ROS). Adiponectin is an adipocyte-derived protein with atheroprotective function and the effect of adiponectin on monocyte SOD2 was analyzed herein. Adiponectin upregulated SOD2 mRNA and dose- and time-dependently induced SOD2 protein in primary human monocytes. Elevated systemic free fatty acids (FFA) are commonly found in T2D patients and palmitic acid as well as oleic acid reduced monocyte SOD2 protein. Adiponectin mediated upregulation of SOD2, however, was not affected by FFA incubation. SOD2 protein was reduced in T2D monocytes compared to monocytes of age- and body mass index-matched healthy controls. Adiponectin still induced SOD2 in T2D monocytes but efficiency tended to be reduced. In summary this study indicates that elevated systemic free fatty acids and impaired adiponectin activity contribute to reduced SOD2 and most likely increased oxidative stress in T2D monocytes.
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- 2011
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42. Sterol Regulatory Element-Binding Protein 2 (SREBP2) Activation after Excess Triglyceride Storage Induces Chemerin in Hypertrophic Adipocytes
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Josef Wanninger, Sandra Schmidhofer, Sabrina Bauer, Nicole Zimara, Charalampos Aslanidis, Christa Buechler, Christoph Dorn, Claus Hellerbrand, Markus Neumeier, Andreas Schäffler, and Johanna Weigert
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medicine.medical_specialty ,Adipose tissue ,Adipokine ,CMKLR1 ,Receptors, G-Protein-Coupled ,Mice ,chemistry.chemical_compound ,Endocrinology ,3T3-L1 Cells ,Adipocyte ,Internal medicine ,Adipocytes ,medicine ,Animals ,Chemerin ,Triglycerides ,Chemotactic Factors ,biology ,Interleukin-6 ,Reverse Transcriptase Polymerase Chain Reaction ,Tumor Necrosis Factor-alpha ,Sterol regulatory element-binding protein ,Mice, Inbred C57BL ,Gene Expression Regulation ,chemistry ,biology.protein ,Intercellular Signaling Peptides and Proteins ,Female ,Receptors, Chemokine ,Sterol regulatory element-binding protein 2 ,Chemokines ,Adipocyte hypertrophy ,Sterol Regulatory Element Binding Protein 2 - Abstract
Chemerin is an adipokine whose systemic concentration and adipose tissue expression is increased in obesity. Chemerin is highly abundant in adipocytes, yet the molecular mechanisms mediating its further induction in obesity have not been clarified. Adipocyte hypertrophy contributes to dysregulated adipokine synthesis, and we hypothesized that excess loading with free fatty acids (FFA) stimulates chemerin synthesis. Chemerin was expressed in mature adipocytes, and differentiation of 3T3-L1 cells in the presence of FFA further increased its level. TNF and IL-6 were induced by FFA, but concentrations were too low to up-regulate chemerin. Sterol regulatory element-binding protein 2 (SREBP2) was activated in these cells, indicative for cholesterol shortage. Suppression of cholesterol synthesis by lovastatin led to activation of SREBP2 and increased chemerin, and supplementation with mevalonate reversed this effect. Knockdown of SREBP2 reduced basal and FFA-induced chemerin. EMSA confirmed binding of 3T3-L1 adipocyte nuclear proteins to a SREBP site in the chemerin promotor. SREBP2 was activated and chemerin was induced in adipose tissue of mice fed a high-fat diet, and higher systemic levels seem to be derived from adipocytes. Lipopolysaccharide-mediated elevation of chemerin was similarly effective as induction by FFA, indicating that both mechanisms are equally important. Chemokine-like receptor 1 was not altered by the incubations mentioned above, and higher expression in fat of mice fed a high-fat diet may reflect increased number of adipose tissue-resident macrophages in obesity. In conclusion, the current data show that adipocyte hypertrophy and chronic inflammation are equally important in inducing chemerin synthesis.
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- 2011
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43. Bile acid signaling after an oral glucose tolerance test
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Andreas Schäffler, Max Scherer, Silke Matysik, Josefine Martin, Gerd Schmitz, and Margarita Bala
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Adult ,Male ,medicine.medical_specialty ,Time Factors ,Adolescent ,medicine.drug_class ,Cholesterol 7 alpha-hydroxylase ,Biochemistry ,Bile Acids and Salts ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Downregulation and upregulation ,Internal medicine ,7α-Hydroxy-4-cholesten-3-one ,medicine ,Humans ,Molecular Biology ,Cholestenones ,030304 developmental biology ,0303 health sciences ,Glucose tolerance test ,Bile acid ,medicine.diagnostic_test ,Chemistry ,Organic Chemistry ,FGF19 ,Cell Biology ,Glucose Tolerance Test ,Middle Aged ,G protein-coupled bile acid receptor ,Fibroblast Growth Factors ,Endocrinology ,Postprandial ,030220 oncology & carcinogenesis ,Female ,Biomarkers ,Signal Transduction - Abstract
Monitoring bile acids as signal molecules in combination with a bile acid synthesis marker and the FXR regulator fibroblast growth factor 19 (FGF19), this study addresses significant postprandial changes. The efficacy of the different pathways to regulate bile acid synthesis through short heterodimer partner (SHP) dependent FXR modulation in liver, and SHP independent activation via FGF19 is demonstrated. Characteristic changes of the bile acid profile during an oral glucose tolerance test (oGTT) were investigated in 73 individuals. 15 bile acid species including conjugated and unconjugated forms were quantitatively determined with LC-MS/MS in serum samples collected at three time points during the oGTT. All conjugated bile acid species showed the same time course, a significant increase at 60 min after the glucose intake and an incline at 120 min. In contrast, a consistent decline of all unconjugated bile acids was monitored. 7α-Hydroxy-4-cholesten-3-one, an early bile acid synthesis marker, showed an inverse response with a significant decrease at 60 min which proves the efficient and rapid downregulation of CYP7A1 via FXR activation through bile acid signaling. Significantly higher levels of FGF19 were observed 120 min after glucose intake and 60 min after bile acid excursion.
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- 2011
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44. Particle size-dependent and surface charge-dependent biodistribution of gold nanoparticles after intravenous administration
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Alexander Wenk, Ulrich Simon, Winfried Möller, Wolfgang G. Kreyling, Martin Schäffler, Stephanie Hirn, Carsten Schleh, Manuela Semmler-Behnke, Jens Lipka, Günter Schmid, and Shinji Takenaka
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Biodistribution ,Metabolic Clearance Rate ,Surface Properties ,Stereochemistry ,Chemie ,Metal Nanoparticles ,Pharmaceutical Science ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,Rats, Inbred WKY ,01 natural sciences ,Article ,Radioligand Assay ,Specific surface area ,Animals ,Tissue Distribution ,Surface charge ,Particle Size ,Microparticle ,Gold Radioisotopes ,Chemistry ,General Medicine ,021001 nanoscience & nanotechnology ,Rats ,3. Good health ,0104 chemical sciences ,Spectrometry, Gamma ,Nanomedicine ,Liver ,Organ Specificity ,Colloidal gold ,Injections, Intravenous ,Drug delivery ,Biophysics ,Female ,Gold ,0210 nano-technology ,Biotechnology - Abstract
Gold nanoparticles (GNP) provide many opportunities in imaging, diagnostics, and therapies of nanomedicine. Hence, their biokinetics in the body are prerequisites for specific tailoring of nanomedicinal applications and for a comprehensive risk assessment. We administered (198)Au-radio-labelled monodisperse, negatively charged GNP of five different sizes (1.4, 5, 18, 80, and 200 nm) and 2.8 nm GNP with opposite surface charges by intravenous injection into rats. After 24h, the biodistribution of the GNP was quantitatively measured by gamma-spectrometry. The size and surface charge of GNP strongly determine the biodistribution. Most GNP accumulated in the liver increased from 50% of 1.4 nm GNP to >99% of 200 nm GNP. In contrast, there was little size-dependent accumulation of 18-200 nm GNP in most other organs. However, for GNP between 1.4 nm and 5 nm, the accumulation increased sharply with decreasing size; i.e. a linear increase with the volumetric specific surface area. The differently charged 2.8 nm GNP led to significantly different accumulations in several organs. We conclude that the alterations of accumulation in the various organs and tissues, depending on GNP size and surface charge, are mediated by dynamic protein binding and exchange. A better understanding of these mechanisms will improve drug delivery and dose estimates used in risk assessment.
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- 2011
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45. Sorbifuranones A–C, sorbicillinoid metabolites from Penicillium strains isolated from Mediterranean sponges
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Rolf Schmaljohann, Stefan Steffens, Jutta Wiese, Katrin Schäffler, Gerhard Bringmann, Johannes F. Imhoff, Gerhard Lang, and Torsten Bruhn
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Circular dichroism ,biology ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Organic Chemistry ,Absolute configuration ,010402 general chemistry ,Penicillium chrysogenum ,biology.organism_classification ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Sponge ,Drug Discovery ,Penicillium ,Ircinia ,Tethya aurantium ,Two-dimensional nuclear magnetic resonance spectroscopy - Abstract
Three novel natural products, sorbifuranones A–C (4–6), were isolated from a Penicillium chrysogenum fungus isolated from the marine sponge Ircinia fasciculata. Sorbifuranones B (5) and C (6) and 2′,3′-dihydrosorbicillin, a putative precursor to sorbifuranone B, were also found in the culture of another Penicillium strain, which was isolated from the sponge Tethya aurantium. Their constitutions were elucidated mainly by 2D NMR. NOE correlations in combination with quantum chemical calculations and comparison of experimental and calculated electronic circular dichroism (CD) spectra permitted assignment of the absolute configuration of sorbifuranone C. The structures hint at a two-step cleavage-cyclization sequence of sorbifuranone A (4) leading to the spiro compound sorbifuranone C, while sorbifuranone B is likely to be the respective cleavage product of a putative 2′,3′-dihydrosorbifuranone A, which cannot cyclize further.
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- 2010
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46. Serum Galectin-3 Is Elevated in Obesity and Negatively Correlates with Glycosylated Hemoglobin in Type 2 Diabetes
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Marcus N. Scherer, Josef Wanninger, Stefan Farkas, Johanna Weigert, Markus Neumeier, Jürgen Schölmerich, Andreas Schäffler, Charalampos Aslanidis, Christa Buechler, Andreas A. Schnitzbauer, and Sabrina Bauer
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Adult ,Leptin ,Male ,medicine.medical_specialty ,Cirrhosis ,Galectin 3 ,Endocrinology, Diabetes and Metabolism ,Blotting, Western ,Clinical Biochemistry ,Adipokine ,Adipose tissue ,Enzyme-Linked Immunosorbent Assay ,Type 2 diabetes ,Intra-Abdominal Fat ,Systemic inflammation ,Biochemistry ,Statistics, Nonparametric ,Body Mass Index ,Mice ,chemistry.chemical_compound ,Endocrinology ,Diabetes mellitus ,Adipocyte ,Internal medicine ,Adipocytes ,otorhinolaryngologic diseases ,medicine ,Animals ,Humans ,Resistin ,Obesity ,Cells, Cultured ,Aged ,Glycated Hemoglobin ,business.industry ,Biochemistry (medical) ,Middle Aged ,medicine.disease ,Metformin ,stomatognathic diseases ,Diabetes Mellitus, Type 2 ,chemistry ,Female ,medicine.symptom ,business - Abstract
Adipocytes synthesize galectin-3 whose deficiency protects from inflammation associated with metabolic diseases. We aimed to study circulating galectin-3 in obesity and type 2 diabetes (T2D).Galectin-3 was measured by ELISA in the serum of male normal-weight and overweight controls and T2D patients and in T2D patients of both sexes. Because visceral fat contributes to systemic inflammation, galectin-3 was analyzed in paired samples of human and rodent sc and visceral adipose tissue. Visceral adipose tissue adipokines are released to the portal vein, and galectin-3 was analyzed in portal, hepatic, and systemic venous serum (PVS, HVS, and SVS, respectively) of patients with liver cirrhosis and in patients who underwent surgery for nonhepatic diseases. The effect of metformin on adipocyte galectin-3 was analyzed by immunoblot.Circulating galectin-3 was similarly elevated in T2D and obesity compared with normal-weight individuals and revealed a body mass index-dependent positive correlation with leptin, resistin, IL-6, and age. In T2D patients, galectin-3 was increased in serum of patients with elevated C-reactive protein and negatively correlated with glycated hemoglobin. Metformin treatment was associated with lower systemic galectin-3. Reduced galectin-3 in metformin-incubated human adipocytes indicated that low galectin-3 may be a direct effect of this drug. Galectin-3 was higher in PVS compared with HVS and SVS, suggesting that the splanchnic region is a major site of galectin-3 synthesis. Low galectin-3 in HVS compared with PVS demonstrated hepatic removal.Systemic galectin-3 is elevated in obesity and negatively correlates with glycated hemoglobin in T2D patients, pointing to a modifying function of galectin-3 in human metabolic diseases.
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- 2010
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47. Stability of polar semiconductor heterostructures
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Friedhelm Bechstedt, R. Leitsmann, Friedrich Schäffler, and Heiko Groiss
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Condensed matter physics ,Chemistry ,Ab initio ,Polar ,Ionic bonding ,Heterojunction ,Nanotechnology ,Density functional theory ,Condensed Matter Physics ,Stability (probability) ,Cadmium telluride photovoltaics ,Semiconductor heterostructures - Abstract
In the present paper we use an ab initio density functional theory approach to investigate the stability of differently terminated PbTe(rs)/CdTe(zb)(100) and ErAs(rs)/InGaAs2(zb)(100) heterostructures for different environmental conditions. While in PbTe/CdTesystems differently terminated interfaces are favored in ErAs/InGaAs2 heterostructure systems with two equivalent interface terminations are the most stable configuration. This behavior is the consequence of the less strong ionic character of InGaAs2 compared to CdTe (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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- 2010
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48. Adiponectin downregulates galectin-3 whose cellular form is elevated whereas its soluble form is reduced in type 2 diabetic monocytes
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Margarita Bala, Daniela Sporrer, Josef Wanninger, Andrea Kopp, Markus Neumeier, Markus Weber, Andreas Schäffler, Johanna Weigert, Fabian Stögbauer, Christa Buechler, and S. Wurm
- Subjects
Male ,Time Factors ,Galectin 3 ,Palmitic Acid ,Type 2 diabetes ,Monocyte ,Biochemistry ,Monocytes ,Body Mass Index ,chemistry.chemical_compound ,Structural Biology ,Galectin-3 ,Cells, Cultured ,Aged, 80 and over ,Reverse Transcriptase Polymerase Chain Reaction ,Chemistry ,Middle Aged ,Metformin ,Cholesterol ,medicine.anatomical_structure ,Adiponectin ,medicine.drug ,Adult ,medicine.medical_specialty ,animal structures ,Immunoblotting ,Biophysics ,Enzyme-Linked Immunosorbent Assay ,Internal medicine ,Type 2 diabetes mellitus ,otorhinolaryngologic diseases ,Genetics ,medicine ,Humans ,Obesity ,Molecular Biology ,Aged ,Messenger RNA ,Dose-Response Relationship, Drug ,nutritional and metabolic diseases ,Cell Biology ,Ribonucleotides ,Aminoimidazole Carboxamide ,medicine.disease ,stomatognathic diseases ,Pyrimidines ,Endocrinology ,Diabetes Mellitus, Type 2 ,Solubility ,Pyrazoles ,Oleic Acid - Abstract
Galectin-3 plays a role in atherosclerotic diseases, and the effect of adiponectin that protects from atherosclerotic diseases on monocytic galectin-3 was analysed. Adiponectin reduced galectin-3 mRNA, its cellular and soluble form, and this effect was impaired in T2D cells. Cellular galectin-3 was higher in monocytes of overweight than normal-weight donors and was highest in T2D cells. Cellular galectin-3 positively correlated with the BMI of the donors and negatively with soluble monocyte galectin-3. Circulating levels of total adiponectin did not correlate with cellular or soluble galectin-3 indicating that additional factors contribute to higher cellular monocytic galectin-3 in obesity and T2D.
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- 2009
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49. Innate Immunity and Adipocyte Function: Ligand-specific Activation of Multiple Toll-like Receptors Modulates Cytokine, Adipokine, and Chemokine Secretion in Adipocytes
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J. Schölmerich, Charalampos Aslanidis, M. Neumeier, Andreas Schäffler, Andrea Kopp, Johanna Weigert, and Christa Buechler
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Lipopolysaccharides ,Chemokine ,medicine.medical_specialty ,Endocrinology, Diabetes and Metabolism ,Subcutaneous Fat ,Medicine (miscellaneous) ,Adipose tissue ,Adipokine ,Intra-Abdominal Fat ,Ligands ,Cell Line ,Mice ,chemistry.chemical_compound ,Endocrinology ,Adipokines ,Adipocyte ,Internal medicine ,Adipocytes ,medicine ,Animals ,Humans ,Resistin ,Cells, Cultured ,Chemokine CCL2 ,Nutrition and Dietetics ,biology ,Interleukin-6 ,Chemistry ,Toll-Like Receptors ,NF-kappa B ,Immunity, Innate ,Toll-Like Receptor 4 ,TLR5 ,Adipogenesis ,Chemokine secretion ,biology.protein ,Cytokines ,Chemokines ,Corticosterone ,Signal Transduction - Abstract
The aim of this study was to analyze Toll-like receptor (TLR) expression in preadipocytes and mature adipocytes and to investigate whether TLR ligands influence the release of cytokines, chemokines, and adipokines. Murine 3T3-L1 preadipocytes and mature adipocytes were used for stimulation experiments. The effects of lipopolysaccharide (LPS), flagellin, Poly (U), Poly (I:C), macrophage-activating lipopeptide-2 (MALP2), Pam3Cys, and CpG on the release of interleukin-6 (IL-6), resistin, and monocyte chemoattractant protein-1 (MCP-1) were determined by enzyme-linked immunosorbent assay (ELISA). Nuclear translocation and promoter binding of NFkappaB were analyzed by electrophoretic mobility shift assays. TLR expression was investigated by reverse-transcriptase (RT-PCR). All TLRs except TLR5 and TRL7 are expressed in the stromal vascular cell (SVC) fraction and in mature adipocytes of different fat stores. Whereas basal and LPS-induced IL-6 release is higher in preadipocytes, basal and LPS-induced MCP-1 release is higher in mature adipocytes. Mature adipocytes respond to corticosterone regarding MCP-1 and resistin release. The ligands for TLRs influence IL-6, MCP-1, and resistin release differentially. Some of these ligands induce nuclear translocation and promoter binding of NFkappaB. Besides TLR5, that is not expressed in mature adipocytes, all TLR family members are involved. There exists a functional TRL pathway in adipocytes that connects innate immunity with adipocyte function. As a consequence, the role of the adipose tissue in both immunity and metabolism has to be investigated in future studies. The results of this approach will help to explain the metabolic changes such as insulin resistance observed during infection and the immunological phenomena such as macrophage infiltration of adipose tissue seen in obesity.
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- 2009
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50. The role of adiponectin in inflammatory gastrointestinal diseases
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Jürgen Schölmerich and Andreas Schäffler
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Male ,Gene isoform ,medicine.medical_specialty ,Adipose tissue ,Adipokine ,Inflammation ,Biology ,Hepatitis ,Mice ,chemistry.chemical_compound ,Internal medicine ,Adipocyte ,medicine ,Animals ,Humans ,Secretion ,Receptor ,Adiponectin ,Gastroenterology ,Gastroenteritis ,Endocrinology ,Pancreatitis ,chemistry ,Acute Disease ,Female ,medicine.symptom - Abstract
Adiponectin was discovered in 1995 by Phillip Scherer’s research group and described as a novel serum protein similar to C1q, being produced exclusively in adipocytes.1 Adiponectin represents an anti-inflammatory, anti-diabetic and anti-fibrotic adipokine that is highly abundant in human plasma. Adiponectin is induced during adipocyte differentiation and secreted from mature adipocytes into the blood stream where it circulates as homo-trimeric, hexameric, nonameric and higher molecular weight isoforms. Mutations in the gene encoding adiponectin result in an impaired multimer formation and cause lower levels of high-molecular weight isoforms in the plasma as well as a reduced abundance of all isoforms due to a disturbed secretion from the adipocyte.2 There are two receptors for adiponectin, AdipoR1 and AdipoR2, which are expressed in a wide variety of organs and cell types. The full-length and the truncated globular isoforms of adiponectin exhibit different receptor binding activities. Processes leading to a cleavage of the full-length protein and the exact mode of receptor interaction of different isoforms are only poorly understood. Adiponectin represents the only adipokine that is downregulated in obesity. Adiponectin exerts pleiotropic effects in several organs and its role in metabolism3 and in inflammation,4–7 in general, are reviewed elsewhere. Obesity can be regarded as a chronic and low-grade state of inflammation8 and the interpretation of the role of the adipose tissue has developed from a simple energy store to a highly active endocrine,9 inflammatory5 and immunological4 organ. In the context of obesity, the adipose tissue undergoes an inflammatory transformation10 and becomes infiltrated by significant amounts of macrophages.8 11 Since adiponectin is secreted by intra-abdominal adipose tissue and acts on monocytes in an anti-inflammatory way, it seems reasonable to review the role of adiponectin with respect to inflammatory gastrointestinal diseases, especially to those …
- Published
- 2009
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