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- Institut für Ernährungswissenschaft (69) (entfernen)
Systemic trafficking and storage of essential metal ions play fundamental roles in living organisms by serving as essential cofactors in various cellular processes. Thereby metal quantification and localization are critical steps in understanding metal homeostasis, and how their dyshomeostasis might contribute to disease etiology and the ensuing pathologies. Furthermore, the amount and distribution of metals in organisms can provide insight into their underlying mechanisms of toxicity and toxicokinetics. While in vivo studies on metal imaging in mammalian experimental animals are complex, time- and resource-consuming, the nematode Caenorhabditis elegans (C. elegans) provides a suitable comparative and complementary model system. Expressing homologous genes to those inherent to mammals, including those that regulate metal homeostasis and transport, C. elegans has become a powerful tool to study metal homeostasis and toxicity. A number of recent technical advances have been made in the development and application of analytical methods to visualize metal ions in C. elegans. Here, we briefly summarize key findings and challenges of the three main techniques and their application to the nematode, namely sensing fluorophores, microbeam synchrotron radiation X-ray fluorescence as well as laser ablation ( LA) coupled to inductively coupled plasma-mass spectrometry (ICP-MS).
Obesity is a key component of equine metabolic syndrome, which is highly associated with laminitis. Feed restriction and/or exercise are known to alleviate the detrimental effects of insulin resistance in obese ponies. However, little is known about changes in the serum lipid patterns due to weight reduction and its association with disease outcomes. Therefore, the lipid patterns in the serum of 14 mature ponies before and after a 14-week body weight reduction program (BWRP) were investigated by multi-one-dimensional thin-layer chromatography (MOD-TLC). Additionally, sensitivity to insulin (SI), body condition scores (BCS) and cresty neck scores (CNS) were measured. A BWRP resulted in a significant loss of body weight (P < 0.001), which was associated with beneficial decreases in BCS and CNS (both, P < 0.001). Serum lipid compositions revealed significantly increased free fatty acid (FFA), sphingomyelin (SM; both P < 0.001), total cholesterol (C) and cholesterol ester (CE) (both P < 0.01) and triacylglycerol (TG; P < 0.05) densities. Improvement of SI after the BWRP was associated with increases in neutral lipids (C, CE and TG, all P < 0.01), FFA and the phospholipid SM (both, P < 0.001). The results show that a BWRP in obese ponies was effective and associated with changes in the concentrations of neutral lipids and the phospholipid SM, indicating that SM may play a role in insulin signaling pathways and thus in the pathogenesis of insulin resistance and the progression of metabolic syndrome in obese ponies.
Controlled delivery of corticosteroids using nanoparticles to the skin and corneal epithelium may reduce their side effects and maximize treatment effectiveness. Dexamethasone-loaded ethyl cellulose, Eudragit® RS and ethyl cellulose/Eudragit® RS nanoparticles were prepared by the solvent evaporation method. Dexamethasone release from the polymeric nanoparticles was investigated in vitro using Franz diffusion cells. Drug penetration was also assessed ex vivo using excised human skin. Nanoparticle toxicity was determined by MTT and H2DCFDA assays. Eudragit® RS nanoparticles were smaller and positively charged but had a lower dexamethasone loading capacity (0.3–0.7%) than ethyl cellulose nanoparticles (1.4–2.2%). By blending the two polymers (1:1), small (105 nm), positively charged (+37 mV) nanoparticles with sufficient dexamethasone loading (1.3%) were obtained. Dexamethasone release and penetration significantly decreased with decreasing drug to polymer ratio and increased when Eudragit® RS was blended with ethyl cellulose. Ex vivo, drug release and penetration from the nanoparticles was slower than a conventional cream. The nanoparticles bear no toxicity potentials except ethyl cellulose nanoparticles had ROS generation potential at high concentration. In conclusion, the nanoparticles showed great potential to control the release and penetration of corticosteroids on the skin and mucus membrane and maximize treatment effectiveness.
BACKGROUNDProduction and the quality of tomato fruits have a strong economic relevance. Microorganisms such as the plant growth-promoting bacterium (PGPB) Kosakonia radicincitans (DSM 16656) have been demonstrated to improve shoot and root growth of young tomato plants, but data on yield increase and fruit quality by K. radicincitans are lacking. RESULTSThis study investigated how K. radicincitans affects tomato fruits. After inoculation of tomato seeds with K. radicincitans or a sodium chloride buffer control solution, stalk length, first flowering and the amount of ripened fruits produced by inoculated and non-inoculated plants were monitored over a period of 21 weeks. Inoculation of tomato seeds with K. radicincitans accelerated flowering and ripening of tomato fruits. Sugars, acidity, amino acids, volatile organic compounds and carotenoids in the fruits were also analyzed. CONCLUSIONIt was found that the PGPBK. radicincitans affected the amino acid, sugar and volatile composition of ripened fruits, contributing to a more pleasant-tasting fruit without forfeiting selected quality indicators. (c) 2017 Society of Chemical Industry
Strong experimental evidence in animal and cellular models supports a pivotal role of sphingosine kinase-1 (SK1) in oncogenesis. In many human cancers, SK1 levels are upregulated and these increases are linked to poor prognosis in patients. Here, by employing untargeted NMR- based metabolomic profiling combined with functional validations, we report the crucial role of SK1 in the metabolic shift known as the Warburg effect in A2780 ovarian cancer cells. Indeed, expression of SK1 induced a high glycolytic rate, characterized by increased levels of lactate along with increased expression of the proton/monocarboxylate symporter MCT1, and decreased oxidative metabolism, associated with the accumulation of intermediates of the tricarboxylic acid cycle and reduction in CO2 production. Additionally, SK1-expressing cells displayed a significant increase in glucose uptake paralleled by GLUT3 transporter upregulation. The role of SK1 is not limited to the induction of aerobic glycolysis, affecting metabolic pathways that appear to support the biosynthesis of macromolecules. These findings highlight the role of SK1 signaling axis in cancer metabolic reprogramming, pointing out innovative strategies for cancer therapies.
Adulteration of food and mislabeled products in global market is a major financial and reputational risk for food manufacturers and trade companies. Consequently, there is a necessity to develop analytical methods to meet these issues. An analytical strategy to check the authenticity of wheat, spelt and rye addition in bread products was developed based on database research, in silico digestion confirming peptide specificity and finally quantification by liquid chromatography-tandem mass spectrometry analysis. Peptide markers for wheat (SQQQISQQPQQLPQQQQIPQQPQQF; QQHQIPQQPQQFPQQQQF and QPHQPQQPYPQQ), spelt (ASIVVGIGGQ; SQQPGQIIPQQPQQPSPL) and rye (LPQSHKQHVGQGAL; AQVQGIIQPQQL and QQFPQQPQQSFPQQPQQPVPQQPL) were identified, verified by protein Basic Local Alignment Search Tool and database research and used for quantification in bread. The specific use of multi-reaction monitoring transitions of selected peptides permitted the identification of closely related species wheat and spelt. Other cereal species (emmer, einkorn, barley, maize, rye and oat) were also checked. The target peptides were quantified at different levels using own reference baked products (bread) after in-solution chymotryptic digestion. Sensitivity of the identification was 0.5-1% using flour-based (0-25%) matrix calibration and the analytical recovery in bread was 80-125%. The analytical strategy described here supplies an emerging, independent and flexible tool in controlling the labeling of bread.
Identification of Endodormancy Release for Cherries (Prunus Avium L.) by
Abscisic Acid and Sugars
(2017)
In order to develop reliable and physiologically sound models for the plant development in spring, the date of endodormancy release is always a crucial and mostly unknown model parameter. Until present, classical approaches - such as climate chamber experiments - are used to derive this unknown parameter. In these experiments, progressive plant development or significant changes in bud’s fresh weight or water content are measurable markers for dormancy release. This study presents an alternative approach, which is based on four well-known metabolites. For 5 seasons (2011/12-2015/16), the content of abscisic acid (ABA) and sugars such as fructose, sucrose and glucose in sweet cherry flower buds (cultivar ‘Summit’) were weekly analysed between beginning of October and April. These data allow comparing the annual course of these metabolites with the date of endodormancy release, derived from a classical climate chamber experiment, published in a previous study. Results showed that ABA and sucrose are two important metabolites which can help to identify the date of endodormancy release of sweet cherries. On average, ABA content reached a plateau of 5.65 μg g-1 DW-1 during endodormancy, which was maintained for 3-6 weeks. The significant reduction of the ABA content after this period to 4.41 μg g-1 DW-1 on average during ecodormancy was nearly in agreement with the date of endodormancy release of ‘Summit’ on 28 November (332 DOY).
The annual cycle of sucrose, which has a cryoprotective effect during winter, is well comprehensible and showed a close relationship to
the annual course of minimum air temperature after leaf fall(r=-0.90). The nearly constant level of sucrose during ecodormancy (21.0 mg g-1 DW-1, 5 yr. mean) did not only allow deriving the date of endodormancy release but can also be helpful to define the beginning of ontogenetic development.
Preclinical assessment of penetration not only in intact, but also in barrier‐disrupted skin is important to explore the surplus value of novel drug delivery systems, which can be specifically designed for diseased skin. Here, we characterized physical and chemical barrier disruption protocols for short‐term ex vivo skin cultures with regard to structural integrity, physiological and biological parameters. Further, we compared the penetration of dexamethasone (Dex) in different nanoparticle‐based formulations in stratum corneum, epidermis and dermis extracts of intact vs. barrier‐disrupted skin as well as by dermal microdialysis at 6, 12 and 24 hours after topical application. Dex was quantified by liquid‐chromatography ‐ tandem‐mass spectrometry (LC‐MS/MS). Simultaneously, we investigated the Dex efficacy by interleukin (IL) analysis. Tape‐stripping (TS) and 4 hours sodium lauryl sulfate 5 % (SLS) exposure were identified as highly effective barrier disruption methods assessed by reproducible transepidermal water loss (TEWL) changes and IL‐6/8 increase which was more pronounced in SLS‐treated skin. The barrier state has also a significant impact on the Dex penetration kinetics: for all formulations, TS highly increased dermal Dex concentration despite the fact that nanocrystals quickly and effectively penetrated both, intact and barrier‐disrupted skin reaching significantly higher dermal Dex concentration after 6 hours compared to Dex cream. The surplus value of encapsulation in ethyl cellulose nanocarriers could mostly be observed when applied on intact skin, in general showing a delayed Dex penetration. Estimation of cytokines was limited due to the trauma caused by probe insertion. In summary, ex vivo human skin is a highly interesting short‐term preclinical model for the analysis of penetration and efficacy of novel drug delivery systems.
Fortsetzung aus Ernährungs Umschau Heft 9/2017
Fettsäurenverteilung
Die Gehalte an den wichtigsten Fettsäuren (FS) sind in • Tabelle 4 und 5 aufgeführt, in g/100 g sowie in Prozent des Fettanteils (Etherextrakt bzw. g FS-Methylester pro 100 g der Summe der FS-Methylester). Erbsen und Ackerbohnen spielen als Fett- und FS-Quelle praktisch keine Rolle. Sojabohnen sind eine wesentliche Quelle für Linolsäure, die häufigste n-6-FS. An zweiter Stelle steht die Ölsäure. Aber auch der Gehalt an der n-3-FS α-Linolensäure (ALA) ist hoch, womit sich Sojaöl in die Reihe der Fette mit mittlerem ALA-Gehalt, wie Raps- und Walnussöl einreiht. Im Gegensatz zu Rapsöl entspricht jedoch das Linolsäure/α-Linolensäure- Verhältnis nicht dem empfohlenen Verhältnis von 5:1 in der Gesamt- Diät [13]. Zum Ausgleich für die Fette aus der übrigen Nahrung (Getreide, Lebensmittel tierischer Herkunft) sollten Pflanzenöle besser noch ein engeres Verhältnis als 5:1 aufweisen. Das trifft für Lupinen-Öl schon eher zu, wenngleich der absolute Beitrag an ALA hier eher gering ist.