S1P Lyase Regulates Intestinal Stem Cell Quiescence via Ki-67 and FOXO3

Background: Reduction of the Sphingosine-1-phosphate (S1P) degrading enzyme S1P lyase 1 (SGPL1) initiates colorectal cancer progression with parallel loss of colon function in mice. We aimed to investigate the effect of SGPL1 knockout on the stem cell niche in these mice. Methods: We performed immunohistochemical and multi-fluorescence imaging on tissue sections of wildtype and SGPL1 knockout colons under disease conditions. Furthermore, we generated SGPL1 knockout DLD-1 cells (SGPL1^−/−M.Ex1) using CRISPR/Cas9 and characterized cell cycle and AKT signaling pathway via Western blot, immunofluorescence, and FACS analysis. Results: SGPL1 knockout mice were absent of anti-Ki-67 staining in the stem cell niche under disease conditions. This was accompanied by an increase of the negative cell cycle regulator FOXO3 and attenuation of CDK2 activity. SGPL1^−/−M.Ex1 cells show a similar FOXO3 increase but no arrest of proliferation, although we found a suppression of the PDK1/AKT signaling pathway, a prolonged G1-phase, and reduced stem cell markers. Conclusions: While already established colon cancer cells find escape mechanisms from cell cycle arrest, in vivo SGPL1 knockout in the colon stem cell niche during progression of colorectal cancer can contribute to cell cycle quiescence. Thus, we propose a new function of the S1P lyase 1 in stemness.     

Identification of off-flavor compounds in high-density polyethylene (HDPE) with different amounts of abscents

The use of synthetic pipes for drinking water distribution has increased. High desnity polyethylene (HPDE) is preferred because of its favorable mechanical properties, ease of handling during manufacturing, and low permeability to external contaminants. Off-flavor drinking water is a problem with plastic pipes. The compounds causing off-flavors are mainly carbonyl compounds. A combined zeolite called Abscents is used to eliminate odors and to remove odor-causing compounds. In this study, four different amounts of Abscents were added to raw HDPE pellets, and the influence on the off-flavor properties were analyzed. When the maximum amount of Abscents was added, almost all the carbonyl compounds disappeared, and the intensities of odors also decreased. The use of Abscents notably increased the acceptability of HDPE pipes. The system used for analysis of volatile organic compounds was a gas chromatographic/mass spectrometric/sniffing system. Purge and trap techniques were used to introduce the volatile, off-flavor components into the gas chromatograph.     

Characterisation of the key aroma compounds in the peel oil of Pontianak oranges (<Emphasis Type="Italic">Citrus nobilis</Emphasis> Lour. var. <Emphasis Type="Italic">microcarpa</Emphasis> Hassk.) by aroma reconstitution experiments

Nineteen odour-active compounds previously identified with high Flavour Dilution factors in an extract from the peel oil of Pontianak oranges (Citrus nobilis Lour. var. microcarpa Hassk.) were quantified using stable isotope dilution assays (SIDA). For this purpose, four new SIDA were developed, i.e. for the quantification of (E)-2-dodecenal, geraniol, nerol, and 1-phenylethanethiol. The results showed that (R)-limonene, myrcene, and (R)-α-pinene were the predominant compounds present in concentrations between 0.4 and 60 mg/g peel. An aroma recombinate containing the nineteen aroma compounds in the concentrations naturally occurring in the peel oil elicited the overall aroma of the peel oil itself, thus confirming the identification experiments. Furthermore, omission experiments showed that the unique odour quality of the peel is significantly influenced by the resinous, sulphurous-smelling 1-phenylethanethiol, although its concentration was only 38 ng/g peel.     

Organ-specific distribution of phenolic compounds in bilberry (Vaccinium myrtillus) and ‘northblue’ blueberry (Vaccinium corymbosum x V. angustifolium)

Blueberries and bilberries are recognized as some of the best sources of flavonoids, especially anthocyanins. The contents of flavonoids (anthocyanins, proanthocyanidins, flavonols) and hydroxycinnamic acids in the flower, fruit skin and pulp, leaf and rhizome of bilberry and the blueberry cultivar ‘Northblue’ were analyzed using high-performance liquid chromatography combined with diode-array detection. The most striking difference in the fruits was the predominance of hydroxycinnamic acids in blueberry, whereas in bilberry the anthocyanin content was much higher, particularly in the pulp. Differences in flavonoid contents of fruits were already apparent at the flower stage. Bilberry and blueberry leaves both contained high amounts of proanthocyanidins, flavonols and hydroxycinnamic acids. Blueberry rhizomes accumulated high amounts of hydroxycinnamic acids. All plant parts of bilberry and blueberry are potential sources of phenolic compounds for use either as dietary botanicals or by the pharmaceutical industry.     

Impact of substrate material and annealing conditions on the microstructure and chemistry of yttria-stabilized-zirconia thin films

Si-diffusion from Si-based substrates into yttria-stabilized-zirconia (YSZ) thin films and its impact on their microstructure and chemistry is investigated. YSZ thin films used in electrochemical applications based on micro-electrochemical systems (MEMS) are deposited via spray pyrolysis onto silicon-based and silicon-free substrates, i.e. Si_xN_y-coated Si wafer, SiO₂ single crystals and Al₂O₃, sapphire. The samples are annealed at 600 °C and 1000 °C for 20 h in air. Transmission electron microscopy (TEM) showed that the Si_xN_y-coated Si wafer is oxidized to SiO_z at the interface to the YSZ thin film at temperatures as low as 600 °C. On all YSZ thin films, silica is detected by X-ray photoelectron spectroscopy (XPS). A particular large Si concentration of up to 11 at% is detected at the surface of the YSZ thin films when deposited on silicon-based substrates after annealing at 1000 °C. Their grain boundary mobility is reduced 2.5 times due to the incorporation of SiO₂. YSZ films on Si-based substrates annealed at 600 °C show a grain size gradient from the interface to the surface of 3 nm to 10 nm. For these films, the silicon content is about 1.5 at% at the thin film's surface.     

Phase behavior, nucleation and optical properties of the binary system isotactic polypropylene/N,N′,N″-tris-isopentyl-1,3,5-benzene-tricarboxamide

The phase behavior of the binary system consisting of isotactic polypropylene (i-PP) and N,N′,N″-tris-isopentyl-1,3,5-benzene-tricarboxamide (1)—a selected member of a class of novel, versatile ‘designer’ nucleating/clarifying agents—was investigated over the entire additive concentration range by means of differential scanning calorimetry (DSC) and optical microscopy. Experimental phase diagrams were constructed from data obtained in melting and crystallization studies, and a simple monotectic is advanced, very similar to the previously studied binary system i-PP/1,3:2,4-bis(3,4-dimethylbenzylidene) sorbitol (DMDBS). In contrast to the latter, the crystallization temperature in the present system i-PP/1 was found to increase to ∼120 °C already at the lowest additive concentration employed and remained constant at further increasing additive concentration. Liquid-liquid phase separation was observed at elevated temperatures for i-PP/1 mixtures comprising more than ∼2 wt% of 1. A study on the optical properties of the i-PP/1 system revealed that the values for haze and clarity of injection-molded plaques progressively decreased and increased, respectively, in the concentration range up to 0.15 wt%. An intermediate region of fairly concentration-independent optical properties was found between 0.15 and 1 wt%, followed by a rapid increase in haze at concentrations exceeding 2 wt%.