Lipid mediators in platelet concentrate and extracellular vesicles: Molecular mechanisms from membrane glycerophospholipids to bioactive molecules

Platelets are collected for transfusion to patients with different hematological disorders, and for logistical reasons, platelets are stored as concentrates. Despite the carefully controlled conditions, platelets become activated during storage, and platelet concentrates (PLCs) may cause adverse inflammatory reactions in the recipients. We studied by mass spectrometry the lipidomic changes during storage of the clinical PLCs, the platelets isolated from PLCs, and the extracellular vesicles (EVs) thereof. The release of EVs from platelets increased with the prolonged storage time. The molar percentages of arachidonic acid -containing species were increased during storage especially in the phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine classes of glycerophopholipids. The increase of these species in the membrane glycerophopholipid composition paralleled the production of both proinflammatory and proresolving lipid mediators (LMs) as the amount of the arachidonic acid-derived LMs such as thromboxane B2 and prostaglandin E2 also increased in time. Moreover, several monohydroxy pathway markers and functionally relevant proinflammatory and proresolving LMs were detected in the PLC and the EVs, and some of these clearly accumulated during storage. By Western blot, the key enzymes of these pathways were shown to be present in the platelets and in many cases also in the EVs. Since the EVs were enriched in the fatty acid precursors of LMs, harbored LM-producing enzymes, contained the related monohydroxy pathway markers, and also secreted the final LM products, the PLC-derived EVs appear to have the potential to regulate inflammation and healing, and may thereby aid the platelets in exerting their essential physiological functions.Peer reviewe

Day-length effects on protein localisation affect water absorption in barley ( Hordeum vulgare ) grains

BACKGROUND: Hordeins are major storage proteins of barley (Hordeum vulgare L.) grains and are considered to influence malting and brewing by forming a matrix surrounding the starch granules which affects the release of fermentable sugars. However, the extent to which environmental factors affect hordein location, and the impact of this on malting performance, have not so far been studied. Therefore the relationship of hordein location to water uptake and malting quality were studied by growing barley cv. Barke under different daylengths (14 h and 18 h of light) in controlled environment conditions. RESULTS: Differences in the locations of hordein storage proteins were observed, with C hordein being located more deeply within the endosperm of both developing grains at 35 days after anthesis and in mature grains under long-day conditions. This deeper location of C hordein was correlated positively with water uptake during the steeping phase of malting. CONCLUSION: An effect of environment (daylength) on the localisation of C hordein was demonstrated. This difference in hordein localisation was also associated with differences in malting quality with water uptake in the steeping phase being associated positively with the deeper location of C hordein. These results indicate that environmental effects on protein location may affect malting performance of barley grains. Copyright (c) 2012 Society of Chemical Industr

Milling, water uptake, and modification properties of different barley (Hordeum vulgare L.) lots in relation to grain composition and structure

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Influence of sulphur application on hordein composition and malting quality of barley (Hordeum vulgare L.) in northern European growing conditions

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Impact of Particle Size Reduction and Carbohydrate-Hydrolyzing Enzyme Treatment on Protein Recovery from Rapeseed (Brassica rapa L.) Press Cake

The aims were to assess how particle size reduction and carbohydrate-hydrolyzing enzyme treatment influence protein recovery from rapeseed cold-pressed cake and to determine the effect of these pretreatments in protein extraction procedures varying in ionic strength, pH, and total solid content. Defatted press cake (median particle size 600 µm) was milled to 21-164 µm and 7 µm median particle sizes by pin disc milling and air-flow milling, respectively. The milled press cake samples were treated with a carbohydrate-hydrolyzing enzyme preparation, after which proteins were extracted in saline (pH 6) or alkaline (pH 12) buffer at 5 % solid content, or in water at 20 % solid content. Particle size reduction of the press cake did not influence enzyme action or protein yield, suggesting that protein release from the press cake is not physically limited by cell walls or internal cell structures. As an exception, protein release from the aleuronic cells appeared to be hindered by intact cell walls. Enzyme treatment improved protein recovery, more substantially when the extraction was carried out in water at 20 % solid content than in saline or alkaline conditions at 5 % solid content. The enzyme mediated its positive effect most probably by reducing the water holding capacity of the press cake, thereby facilitating solid-liquid separation, and releasing anionic compounds which improved protein solubility through electrostatic stabilization. The results suggest that carbohydrate-hydrolyzing enzymes are beneficial for rapeseed protein extraction at reduced water content or when no salt or alkali is added to increase protein solubility

Bilberry and bilberry press cake as sources of dietary fibre

Background: Dietary recommendations for Nordic countries urge the use of plant foods as a basis for healthy nutrition. Currently, the level of dietary fibre (DF) intake is not adequate. Berries are an elementary part of the recommended Nordic healthy diet and could be consumed in higher amounts. Materials and methods: Finnish bilberries and a bilberry press cake from juice processing were studied for DF content, carbohydrate composition, and non-carbohydrate fibre content, which was analysed as sulphuric acid insoluble and soluble material. The microstructure of all samples was also studied using light microscopy and toluidine blue O, calcofluor, and acid fuchsin staining. Results: The total DF contents of fresh and freeze-dried bilberries and the press cake were 3.0, 24.1, and 58.9%, respectively. Most of the DF was insoluble. Only about half of it was carbohydrate, the rest being mostly sulphuric acid–insoluble material, waxy cutin from skins, and resilient seeds. Bilberry seeds represented over half of the press cake fraction, and in addition to skin, they were the major DF sources. Microscopy revealed that skins in the press cake were intact and the surface of the seeds had thick-walled cells. Conclusions: Bilberry press cake is thus a good source of insoluble non-carbohydrate DF, and could be used to provide DF-rich foods to contribute to versatile intake of DF