Peroxisome Proliferator Activated Receptor Gamma Controls Mature Brown Adipocyte Inducibility through Glycerol Kinase

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Tree gum-based renewable materials: Sustainable applications in nanotechnology,biomedical and environmental fields

The prospective uses of tree gum polysaccharides and their nanostructures in various aspects of food, water, energy, biotechnology, environment and medicine industries, have garnered a great deal of attention recently. In addition to extensive applications of tree gums in food, there are substantial non-food applications of these commercial gums, which have gained widespread attention due to their availability, structural diversity and remarkable properties as ‘green’ bio-based renewable materials. Tree gums are obtainable as natural polysaccharides from various tree genera possessing exceptional properties, including their renewable, biocompatible, biodegradable, and non-toxic nature and their ability to undergo easy chemical modifications. This review focuses on non-food applications of several important commercially available gums (arabic, karaya, tragacanth, ghatti and kondagogu) for the greener synthesis and stabilization of metal/metal oxide NPs, production of electrospun fibers, environmental bioremediation, bio-catalysis, biosensors, coordination complexes of metal–hydrogels, and for antimicrobial and biomedical applications. Furthermore, polysaccharides acquired from botanical, seaweed, animal, and microbial origins are briefly compared with the characteristics of tree gum exudates.     

Quantitative Analysis of Ingenol in Euphorbia species via Validated Isotope Dilution Ultra‐high Performance Liquid Chromatography Tandem Mass Spectrometry

Introduction

Various species of the Euphorbia genus contain diterpene ingenol and ingenol mebutate (ingenol‐3‐angelate), a substance found in the sap of the plant Euphorbia peplus and an inducer of cell death. A gel formulation of the drug has been approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the topical treatment of actinic keratosis.

Objective

To develop a rapid and reliable method for quantification of ingenol in various plant extracts.

Methodology

Methanolic extracts of 38 species of the Euphorbia genus were analysed via ultra‐high performance liquid chromatography with tandem mass spectrometry (UHPLC–MS/MS) after methanolysis and solid‐phase extraction (SPE) purification. The ¹⁸O–labelled ingenol analogue was prepared and used as an internal standard for ingenol content determination and method validation.

Results

The highest ingenol concentration (547 mg/kg of dry weight) was found in the lower leafless stems of E. myrsinites. The screening confirms a substantial amount of ingenol in species studied previously and furthermore, reveals some new promising candidates.

Conclusion

The newly established UHPLC–MS/MS method shows to be an appropriate tool for screening of the Euphorbia genus for ingenol content and allows selection of species suitable for raw material production and/or in vitro culture initiation. Copyright © 2017 John Wiley & Sons, Ltd.     

Endogenous brassinosteroids in microalgae exposed to salt and low temperature stress

Brassinosteroids are part of the hormonal network that regulates growth processes and stress responses in plants. There is evidence for a similar hormonal network in microalgae. In the present study, six microalgae (Chlorococcum ellipsoideum, Gyoerffyana humicola, Nautococcus mamillatus, Acutodesmus acuminatus, Protococcus viridis and Chlorella vulgaris) were subjected to salt and low temperature stress with the addition of 36 g l^–1 NaCl and transfer from 25°C to 15°C. There was a rapid response to salt stress with the brassinosteroid content (mainly castasterone with lower amounts of brassinolide, homocastasterone and typhasterol) increasing within 30 min of the salt treatment and remaining at these elevated levels after 7 h. The decrease in temperature had little effect on the brassinosteroid content. This was the first study to show that endogenous brassinosteroids increase in response to abiotic stress in a number of microalgae species.     

Circadian clock components control daily growth activities by modulating cytokinin levels and cell division‐associated gene expression in Populus trees

Trees are carbon dioxide sinks and major producers of terrestrial biomass with distinct seasonal growth patterns. Circadian clocks enable the coordination of physiological and biochemical temporal activities, optimally regulating multiple traits including growth. To dissect the clock's role in growth, we analysed Populus tremula × P. tremuloides trees with impaired clock function due to down‐regulation of central clock components. late elongated hypocotyl (lhy‐10) trees, in which expression of LHY1 and LHY2 is reduced by RNAi, have a short free‐running period and show disrupted temporal regulation of gene expression and reduced growth, producing 30–40% less biomass than wild‐type trees. Genes important in growth regulation were expressed with an earlier phase in lhy‐10, and CYCLIN D3 expression was misaligned and arrhythmic. Levels of cytokinins were lower in lhy‐10 trees, which also showed a change in the time of peak expression of genes associated with cell division and growth. However, auxin levels were not altered in lhy‐10 trees, and the size of the lignification zone in the stem showed a relative increase. The reduced growth rate and anatomical features of lhy‐10 trees were mainly caused by misregulation of cell division, which may have resulted from impaired clock function.     

Evolution of Tribolium madens (Insecta,Coleoptera) Satellite DNA Through DNA Inversion and Insertion

Two different satellite DNAs from tenebrionid speciesTribolium madens (Insecta, Coleoptera) have been detected, cloned, and sequenced. Satellite I comprises 30% of the genome; it has a monomer size of 225 by and a high A + T content of 74%. Satellite 11, with a monomer size of 711 by and A + T content of 70%, is less abundant, making 4% of the total DNA. Sequence variability of the monomers relative to consensus sequence is 4.1% and 1.2% for satellite I and II, respectively. Both satellites are localized in the heterochromatic regions of all chromosomes. A search for internal motifs showed that both satellites contain a related subsequences, about 100 by long. The creation of satellite I monomer is explained by duplication of the basic subunit, followed by subsequent divergence by single point mutations, deletions, and gene conversion. Inversion of the subsequence in addition to its duplication has occurred in satellite II. The result of this inversion is possible formation of a long, stable dyad structure. The 408-bp sequence, inserted within satellite II monomer, shares no similarity with a basic subunit. Frequent direct repeats found within the inserted sequence point to its evolution by duplication of shorter motifs. It is proposed that both satellites have been derived from a common ancestral sequence whose duplication played a major role in the formation of satellite I monomer, while insertion of a new sequence together with inversion of an ancestral one induced the occurrence of satellite II. Correspondence to: D. Ugarković     

Heart glycogen content and isoprenaline-induced myocardial lesions

The role of glycogen content in the heart for the development of isoprenaline-induced myocardial lesions (IML) was studied in Wistar rats and in two inbred rat strains: In IR rats (resistant to the development of IML) and in IS rats (sensitive to IML development).Glycogen content in the heart can be dramatically lowered or increased by various interventions. IML develop during the period of very low heart glycogen content (about 0.6 mg.g^–1) induced by isoprenaline administration. In animals with increased resistance to IML, either due to genetic factors or induced by isoprenaline pretreatment a high glycogen content in the heart is found (up to 7.5 mg.g^–1).The increase of resistance to IML development and increased glycogen content induced by isoprenaline pretreatment were accompanied by lower basal or ISO-, guanylylimidodiphosphate- (Gpp/NH/p) and forskolin-stimulated activities of adenylyl cyclase. On the other hand, these parameters did not differ between IR and IS rats in spite of the presence of significant differences in the resistance to the development of IML and in heart glycogen content in these two rats strains.These results suggest that genetically determined differences between two inbred rat strains in the resistance of the heart to the development of IML and in the heart glycogen content are caused by factors which are independent of the receptor-adenylyl cyclase complex and are therefore different from those involved in the increase of resistance and glycogen content due to isoprenaline pretreatment.