Geographical trends in the yolk carotenoid composition of the pied flycatcher (Ficedula hypoleuca)

Carotenoids in the egg yolks of birds are considered to be important antioxidants and immune stimulants during the rapid growth of embryos. Yolk carotenoid composition is strongly affected by the carotenoid composition of the female??s diet at the time of egg formation. Spatial and temporal differences in carotenoid availability may thus be reflected in yolk concentrations. To assess whether yolk carotenoid concentrations or carotenoid profiles show any large-scale geographical trends or differences among habitats, we collected yolk samples from 16 European populations of the pied flycatcher, Ficedula hypoleuca. We found that the concentrations and proportions of lutein and some other xanthophylls in the egg yolks decreased from Central Europe northwards. The most southern population (which is also the one found at the highest altitude) also showed relatively low carotenoid levels. Concentrations of ??-carotene and zeaxanthin did not show any obvious geographical gradients. Egg yolks also contained proportionally more lutein and other xanthophylls in deciduous than in mixed or coniferous habitats. We suggest that latitudinal gradients in lutein and xanthophylls reflect the lower availability of lutein-rich food items in the northern F. hypoleuca populations and in montane southern populations, which start egg-laying earlier relative to tree phenology than the Central European populations. Similarly, among-habitat variation is likely to reflect the better availability of lutein-rich food in deciduous forests. Our study is the first to indicate that the concentration and profile of yolk carotenoids may show large-scale spatial variation among populations in different parts of the species?? geographical range. Further studies are needed to test the fitness effects of this geographical variation.     

Purification of chondroitin precursor from Escherichia coli K4 fermentation broth using membrane processing

Recently the possibility of producing the capsular polysaccharide K4, a fructosylated chondroitin, in fed-batch experiments was assessed. In the present study, a novel downstream process to obtain chondroitin from Escherichia coli K4 fermentation broth was developed. The process is simple, scalable and economical. In particular, downstream procedures were optimized with a particular aim of purifying a product suitable for further chemical modifications, in an attempt to develop a biotechnological platform for chondroitin sulfate production. During process development, membrane devices (ultrafiltration/diafiltration) were exploited, selecting the right cassette cut-offs for different phases of purification. The operational conditions (cross-flow rate and transmembrane pressure) used for the process were determined on an ?KTA cross-flow instrument (GE Healthcare, USA), a lab-scale automatic tangential flow filtration system. In addition, parameters such as selectivity and throughput were calculated based on the analytical quantification of K4 and defructosylated K4, as well as the major contaminants. The complete downstream procedure yielded about 75% chondroitin with a purity higher than 90%.     

Functional characterization of a synthetic abscisic acid analog with anti-inflammatory activity on human granulocytes and monocytes

The phytohormone abscisic acid (ABA), in addition to regulating several important physiological functions in plants, is also produced and released by human granulocytes and monocytes where it stimulates cell activities involved in the innate immune response.Here we describe the properties of an ABA synthetic analog that competes with the hormone for binding to human granulocyte membranes and to purified recombinant LANCL2 (the human ABA receptor) and inhibits several ABA-triggered inflammatory functions of granulocytes and monocytes in vitro: chemotaxis, phagocytosis, reactive oxygen species production and release of prostaglandin E₂ (PGE₂) by human granulocytes, release of PGE₂ and of monocyte chemoattractant protein-1 by human monocytes. This observation provides a proof of principle that ABA antagonists may represent a new class of anti-inflammatory agents.     

Multiple Propofol-binding Sites in a γ-Aminobutyric Acid Type A Receptor (GABAAR) Identified Using a Photoreactive Propofol Analog

Propofol acts as a positive allosteric modulator of γ-aminobutyric acid type A receptors (GABA_ARs), an interaction necessary for its anesthetic potency in vivo as a general anesthetic. Identifying the location of propofol-binding sites is necessary to understand its mechanism of GABA_AR modulation. [³H]2-(3-Methyl-3H-diaziren-3-yl)ethyl 1-(phenylethyl)-1H-imidazole-5-carboxylate (azietomidate) and R-[³H]5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid (mTFD-MPAB), photoreactive analogs of 2-ethyl 1-(phenylethyl)-1H-imidazole-5-carboxylate (etomidate) and mephobarbital, respectively, have identified two homologous but pharmacologically distinct classes of intersubunit-binding sites for general anesthetics in the GABA_AR transmembrane domain. Here, we use a photoreactive analog of propofol (2-isopropyl-5-[3-(trifluoromethyl)-3H-diazirin-3-yl]phenol ([³H]AziPm)) to identify propofol-binding sites in heterologously expressed human α1β3 GABA_ARs. Propofol, AziPm, etomidate, and R-mTFD-MPAB each inhibited [³H]AziPm photoincorporation into GABA_AR subunits maximally by ∼50%. When the amino acids photolabeled by [³H]AziPm were identified by protein microsequencing, we found propofol-inhibitable photolabeling of amino acids in the β3-α1 subunit interface (β3Met-286 in β3M3 and α1Met-236 in α1M1), previously photolabeled by [³H]azietomidate, and α1Ile-239, located one helical turn below α1Met-236. There was also propofol-inhibitable [³H]AziPm photolabeling of β3Met-227 in βM1, the amino acid in the α1-β3 subunit interface photolabeled by R-[³H]mTFD-MPAB. The propofol-inhibitable [³H]AziPm photolabeling in the GABA_AR β3 subunit in conjunction with the concentration dependence of inhibition of that photolabeling by etomidate or R-mTFD-MPAB also establish that each anesthetic binds to the homologous site at the β3-β3 subunit interface. These results establish that AziPm as well as propofol bind to the homologous intersubunit sites in the GABA_AR transmembrane domain that binds etomidate or R-mTFD-MPAB with high affinity.     

Removal of Vanadium(III) and Molybdenum(V) from Wastewater Using Posidonia oceanica (Tracheophyta) Biomass

The use of dried and re-hydrated biomass of the seagrass Posidonia oceanica was investigated as an alternative and –low-cost biomaterial for removal of vanadium(III) and molybdenum(V) from wastewaters. Initial characterisation of this biomaterial identified carboxylic groups on the cuticle as potentially responsible for cation sorption, and confirmed the toxic-metal bioaccumulation. The combined effects on biosorption performance of equilibrium pH and metal concentrations were investigated in an ideal single-metal system and in more real-life multicomponent systems. There were either with one metal (vanadium or molybdenum) and sodium nitrate, as representative of high ionic strength systems, or with the two metals (vanadium and molybdenum). For the single-metal solutions, the optimum was at pH 3, where a significant proportion of vanadium was removed (ca. 70%) while there was ca. 40% adsorption of molybdenum. The data obtained from the more real-life multicomponent systems showed that biosorption of one metal was improved both by the presence of the other metal and by high ionic strength, suggesting a synergistic effect on biosorption rather than competition. There data ware used for the development of a simple multi-metal equilibrium model based on the non-competitive Langmuir approach, which was successfully fitted to experimental data and represents a useful support tool for the prediction of biosorption performance in such real-life systems. Overall, the results suggest that biomass of P. oceanica can be used as an efficient biosorbent for removal of vanadium(III) and molybdenum(V) from aqueous solutions. This process thus offers an eco-compatible solution for the reuse of the waste material of leaves that accumulate on the beach due to both human activities and to storms at sea.     

Regulation of Gdnf expression by retinoic acid in Sertoli cells

Glial cell line‐derived neurotrophic factor (GDNF) and retinoic acid (RA) are two molecules crucial for the regulation of the spermatogonial compartment of the testis. During the cycle of the seminiferous epithelium, their relative concentration oscillates with lower GDNF levels in stages where RA levels are high. It has been recently shown that RA negatively regulates Gdnf expression but the mechanisms behind are so far unknown. Here, we show that RA directly downregulates Gdnf mRNA levels in primary murine Sertoli cells through binding of RARα to a novel DR5‐RARE on Gdnf promoter. Pharmacological inhibition and chromatin immunoprecipitation–quantitative polymerase chain reaction analysis suggested that the underlying mechanism involved histone deacetylase activity and epigenetic repression of Gdnf promoter upon RA treatment.     

Synergistic inhibition of pancreatic adenocarcinoma cell growth by trichostatin A and gemcitabine

We investigated the ability of the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) to interact with gemcitabine (GEM) in inducing pancreatic cancer cell death. The combined treatment with TSA and GEM synergistically inhibited growth of four pancreatic adenocarcinoma cell lines and induced apoptosis. This effect was associated with the induction of reactive oxygen species (ROS) by GEM, increased expression of the pro-apoptotic BIM gene by both TSA and GEM and downregulation of the 5'-nucleotidase UMPH type II gene by TSA. The expression of other genes critical for GEM resistance (nucleoside transporters, deoxycytidine kinase, cytidine deaminase, and ribonucleotide reductase genes) was not affected by TSA. The functional role of ROS in cell growth inhibition by GEM was supported by (i) a significantly reduced GEM-associated growth inhibition by the free radical scavenger N-acetyl-L-cysteine, and (ii) a positive correlation between the basal level of ROS and sensitivity to GEM in 10 pancreatic cancer cell lines. The functional role of both Bim and 5'-nucleotidase UMPH type II in cell growth inhibition by TSA and GEM was assessed by RNA interference assays. In vivo studies on xenografts of pancreatic adenocarcinoma cells in nude mice showed that the association of TSA and GEM reduced to 50% the tumour mass and did not cause any apparent form of toxicity, while treatments with TSA or GEM alone were ineffective. In conclusion, the present study demonstrates a potent anti-tumour activity of TSA/GEM combination against pancreatic cancer cells in vitro and in vivo, strongly supporting the use of GEM in combination with an HDAC inhibitor for pancreatic cancer therapy.