The Diverse Transformer (Trf) Protein Family in the Sea Urchin Paracentrotus lividus Acts through a Collaboration between Cellular and Humoral Immune Effector Arms

Sea urchins are long-living marine invertebrates with a complex innate immune system, which includes expanded families of immune receptors. A central immune gene family in sea urchins encodes the Transformer (Trf) proteins. The Trf family has been studied mainly in the purple sea urchin Strongylocentrotus purpuratus. Here, we explore this protein family in the Mediterranean Sea urchin Paracentrotus lividus. The PlTrf genes and predicted proteins are highly diverse and show a typical Trf size range and structure. Coelomocytes and cell-free coelomic fluid from P. lividus contain different PlTrf protein repertoires with a shared subset, that bind specifically to E. coli. Using FACS, we identified five different P. lividus coelomocyte sub-populations with cell surface PlTrf protein expression. The relative abundance of the PlTrf-positive cells increases sharply following immune challenge with E. coli, but not following challenge with LPS or the sea urchin pathogen, Vibrio penaeicida. Phagocytosis of E. coli by P. lividus phagocytes is mediated through the cell-free coelomic fluid and is inhibited by blocking PlTrf activity with anti-SpTrf antibodies. Together, our results suggest a collaboration between cellular and humoral PlTrf-mediated effector arms in the P. lividus specific immune response to pathogens.     

Effect of Lactic Acid Bacteria Fermentation on Rosmarinic Acid and Antioxidant Properties of in vitro Shoot Culture of Orthosiphon aristatus as a Model Study

In vitro shoot culture of Orthosiphon aristatus was selected as a model system for lactic acid bacteria (LAB) fermentation study. This in vitro plant was subjected to different types of LAB fermentations (Lactobacillus plantarum ATCC 8014 and Lactobacillus acidophilus NCFM) for a different time periods of 24, 48, and 72 h at 37^oC. The LAB fermentations consisted of solid state fermentations in a climatic incubator and liquid state of fermentations in a DCU fermenter system. The aim was to determine the effect of fermentation on antioxidant properties of the in vitro plant extract. Results indicate that all types of LAB fermentation decreased the level of rosmarinic acid and total phenolic compounds; however, a slight increase in total flavonoids and flavonols was observed in solid state fermentations samples. The highest reduction was obtained in the sample of liquid state fermentation inoculated with L. plantarum for a period of 72 h. The loss in rosmarinic acid and phenolics was concomitant with a loss of total antioxidant activity (DPPH, TEAC, and SOD-like activity). HPLC result confirmed that the longer fermentation was the greater reduction phenolic acids content was found. These results indicate LAB fermentation caused a decrease on antioxidant properties of in vitro shoot culture of Orthosiphon aristatus.     

Interaction of Alpha Synuclein and Microtubule Organization Is Linked to Impaired Neuritic Integrity in Parkinson’s Patient-Derived Neuronal Cells

Parkinson’s disease (PD) is neuropathologically characterized by the loss of dopaminergic neurons and the deposition of aggregated alpha synuclein (aSyn). Mounting evidence suggests that neuritic degeneration precedes neuronal loss in PD. A possible underlying mechanism could be the interference of aSyn with microtubule organization in the neuritic development, as implied by several studies using cell-free model systems. In this study, we investigate the impact of aSyn on microtubule organization in aSyn overexpressing H4 neuroglioma cells and midbrain dopaminergic neuronal cells (mDANs) generated from PD patient-derived human induced pluripotent stem cells (hiPSCs) carrying an aSyn gene duplication (SNCA^Dupl). An unbiased mass spectrometric analysis reveals a preferential binding of aggregated aSyn conformers to a number of microtubule elements. We confirm the interaction of aSyn with beta tubulin III in H4 and hiPSC-derived mDAN cell model systems, and demonstrate a remarkable redistribution of tubulin isoforms from the soluble to insoluble fraction, accompanied by a significantly increased insoluble aSyn level. Concordantly, SNCA^Dupl mDANs show impaired neuritic phenotypes characterized by perturbations in neurite initiation and outgrowth. In summary, our findings suggest a mechanistic pathway, through which aSyn aggregation interferes with microtubule organization and induces neurite impairments.     

Effects of social support and personality on emotional disclosure on Facebook and in real life

This paper focuses on the roles of personality and social support in affecting the extent of emotional disclosure in social media (SM) and compares them to those in face-to-face encounters. Specifically, we consider the effects of the Big Five personality traits and perceptions of social support from friends, significant others, and family on the extent of sharing positive and negative emotions on Facebook (FB) vs. real life (RL). The data are collected via an online survey of a broad demographic range of FB users. Our findings suggest that certain personality traits (extroversion, agreeableness, and conscientiousness), as well as perceived social support from friends, are significantly related to the disclosure of positive emotions on FB. We also report and discuss the differences between drivers of emotional disclosure in SM and RL, as well as offer suggestions for future research.     

Nanobiosensors based on individual olfactory receptors

The animal olfactory system represents the gold standard of biosensors, due to its ability to identify and discriminate thousands of odorant compounds with very low thresholds. Using olfactory receptors (ORs) as sensing elements instead of chemical sensors, biosensors would benefit the naturally optimized molecular recognition of odorants to develop a new generation of bioelectronic noses. The purpose of SPOT-NOSED European project was the development of nanobiosensors based on single ORs anchored between nanoelectrodes, to mimic the performances of natural olfactory system. Nanobiosensors arrays could then increase odorant sensitivity or widen the odorant detection spectrum. ORs were expressed in yeasts plasmic membrane, and their functionality tested in whole yeasts. Then, nanosomes bearing the ORs were prepared from S. cerevisiae, and Surface Plasmon Resonance was performed on nanosomes for quantitative evaluation of OR response to odorant stimulation. ORs retain full activity and discrimination power in immobilized nanosomes, thus allowing their use in the fabrication of the nanobiosensors. Nanoelectrodes were fabricated using conventional photolithography and focused ion beam milling, with sizes in adequation with the nanosomes. ORs borne by nanosomes were specifically immobilized onto conducting substrates via mixed Self Assembled Monolayers, neutravidin and specific antibody to the ORs. The process was optimized by microcontact printing, and the anchored nanovesicles visualized by Atomic Force Microscopy. A transimpedance preamplifier suited for low-noise wide-bandwidth measurements was designed to be directly connected to the nanoelectrodes. Electrochemical Impedancemetric Spectroscopy detected significant changes upon electrodes functionalization, grafting of ORs carried by nanosomes, and ORs conformational change induced by odorant binding.     

Use of Desulfovibrio and Escherichia coli Pd‐nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil

BACKGROUND: Desulfovibrio spp. biofabricate metallic nanoparticles (e.g. ‘Bio‐Pd’) which catalyse the reduction of Cr(VI) to Cr(III) and dehalogenate polychlorinated biphenyls (PCBs). Desulfovibrio spp. are anaerobic and produce H₂S, a potent catalyst poison, whereas Escherichia coli can be pre‐grown aerobically to high density, has well defined molecular tools, and also makes catalytically‐active ‘Bio‐Pd’. The first aim was to compare ‘Bio‐Pd’ catalysts made by Desulfovibrio spp. and E. coli using suspended and immobilized catalysts. The second aim was to evaluate the potential for Bio‐Pd‐mediated dehalogenation of PCBs in used transformer oils, which preclude recovery and re‐use. RESULTS: Catalysis via Bio‐Pd_{D.desulfuricans} and Bio‐Pd_E.coli was compared at a mass loading of Pd:biomass of 1:3 via reduction of Cr(VI) in aqueous solution (immobilized catalyst) and hydrogenolytic release of Cl^? from PCBs and used transformer oil (catalyst suspensions). In both cases Bio‐Pd_{D.desulfuricans} outperformed Bio‐Pd_E.coli by ～3.5‐fold, attributable to a ～3.5‐fold difference in their Pd‐nanoparticle surface areas determined by magnetic measurements (Bio‐Pd_{D.desulfuricans}) and by chemisorption analysis (Bio‐Pd_E.coli). Small Pd particles were confirmed on D. desulfuricans and fewer, larger ones on E. coli via electron microscopy. Bio‐Pd_{D.desulfuricans}‐mediated chloride release from used transformer oil (5.6 ± 0.8 µg mL^?1) was comparable with that observed using several PCB reference materials. CONCLUSIONS: At a loading of 1:3 Pd:biomass Bio‐Pd_{D.desulfuricans} is 3.5‐fold more active than Bio‐Pd_E.coli, attributable to the relative catalyst surface areas reflected in the smaller nanoparticle sizes of the former. This study also shows the potential of Bio‐Pd_{D.desulfuricans} to remediate used transformer oil. Copyright © 2012 Society of Chemical Industry     

Microscopic evaluation of vesicles shed by erythrocytes at elevated temperatures

The images of human erythrocytes and vesicles were analyzed by a light microscopy system with spatial resolution of better than 90 nm. The samples were observed in an aqueous environment and required no freezing, dehydration, staining, shadowing, marking, or any other manipulation. Temperature elevation resulted in significant concentration increase of structurally transformed erythrocytes (echinocytes) and vesicles in the blood. The process of vesicle separation from spiculated erythrocytes was video recorded in real time. At a temperature of 37°C, mean vesicle concentrations and diameters were found to be 1.50 ± 0.35 × 10⁶ vesicles per microliter and 0.365 ± 0.065 μm, respectively. The vesicle concentration increased approximately threefold as the temperature increased from 37 to 40°C. It was estimated that 80% of all vesicles found in the blood are smaller than 0.4 μm. Accurate account of vesicle numbers and dimensions suggest that 86% of the lost erythrocyte material is lost not by vesiculation but by another, as yet, unknown mechanism. Microsc. Res. Tech. 76:1163–1170, 2013. © 2013 Wiley Periodicals, Inc.     

Impact of processing of red beet on betalain content and antioxidant activity

Red beet has high concentration betalains that are used as food colorants and food additives due to their health promoting properties. Redbeet is generally processed before consumption which influences the stability of betalains in turn which affects the acceptability and health properties. The objective of the study was to investigate the influence of processing techniques as microwaving, boiling, roasting and vacuuming on the red beet. The impact of processing was evaluated on the basis of belatains content and antioxidant activity of the processed samples. With spectrophotometric results betalains content were found to add up to 20% with vacuum treatment and also with microwave treatment of 900 W and 1800 W for 30 s up to7% and 19% respectively, however there was decrease in boiling and roasting treatments. With HPLC analyses the content of betanin seems to increase in microwave treatments with 450 W and 900 W but reduced with 1800 W. In the case of antioxidant activity there was 2 to 3 fold increase in boiling, roasting and microwave treatments as compared to the control.     

Surface modification of silver microparticles with 4-thioaniline

Silver microparticles have been prepared by chemical reduction method onto a rotating copper disc. It was found that in the presence of polyvinylpyrrolidone (PVP) in the initial AgNO₃ aqueous solution the radius of the Ag particles decreased from 1.18 to 0.48 μm and the formation of dendritic clusters with the fractal dimension of 1.61 occurred. The two-stage modification of the surface of synthesized silver particles with bifunctional 4-thioaniline (TAn) and further grafting of polyaniline (PAn) chains to the end amino-group of formed self-assembled surface layer were carried out. The modified surfaces were studied by scanning electron microscopy and X-ray diffraction methods, the physico-chemical properties of the formed products have been investigated. The obtained results indicate that the highest thermal stability is displayed by the silver particles produced in the presence of PVP, while the sample with grafted polyaniline exhibits the lowest thermal stability among the investigated samples. The reactivity of TAn has been examined by cyclic voltammetric method. In contrast to aniline, the electrochemical oxidation of TAn did not result in the formation of an electroconductive film on Pt electrode. It was found that oxidative condensation of aniline is suppresses by the TAn: when the molar ratio of aniline/TAn is 2:1 the formation of an electrochemically active product is stopped. The phenomenon of inhibition of the oxidative polymerization of aniline with TAn is related to an impossibility of growing of polymeric chains in the result of the “head-to-tail” type of bonding of the thioaniline links.