Differential Effects of apoE4 and Activation of ABCA1 on Brain and Plasma Lipoproteins

Apolipoprotein E4 (apoE4), the leading genetic risk factor for Alzheimer''s disease (AD), is less lipidated compared to the most common and AD-benign allele, apoE3. We have recently shown that i.p. injections of the ATP-binding cassette A1 (ABCA1) agonist peptide CS-6253 to apoE mice reverse the hypolipidation of apoE4 and the associated brain pathology and behavioral deficits. While in the brain apoE is the main cholesterol transporter, in the periphery apoE and apoA-I both serve as the major cholesterol transporters. We presently investigated the extent to which apoE genotype and CS-6253 treatment to apoE3 and apoE4-targeted replacement mice affects the plasma levels and lipid particle distribution of apoE, and those of plasma and brain apoA-I and apoJ. This revealed that plasma levels of apoE4 were lower and eluted faster following FPLC than plasma apoE3. Treatment with CS-6253 increased the levels of plasma apoE4 and rendered the elution profile of apoE4 similar to that of apoE3. Similarly, the levels of plasma apoA-I were lower in the apoE4 mice compared to apoE3 mice, and this effect was partially reversed by CS-6253. Conversely, the levels of apoA-I in the brain which were higher in the apoE4 mice, were unaffected by CS-6253. The plasma levels of apoJ were higher in apoE4 mice than apoE3 mice and this effect was abolished by CS-6253. Similar but less pronounced effects were obtained in the brain. In conclusion, these results suggest that apoE4 affects the levels of apoA-I and apoJ and that the anti-apoE4 beneficial effects of CS-6253 may be related to both central and peripheral mechanisms.     

Ontogenetic integration between force production and force reception: a case study in Ctenomys (Rodentia: Caviomorpha)

During ontogeny, complex adaptations undergo changes that sometimes entail different functional capabilities. This fact constrains the behaviour of organisms at each developmental stage. Rodents have ever‐growing incisors for gnawing, and a powerful jaw musculature. The incisors are long enough, relative to their diameter, to be affected by bending stresses. This is particularly true in the subterranean Ctenomys that uses its incisors for digging. We measured bite force (BF) in individuals of different ages using a force transducer. We estimated incisor section modulus Z, a geometrical parameter proportional to bending strength. A relative strength indicator was calculated as S = Z/BF incisor length. We found that ontogenetic BF scales to body mass with positive allometry. However, an anova showed non‐significant differences in S, neither between sexes nor among age classes. This result implies that during growth, incisors might have a rather similar ability to withstand bending stresses from increasing masticatory forces, what may be considered evidence of ontogenetic integration of force production (by muscles) and force reception (by the incisors). This fact well correlates with the observation that pups and juveniles of C. talarum incorporate solid foods shortly after birth, and they are able to dig burrows early in life.     

Determination of T-2 toxin,HT-2 toxin,and three other type A trichothecenes in layer feed by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS)—comparison of two sample preparation methods

A sensitive method for the simultaneous determination of T-2 toxin, HT-2 toxin, neosolaniol, T-2 triol, and T-2 tetraol in layer feed using high-performance liquid chromatography coupled to triple quadrupole mass spectrometry in the positive ionization mode (LC-ESI-MS/MS) is described. Two fast and easy clean-up methods—with BondElut Mycotoxin and MycoSep 227 columns, respectively—were tested. The separation of the toxins was conducted on a Pursuit XRs Ultra 2.8 HPLC column using 0.13 mM ammonium acetate as eluent A and methanol as eluent B. Detection of the mycotoxins was carried out in the multiple reaction monitoring (MRM) mode using ammonium adducts as precursor ions. Quantification of all analytes was performed with d₃-T-2 toxin as an internal standard. The clean-up method with MycoSep 227 columns gave slightly better results for layer feed compared to the method using BondElut Mycotoxin columns (MycoSep 227: recovery between 50 and 63 %, BondElut Mycotoxin: recovery between 32 and 67 %) and was therefore chosen as the final method. The limits of detection ranged between 0.9 and 7.5 ng/g depending on the mycotoxin. The method was developed for the analysis of layer feed used at carry-over experiments with T-2 toxin in laying hens. For carry-over experiments, it is necessary that the method includes not only T-2 toxin but also the potential metabolites in animal tissues HT-2 toxin, neosolaniol, T-2 triol, and T-2 tetraol which could naturally occur in cereals used as feed stuff as well.     

Alpha-glucosidase inhibitory and antiplasmodial properties of terpenoids from the leaves of Buddleja saligna Willd

In our continuing search for biologically active natural product(s) of plant origin, Buddleja saligna, a South African medicinal plant, was screened in line with its traditional use for antidiabetic (yeast alpha glucosidase inhibitory) and antiplasmodial (against a chloroquine sensitive strain of Plasmodium falciparum (NF54)) activities. The hexane fraction showed the most promising activity with regards to its antidiabetic (IC₅₀?=?260?±?0.112?µg/ml) and antiplasmodial (IC₅₀?=?8.5?±?1.6?µg/ml) activities. Using activity guided fractionation three known terpenoids (betulonic acid, betulone and spinasterol) were isolated from this species for the first time. The compounds displayed varying levels of biological activities (antidiabetic: 27.31?µg/ml?≥?IC₅₀?≥?5.6?µg/ml; antiplasmodial: 14?µg/ml?≥?IC₅₀?≥?2?µg/ml) with very minimal toxicity.     

Deacylated lipopolysaccharides inhibit biofilm formation by Gram-negative bacteria

The extracellular polysaccharides of Vibrio vulnificus play different roles during biofilm development. Among them, the effect of lipopolysaccharide (LPS), which is crucial for bacterial adherence to surfaces during the initial stage of biofilm formation, on the formation process was examined using various types of LPS extracts. Exogenously added LPS strongly inhibited biofilm formation in a dose-dependent manner. In addition, the exogenous addition of a deacylated form of LPS (dLPS) also inhibited biofilm formation. However, an LPS fraction extracted from a mutant not able to produce O-antigen polysaccharides (O-Ag) did not have an inhibitory effect. Furthermore, biofilm formation by several Gram-negative bacteria was inhibited by dLPS addition. In contrast, biofilm formation by Gram-positive bacteria was not influenced by dLPS but was affected by lipoteichoic acid. Therefore, this study demonstrates that O-Ag in LPS is important for inhibiting biofilm formation and may serve an efficient anti-biofilm agent specific for Gram-negative bacteria.     

Driving Precision Medicine through Proteomics and Metabolomics - 12th Central and Eastern European Proteomic Conference (CEEPC), Bucharest,Romania

As Romanians prepared to celebrate 100 years of the '‘Great Unification of 1918?' which united all provinces into one Romania, the 12^th Central and Eastern European Proteomic Conference (CEEPC) jointly with the 39^th Anniversary of the Institute of Cellular Biology and Pathology '‘N. Simionescu’' (ICBP-NS), held their inaugural meeting at the Romanian Academy in Bucharest – a national forum of highest scientific recognition. With an exciting theme entitled, ‘Advances in Proteomics and Progress in Precision Medicine’, delegates gathered to debate Precision medicine’s revolution in diagnosis and treatment, which now accounts for predictive, preventative, and targeted treatment strategies with informed decisions according to individual’s unique clinical, molecular and genetic profile. Proteomics has a pivotal role to play in furthering precision health and medicine for the benefit of mankind. To this end, CEEPC continues to drive advances in proteomics, metabolomics, and diseases as well as raising awareness of pressing global humanitarian and health-care issues including mental health diseases, aging, chronic diseases, global epidemics and environmental issues. Today, CEEPC is a well-recognized major annual conference with a focused vision and a highly valued ideology as it continues to propagate scientific, medical and proteomic collaborations whilst expanding as more Eastern European countries prepare to join.     

Role of school climate and personality in the development of Czech adolescents’ political self-efficacy

This study examined the effects of school climate (open classroom and positive student relationships) and personality dispositions (shyness and need for cognition) on adolescents’ political self-efficacy. Data were collected in 2014 from 1,954 Czech ninth- and tenth-graders (mean age?=?15.60). A multilevel analysis showed that school-level political self-efficacy predicted self-efficacy for local politics. However, schools and classrooms were rather homogeneous in terms of students’ mean political self-efficacy and students’ self-reported acquisition of civic skills at school. Hence, school characteristics had only limited associations with adolescents’ political self-efficacy. At the same time, students’ political efficacy had a considerable association with lower shyness and higher need for cognition. These results suggest that the development of political efficacy at school goes beyond simple general influences of school environment and individual differences between students must be considered.     

Variations in yeast plasma‐membrane lipid composition affect killing activity of three families of insect antifungal peptides

Naturally occurring antimicrobial peptides and their synthetic analogues are promising candidates for new antifungal drugs. We focused on three groups of peptides isolated from the venom of bees and their synthetic analogues (lasioglossins, halictines and hylanines), which all rapidly permeabilised the plasma membrane. We compared peptides' potency against six pathogenic Candida species (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei and C. dubliniensis) and the non‐pathogenic model yeast Saccharomyces cerevisiae. Their activity was independent of the presence of the multidrug‐resistant pumps of C. glabrata but was influenced by the lipid composition of cell plasma membranes. Although the direct interaction of the peptides with ergosterol was negligible in comparison with amphotericin B, the diminished ergosterol content after terbinafine pretreatment resulted in an increased resistance of C. glabrata to the peptides. The tested peptides strongly interacted with phosphatidylglycerol, phosphatidic acid and cardiolipin and partly with phosphatidylinositol and phosphatidylethanolamine. The interactions between predominantly anionic phospholipids and cationic peptides indicated a mainly electrostatic binding of peptides to the membranes. The results obtained also pointed to a considerable role of the components of lipid rafts (composed from sphingolipids and ergosterol) in the interaction of yeast cells with the peptides.