Alpha-methylated derivatives of 2-arachidonoyl glycerol: synthesis, CB1 receptor activity, and enzymatic stability

Alpha-methylated analogues of the endogenous cannabinoid, 2-arachidonoyl glycerol (2-AG), were synthesized aiming to the improved enzymatic stability of 2-AG. In addition, the CB1 activity properties of fluoro derivatives of 2-AG were studied. The CB1 receptor activity was determined by the [35S]GTPgammaS binding assay, and the enzymatic stability of alpha-methylated analogues was determined in rat cerebellar membranes. The results indicate that even if the alpha-methylated 2-AG derivatives are slightly weaker CB1 receptor agonists than 2-AG, they are clearly more stable than 2-AG. In addition, the results showed that the replacement of the hydroxyl group(s) of 2-AG by fluorine does not improve the CB1 activity of 2-AG.     

Estimation of breed contributions to present and future genetic diversity of 44 North Eurasian cattle breeds using core set diversity measures

Extinction of breeds threatens genetic diversity of livestock species. The need to conserve genetic diversity is widely accepted but involves in general two questions: (i) is the expected loss of diversity in a set of breeds within a defined future time horizon large enough to establish a conservation plan, and if so (ii) which breeds should be prioritised for such a conservation plan? The present study uses a marker assisted methodology to address these questions. The methodology combines core set diversity measures with a stochastic method for the estimation of expected future diversity and breed marginal diversities. The latter is defined as the change in the total diversity of all breeds caused by a one unit decrease in extinction probability of a particular breed. The stochastic method was validated by means of simulations. A large field data set consisting of 44 North Eurasian cattle breeds was analysed using simplified determined extinction probabilities. The results show that the expected loss of diversity in this set within the next 20 to 50 years is between 1 and 3% of the actual diversity, provided that the extinction probabilities which were used are approximately valid. If this loss is to be reduced, it is sufficient to include those three to five breeds with the highest marginal diversity in a conservation scheme.     

Higher Free Fatty Acid Uptake in Visceral Than in Abdominal Subcutaneous Fat Tissue in Men

Visceral adipose tissue has been shown to have high lipolytic activity. The aim of this study was to examine whether free fatty acid (FFA) uptake into visceral adipose tissue is enhanced compared to abdominal subcutaneous tissue in vivo. Abdominal adipose tissue FFA uptake was measured using positron emission tomography (PET) and [¹⁸F]‐labeled 6‐thia‐hepta‐decanoic acid ([¹⁸F]FTHA) and fat masses using magnetic resonance imaging (MRI) in 18 healthy young adult males. We found that FFA uptake was 30% higher in visceral compared to subcutaneous adipose tissue (0.0025 ± 0.0018 vs. 0.0020 ± 0.0016 µmol/g/min, P = 0.005). Visceral and subcutaneous adipose tissue FFA uptakes were strongly associated with each other (P < 0.001). When tissue FFA uptake per gram of fat was multiplied by the total tissue mass, total FFA uptake was almost 1.5 times higher in abdominal subcutaneous than in visceral adipose tissue. In conclusion, we observed enhanced FFA uptake in visceral compared to abdominal subcutaneous adipose tissue and, simultaneously, these metabolic rates were strongly associated with each other. The higher total tissue FFA uptake in subcutaneous than in visceral adipose tissue indicates that although visceral fat is active in extracting FFA, its overall contribution to systemic metabolism is limited in healthy lean males. Our results indicate that subcutaneous, rather than visceral fat storage plays a more direct role in systemic FFA availability. The recognized relationship between abdominal visceral fat mass and metabolic complications may be explained by direct effects of visceral fat on the liver.     

The European radiobiological archives: online access to data from radiobiological experiments

For financial and ethical reasons, the large-scale radiobiological animal studies conducted over the past 50 years are, to a large extent, unrepeatable experiments. It is therefore important to retain the primary data from these experiments to allow reanalysis, reinterpretation and re-evaluation of results from, for example, carcinogenicity studies, in the light of new knowledge in radiation biology. Consequently, there is an imperative need to keep these data available for the research community. The European Radiobiological Archives (ERA) were developed to fulfill this task. ERA has become a unique archive, including information from almost all European long-term studies carried out between the 1960s and the 1990s. The legacy database was originally developed in a manner that precluded online use. Therefore, strong efforts were made to transform it into a version that is available online through the web. This went together with quality assurance measures, including first the estimation of the rate of non-systematic errors in data entry, which at 2% proved to be very low. Second, every data set was compared against two external sources of information. Standardization of terminology and histopathology is a prerequisite for meaningful comparison of data across studies and analysis of potential carcinogenic effects. Standardization is particularly critical for the construction of a database that includes data from different studies evaluated by pathologists in different laboratories. A harmonized pathology nomenclature with modern standard pathology terms was introduced. As far as possible, references for the various studies were directly linked to the studies themselves. Further, a direct link to the JANUS database was established. ERA is now in a position where it has the potential to become a worldwide radiobiological research tool. ERA can be accessed at no cost at https://era.bfs.de. An ID and password can be obtained from the curators at era@bfs.de .     

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.     

Chlorophyllase 1, a damage control enzyme, affects the balance between defense pathways in plants

Accumulation of reactive oxygen species (ROS) is central to plant response to several pathogens. One of the sources of ROS is the chloroplast because of the photoactive nature of the chlorophylls. Chlorophyllase 1 (encoded by AtCLH1) of Arabidopsis thaliana is quickly induced after tissue damage (e.g., caused by the bacterial necrotroph Erwinia carotovora or the necrotrophic fungus Alternaria brassicicola). RNA interference silencing of AtCLH1 resulted in failure to degrade free chlorophyll after tissue damage and in resistance to E. carotovora. Both inoculation with E. carotovora and exposure to high light caused elevated accumulation of hydrogen peroxide in AtCLH1 silenced plants. This was accompanied by expression of marker genes for systemic acquired resistance and induction of antioxidant defenses. Interestingly, downregulation of AtCLH1 resulted in increased susceptibility to A. brassicicola, resistance to which requires jasmonate signaling. We propose that AtCLH1 is involved in plant damage control and can modulate the balance between different plant defense pathways.     

A trade-off between current and future sex allocation revealed by maternal energy budget in a small mammal

Sex-allocation theories generally assume differential fitness costs of raising sons and daughters. Yet, experimental confirmation of such costs is scarce and potential mechanisms are rarely addressed. While the most universal measure of physiological costs is energy expenditure, only one study has related the maternal energy budget to experimentally controlled offspring sex. Here, we experimentally test this in the bank vole (Myodes glareolus) by simultaneously manipulating the litter's size and sex ratio immediately after birth. Two weeks after manipulation, when mothers were at the peak of lactation and were pregnant with concurrent litters, we assessed their energy budget. We found that maternal food consumption and daily energy expenditure increased with the size of the litters being lactated. Importantly, the effects of offspring sex on energy budget depended on the characteristics of the simultaneously gestating litters. Specifically, the mothers nursing all-male litters and concurrently pregnant with male-biased litters had the highest energy expenditure. These had consequences for the next generation, as size of female offspring from the concurrent pregnancy of these mothers was compromised. Our study attests a higher cost of sons, consequently leading to a lower investment in them, and reveals the significance of offspring sex in moulding the trade-off between current and future maternal investment.     

Contribution of ARLTS1 Cys148Arg (T442C) variant with prostate cancer risk and ARLTS1 function in prostate cancer cells

ARLTS1 is a recently characterized tumor suppressor gene at 13q14.3, a region frequently deleted in both sporadic and hereditary prostate cancer (PCa). ARLTS1 variants, especially Cys148Arg (T442C), increase susceptibility to different cancers, including PCa. In this study the role of Cys148Arg substitution was investigated as a risk factor for PCa using both genetic and functional analysis. Cys148Arg genotypes and expression of the ARLTS1 were explored in a large set of familial and unselected PCa cases, clinical tumor samples, xenografts, prostate cancer cell lines and benign prostatic hyperplasia (BPH) samples. The frequency of the variant genotype CC was significantly higher in familial (OR = 1.67, 95% CI = 1.08–2.56, P = 0.019) and unselected patients (OR = 1.52, 95% CI = 1.18–1.97, P = 0.001) and the overall risk was increased (OR = 1.54, 95% CI = 1.20–1.98, P = 0.0007). Additional analysis with clinicopathological data revealed an association with an aggressive disease (OR = 1.28, 95% CI = 1.05-∞, P = 0.02). The CC genotype of the Cys148Arg variant was also contributing to the lowered ARLTS1 expression status in lymphoblastoid cells from familial patients. In addition significantly lowered ARLTS1 expression was observed in clinical tumor samples compared to BPH samples (P = 0.01). The ARLTS1 co-expression signature based on previously published microarray data was generated from 1587 cancer samples confirming the low expression of ARLTS1 in PCa and showed that ARLTS1 expression was strongly associated with immune processes. This study provides strong confirmation of the important role of ARLTS1 Cys148Arg variant as a contributor in PCa predisposition and a potential marker for aggressive disease outcome.     

Base 2661 in Escherichia coli 23S rRNA influences the binding of elongation factor Tu during protein synthesis in vivo.

The binding of the EF-Tu.GTP.aminoacyl-tRNA ternary complex (EF, elongation factor) to the ribosome is known to be strengthened by a 2661G-to-C mutation in 23S ribosomal RNA, whereas the binding to normal ribosomes is weakened if the factor is in an appropriate mutant form (Aa). In this report we describe the mutual effects by the 2661C alteration in 23S rRNA and EF-Tu(Aa) on bacterial viability and translation efficiency in strains with normal or mutationally altered ribosomes. The rrnB(2661C) allele on a multicopy plasmid was introduced by transformation into Escherichia coli K-12 strains, harbouring either the wild-type or the mutant gene (tufA) for EF-Tu as well as normal or mutant ribosomal protein S12 (rpsL). Together with wild-type EF-Tu, the 2661C mutant ribosomes decreased the translation elongation rate in a rpsL+ strain or a non-restrictive rpsL224 strain. This reduction was not seen in strains which harbored EF-Tu(Aa) instead of EF-Tu(As) (As, wild-type form). Nonsense codon suppression by tyrT(Su3) suppressor tRNA was reduced by 2661C in a rpsL224 strain in the presence of EF-Tu(As) but not in the presence of EF-Tu(Aa). The lethal effect obtained by the combination of 2661C and a restrictive ribosomal protein S12 mutation (rpsL282) disappeared if EF-Tu(As) was replaced by EF-Tu(Aa) in the strain. In such a viable strain, 2661C had no effect on either the translation elongation rate or nonsense codon suppression. Our data suggest that the G base at position 2661 in 23S rRNA is important for binding of EF-Tu during protein synthesis in vivo. The interaction between this base and EF-Tu is strongly influenced by the structure of ribosomal protein S12.     

Amyloid-beta 1-42 induced endocytosis and clusterin/apoJ protein accumulation in cultured human astrocytes

Recent studies indicate that astrocytes may be the primary target of secreted amyloid-beta 1-42 peptides, with the neurotoxicity representing a secondary response to astrocytic stress. Our purpose was to clarify the astrocytic stress response induced by amyloid-beta peptides in human and rat astrocytes. Human amyloid-beta 1-42 peptides and fibrils induced the appearance of cytoplasmic vacuoles in normal human astrocytes (NHA) and CCFsttg1 astrocytoma cells. Vacuoles appeared 9-12h after the amyloid-beta exposure and remained present for several days. Rat primary neonatal astrocytes showed similar but less prominent vacuolar response. Human amyloid-beta peptides 1-16, 1-28, 10-20, 17-21 and 25-35 did not cause vacuole formation. Electron microscopic observations revealed large endocytic vacuoles containing fibrillar amyloid material. Stress marker analysis did not show any increase in protein levels of HSP70, HSP90, GRP78 and GRP94. However, the protein level of clusterin/apoJ, a secreted chaperone, was strongly increased both in NHA and CCFsttg1 astrocytes. Endocytic response associated with the accumulation of clusterin/apoJ protein suggests that clusterin/apoJ has a role in the clearance of amyloid-beta peptides.