MTHFR C677T polymorphism in chronic pancreatitis and pancreatic adenocarcinoma

Chronic pancreatitis and pancreatic adenocarcinoma are extensively studied as common and potentially lethal disorders. However, their causes and genetic background in most cases remain unclear. The C677T polymorphism in 5',10'-methylenetetrahydrofolate reductase (MTHFR) gene may modulate the risk of pancreatic disorders. In this study, we tested whether MTHFR C677T polymorphism is associated with chronic pancreatitis and pancreatic adenocarcinoma in the Serbian population. DNA was extracted from blood samples of 51 chronic pancreatitis patients, 21 pancreatic adenocarcinoma patients, and a control group consisting of 50 healthy smokers. The MTHFR C677T polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Although, no statistically significant differences were observed in the distribution of MTHFR genotype or allele frequencies between patients and control groups, the results showed an increased frequency of homozygotes for MTHFR C677T polymorphism in chronic pancreatitis patients (14%) and a decreased frequency in pancreatic adenocarcinoma patients (5%) in comparison to the control group (8%). We speculate that the MTHFR C677T polymorphism could act as a possible risk factor for chronic pancreatitis and a possible protective factor in pancreatic adenocarcinoma. This observation needs further investigation in prospective studies on a larger number of patients, in which the effect of other genetic and environmental factors should also be taken into consideration.     

TGF-β1 increases invasiveness of SW1990 cells through Rac1/ROS/NF-κB/IL-6/MMP-2

Post-translational acetylation is an important molecular regulatory mechanism affecting the biological activity of proteins. Polypeptide GalNAc transferases (ppGalNAc-Ts) are a family of enzymes that catalyze initiation of mucin-type O-glycosylation. All ppGalNAc-Ts in mammals are type II transmembrane proteins having a Golgi lumenal region that contains a catalytic domain with glycosyltransferase activity, and a C-terminal R-type (“ricin-like”) lectin domain. We investigated the effect of acetylation on catalytic activity of glycosyltransferase, and on fine carbohydrate-binding specificity of the R-type lectin domain of ppGalNAc-T2. Acetylation effect on ppGalNAc-T2 biological activity in vitro was studied using a purified human recombinant ppGalNAc-T2. Mass spectrometric analysis of acetylated ppGalNAc-T2 revealed seven acetylated amino acids (K103, S109, K111, K363, S373, K521, and S529); the first five are located in the catalytic domain. Specific glycosyltransferase activity of ppGalNAc-T2 was reduced 95% by acetylation. The last two amino acids, K521 and S529, are located in the lectin domain, and their acetylation results in alteration of the carbohydrate-binding ability of ppGalNAc-T2. Direct binding assays showed that acetylation of ppGalNAc-T2 enhances the recognition to αGalNAc residue of MUC1αGalNAc, while competitive assays showed that acetylation modifies the fine GalNAc-binding form of the lectin domain. Taken together, these findings clearly indicate that biological activity (catalytic capacity and glycan-binding ability) of ppGalNAc-T2 is regulated by acetylation.     

Impedimetric immunosensor for the specific label free detection of ciprofloxacin antibiotic

Impedance spectroscopy approaches combined with the immunosensor technology have been used for the determination of trace amounts of ciprofloxacin antibiotic belonging to the fluoroquinolone family. The sensor electrode was based on the immobilization of anti-ciprofloxacin antibodies by chemical binding onto a poly(pyrrole-NHS) film electrogenerated on a solid gold substrate. The electrode surface was modified by electropolymerization of pyrrole-NHS, antibody grafting and ciprofloxacin immunoreaction. The sensitive steps of surface modification, cyclic voltammetry (CV) and atomic force microscopy (AFM) imaging have been used for electrode surface characterization. The immunoreaction of ciprofloxacin on the grafted anti-ciprofloxacin antibody directly triggers a signal via impedance spectroscopy measurements which allows the detection of extremely low concentration of 10 pg/ml ciprofloxacin.     

Minor contribution of leaf litter to N nutrition of beech (Fagus sylvatica) seedlings in a mountainous beech forest of Southern Germany

Aims

Our aims were to characterize the fate of leaf-litter-derived nitrogen in the plant-soil-microbe system of a temperate beech forest of Southern Germany and to identify its importance for N nutrition of beech seedlings.

Methods

¹⁵N-labelled leaf litter was traced in situ into abiotic and biotic N pools in mineral soil as well as into beech seedlings and mycorrhizal root tips over three growing seasons.

Results

There was a rapid transfer of ¹⁵N into the mineral soil already 21 days after tracer application with soil microbial biomass initially representing the dominant litter-N sink. However, ¹⁵N recovery in non-extractable soil N pools strongly increased over time and subsequently became the dominant ¹⁵N sink. Recovery in plant biomass accounted for only 0.025 % of ¹⁵N excess after 876 days. After three growing seasons, ¹⁵N excess recovery was characterized by the following sequence: non-extractable soil N?>>?extractable soil N including microbial biomass?>>?plant biomass?>?ectomycorrhizal root tips.

Conclusions

After quick vertical dislocation and cycling through microbial N pools, there was a rapid stabilization of leaf-litter-derived N in non-extractable N pools of the mineral soil. Very low ¹⁵N recovery in beech seedlings suggests a high importance of other N sources such as root litter for N nutrition of beech understorey.     

Soil and root nutrient chemistry structure root-associated fungal assemblages in temperate forests

Root-associated fungi (RAF) link nutrient fluxes between soil and roots and thus play important roles in ecosystem functioning. To enhance our understanding of the factors that control RAF, we fitted statistical models to explain variation in RAF community structure using data from 150 temperate forest sites covering a broad range of environmental conditions and chemical root traits. We found that variation in RAF communities was related to both root traits (e.g., cations, carbohydrates, NO₃⁻) and soil properties (pH, cations, moisture, C/N). The identified drivers were the combined result of distinct response patterns of fungal taxa (determined at the rank of orders) to biotic and abiotic factors. Our results support that RAF community variation is related to evolutionary adaptedness of fungal lineages and consequently, drivers of RAF communities are context-dependent.     

Empathy manipulation impacts music-induced emotions: a psychophysiological study on opera

This study investigated the effects of voluntarily empathizing with a musical performer (i.e., cognitive empathy) on music-induced emotions and their underlying physiological activity. N = 56 participants watched video-clips of two operatic compositions performed in concerts, with low or high empathy instructions. Heart rate and heart rate variability, skin conductance level (SCL), and respiration rate (RR) were measured during music listening, and music-induced emotions were quantified using the Geneva Emotional Music Scale immediately after music listening. Listening to the aria with sad content in a high empathy condition facilitated the emotion of nostalgia and decreased SCL, in comparison to the low empathy condition. Listening to the song with happy content in a high empathy condition also facilitated the emotion of power and increased RR, in comparison to the low empathy condition. To our knowledge, this study offers the first experimental evidence that cognitive empathy influences emotion psychophysiology during music listening.     

Molecular diversity and phylogeny of indigenous <Emphasis Type="Italic">Rhizobium leguminosarum</Emphasis> strains associated with <Emphasis Type="Italic">Trifolium repens</Emphasis> plants in Romania

The symbiotic nitrogen fixing legumes play an essential role in sustainable agriculture. White clover (Trifolium repens L.) is one of the most valuable perennial legumes in pastures and meadows of temperate regions. Despite its great agriculture and economic importance, there is no detailed available information on phylogenetic assignation and characterization of rhizobia associated with native white clover plants in South-Eastern Europe. In the present work, the diversity of indigenous white clover rhizobia originating in 11 different natural ecosystems in North-Eastern Romania were assessed by a polyphasic approach. Initial grouping showed that, 73 rhizobial isolates, representing seven distinct phenons were distributed into 12 genotypes, indicating a wide phenotypic and genotypic diversity among the isolates. To clarify their phylogeny, 44 representative strains were used in sequence analysis of 16S rRNA gene and IGS fragments, three housekeeping genes (atpD, glnII and recA) and two symbiosis-related genes (nodA and nifH). Multilocus sequence analysis (MLSA) phylogeny based on concatenated housekeeping genes delineated the clover isolates into five putative genospecies. Despite their diverse chromosomal backgrounds, test strains shared highly similar symbiotic genes closely related to Rhizobium leguminosarum biovar trifolii. Phylogenies inferred from housekeeping genes were incongruent with those of symbiotic genes, probably due to occurrence of lateral transfer events among native strains. This is the first polyphasic taxonomic study to report on the MLSA-based phylogenetic diversity of indigenous rhizobia nodulating white clover plants grown in various soil types in South-Eastern Europe. Our results provide valuable taxonomic data on native clover rhizobia and may increase the pool of genetic material to be used as biofertilizers.     

Erythrocyte Phospholipid and Polyunsaturated Fatty Acid Composition in Diabetic Retinopathy

Background

Long chain polyunsaturated fatty acids (LCPUFAs) including docosahexaenoic acid and arachidonic acid are suspected to play a key role in the pathogenesis of diabetes. LCPUFAs are known to be preferentially concentrated in specific phospholipids termed as plasmalogens. This study was aimed to highlight potential changes in the metabolism of phospholipids, and particularly plasmalogens, and LCPUFAs at various stages of diabetic retinopathy in humans.

Methodology and Principal Findings

We performed lipidomic analyses on red blood cell membranes from controls and mainly type 2 diabetes mellitus patients with or without retinopathy. The fatty acid composition of erythrocytes was determined by gas chromatography and the phospholipid structure was determined by liquid chromatography equipped with an electrospray ionisation source and coupled with a tandem mass spectrometer (LC-ESI-MS/MS). A significant decrease in levels of docosahexaenoic acid and arachidonic acid in erythrocytes of diabetic patients with or without retinopathy was observed. The origin of this decrease was a loss of phosphatidyl-ethanolamine phospholipids esterified with these LCPUFAs. In diabetic patients without retinopathy, this change was balanced by an increase in the levels of several phosphatidyl-choline species. No influence of diabetes nor of diabetic retinopathy was observed on the concentrations of plasmalogen-type phospholipids.

Conclusions and Significance

Diabetes and diabetic retinopathy were associated with a reduction of erythrocyte LCPUFAs in phosphatidyl-ethanolamines. The increase of the amounts of phosphatidyl-choline species in erythrocytes of diabetic patients without diabetic retinopathy might be a compensatory mechanism for the loss of LC-PUFA-rich phosphatidyl-ethanolamines.     

Nitrogen nutrition of beech forests in a changing climate: importance of plant-soil-microbe water,carbon, and nitrogen interactions

Background

For 15+ years, a beech (Fagus sylvatica L.) dominated forest on calcareous soil was studied on two opposing slopes with contrasting microclimate in Tuttlingen, Swabian Alb, Germany. The cool-humid NE aspect of these slopes represents the majority of beech forests under current climate, the warmer and drier SW aspect represents beech forests under future climate conditions. The field studies were supplemented by investigations under controlled conditions.

Scope

The research program aimed to provide a comprehensive understanding of plant-soil-microbe water, carbon and nitrogen feedbacks in a changing climate and a holistic view of the sensitivity of beech to climate change.

Conclusions

The results of comparative and experimental studies underpin the high vulnerability of adult beech and its natural regeneration on calcareous soil to both direct climate change effects on plant physiology and indirect effects mediated by soil biogeochemical cycles. Mechanisms contributing to this vulnerability at the ecosystem and organismic level indicate a high significance of competitive interactions of beech with other vegetation components and soil microbial communities. Obvious forest management practices such as selective felling did not necessarily counteract negative effects of climate change.