Variation in the FFAR1 gene modifies BMI, body composition and plasma lipids but not plasma insulin or Beta-cell function in overweight subjects

Background FFAR1 receptor is a long chain fatty acid G-protein coupled receptor which is expressed widely, but found in high density in the pancreas and central nervous system. It has been suggested that FFAR1 may play a role in insulin sensitivity, lipotoxicity and is associated with type 2 diabetes. Here we investigate the effect of three common SNPs of FFAR1 (rs2301151; rs16970264; rs1573611) on pancreatic function, BMI, body composition and plasma lipids. Methodology/Principal Findings For this enquiry we used the baseline RISCK data, which provides a cohort of overweight subjects at increased cardiometabolic risk with detailed phenotyping. The key findings were SNPs of the FFAR1 gene region were associated with differences in body composition and lipids, and the effects of the 3 SNPs combined were cumulative on BMI, body composition and total cholesterol. The effects on BMI and body fat were predominantly mediated by rs1573611 (1.06 kg/m2 higher (P = 0.009) BMI and 1.53% higher (P = 0.002) body fat per C allele). Differences in plasma lipids were also associated with the BMI-increasing allele of rs2301151 including higher total cholesterol (0.2 mmol/L per G allele, P = 0.01) and with the variant A allele of rs16970264 associated with lower total (0.3 mmol/L, P = 0.02) and LDL (0.2 mmol/L, P<0.05) cholesterol, but also with lower HDL-cholesterol (0.09 mmol/L, P<0.05) although the difference was not apparent when controlling for multiple testing. There were no statistically significant effects of the three SNPs on insulin sensitivity or beta cell function. However accumulated risk allele showed a lower beta cell function on increasing plasma fatty acids with a carbon chain greater than six. Conclusions/Significance Differences in body composition and lipids associated with common SNPs in the FFAR1 gene were apparently not mediated by changes in insulin sensitivity or beta-cell function.

Variation in antibiotic-induced microbial recolonization impacts on the host metabolic phenotypes of rats

The interaction between the gut microbiota and their mammalian host is known to have far-reaching consequences with respect to metabolism and health. We investigated the effects of eight days of oral antibiotic exposure (penicillin and streptomycin sulfate) on gut microbial composition and host metabolic phenotype in male Han-Wistar rats (n = 6) compared to matched controls. Early recolonization was assessed in a third group exposed to antibiotics for four days followed by four days recovery (n = 6). Fluorescence in situ hybridization analysis of the intestinal contents collected at eight days showed a significant reduction in all bacterial groups measured (control, 1010.7 cells/g feces; antibiotic-treated, 108.4). Bacterial suppression reduced the excretion of mammalian-microbial urinary cometabolites including hippurate, phenylpropionic acid, phenylacetylglycine and indoxyl-sulfate whereas taurine, glycine, citrate, 2-oxoglutarate, and fumarate excretion was elevated. While total bacterial counts remained notably lower in the recolonized animals (109.1 cells/g faeces) compared to the controls, two cage-dependent subgroups emerged with Lactobacillus/Enterococcus probe counts dominant in one subgroup. This dichotomous profile manifested in the metabolic phenotypes with subgroup differences in tricarboxylic acid cycle metabolites and indoxyl-sulfate excretion. Fecal short chain fatty acids were diminished in all treated animals. Antibiotic treatment induced a profound effect on the microbiome structure, which was reflected in the metabotype. Moreover, the recolonization process was sensitive to the microenvironment, which may impact on understanding downstream consequences of antibiotic consumption in human populations.

Variation in the human Cannabinoid Receptor (CNR1) gene modulates gaze duration for happy faces

BACKGROUND: Humans from an early age look longer at preferred stimuli, and also typically look longer at facial expressions of emotion, particularly happy faces. Atypical gaze patterns towards social stimuli are common in Autism Spectrum Conditions (ASC). However, it is unknown if gaze fixation patterns have any genetic basis. In this study, we tested if variations in the cannabinoid receptor 1 (CNR1) gene are associated with gaze duration towards happy faces. This gene was selected because CNR1 is a key component of the endocannabinoid system, involved in processing reward, and in our previous fMRI study we found variations in CNR1 modulates the striatal response to happy (but not disgust) faces. The striatum is involved in guiding gaze to rewarding aspects of a visual scene. We aimed to validate and extend this result in another sample using a different technique (gaze tracking). METHODS: 30 volunteers (13 males, 17 females) from the general population observed dynamic emotion expressions on a screen while their eye movements were recorded. They were genotyped for the identical four SNPs in the CNR1 gene tested in our earlier fMRI study. RESULTS: Two SNPs (rs806377 and rs806380) were associated with differential gaze duration for happy (but not disgust) faces. Importantly, the allelic groups associated with greater striatal response to happy faces in the fMRI study were associated with longer gaze duration for happy faces. CONCLUSIONS: These results suggest CNR1 variations modulate striatal function that underlies the perception of signals of social reward such as happy faces. This suggests CNR1 is a key element in the molecular architecture of perception of certain basic emotions. This may have implications for understanding neurodevelopmental conditions marked by atypical eye contact and facial emotion processing, such as ASC.

Structure variation and evolution in microphase-separated grafted diblock copolymer films

The phase behavior of grafted d-polystyrene-block-poly(methyl methacrylate) diblock copolymer films is examined, with particular focus on the effect of solvent and annealing time. It was observed that the films undergo a two-step transformation from an initially disordered state, through an ordered metastable state, to the final equilibrium configuration. It was also found that altering the solvent used to wash the films, or complete removal of the solvent prior to thermal annealing using supercritical CO2, could influence the structure of the films in the metastable state, though the final equilibrium state was unaffected. To aid in the understanding to these experimental results, a series of self-consistent field theory calculations were done on a model diblock copolymer brush containing solvent. Of the different models examined, those which contained a solvent selective for the grafted polymer block most accurately matched the observed experimental behavior. We hypothesize that the structure of the films in the metastable state results from solvent enrichment of the film near the film/substrate interface in the case of films washed with solvent or faster relaxation of the nongrafted block for supercritical CO2 treated (solvent free) films. The persistence of the metastable structures was attributed to the slow reorganization of the polymer chains in the absence of solvent.

The effects of variation in snow properties on passive microwave snow mass estimation

Estimating snow mass at continental scales is difficult, but important for understanding land-atmosphere interactions, biogeochemical cycles and the hydrology of the Northern latitudes. Remote sensing provides the only consistent global observations, butwith unknown errors. Wetest the theoretical performance of the Chang algorithm for estimating snow mass from passive microwave measurements using the Helsinki University of Technology (HUT) snow microwave emission model. The algorithm's dependence upon assumptions of fixed and uniform snow density and grainsize is determined, and measurements of these properties made at the Cold Land Processes Experiment (CLPX) Colorado field site in 2002–2003 used to quantify the retrieval errors caused by differences between the algorithm assumptions and measurements. Deviation from the Chang algorithm snow density and grainsize assumptions gives rise to an error of a factor of between two and three in calculating snow mass. The possibility that the algorithm performsmore accurately over large areas than at points is tested by simulating emission from a 25 km diameter area of snow with a distribution of properties derived from the snow pitmeasurements, using the Chang algorithm to calculate mean snow-mass from the simulated emission. The snowmass estimation froma site exhibiting the heterogeneity of the CLPX Colorado site proves onlymarginally different than that from a similarly-simulated homogeneous site. The estimation accuracy predictions are tested using the CLPX field measurements of snow mass, and simultaneous SSM/I and AMSR-E measurements.

Cryopreservation of winter-dormant apple buds: 1 - variation in recovery with cultivar and winter conditions

The widely-adopted protocol for the cryopreservation of winter buds of fruit trees, such as Malus and Pyrus, was developed in a region with a continental climate, that provides relatively hard winters with a consequent effect on adaptive plant hardiness. In this study the protocol was evaluated in a typical maritime climate (eastern Denmark) where milder winters can be expected. The survival over two winters was evaluated, looking at variation between seasons and cultivars together with the progressive reduction in survival due to individual steps in the protocol. The study confirms that under such conditions significant variation in survival can be expected and that an extended period of imposed dehydration at -4oC is critical for bud survival. The occurrence of freezing events during this treatment suggests that cryodehydration may be involved, as well as evaporative water loss. To optimize the protocol for maritime environments, further investigation into the water status of the explants during cryopreservation is proposed. Keywords: Malus x domestica, cryopreservation, dormant bud, survival, grafting

A gene variation (rs12691) in the CCAT/enhancer building α modulates glucose metabolism in metabolic syndrome

Background and aims CCAAT/enhancer-binding protein alpha (CEBPA) is a transcription factor involved in adipogenesis and energy homeostasis. Caloric restriction reduces CEBPA protein expression in patients with metabolic syndrome (MetS). A previous report linked rs12691 SNP in CEBPA to altered concentration of fasting triglycerides. Our objective was to assess the effects of rs12691 in glucose metabolism in Metabolic Syndrome (MetS) patients. Methods and results Glucose metabolism was assessed by static (glucose, insulin, adiponectin, leptin and resistin plasma concentrations) and dynamic (disposition index, insulin sensitivity index, HOMA-IR and acute insulin response to glucose) indices, performed at baseline and after 12 weeks of 4 dietary interventions (high saturated fatty acid (SFA), high monounsaturated fatty acid (MUFA), low-fat and low-fat-high-n3 polyunsaturated fatty acid (PUFA)) in 486 subjects with MetS. Carriers of the minor A allele of rs12691 had altered disposition index (p = 0.0003), lower acute insulin response (p = 0.005) and a lower insulin sensitivity index (p = 0.025) indicating a lower insulin sensitivity and a lower insulin secretion, at baseline and at the end of the diets. Furthermore, A allele carriers displayed lower HDL concentration. Conclusion The presence of the A allele of rs12691 influences glucose metabolism of MetS patients. Clinical Trials Registry number NCT00429195.

Variation in the sensitivity of Callosobruchus (Coleoptera: Bruchidae) acetylcholinesterase to the organophosphate insecticide malaoxon: effect of species, geographical strain and food type

BACKGROUND: Bruchid beetles, Callosobruchus species, are serious pests of economically important grain legumes; their activity in stores is often controlled by use of synthetic insecticides. Esterases are known to be involved in insecticide resistance in insects. However, there is dearth of information on esterase activity in the genus Callosobruchus. In this study we investigated the effect of species, geographical strain and food type on the variation of acetylcholinesterase (AChE) activity and its inhibition by malaoxon (malathion metabolite) using an in vitro spectrophotometric method. RESULT: AChE activity varied significantly among species and strains and also among legume type used for rearing them. Generally irrespective of species, strain or food type, the higher the AChE activity of a population, the higher its inhibition by malaoxon. C. chinensis had the highest AChE activity of the species studied and in the presence of malaoxon it had the lowest remaining AChE activity, while C. rhodesianus retained the highest activity. CONCLUSION: A firsthand knowledge of AChE activity in regional Callosobruchus in line with the prevailing food types should be of utmost importance to grain legume breeders, researchers on plant materials for bruchid control and pesticide manufacturer/applicators for a robust integrated management of these bruchids.

Optical genetic mapping defines regions of chromosomal variation in serovars of S. enterica subsp enterica of concern for human and animal health

Infections involving Salmonella enterica subsp. enterica serovars have serious animal and human health implications; causing gastroenteritis in humans and clinical symptoms, such as diarrhoea and abortion, in livestock. In this study an optical genetic mapping technique was used to screen 20 field isolate strains from four serovars implicated in disease outbreaks. The technique was able to distinguish between the serovars and the available sequenced strains and group them in agreement with similar data from microarrays and PFGE. The optical maps revealed variation in genome maps associated with antimicrobial resistance and prophage content in S. Typhimurium, and separated the S. Newport strains into two clear geographical lineages defined by the presence of prophage sequences. The technique was also able to detect novel insertions that may have had effects on the central metabolism of some strains. Overall optical mapping allowed a greater level of differentiation of genomic content and spatial information than more traditional typing methods.

Identification of genetic and phenotypic differences associated with prevalent and non-prevalent Salmonella Enteritidis phage types: analysis of variation in amino acid transport

In this study, differences at the genetic level of 37 Salmonella Enteritidis strains from five phage types (PTs) were compared using comparative genomic hybridization (CGH) to assess differences between PTs. There were approximately 400 genes that differentiated prevalent (4, 6, 8 and 13a) and sporadic (11) PTs, of which 35 were unique to prevalent PTs, including six plasmid-borne genes, pefA, B, C, D, srgC and rck, and four chromosomal genes encoding putative amino acid transporters. Phenotype array studies also demonstrated that strains from prevalent PTs were less susceptible to urea stress and utilized L-histidine, L-glutamine, L-proline, L-aspartic acid, gly-asn and gly-gln more efficiently than PT11 strains. Complementation of a PT11 strain with the transporter genes from PT4 resulted in a significant increase in utilization of the amino acids and reduced susceptibility to urea stress. In epithelial cell association assays, PT11 strains were less invasive than other prevalent PTs. Most strains from prevalent PTs were better biofilm formers at 37 degrees C than at 28 degrees C, whilst the converse was true for PT11 strains. Collectively, the results indicate that genetic and corresponding phenotypic differences exist between strains of the prevalent PTs 4, 6, 8 and 13a and non-prevalent PT11 strains that are likely to provide a selective advantage for strains from the former PTs and could help them to enter the food chain and cause salmonellosis.

Effects of gelation temperature on the Mozzarella-type curd made from buffalo and cows’ milk. 1: Rheology & microstructure

The rheology and microstructure of Mozzarella-type curds made from buffalo and cows’ milk were measured at gelation temperatures of 28, 34 and 39 °C after chymosin addition. The maximum curd strength (G′) was obtained at a gelation temperature of 34 °C in both types of bovine milk. The viscoelasticity (tan δ) of both curds was increased with increasing gelation temperature. The rennet coagulation time was reduced with increase of gelation temperature in both types of milk. Frequency sweep data (0.1–10Hz was recorded 90 min after chymosin addition, and both milk samples showed characteristics of weak viscoelastic gel systems. When both milk samples were subjected to shear stress to break the curd system at constant shear rate, 95 min after chymosin addition, the maximum yield stress was obtained at the gelation temperatures of 34 °C and 28 °C in buffalo and cows’ curd respectively. The cryo-SEM and CLSM techniques were used to observe the microstructure of Mozzarella-type curd. The porosity was measured using image J software. The cryo-SEM and CLSM micrographs showed that minimum porosity was observed at the gelation temperature of 34 °C in both types of milk. Buffalo curd showed minimum porosity at similar gelation temperature when compared to cows’ curd. This may be due to higher protein concentration in buffalo milk.

Mozzarella-type curd made from buffalo, cows’ and ultrafiltered cows’ milk. 1. Rheology and microstructure

Rennet-induced curd was made from both natural buffalo and cows’ milk, and ultrafiltered cows’ milk (cows’ milk was concentrated such that it had a chemical composition approximately equivalent to that of the buffalo milk). These milk samples were compared on the basis of their rheology, physicochemical characteristics and curd microstructure. The ionic and soluble calcium contents were found to be similar in all milk samples studied. The total and casein bound calcium were higher in concentrated cows’ milk than in standard cows’ milk. Both cows’ milk types were found to have lower total and casein bound calcium than the buffalo milk. This is probably due to concentration of the colloidal part of milk (casein), during the ultrafiltration (UF) process. The rennet coagulation time was similar in UF cows’ and buffalo milk while both were shorter when compared with that of the cows’ milk. The dynamic moduli (G′, G″) values were higher in both the buffalo and UF cows’ milk than in the cows’ milk after 90 min coagulation. The loss tangent, however, was found to be similar in both the UF cows’ and buffalo milk curds and was lower than that observed for the cows’ milk (0.42, 0.42 and 0.48, respectively). The frequency profile of each type of curd was recorded 90 min after the enzyme addition (0.1–10 Hz); all samples were found to be “weak” viscoelastic, frequency dependent gels. The yield stress was also measured 95 min after the enzyme addition, and a higher value was observed in buffalo milk curd when compared with other curd samples made from both the natural cows’ milk and the UF cows’ milk. The cryo-scanning electron and confocal laser scanning micrographs showed that curd structure appeared to be more “dense” and less porous in buffalo milk than cows’ milk even after concentration to equivalent levels of protein/total solids to those found in the buffalo milk.