Dibutyryl-cAMP affecting fat deposition of finishing pigs by decreasing the inflammatory system related to insulin sensitive or lipolysis

Background

The mechanism of db-cAMP regulating fat deposition and improving lean percentage is unclear and needs to be further studied.

Methods

Eighteen 100-day-old Duroc × Landrance × Large White barrows (49.75?±?0.75 kg) were used for experiment 1, and 15 eighteen 135-day-old barrows (78.34?±?1.22 kg) were used for experiment 2 to investigate the effects of dietary dibutyryl-cAMP (db-cAMP) on fat deposition in finishing pigs. Pigs were fed with a corn-soybean meal-based diet supplemented with 0 or 15 mg/kg db-cAMP, and both experiments lasted 35 days, respectively.

Results

The results showed that db-cAMP decreased the backfat thickness, backfat percentage, and diameter of backfat cells without changing the growth performance or carcass characteristics in both experiments, and this effect was more marked in experiment 1 than in experiment 2; db-cAMP enhanced the activity of the growth hormone–insulin-like growth factor-1 (GH-IGF-1) axis and pro-opiomelanocortin (POMC) system in both experiments, which suppressed the accumulation of backfat deposition; microarray analysis showed that db-cAMP suppressed the inflammatory system within the adipose tissue related to insulin sensitivity, which also reduced fat synthesis.

Conclusions

In summary, the effect of db-cAMP on suppressing fat synthesis and accumulation is better in the earlier phase than in the later phase of finishing pigs, and db-cAMP plays this function by increasing the activity of the GH-IGF-1 axis and POMC system, while decreasing the inflammatory system within the adipose tissue related to insulin sensitive or lipolysis.

     

Osmotic Dehydration of Liposomal Dispersions: Influence of Particle Size and Electrostatic Deposition of Cold Water Fish Skin Gelatin

Liposomes are a promising delivery system for bioactives in food and nutraceuticals. Their practical application is limited by their physical and chemical instability caused by extrinsic factors. The physical stability of liposomes of three different sizes coated with cold water fish skin gelatin was assessed during osmotic dehydration at 2, 21 and 70 °C. Soy lecithin was used to prepare 1 % liposomal dispersions. The size distribution was controlled with high pressure homogenization (1500 bar) and extrusion through polycarbonate membrane (3 and 0.8 μm). Fish gelatin was adsorbed to the interface to make secondary liposomes. Liposomal dispersions were osmotically dehydrated while monitoring the relative weight, size and rheological properties. The primary liposomes had an initial mean volume diameter (d_4,3) of 0.09, 0.40 and 2.7 μm and a ζ-potential of ?55 mV. Secondary liposomes were 0.11, 0.45 and 3.4 μm with a ζ-potential of 25 mV. The size of liposomes influenced the stability of liposomes, with the smallest liposomes being stable for 30 min, corresponding to 80 % of the initial weight, while the larger liposomes were already aggregated. Secondary liposomes were stable to 120 min for the smaller liposomes and to 150 min for the largest liposomes corresponding to 40 % of the initial weight. Stability increased during dehydration at 2 °C. Coating the liposomes increased the physical stability of the liposomal dispersions at all temperatures. The results show that cold water fish skin gelatin is a viable option to coat liposomes of a wide size range.     

Effect of Hydrothermal Modifications on Functional,Pasting and Structural Properties of False Banana (<Emphasis Type="Italic">Ensete ventricosum</Emphasis>) Starch

Starch extracted from ensete (Ensete ventricosum, Musaceae) also called false banana, was modified by hydrothermal methods of annealing (ANN) and heat moisture treatment (HMT) processes. The effects of treatments on functional, pasting properties, morphology and diffraction pattern of the starch were studied. Swelling power and solubility changed significantly (p < 0.05) with modification. Water absorption (89.3–152.4 %) and oil absorption (105.0–161.3 %) capacities increased significantly (p < 0.05) with ANN and HMT. Alkaline water retention decreased with ANN but increased significantly (p < 0.05) with HMT. Hydrothermal modifications led to reduction in least gelation capacity of ensete starch. In terms of the pasting properties studied, the hydrothermal modifications imparted improved gel strength, increased paste stability, reduced retrogradation tendency and slowed staling rate on ensete starch. Scanning electron micrographs depicted fairly angular and elliptical shapes with diverse sizes for the starch granules. Clustering of granules, mucilage formation, fissures and surface indentation which were gaining prominence with increasing moisture level and temperature of treatment were the hallmarks of modified samples. Native and modified ensete starches showed similar type-B diffraction pattern with maximum peak range of 19.8–20.0^o (2θ). Findings of this work showed that hydrothermally modified ensete starches possess excellent value-added potentials for utilization in pharmaceuticals and food applications.     

Simplifying Hansen Solubility Parameters for Complex Edible Fats and Oils

Hansen solubility parameters (HSPs), often used to predict the miscibility between two compounds, are an alternative tool in evaluating the ability of the solvent to interact via dispersion, dipole-dipole, and hydrogen bonding interactions. The aim of this paper is to find a simple way to calculate HSPs for complex mixtures of triglycerides (TAGs). HSPs were calculated using two approaches: the first assumes that the contributions to the dispersion, dipole-dipole, and hydrogen bonding interactions may be subdivided into larger functional moieties (i.e., fatty acids and fatty acid methyl esters) that are additive, while the second approach assumes that vegetable oils are comprised of mixtures of simple TAGs in the same mass fractions as the fatty acids. The HSPs obtained using the two approaches are compared to reference values determined using the “Hansen Solubility Parameters in Practice” software (HSPiP) considering the complex TAG profile for each vegetable oil.HSPs for vegetable oils, obtained with the HSPiP software, did not correspond well to the HSPs obtained from the group contribution approach, when using fatty acids, fatty acids + glycerol or fatty acid methyl esters. In contrast, the HSPs calculated for vegetable oils, assuming that all TAGs are simple and in the same mass fractions as the fatty acids, provide similar values to the HSPs obtained from the HSPiP software. Therefore, it is possible to calculate the HSPs for complex oils by simply knowing the fatty acid composition. Knowledge of HSPs may be used to rationalize the ability of certain low molecular weight molecules to develop organogels in vegetable oils as well as the crystallization of triglycerides.     

Identification of Symptomatic Fetuses Infected with Cytomegalovirus Using Amniotic Fluid Peptide Biomarkers

Cytomegalovirus (CMV) is the most common cause of congenital infection, and is a major cause of sensorineural hearing loss and neurological disabilities. Evaluating the risk for a CMV infected fetus to develop severe clinical symptoms after birth is crucial to provide appropriate guidance to pregnant women who might have to consider termination of pregnancy or experimental prenatal medical therapies. However, establishing the prognosis before birth remains a challenge. This evaluation is currently based upon fetal imaging and fetal biological parameters, but the positive and negative predictive values of these parameters are not optimal, leaving room for the development of new prognostic factors. Here, we compared the amniotic fluid peptidome between asymptomatic fetuses who were born as asymptomatic neonates and symptomatic fetuses who were either terminated in view of severe cerebral lesions or born as severely symptomatic neonates. This comparison allowed us to identify a 34-peptide classifier in a discovery cohort of 13 symptomatic and 13 asymptomatic neonates. This classifier further yielded 89% sensitivity, 75% specificity and an area under the curve of 0.90 to segregate 9 severely symptomatic from 12 asymptomatic neonates in a validation cohort, showing an overall better performance than that of classical fetal laboratory parameters. Pathway analysis of the 34 peptides underlined the role of viral entry in fetuses with severe brain disease as well as the potential importance of both beta-2-microglobulin and adiponectin to protect the injured fetal brain infected with CMV. The results also suggested the mechanistic implication of the T calcium channel alpha-1G (CACNA1G) protein in the development of seizures in severely CMV infected children. These results open a new field for potential therapeutic options. In conclusion, this study demonstrates that amniotic fluid peptidome analysis can effectively predict the severity of congenital CMV infection. This peptidomic classifier may therefore be used in clinical settings during pregnancy to improve prenatal counseling.     

Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology

Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form.     

Population size and land use affect the genetic variation and performance of the endangered plant species <Emphasis Type="Italic">Dianthus seguieri</Emphasis> ssp. <Emphasis Type="Italic">glaber</Emphasis>

Human activity and land use changes in the past decades have led to landscape homogenization and small-scale fragmentation of grassland habitats in most regions of central Europe. As a result, populations of many grassland species are small and strongly fragmented, facing extinction due to genetic depauperation and local maladaptation in remnant habitats. In this study, remaining populations of the strongly endangered grassland species Dianthus seguieri ssp. glaber (“Ragged Pink”) in Bavaria were investigated in order to evaluate the environmental factors influencing its genetic variation and performance. We first evaluated habitat, vegetation and population structure. Species performance was then studied by assessing the number of generative shoots, flowers and fertile capsules; and evaluating seed weight and seed viability. Finally, genetic variation was analyzed using molecular markers (AFLPs). Our analyses revealed that population size and land use abandonment have the strongest impact on genetic variation and species’ performance. Large and extended populations were most variable. 72 % of overall genetic variability of Dianthus seguieri ssp. glaber was found to be within populations, whereas 28 % remained between populations. Increased vegetation height and coverage, and a high proportion of gramineous species resulting from the lack of land use, reduced genetic variation, effective fruit and seed set. Our study shows that both population size and land use abandonment need to be considered to ensure the long term protection of endangered plant species. Maintaining an open habitat structure and adequate soil nutrient conditions through targeted annual mowing regime, over-storey vegetation trimming and green waste removal and the establishment of vegetation buffer strips will allow this species’ persistence and continuous recruitment.     

Genetic evidence of recent migration among isolated-by-sea populations of the freshwater blenny (<Emphasis Type="Italic">Salaria fluviatilis</Emphasis>)

Genetic diversity is the raw material for evolutionary change, so a species’ capacity to maintain its genetic diversity is a major concern in conservation genetics. Although genetic diversity within a population is reduced through time by genetic drift, gene flow among populations can act to recover or add new genetic variants. The goal of this study was to infer potential connectivity among isolated-by-sea populations of the vulnerable freshwater blenny (Salaria fluviatilis) and to determine if gene flow could contribute to maintaining genetic diversity in connected populations. Four genetic clusters (one small at the North, one large at the South for both East and West coasts) were detected with different clustering methods (FLOCK, STUCTURE, UPGMA, AMOVA). The two larger genetic clusters with higher migration-rate estimates among localities had higher genetic diversity and allelic richness and lower relatedness between individuals, compared to isolated localities found in smaller clusters. Our results also suggest that sea currents may facilitate fish movements among neighbouring rivers. Overall, gene flow among isolated-by-sea but close rivers could maintain the evolutionary potential of freshwater blenny populations. This finding should be considered when elaborating a conservation program for this species.