Bisphenol A and bisphenol S disruptions of the mouse placenta and potential effects on the placenta-brain axis.

Placental trophoblast cells are potentially at risk from circulating endocrine-disrupting chemicals, such as bisphenol A (BPA). To understand how BPA and the reputedly more inert bisphenol S (BPS) affect the placenta, C57BL6J mouse dams were fed 200 µg/kg body weight BPA or BPS daily for 2 wk and then bred. They continued to receive these chemicals until embryonic day 12.5, whereupon placental samples were collected and compared with unexposed controls. BPA and BPS altered the expression of an identical set of 13 genes. Both exposures led to a decrease in the area occupied by spongiotrophoblast relative to trophoblast giant cells (GCs) within the junctional zone, markedly reduced placental serotonin (5-HT) concentrations, and lowered 5-HT GC immunoreactivity. Concentrations of dopamine and 5-hydroxyindoleacetic acid, the main metabolite of serotonin, were increased. GC dopamine immunoreactivity was increased in BPA- and BPS-exposed placentas. A strong positive correlation between 5-HT+ GCs and reductions in spongiotrophoblast to GC area suggests that this neurotransmitter is essential for maintaining cells within the junctional zone. In contrast, a negative correlation existed between dopamine+ GCs and reductions in spongiotrophoblast to GC area ratio. These outcomes lead to the following conclusions. First, BPS exposure causes almost identical placental effects as BPA. Second, a major target of BPA/BPS is either spongiotrophoblast or GCs within the junctional zone. Third, imbalances in neurotransmitter-positive GCs and an observed decrease in docosahexaenoic acid and estradiol, also occurring in response to BPA/BPS exposure, likely affect the placental-brain axis of the developing mouse fetus.

Proteomic and Metabolomic Analysis of Azospirillum brasilensentrC Mutant under High and Low Nitrogen Conditions.

Azospirillum brasilense is a diazotrophic microorganism capable of associating with roots of important grasses and cereals, promoting plant growth and increasing crop yields. Nitrogen levels and the Ntr regulatory system control the nitrogen metabolism in A. brasilense. This system comprises the nitrogen regulatory proteins GlnD, which is capable of adding uridylyl groups to the PII proteins, GlnB (PII-1) and GlnZ (PII-2), under limiting nitrogen levels. Under such conditions, the histidine kinase NtrB (nitrogen regulatory protein B) cannot interact with GlnB and phosphorylate NtrC (nitrogen regulatory protein C). The phosphorylated form of NtrC acts as a transcriptional activator of genes involved in the metabolism of alternative nitrogen sources. Considering the key role of NtrC in nitrogen metabolism in A. brasilense, in this work we evaluated the proteomic and metabolomic profiles of the wild-type FP2 strain and its mutant ntrC grown under high and low nitrogen. Analysis of the integrated data identifies novel NtrC targets, including proteins involved in the response against oxidative stress (i.e., glutathione S-transferase and hydroperoxide resistance protein), underlining the importance of NtrC to bacterial survival under oxidative stress conditions.

UHPLC-MS Analyses of Plant Flavonoids.

Flavonoids are a class of specialized metabolites found in many different plant species. They protect against UV radiation, scavenge reactive oxygen species, are involved in plant defense responses, and are associated with plant-microorganism interactions. They have also been reported to possess health-promoting effects including anti-inflammatory, antioxidant, anticancer activity, and antihypertensive effects. Flavonoids encompass >10,000 structures where the types and amounts depend on the plant species, developmental stage, organ, and growth conditions. The diversity of flavonoid structures represents a significant challenge in the analysis of plant flavonoids. Many analytical techniques have been developed to detect and quantify flavonoids, and the most productive of these techniques use liquid chromatography (LC) coupled to mass spectrometry (MS) to analyze flavonoids due to the excellent combination of selectivity and sensitivity of MS. In addition, mass spectral libraries have been constructed to further aid flavonoid identification. Here, the use of ultra-high pressure liquid chromatography coupled to mass spectrometry (UHPLC-MS) in plant flavonoid analyses, with an emphasis on sample extraction, flavonoid separation, and MS detection, is described. © 2018 by John Wiley & Sons, Inc.

Metabolomics of Two Pecan Varieties Provides Insights into Scab Resistance.

UHPLC-MS-based non-targeted metabolomics was used to investigate the biochemical basis of pecan scab resistance. Two contrasting pecan varieties, Kanza (scab-resistant) and Pawnee (scab-susceptible), were profiled and the metabolomics data analyzed using multivariate statistics. Significant qualitative and quantitative metabolic differences were observed between the two varieties. Both varieties were found to have some unique metabolites. Metabolites that were only present or more abundant in Kanza relative to Pawnee could potentially contribute to the scab resistance in Kanza. Some of these metabolites were putatively identified as quercetin derivatives using tandem mass spectrometry. This suggests that quercetin derivatives could be important to pecan scab resistance.

Early weaning results in less active behaviour, accompanied by lower 5-HT1A and higher 5-HT2A receptor mRNA expression in specific brain regions of female pigs.

In rodents and humans stressful events in early life e.g. maternal deprivation, can increase sensitivity to stress in later life. Humans may become more susceptible to mood disorders, e.g. depression. In livestock species, such as pigs, early weaning is a form of maternal deprivation. We investigated behavioural consequences in 99 female pigs weaned at three different ages (12, 21 and 42 days; d12, d21, d42). Pigs were habituated to an open field arena over 6 days before being given 5-min open-field tests over three subsequent days (days 77-79). Early-weaned pigs (d12) showed behavioural inhibition (reduced vocalisations and lower activity) compared with later-weaned pigs, although in all groups these measures declined over the three tests, so this treatment difference might reflect more rapid habituation to the test in d12 pigs. Long-term effects on mood-related 5-HT receptor subtypes were measured in the brain at 90 days in a random sample of the d12 (n=8) and d42 pigs (n=8), using (3)H-ligand-binding and autoradiography and in situ hybridisation histochemistry. There were no differences between weaning ages in binding of (3)H-8-OH-DPAT (5-HT(1A) receptor agonist) or of (3)H-ketanserin (5-HT(2A) receptor antagonist) to any brain region studied. In d12 pigs, 5-HT(1A) receptor mRNA expression per unit area was 29%, 63%, 52% and 64% lower than in d42 pigs in the parvocellular PVN, amygdala and hippocampal dentate gyrus and pyramidal cell layer, respectively. The ratio of expression per cell to expressing cells per unit area was also lower, by 31%, in the pars horizontalis of the PVN in d12 pigs. Conversely, 5-HT(2A) receptor mRNA was expressed at a 25% and 28% higher density per unit area in the amygdala and pyramidal cell layer of the hippocampus, respectively, in these d12 pigs. In individual pigs, across brain regions, 5-HT(1A) receptor mRNA data were 70-79% correlated with binding data but no correlation was found for 5-HT(2A) data, suggesting different regulatory mechanisms. The behavioural and neurobiological responses to early weaning might represent either dysfunction or adaptation. Further investigation is required.

Silver stain removal using H2O2 for enhanced peptide mass mapping by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Hydrogen peroxide solutions are reported for the removal of silver stain from proteins isolated in polyacrylamide gels. Removal of silver stain prior to in-gel digestion is shown to enhance sensitivity and sequence coverage of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) peptide mass maps. The rate of silver removal using H2O2 is influenced by H2O2 concentration and increases with increasing pH. The presence of complexation reagents such as ammonia from mass spectrometry compatible ammonium bicarbonate solutions enhances the efficiency and speed of H2O2-mediated silver removal. H2O2-mediated silver removal using the described procedure does not appear to have any detrimental effects on proteins but is observed to produce a slightly elevated level of methionine oxidization over that usually observed in in-gel tryptic digestion.