A novel experimental approach for liver analysis in rats exposed to Bisphenol A by means of LC-mass spectrometry and infrared spectroscopy

An innovative complementary approach using a liquid chromatographic-mass spectrometer method and infrared spectroscopy is proposed for measuring internal biological exposure to dangerous chemical contaminants and for monitoring biochemical changes in target organs. The proposed methodologies were validated and applied in the case of rats exposed to low-doses of Bisphenol A (BPA). A liquid chromatographic method coupled to a tandem mass spectrometer was used in order to measure BPA concentration in rat livers. BPA was detected at different levels in all liver samples from BPA-treated rats, although the exposure dose was the same in all treated animals, and also from control rats, highlighting the difficulties in eliminating external uncontrolled exposure and the need for internal biological monitoring. Fourier Transform Infrared analysis was applied to detect structural changes occurring in several molecules (lipids, proteins, carbohydrates and nucleic acids) as well as the presence of specific metabolic processes. The spectroscopic analyses clearly demonstrated a different lipid composition more than an evident lipid accumulation and a glycogen accumulation decrease, revealing a metabolic disturbance in livers with a normal histological aspect. These results demonstrated the potential of an integrated approach based on mass spectrometry and infrared spectroscopy to evaluate at an early stage the hepatotoxic effect of BPA exposure in an animal model. This approach can be usefully exploited in all the investigations aimed to provide better information concerning the interrelationships between contaminant exposure, dose, and health effects

An FTIR Spectroscopy Investigation on Different Methods of Lipid Extraction from HepG2 Cells

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Environmental bisphenol A exposure triggers trained immunity-related pathways in monocytes

IntroductionTrained Immunity represents a novel revolutionary concept of the immunological response involving innate immune cells. Bisphenol A is a well-known endocrine disrupter, widely disseminated worldwide and accumulated in the human body. Due to the increased interest regarding the effects of plastic-derived compounds on the immune system, our purpose was to explore whether BPA was able to induce trained immunity in human primary monocytes in vitro using low environmental concentrations.Materials and methodsWe extracted BPA from the serum of 10 healthy individuals through a liquid-liquid extraction followed by a solid phase extraction and measured the concentration using an HPLC system coupled to a triple quadrupole mass spectrometer. In parallel, monocytes were isolated from whole blood and acutely stimulated or trained with BPA at three different concentrations (1 nM, 10 nM, 20 nM). Pro- and anti-inflammatory cytokines (IL-1β, TNF-α, IL-6, and IL-10) production were assessed after 24 hours of acute stimulation and after Lipopolysaccharide (LPS) rechallenge. A comprehensive overview of the metabolic changes after BPA acute stimulation and trained immunity induction was assessed through extracellular lactate measurements, Seahorse XFb metabolic flux analysis and ROS production.ResultsMonocytes primed with BPA showed increased pro- and anti-inflammatory cytokine responses upon restimulation, sustained by the modulation of the immunometabolic circuits. Moreover, we proved the non-toxic effect of BPA at each experimental concentration by performing an MTT assay. Additionally, correlation analysis were performed between pro- and anti-inflammatory cytokines production after LPS acute stimulation or BPA-mediated trained immunity and BPA serum concentrations showing a significant association between TNF-α and BPA circulating levels.DiscussionOverall, this study pointed out for the first time the immunological effects of an environmental chemical and plastic-derived compound in the induction of trained immunity in a healthy cohort

Nat Metab.

Bile acids (BAs) are signalling molecules that mediate various cellular responses in both physiological and pathological processes. Several studies report that BAs can be detected in the brain1, yet their physiological role in the central nervous system is still largely unknown. Here we show that postprandial BAs can reach the brain and activate a negative-feedback loop controlling satiety in response to physiological feeding via TGR5, a G-protein-coupled receptor activated by multiple conjugated and unconjugated BAs2 and an established regulator of peripheral metabolism3,4,5,6,7,8. Notably, peripheral or central administration of a BA mix or a TGR5-specific BA mimetic (INT-777) exerted an anorexigenic effect in wild-type mice, while whole-body, neuron-specific or agouti-related peptide neuronal TGR5 deletion caused a significant increase in food intake. Accordingly, orexigenic peptide expression and secretion were reduced after short-term TGR5 activation. In vitro studies demonstrated that activation of the Rho–ROCK–actin-remodelling pathway decreases orexigenic agouti-related peptide/neuropeptide Y (AgRP/NPY) release in a TGR5-dependent manner. Taken together, these data identify a signalling cascade by which BAs exert acute effects at the transition between fasting and feeding and prime the switch towards satiety, unveiling a previously unrecognized role of physiological feedback mediated by BAs in the central nervous system.Développment d'une infrastructure française distribuée coordonnéeLa signalisation des acides biliaires dans le cerveau et son rôle dans le contrôle métaboliqueInnovations instrumentales et procédurales en psychopathologie expérimentale chez le rongeu

Adverse effects of bisphenol a exposure on glucose metabolism regulation

Bisphenol A (BPA) is used as basic chemical compound in the production of polycarbonate food containers or epoxy resins coating metallic cans for food and beverages conservation. Its xeno-estrogenic activity alters endocrine-metabolic pathways modulating glucose metabolism and increasing the risk of developing diabetes, insulin resistance, and obesity. Based on in vitro and in vivo experimental research, here we report some of the major BPA adverse effects on tissues that play a key role in the regulation on the whole body’s metabolism. Evidences have shown that BPA is able to exert its endocrine disrupting action altering glucose metabolism and contributing to the onset of metabolic disorders, acting on liver functions and affecting insulin production by the pancreas. Exposure to BPA has been reported also to modulate glucose utilization in muscles, as well as to interfere with adipose tissue endocrine function. In addition, to peripheral tissues, recent studies have shown that BPA by acting in the Central Nervous System affects neuroendocrine regulation of glucose metabolism, promoting glucose metabolism dysfunction such as glucose intolerance and insulin resistance. Thus, exposure to BPA seems to be an important risk factor in the onset of obesity and metabolic syndrome. However, its mechanisms of action need to be further investigated to provide a major evaluation of risk assessment

Advanced Optical Sensing of Phenolic Compounds for Environmental Applications

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A Sphingolipidomic Profiling Approach for Comparing X-ray-Exposed and Unexposed HepG2 Cells

: An analytical method based on tandem mass spectrometry-shotgun is presently proposed to obtain sphingolipidomic profiles useful for the characterization of lipid extract from X-ray-exposed and unexposed hepatocellular carcinoma cells (HepG2). To obtain a targeted lipidic profile from a specific biological system, the best extraction method must be identified before instrumental analysis. Accordingly, four different classic lipid extraction protocols were compared in terms of efficiency, specificity, and reproducibility. The performance of each procedure was evaluated using the Fourier-transform infrared spectroscopic technique; subsequently, the quality of extracts was estimated using electrospray ionization tandem mass spectrometry. The selected procedure based on chloroform/methanol/water was successfully used in mass spectrometry-based shotgun sphingolipidomics, allowing for evaluation of the response of cells to X-ray irradiation, the most common anticancer therapy. Using a relative quantitative approach, the changes in the sphingolipid profiles of irradiated cell extracts were demonstrated, confirming that lipidomic technologies are also useful tools for studying the key sphingolipid role in regulating cancer growth during radiotherapy

BPA Free Water Essential to Perform Laboratory Studies.

The present study aims at assessing Bisphenol A (BPA) level in water used in laboratories. A total of five types of water commonly used in laboratory (tap, softened, distilled, double distilled, commercial LC-MS pure water), were analyzed and BPA was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Only the samples of ultrapure water showed BPA levels above detection limits (>0.004 ng/mL). The mean BPA level ranged from 0.008 to 0.473 ng/mL. A higher mean BPA level was found in water obtained from ultrafilter process compared to commercial sources. Activated carbon filtration is necessary to achieve a BPA free level in ultrapure water