Concordant inter-laboratory derived concentrations of ceramides in human plasma reference materials via authentic standards.

In this community effort, we compare measurements between 34 laboratories from 19 countries, utilizing mixtures of labelled authentic synthetic standards, to quantify by mass spectrometry four clinically used ceramide species in the NIST (National Institute of Standards and Technology) human blood plasma Standard Reference Material (SRM) 1950, as well as a set of candidate plasma reference materials (RM 8231). Participants either utilized a provided validated method and/or their method of choice. Mean concentration values, and intra- and inter-laboratory coefficients of variation (CV) were calculated using single-point and multi-point calibrations, respectively. These results are the most precise (intra-laboratory CVs ≤ 4.2%) and concordant (inter-laboratory CVs < 14%) community-derived absolute concentration values reported to date for four clinically used ceramides in the commonly analyzed SRM 1950. We demonstrate that calibration using authentic labelled standards dramatically reduces data variability. Furthermore, we show how the use of shared RM can correct systematic quantitative biases and help in harmonizing lipidomics. Collectively, the results from the present study provide a significant knowledge base for translation of lipidomic technologies to future clinical applications that might require the determination of reference intervals (RIs) in various human populations or might need to estimate reference change values (RCV), when analytical variability is a key factor for recall during multiple testing of individuals.

The lipidomic profile of the nanoparticle-biomolecule corona reflects the diversity of plasma lipids.

The spontaneous self-assembly of biomolecules around the surface of nanoparticles (NPs) once exposed to plasma and other biofluids, has been termed the 'biomolecule corona'. While the protein composition of the biomolecule corona has been widely characterised, the interaction of NPs with the plasma lipidome has not been fully investigated. Here, we use targeted and untargeted lipidomics to analyse a wide spectrum of bioactive lipids adsorbed onto the surface of liposome NPs post-incubation with human plasma. Our data indicate that the biomolecule corona contains a diverse mixture of simple and complex lipid species, including sphingolipids such as ceramides and sphingomyelins, glycerolipids, glycerophospholipids, cholesteryl esters, as well as oxylipin and N-acyl ethanolamine derivatives of fatty acids. Although the corona lipidomic profiles reflected the overall composition of the plasma lipidome, monohydroxy- and oxo-fatty acid oxylipins, mono-, di- and tri- acylglycerols, sphingomyelins and ceramides showed a preferential binding for liposome NP surface. Interestingly, the biomolecule corona lipid profiles appeared to mirror those of the lipoprotein lipid cargo, suggesting that lipid species may be carried within the lipoprotein complexes attached to the corona. Proteomic analysis of corona-associated proteins showed the presence of several apolipoproteins (A-I, A-II, A-IV, B, C-I, C-III, C-IV, C2-C4, D, E, L, M and lipoprotein Lp(A)), supporting this notion. Our findings reveal the wide lipid diversity of the biomolecule corona and indicate a potential lipoprotein-mediated adsorption mechanism of lipids onto liposome NPs, highlighting the importance of bridging proteomics with lipidomics to fully comprehend the interactions at the bio-nano interface.

Solar-driven semi-conductor photocatalytic water treatment (TiO2, g-C3N4, and TiO2+g-C3N4) of cyanotoxins: Proof-of-concept study with microcystin-LR.

Cyanobacteria and their toxins are a threat to drinking water safety as increasingly cyanobacterial blooms (mass occurrences) occur in lakes and reservoirs all over the world. Photocatalytic removal of cyanotoxins by solar light active catalysts is a promising way to purify water at relatively low cost compared to modifying existing infrastructure. We have established a facile and low-cost method to obtain TiO2 and g-C3N4 coated floating photocatalysts using recycled glass beads. g-C3N4 coated and TiO2+g-C3N4 co-coated beads were able to completely remove microcystin-LR in artificial fresh water under both natural and simulated solar light irradiation without agitation in less than 2 h. TiO2 coated beads achieved complete removal within 8 h of irradiation. TiO2+g-C3N4 beads were more effective than g-C3N4 beads as demonstrated by the increase reaction rate with reaction constants, 0.0485 min-1 compared to 0.0264 min-1 respectively, with TiO2 alone found to be considerably slower 0.0072 min-1. g-C3N4 based photocatalysts showed a similar degradation pathway to TiO2 based photocatalysts by attacking the C6-C7 double bond on the Adda side chain.

Omega-3 polyunsaturated fatty acids reverse the impact of western diets on regulatory T cell responses through averting ceramide-mediated pathways.

Western diet (WD), high in sugar and fat, promotes obesity and associated chronic low-grade pro-inflammatory environment, leading to impaired immune function, reprogramming of innate and adaptive immune cells, and development of chronic degenerative diseases, including cardiovascular disease. Increased concentrations of circulating and tissue ceramides contribute to inflammation and cellular dysfunction common in immune metabolic and cardiometabolic disease. Therefore, ceramide-lowering interventions have been considered as strategies to improve adipose tissue health. Here, we report the ability of omega-3 polyunsaturated fatty acids (n-3PUFA) to attenuate inflammatory phenotypes promoted by WD, through ceramide-dependent pathways. Using an animal model, we show that enrichment of WD diet with n-3PUFA, reduced the expression of ceramide synthase 2 (CerS2), and lowered the concentration of long-chain ceramides (C23-C26) in plasma and adipose tissues. N-3PUFA also increased prevalence of the anti-inflammatory CD4+Foxp3+ and CD4+Foxp3+CD25+ Treg subtypes in lymphoid organs. The CerS inhibitor FTY720 mirrored the effect of n-3PUFA. Treatment of animal and human T cells with ceramide C24 in vitro, reduced CD4+Foxp3+ Treg polarisation and IL-10 production, and increased IL-17, while it decreased Erk and Akt phosphorylation downstream of T cell antigen receptors (TCR). These findings suggest that molecular mechanisms mediating the adverse effect of ceramides on regulatory T lymphocytes, progress through reduced TCR signalling. Our findings suggest that nutritional enrichment of WD with fish oil n-3PUFA can partially mitigate its detrimental effects, potentially improving the low-grade inflammation associated with immune metabolic disease. Compared to pharmacological interventions, n-3PUFA offer a simpler approach that can be accommodated as lifestyle choice.

Gut-derived short-chain fatty acids modulate skin barrier integrity by promoting keratinocyte metabolism and differentiation.

Barrier integrity is central to the maintenance of healthy immunological homeostasis. Impaired skin barrier function is linked with enhanced allergen sensitization and the development of diseases such as atopic dermatitis (AD), which can precede the development of other allergic disorders, for example, food allergies and asthma. Epidemiological evidence indicates that children suffering from allergies have lower levels of dietary fibre-derived short-chain fatty acids (SCFA). Using an experimental model of AD-like skin inflammation, we report that a fermentable fibre-rich diet alleviates systemic allergen sensitization and disease severity. The gut-skin axis underpins this phenomenon through SCFA production, particularly butyrate, which strengthens skin barrier function by altering mitochondrial metabolism of epidermal keratinocytes and the production of key structural components. Our results demonstrate that dietary fibre and SCFA improve epidermal barrier integrity, ultimately limiting early allergen sensitization and disease development.The Graphical Abstract was designed using Servier Medical Art images ( https://smart.servier.com ).

Omega-3 carboxylic acids and fenofibrate differentially alter plasma lipid mediators in patients with non-alcoholic fatty liver disease.

Fibrates and omega-3 polyunsaturated acids are used for the treatment of hypertriglyceridemia but have not demonstrated consistent effects on cardiovascular (CV) risk. In this study, we investigate how these two pharmacological agents influence plasma levels of bioactive lipid mediators, aiming to explore their efficacy beyond that of lipid-lowering agents. Plasma from overweight patients with non-alcoholic fatty liver disease (NAFLD) and hypertriglyceridemia, participating in a randomized placebo-controlled study investigating the effects of 12 weeks treatment with fenofibrate or omega-3 free carboxylic acids (OM-3CA) (200 mg or 4 g per day, respectively), were analyzed for eicosanoids and related PUFA species, N-acylethanolamines (NAE) and ceramides. OM-3CA reduced plasma concentrations of proinflammatory PGE2 , as well as PGE1 , PGD1 and thromboxane B2 but increased prostacyclin, and eicosapentaenoic acid- and docosahexaenoic acid-derived lipids of lipoxygenase and cytochrome P450 monooxygenase (CYP) (e.g., 17-HDHA, 18-HEPE, 19,20-DiHDPA). Fenofibrate reduced plasma concentrations of vasoactive CYP-derived eicosanoids (DHETs). Although OM-3CA increased plasma levels of the NAE docosahexaenoyl ethanolamine and docosapentaenoyl ethanolamine, and fenofibrate increased palmitoleoyl ethanolamine, the effect of both treatments may have been masked by the placebo (olive oil). Fenofibrate was more efficacious than OM-3CA in significantly reducing plasma ceramides, pro-inflammatory lipids associated with CV disease risk. Neither treatment affected putative lipid species associated with NAFLD. Our results show that OM-3CA and fenofibrate differentially modulate the plasma mediator lipidome, with OM-3CA promoting the formation of lipid mediators with potential effects on chronic inflammation, while fenofibrate mainly reducing ceramides. These findings suggest that both treatments could ameliorate chronic inflammation with possible impact on disease outcomes, independent of triglyceride reduction.

Omega-3 polyunsaturated fatty acids protect against inflammation through production of LOX and CYP450 lipid mediators: relevance for major depression and for human hippocampal neurogenesis.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can exert antidepressant, anti-inflammatory and neuroprotective properties, but the exact molecular mechanism underlying their effects is still not fully understood. We conducted both in vitro and clinical investigations to test which EPA or DHA metabolites are involved in these anti-inflammatory, neuroprotective and antidepressant effects. In vitro, we used the human hippocampal progenitor cell line HPC0A07/03C, and pre-treated cells with either EPA or DHA, followed by interleukin 1beta (IL1ß), IL6 and interferon-alpha (IFN-α). Both EPA and DHA prevented the reduction in neurogenesis and the increase in apoptosis induced by these cytokines; moreover, these effects were mediated by the lipoxygenase (LOX) and cytochrome P450 (CYP450) EPA/DHA metabolites, 5-hydroxyeicosapentaenoic acid (HEPE), 4-hydroxydocosahexaenoic acid (HDHA), 18-HEPE, 20-HDHA, 17(18)-epoxyeicosatetraenoic acid (EpETE) and 19(20)-epoxydocosapentaenoic acid (EpDPA), detected here for the first time in human hippocampal neurones using mass spectrometry lipidomics of the supernatant. In fact, like EPA/DHA, co-treatment with these metabolites prevented cytokines-induced reduction in neurogenesis and apoptosis. Moreover, co-treatment with 17(18)-EpETE and 19(20)-EpDPA and the soluble epoxide hydroxylase (sEH) inhibitor, TPPU (which prevents their conversion into dihydroxyeicosatetraenoic acid (DiHETE)/ dihydroxydocosapentaenoic acid (DiHDPA) metabolites) further enhanced their neurogenic and anti-apoptotic effects. Interestingly, these findings were replicated in a sample of n = 22 patients with a DSM-IV Major Depressive Disorder, randomly assigned to treatment with either EPA (3.0 g/day) or DHA (1.4 g/day) for 12 weeks, with exactly the same LOX and CYP450 lipid metabolites increased in the plasma of these patients following treatment with their precursor, EPA or DHA, and some evidence that higher levels of these metabolites were correlated with less severe depressive symptoms. Overall, our study provides the first evidence for the relevance of LOX- and CYP450-derived EPA/DHA bioactive lipid metabolites as neuroprotective molecular targets for human hippocampal neurogenesis and depression, and highlights the importance of sEH inhibitors as potential therapeutic strategy for patients suffering from depressive symptoms.

Unwrapping the mechanisms of ceramide and fatty acid-initiated signals leading to immune-inflammatory responses in obesity.

Obesity is considered a global epidemic developed in part as a consequence of the overconsumption of high fat diets. One of the main negative outcomes of obesity is the development of low-grade chronic systemic inflammation, induced by dysregulated immune responses, which can lead to multiple obesity-related diseases. Ceramides are a group of bioactive lipids known to be elevated in obesity and obesity-associated conditions, including cardiovascular disease and type II diabetes. Ceramides may be key players in promoting an obesity-induced inflammatory environment due to their ability to activate key pathways such as Toll-like receptor 4 (TLR4) and NLR pyrin domain containing receptor 3 (Nlrp3), while studies have shown that inhibition of ceramide synthesis gives rise to an anti-inflammatory environment. N-3 polyunsaturated fatty acids (n-3 PUFA) have been of interest due to their anti-inflammatory actions and shown to have beneficial effects in obesity-related diseases. This review will highlight the impact of ceramides in promoting an obesity-induced inflammatory microenvironment and discuss how n-3 PUFA could potentially counteract these responses and have a regulatory effect promoting immune homeostasis.

Degradation of Multiple Peptides by Microcystin-Degrader Paucibacter toxinivorans (2C20).

Since conventional drinking water treatments applied in different countries are inefficient at eliminating potentially toxic cyanobacterial peptides, a number of bacteria have been studied as an alternative to biological filters for the removal of microcystins (MCs). Here, we evaluated the degradation of not only MCs variants (-LR/DM-LR/-RR/-LF/-YR), but also non-MCs peptides (anabaenopeptins A/B, aerucyclamides A/D) by Paucibactertoxinivorans over 7 days. We also evaluated the degradation rate of MC-LR in a peptide mix, with all peptides tested, and in the presence of M. aeruginosa crude extract. Furthermore, biodegradation was assessed for non-cyanobacterial peptides with different chemical structures, such as cyclosporin A, (Glu1)-fibrinopeptide-B, leucine-enkephalin, and oxytocin. When cyanopeptides were individually added, P. toxinivorans degraded them (99%) over 7 days, except for MC-LR and -RR, which decreased by about 85 and 90%, respectively. The degradation rate of MC-LR decreased in the peptide mix compared to an individual compound, however, in the presence of the Microcystis extract, it was degraded considerably faster (3 days). It was noted that biodegradation rates decreased in the mix for all MCs while non-MCs peptides were immediately degraded. UPLC-QTOF-MS/MS allowed us to identify two linear biodegradation products for MC-LR and MC-YR, and one for MC-LF. Furthermore, P. toxinivorans demonstrated complete degradation of non-cyanobacterial peptides, with the exception of oxytocin, where around 50% remained after 7 days. Thus, although P. toxinivorans was previously identified as a MC-degrader, it also degrades a wide range of peptides under a range of conditions, which could be optimized as a potential biological tool for water treatment.

Rapid uptake and slow depuration: Health risks following cyanotoxin accumulation in mussels?

Freshwater cyanobacteria produce highly toxic secondary metabolites, which can be transported downstream by rivers and waterways into the sea. Estuarine and coastal aquaculture sites exposed to toxic cyanobacteria raise concerns that shellfish may accumulate and transfer cyanotoxins in the food web. This study aims to describe the competitive pattern of uptake and depuration of a wide range of microcystins (MC-LR, MC-LF, MC-LW, MC-LY, [Asp3]-MC-LR/[Dha7]-MC-LR, MC-HilR) and nodularins (NOD cyclic and linear) within the common blue mussel Mytilus edulis exposed to a combined culture of Microcystis aeruginosa and Nodularia spumigena into the coastal environment. Different distribution profiles of MCs/NODs in the experimental system were observed. The majority of MCs/NODs were present intracellularly which is representative of healthy cyanobacterial cultures, with MC-LR and NOD the most abundant analogues. Higher removal rate was observed for NOD (≈96%) compared to MCs (≈50%) from the water phase. Accumulation of toxins in M. edulis was fast, reaching up to 3.4 µg/g shellfish tissue four days after the end of the 3-days exposure period, with NOD (1.72 µg/g) and MC-LR (0.74 µg/g) as the dominant toxins, followed by MC-LF (0.35 µg/g) and MC-LW (0.31 µg/g). Following the end of the exposure period depuration was incomplete after 27 days (0.49 µg/g of MCs/NODs). MCs/NODs were also present in faecal material and extrapallial fluid after 24 h of exposure with MCs the main contributors to the total cyanotoxin load in faecal material and NOD in the extrapallial fluid. Maximum concentration of MCs/NODs accumulated in a typical portion of mussels (20 mussels, ≈4 g each) was beyond greater the acute, seasonal and lifetime tolerable daily intake. Even after 27 days of depuration, consuming mussels harvested during even short term harmful algae blooms in close proximity to shellfish beds might carry a high health risk, highlighting the need for testing.

Degradation of microcystin-LR and cylindrospermopsin by continuous flow UV-A photocatalysis over immobilised TiO2.

The increasing presence of freshwater toxins have brought new challenges to preserve water quality due to their potential impact on the environment and human health. Two commonly occurring cyanotoxins, microcystin-LR and cylindrospermopsin, with different physico-chemical properties were used to evaluate the efficiency of photocatalysis using a continuous-flow reactor with immobilized TiO2 on glass tubes and UV-A light. The effect of flow rate and hydrogen peroxide addition on the efficiency of cyanotoxin removal were evaluated. An analysis of the effects on microcystin-LR removal efficiency showed that low flow rates (1 mL/min) and high H2O2 concentrations (120 mg/L) were needed to provide effective degradation. Up to 27.9% and 39.1% removal of MC-LR and CYN, respectively were achieved by UV-A/TiO2 after a single pass through the reactor. A slight increase of the removal of both cyanotoxins was observed when they were in a mixture (35.5% of MC-LR and 51.3% of CYN). The addition of H2O2 to the UV/TiO2 system led to an average removal enhancement of 92.6% of MC-LR and of 29.5% of CYN compared to the UV/TiO2 system. Photolysis assisted by H2O2 degraded MC-LR by up to 77.7%. No significant removal (<10%) was observed by photolysis alone or physical adsorption. This study presents a proof-of-principle that demonstrates the feasibility for this technology to be integrated in large-scale applications.

(Fluoro)quinolones and quinolone resistance genes in the aquatic environment: A river catchment perspective.

This study provides an insight into the prevalence of (fluoro)quinolones (FQs) and their specific quinolone qnrS resistance gene in the Avon river catchment area receiving treated wastewater from 5 wastewater treatment plants (WWTPs), serving 1.5 million people and accounting for 75% of inhabitants living in the catchment area in the South West of England.. Ofloxacin, ciprofloxacin, nalidixic acid and norfloxacin were found to be ubiquitous with daily loads reaching a few hundred g/day in wastewater influent and tens of g/day in receiving waters. This was in contrast to other FQs analysed: flumequine, nadifloxacin, lomefloxacin, ulifloxacin, prulifloxacin, besifloxacin and moxifloxacin, which were hardly quantified. Enantiomeric profiling revealed that ofloxacin was enriched with the S-(-)-enantiomer, likely deriving from its prescription as the more potent enantiomerically pure levofloxacin, alongside racemic ofloxacin. While ofloxacin's enantiomeric fraction (EF) remained constant, high stereoselectivity was observed in the case of its metabolite ofloxacin-N-oxide. The removal efficiency of quinolones during wastewater treatment at 5 WWTPs utilising either trickling filters (TF) or activated sludge (AS), was compound and wastewater treatment process dependent, with AS providing better efficiency than TF. The qnrS resistance gene was ubiquitous in wastewater. Its removal was WWTP treatment process dependent with TF performing best and resulting in significant removal of the gene (from 28 to 75%). AS underperformed with only 9% removal in the case of activated sludge and actual increase in the gene copy number within sequencing batch reactors (SBRs). Interestingly, the data suggests that higher removal of antibiotics could be linked with high prevalence of the gene (SBR and WWTP E) and vice versa, low removal of antibiotic is correlated with lower prevalence of the gene in wastewater effluent (TF, WWTP B and D). This is especially prominent in the case of ofloxacin and could indicate that AS might be facilitating antimicrobial resistance (AMR) prevalence to higher extent than TF. Wastewater-based epidemiology (WBE) was also applied to monitor any potential misuse (e.g. direct disposal) of FQs in the catchment. In most cases higher use of antibiotics with respect to official statistics (i.e. ciprofloxacin, ofloxacin) was observed, which suggests that FQs management practice require further attention.

Degradation of okadaic acid in seawater by UV/TiO2 photocatalysis - Proof of concept.

The consumption of contaminated shellfish with marine toxins causes adverse socioeconomical, environmental and health impacts. The marine toxin okadaic acid (OA) provokes diarrhetic shellfish poisoning (DSP) syndrome characterized by severe gastrointestinal symptoms. Therefore, there is increasing interest in removing these toxins from the marine environment to protect shellfish harvesting sites. Photocatalysis is proposed as an efficient method to detoxify the marine environment. In this study, Prorocentrum lima was used to produce high purity DSP toxins, in particular OA, for degradation studies. The profiling, characterization and quantification of DSP toxins in the culture of P. lima were achieved by ultrahigh performance liquid chromatography coupled to quadrupole-time of flight mass spectrometry (UPLC-QTOF-MSE) for accurate-mass full spectrum acquisition data. The effectiveness of UV/TiO2 system to degrade OA in seawater was assessed in lab-scale experiments and identification of transformation products was proposed based on the data obtained during analysis by UPLC-QTOF-MSE. The detoxification potential of the UV/TiO2 system was investigated using the phosphatase inhibition assay. Sufficient amount of high-purity OA (25 mg, >90% purity) was produced in-house for use in photocatalysis experiments by simple reversed-phase flash chromatography. Complete degradation of OA was observed in seawater after 30 min and 7.5 min in deionized water. The rate constants fitted with the pseudo-first order kinetic model (R2 > 0.96). High-resolution mass spectrometry analysis of the photocatalyzed OA allowed tentative identification of four transformation products. Detoxification was achieved in parallel with the degradation of OA in deionized water and artificial ocean water (≤20 min) but not for seawater. Overall, results suggest that UV/TiO2 photocatalysis can be an effective approach for degrading OA and their TPs in the marine environment. To the best of our knowledge, this is the first report on the use of photocatalysis to degrade marine toxins and its promising potential to protect shellfish harvesting sites.

Omega-3 polyunsaturated fatty acids impinge on CD4+ T cell motility and adipose tissue distribution via direct and lipid mediator-dependent effects.

AIMS: Adaptive immunity contributes to the pathogenesis of cardiovascular metabolic disorders (CVMD). The omega-3 polyunsaturated fatty acids (n-3PUFA) are beneficial for cardiovascular health, with potential to improve the dysregulated adaptive immune responses associated with metabolic imbalance. We aimed to explore the mechanisms through which n-3PUFA may alter T cell motility and tissue distribution to promote a less inflammatory environment and improve lymphocyte function in CVMD. METHODS AND RESULTS: Using mass spectrometry lipidomics, cellular, biochemical, and in vivo and ex vivo analyses, we investigated how eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main n-3PUFA, modify the trafficking patterns of activated CD4+ T cells. In mice subjected to allogeneic immunization, a 3-week n-3PUFA-enriched diet reduced the number of effector memory CD4+ T cells found in adipose tissue, and changed the profiles of eicosanoids, octadecanoids, docosanoids, endocannabinoids, 2-monoacylglycerols, N-acyl ethanolamines, and ceramides, in plasma, lymphoid organs, and fat tissues. These bioactive lipids exhibited differing chemotactic properties when tested in chemotaxis assays with activated CD4+ T cells in vitro. Furthermore, CD4+ T cells treated with EPA and DHA showed a significant reduction in chemokinesis, as assessed by trans-endothelial migration assays, and, when implanted in recipient mice, demonstrated less efficient migration to the inflamed peritoneum. Finally, EPA and DHA treatments reduced the number of polarized CD4+ T cells in vitro, altered the phospholipid composition of membrane microdomains and decreased the activity of small Rho GTPases, Rhoα, and Rac1 instrumental in cytoskeletal dynamics. CONCLUSIONS: Our findings suggest that EPA and DHA affect the motility of CD4+ T cells and modify their ability to reach target tissues by interfering with the cytoskeletal rearrangements required for cell migration. This can explain, at least in part, the anti-inflammatory effects of n-3PUFA supporting their potential use in interventions aiming to address adipocyte low-grade inflammation associated with cardiovascular metabolic disease.

Stereoisomeric profiling of chiral pharmaceutically active compounds in wastewaters and the receiving environment - A catchment-scale and a laboratory study.

Chiral pharmaceutically active compounds (cPACs) are not currently governed by environmental regulation yet are expected to be in the future. As cPACs can exert stereospecific toxicity in the aquatic environment, it is essential to better understand their stereoselective behaviour here. Therefore, this study aims to provide a new perspective towards comprehensive evaluation of cPACs at a river catchment level, including their stereochemistry as a chemical phenomenon driving fate of chiral molecules in the environment. A large spatial and temporal monitoring program was performed in Southwest England. It included 5 sewage treatment works and the receiving waters of the largest river catchment in Southwest England. Simultaneously, lab-scale microcosm studies in simulated activated sludge bioreactors and river water microcosm were performed to evaluate stereoselective degradation of cPACs. A multi-residue enantioselective method allowed the analysis of a total of 18 pairs of enantiomers and 3 single enantiomers in wastewater and river water samples. Our monitoring program revealed: (1) spatial and temporal variations of cPACs in influent wastewaters resulting from different patterns of usage as well as an (2) enantiomeric enrichment of cPACs, likely due to human metabolism, despite their commercialization as racemic mixtures. A similar chiral signature was observed in effluent and receiving waters. Stereoselective degradation was observed in trickling filters (TF) for naproxen, ketoprofen, cetirizine and 10,11-dihydroxy-10-hydroxycarbamazepine, in sequencing batch reactors (SBR) for ifosfamide and in activated sludge (AS) for cetirizine. The extent of enantiomer-specific fate was wastewater treatment dependent in the case of naproxen (TF showed higher stereoselectivity than AS and SBR) and cetirizine (TF and AS showed higher stereoselectivity than SBR) due to differing microbial population. Furthermore, stereoselective degradation of naproxen was highly variable among STWs using similar treatments (TF) and operating in the same region. Microbial stereoselective degradation was also confirmed by both activated and river water simulated microcosm for chloramphenicol, ketoprofen, indoprofen, naproxen and 10,11-dihydroxy-10-hydroxycarbamazepine. Results from our large scale river catchment monitoring study and lab simulated microcosm show wide-ranging implications of enantiomerism of cPACs on environmental risk assessment (ERA). As two enantiomers of the same compound show different biological effects (e.g. toxicity), their non-racemic presence in the environment might lead to inaccurate ERA. This is because current ERA approaches do not require analysis at enantiomeric level.

Fatty acids - from energy substrates to key regulators of cell survival, proliferation and effector function.

Recent advances in immunology and cancer research show that fatty acids, their metabolism and their sensing have a crucial role in the biology of many different cell types. Indeed, they are able to affect cellular behaviour with great implications for pathophysiology. Both the catabolic and anabolic pathways of fatty acids present us with a number of enzymes, receptors and agonists/antagonists that are potential therapeutic targets, some of which have already been successfully pursued. Fatty acids can affect the differentiation of immune cells, particularly T cells, as well as their activation and function, with important consequences for the balance between anti- and pro-inflammatory signals in immune diseases, such as rheumatoid arthritis, psoriasis, diabetes, obesity and cardiovascular conditions. In the context of cancer biology, fatty acids mainly provide substrates for energy production, which is of crucial importance to meet the energy demands of these highly proliferating cells. Fatty acids can also be involved in a broader transcriptional programme as they trigger signals necessary for tumorigenesis and can confer to cancer cells the ability to migrate and generate distant metastasis. For these reasons, the study of fatty acids represents a new research direction that can generate detailed insight and provide novel tools for the understanding of immune and cancer cell biology, and, more importantly, support the development of novel, efficient and fine-tuned clinical interventions. Here, we review the recent literature focusing on the involvement of fatty acids in the biology of immune cells, with emphasis on T cells, and cancer cells, from sensing and binding, to metabolism and downstream effects in cell signalling.

Enantioselective LC-MS/MS for anthropogenic markers of septic tank discharge.

Households in rural locations utilize septic tanks for wastewater treatment and can cause surface water contamination. A new methodology was developed to help investigate the role septic tanks play in the dissemination of prescription and over-the-counter drugs, personal care products and stimulants in the aqueous environment. Simultaneous analysis of 16 chiral and achiral anthropogenic markers was achieved using a Chirobiotic V2® enantioselective column in polar ionic mode. The optimized method achieved quantitation limits for 16 compounds in the range 0.001-2.9 µg L-1 and 0.0002-0.43 µg L-1 for septic tank effluent and stream water, respectively. Application of the method to samples collected in North East Scotland found caffeine to be ubiquitous in all samples studied suggesting it as a good indicator of septic tank discharge. In rural streams studied, concentrations of all prescription drugs investigated were ≤0.02 µg L-1. However, analgesics and stimulants were at high concentration in one location indicating direct discharge of septic tank wastewater (i.e., not dissipated through a soak away). For example, paracetamol, cotinine and caffeine were measured at 1100 µg L-1, 31 µg L-1 and 200 µg L-1, respectively, which is comparable to septic tank effluents. Furthermore, S(+)-amphetamine and R(-)-amphetamine were present in this stream sample at 0.20 and 0.27 µg L-1. This corresponds to an enantiomeric fraction of 0.43, which is typical of untreated wastewaters in the UK. Findings illustrate further study on the diffuse impact of septic tanks to surface water is needed and can be supported using this new multi-residue enantioselective method.

Simultaneous enantiomeric analysis of pharmacologically active compounds in environmental samples by chiral LC-MS/MS with a macrocyclic antibiotic stationary phase.

This paper presents a multi-residue method for direct enantioselective separation of chiral pharmacologically active compounds in environmental matrices. The method is based on chiral liquid chromatography and tandem mass spectrometry detection. Simultaneous chiral discrimination was achieved with a macrocyclic glycopeptide-based column with antibiotic teicoplanin as a chiral selector working under reverse phase mode. For the first time, enantioresolution was reported for metabolites of ibuprofen: carboxyibuprofen and 2-hydroxyibuprofen with this chiral stationary phase. Moreover, enantiomers of chloramphenicol, ibuprofen, ifosfamide, indoprofen, ketoprofen, naproxen and praziquantel were also resolved. The overall performance of the method was satisfactory in terms of linearity, precision, accuracy and limits of detection. The method was successfully applied for monitoring of pharmacologically active compounds at enantiomeric level in influent and effluent wastewater and in river water. In addition, the chiral recognition and analytical performance of the teicoplanin-based column was critically compared with that of the α1 -acid glycoprotein chiral stationary phase. Copyright © 2017 John Wiley & Sons, Ltd.

Enantiomeric Profiling of Chiral Pharmacologically Active Compounds in the Environment with the Usage of Chiral Liquid Chromatography Coupled with Tandem Mass Spectrometry.

The issue of drug chirality is attracting increasing attention among the scientific community. The phenomenon of chirality has been overlooked in environmental research (environmental occurrence, fate and toxicity) despite the great impact that chiral pharmacologically active compounds (cPACs) can provoke on ecosystems. The aim of this paper is to introduce the topic of chirality and its implications in environmental contamination. Special attention has been paid to the most recent advances in chiral analysis based on liquid chromatography coupled with mass spectrometry and the most popular protein based chiral stationary phases. Several groups of cPACs of environmental relevance, such as illicit drugs, human and veterinary medicines were discussed. The increase in the number of papers published in the area of chiral environmental analysis indicates that researchers are actively pursuing new opportunities to provide better understanding of environmental impacts resulting from the enantiomerism of cPACs.

Monitoring of emerging pollutants in Guadiamar River basin (South of Spain): analytical method, spatial distribution and environmental risk assessment.

Guadiamar River is located in the southwest of the Iberian Peninsula and connects two protected areas in the South of Spain: Sierra Morena and Doñana National Park. It is sited in an area affected by urban, industrial and agriculture sewage pollution and with tradition on intensive mining activities. Most of the studies performed in this area have been mainly focused on the presence of heavy metals and, until now, little is known about the occurrence of other contaminants such as emerging organic pollutants (EOPs). In this work, an analytical method has been optimized and validated for monitoring of forty-seven EOPs in surface water. The analytical method has been applied to study the distribution and environmental risk of these pollutants in Guadiamar River basin. The analytical method was based on solid-phase extraction and determination by liquid chromatography-triple quadrupole-tandem mass spectrometry. The 60 % of the target compounds were found in the analyzed samples. The highest concentrations were found for two plasticizers (bisphenol A and di(2-ethyhexyl)phthalate, mean concentration up to 930 ng/L) and two pharmaceutical compounds (caffeine (up to 623 ng/L) and salicylic acid (up to 318 ng/L)). This study allowed to evaluate the potential sources (industrial or urban) of the studied compounds and the spatial distribution of their concentrations along the river. Environmental risk assessment showed a major risk on the south of the river, mainly due to discharges of wastewater effluents.