Publications by authors named "Pauline Le Faouder"

The newly identified bacterium Dysosmobacter welbionis J115 improves host metabolism in high-fat diet (HFD)-fed mice. To investigate mechanisms, we used targeted lipidomics to identify and quantify bioactive lipids produced by the bacterium in the culture medium, the colon, the brown adipose tissue (BAT), and the blood of mice. In vitro, we compared the bioactive lipids produced by D.

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Oxylipins are major immunomodulating mediators, yet studies of inflammation focus mainly on cytokines. Here, using a standardized whole-blood stimulation system, we characterized the oxylipin-driven inflammatory responses to various stimuli and their relationships with cytokine responses. We performed a pilot study in 25 healthy individuals using 6 different stimuli: 2 bacterial stimuli (LPS and live BCG), 2 viral stimuli (vaccine-grade poly I:C and live H1N1 attenuated influenza), an enterotoxin superantigen and a Null control.

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Leishmania parasites are the causative agents of visceral or cutaneous leishmaniasis in humans and of canine leishmaniosis. The macrophage is the predilected host cell of Leishmania in which the promastigote stage is transformed into amastigote. We previously showed changes in the fatty acid composition (FA) of lipids in two strains of Leishmania donovani upon differentiation of promastigote to amastigote, including increased proportions of arachidonic acid (AA) and to a less extent of docosahexaenoic acid (DHA).

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Article Synopsis
  • Early-life adverse events, specifically prenatal stress, may predispose individuals to Irritable Bowel Syndrome (IBS) in adulthood by affecting gut microbiota and visceral sensitivity.
  • Researchers used a mouse model to explore these relationships, focusing on the production of lipopeptides containing γ-aminobutyric acid (GABA) by bacteria.
  • The study found that prenatal stress leads to gut microbiota dysbiosis and visceral hypersensitivity in mice, and treatment with specific GABA lipopeptides can reduce hypersensitivity, suggesting a potential mechanism connecting prenatal stress to IBS development.
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Improving knowledge about metabolites produced by the microbiota is a key point to understand its role in human health and disease. Among them, lipoamino acid (LpAA) containing asparagine and their derivatives are bacterial metabolites which could have an impact on the host. In this study, our aim was to extend the characterization of this family.

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Lipids are essential cellular constituents that have many critical roles in physiological functions. They are notably involved in energy storage and cell signaling as second messengers, and they are major constituents of cell membranes, including lipid rafts. As a consequence, they are implicated in a large number of heterogeneous diseases, such as cancer, diabetes, neurological disorders, and inherited metabolic diseases.

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Symbiosis with arbuscular mycorrhizal fungi (AMF) improves plant nutrition in most land plants, and its contribution to the colonization of land by plants has been hypothesized. Here, we identify a conserved transcriptomic response to AMF among land plants, including the activation of lipid metabolism. Using gain of function, we show the transfer of lipids from the liverwort to AMF and its direct regulation by the transcription factor WRINKLED (WRI).

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Urinary tract infections (UTIs) are among the most common outpatient infections, with a lifetime incidence of around 60% in women. We analysed urine samples from 223 patients with community-acquired UTIs and report the presence of the cleavage product released during the synthesis of colibactin, a bacterial genotoxin, in 55 of the samples examined. Uropathogenic Escherichia coli strains isolated from these patients, as well as the archetypal E.

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Objective: Data from clinical research suggest that certain probiotic bacterial strains have the potential to modulate colonic inflammation. Nonetheless, these data differ between studies due to the probiotic bacterial strains used and the poor knowledge of their mechanisms of action.

Design: By mass-spectrometry, we identified and quantified free long chain fatty acids (LCFAs) in probiotics and assessed the effect of one of them in mouse colitis.

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Introduction: To interpret metabolomic and lipidomic profiles, it is necessary to identify the metabolic reactions that connect the measured molecules. This can be achieved by putting them in the context of genome-scale metabolic network reconstructions. However, mapping experimentally measured molecules onto metabolic networks is challenging due to differences in identifiers and level of annotation between data and metabolic networks, especially for lipids.

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The in-gel detection of proteins for various proteomic experiments is commonly done with the fluorescent Ru tris(bathophenanthroline disulfonate) complex (Ru(BPS)), which is more cost-effective compared to commercial Ru-based formulations but requires tedious procedures for its preparation and strongly acidic staining conditions. Herein, we report the synthesis and characterization of heteroleptic Ru complexes Ru(BPS)(BP) and Ru(BPS)(BP) containing bathophenanthroline (BP) and bathophenanthroline disulfonate disodium salt (BPS) in comparison with Ru(BPS). It was shown by fluorescent and UV-vis measurements that novel Ru complexes were excitable in both UV and visible light, close to emission bands of classical lasers, which is important for successful in-gel protein detection.

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Transcatheter aortic valve implantation (TAVI) is an established treatment option for symptomatic patients with severe aortic valve stenosis (AS). During and early after the procedure, both ischemic events (predominantly stroke) and bleedings remain prevalent. The optimal antithrombotic regimen is still debated.

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Article Synopsis
  • The infection process begins when macrophages engulf infective promastigotes, but the parasite has evolved ways to manipulate these immune cells.
  • During the study, the team examined how different stages of the parasite produce lipid metabolites and their role in modifying macrophage behavior.
  • Results showed that infective stages increased specific fatty acid metabolites, directing macrophages toward a M2 proresolving phenotype, which suppresses the inflammatory M1 response.
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Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that is characterized by chronic abdominal pain concurrent with altered bowel habit. Polyunsaturated fatty acid (PUFA) metabolites are increased in abundance in IBS and are implicated in the alteration of sensation to mechanical stimuli, which is defined as visceral hypersensitivity. We sought to quantify PUFA metabolites in patients with IBS and evaluate their role in pain.

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Objective: Sustained inflammation originating from macrophages is a driving force of fibrosis progression and resolution. Monoacylglycerol lipase (MAGL) is the rate-limiting enzyme in the degradation of monoacylglycerols. It is a proinflammatory enzyme that metabolises 2-arachidonoylglycerol, an endocannabinoid receptor ligand, into arachidonic acid.

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Unlabelled: Oxylipins are secondary messengers used universally in the living world for communication and defense. The paradigm is that they are produced enzymatically for the eicosanoids and non-enzymatically for the isoprostanoids. They are supposed to be degraded into volatile organic compounds (VOCs) and to participate in aroma production.

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Administration of the probiotic Escherichia coli strain Nissle 1917 (EcN) decreases visceral pain associated with irritable bowel syndrome. Mutation of clbA, a gene involved in the biosynthesis of secondary metabolites, including colibactin, was previously shown to abrogate EcN probiotic activity. Here, we show that EcN, but not an isogenic clbA mutant, produces an analgesic lipopeptide.

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Blood platelets are the first line of defense against hemorrhages and are also strongly involved in the processes of arterial thrombosis, a leading cause of death worldwide. Besides their well-established roles in hemostasis, vascular wall repair and thrombosis, platelets are now recognized as important players in other processes such as inflammation, healing, lymphangiogenesis, neoangiogenesis or cancer. Evidence is accumulating they are key effector cells in immune and inflammatory responses to host infection.

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Farber disease is a rare autosomal recessive disorder caused by acid ceramidase deficiency that usually presents as early-onset progressive visceral and neurologic disease. To understand the neurologic abnormality, we investigated behavioral, biochemical, and cellular abnormalities in the central nervous system of Asah1 mice, which serve as a model of Farber disease. Behaviorally, the mutant mice had reduced voluntary locomotion and exploration, increased thigmotaxis, abnormal spectra of basic behavioral activities, impaired muscle grip strength, and defects in motor coordination.

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Sphingolipids are sphingoid base-containing lipids, among which some metabolites behave as bioactive molecules in various biological processes, including cell death. Whereas ceramide is now viewed as an anti-oncometabolite, leading to cancer cell death, CD95L-induced apoptosis is associated with sphingolipid changes, which likely contribute to caspase-dependent signaling pathway activation. Here, we describe Liquid Chromatography-high resolution mass spectrometry method (LC-HRMS) to analyze sphingolipid metabolism changes triggered by CD95L.

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Lipidomics calls for information on detected lipids and conjugates whose structural elucidation by mass spectrometry requires to rationalization of their gas phase dissociations toward collision-induced dissociation (CID) processes. This study focused on activated dissociations of two lipoamino acid (LAA) systems composed of N-palmitoyl acyl coupled with aspartic and glutamic acid mono ethyl esters (as LAA and LAA). Although in MS/MS, their CID spectra show similar trends, e.

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Isoprostanoids are a group of non-enzymatic oxygenated metabolites of polyunsaturated fatty acids. It belongs to oxylipins group, which are important lipid mediators in biological processes, such as tissue repair, blood clotting, blood vessel permeability, inflammation and immunity regulation. Recently, isoprostanoids from eicosapentaenoic, docosahexaenoic, adrenic and α-linolenic namely F3-isoprostanes, F4-neuroprostanes, F2-dihomo-isoprostanes and F1-phytoprostanes, respectively have attracted attention because of their putative contribution to health.

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A new sphingolipid hybrid molecule was designed to assemble, within a tail-to-tail double-chain structure, the ceramide hydrophilic moiety and the tetrahydrofuran pharmacophore of jaspine B, a natural product known to interfere with sphingolipid metabolism. This compound was prepared through acylation of sphingosine with a jaspine B derivative bearing a COOH group in the terminal position of the aliphatic backbone. This new hybrid molecule was evaluated for its capacities to affect melanoma cell viability and sphingolipid metabolism.

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Introduction: Congenital infection by human cytomegalovirus (HCMV) is a leading cause of congenital abnormalities of the central nervous system. Placenta infection by HCMV allows for viral spread to fetus and may result in intrauterine growth restriction, preeclampsia-like symptoms, or miscarriages. We previously reported that HCMV activates peroxisome proliferator-activated receptor gamma (PPARγ) for its own replication in cytotrophoblasts.

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Background & Aims: In mice, activation of the transient receptor potential cation channels (TRP) TRPV1, TRPV4, and TRPA1 causes visceral hypersensitivity. These receptors and their agonists might be involved in development of irritable bowel syndrome (IBS). We investigated whether polyunsaturated fatty acid (PUFA) metabolites, which activate TRPs, are present in colon tissues from patients with IBS and act as endogenous agonists to induce hypersensitivity.

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