0000000001264219
AUTHOR
Jacques Grober
Avis de l'Anses relatif à l'actualisation de la méthode d'imputabilité des signalements d'effets indésirables de nutrivigilance
A l’instar des autres systèmes de vigilance français et compte tenu de l’importance des conséquences en matière de santé et des décisions industrielles qui en découlent, l’analyse de la relation de causalité entre un produit visé par le dispositif national de nutrivigilance et l’effetindésirable déclaré doit être réalisée avec une méthode d’analyse appropriée et objective. Cette méthode dite « méthode d’imputabilité de nutrivigilance » estime le degré de causalité, d’un ou de plusieurs produits dans la survenue de l’effet indésirable déclaré, de manière standardisée, permettant d’éliminer les divergences d’opinion pouvant exister entre plusieurs observateurs. De telles méthodes sont couramm…
Liver X Receptor–Mediated Induction of Cholesteryl Ester Transfer Protein Expression Is Selectively Impaired in Inflammatory Macrophages
Objective— Cholesteryl ester transfer protein (CETP) is a target gene for the liver X receptor (LXR). The aim of this study was to further explore this regulation in the monocyte-macrophage lineage and its modulation by lipid loading and inflammation, which are key steps in the process of atherogenesis. Methods and Results— Exposure of bone marrow–derived macrophages from human CETP transgenic mice to the T0901317 LXR agonist increased CETP, PLTP, and ABCA1 mRNA levels. T0901317 also markedly increased CETP mRNA levels and CETP production in human differentiated macrophages, whereas it had no effect on CETP expression in human peripheral blood monocytes. In inflammatory mouse and human mac…
Immune Cell Toll-like Receptor 4 Mediates the Development of Obesity- and Endotoxemia-Associated Adipose Tissue Fibrosis
International audience; Adipose tissue fibrosis development blocks adipocyte hypertrophy and favors ectopic lipid accumulation. Here, we show that adipose tissue fibrosis is associated with obesity and insulin resistance in humans and mice. Kinetic studies in C3H mice fed a high-fat diet show activation of macrophages and progression of fibrosis along with adipocyte metabolic dysfunction and death. Adipose tissue fibrosis is attenuated by macrophage depletion. Impairment of Toll-like receptor 4 signaling protects mice from obesity-induced fibrosis. The presence of a functional Toll-like receptor 4 on adipose tissue hematopoietic cells is necessary for the initiation of adipose tissue fibros…
Muricholic Acids Promote Resistance to Hypercholesterolemia in Cholesterol-Fed Mice
International audience; Background and aims: Hypercholesterolemia is a major risk factor for atherosclerosis and cardiovascular diseases. Although resistant to hypercholesterolemia, the mouse is a prominent model in cardiovascular research. To assess the contribution of bile acids to this protective phenotype, we explored the impact of a 2-week-long dietary cholesterol overload on cholesterol and bile acid metabolism in mice. Methods: Bile acid, oxysterol, and cholesterol metabolism and transport were assessed by quantitative real-time PCR, western blotting, GC-MS/MS, or enzymatic assays in the liver, the gut, the kidney, as well as in the feces, the blood, and the urine. Results: Plasma tr…
Increased Phospholipid Transfer Protein Activity Is Associated With Markers of Enhanced Lipopolysaccharide Clearance in Human During Cardiopulmonary Bypass
Introduction: Lipopolysaccharide (LPS) is a component of gram-negative bacteria, known for its ability to trigger inflammation. The main pathway of LPS clearance is the reverse lipopolysaccharide transport (RLT), with phospholipid transfer protein (PLTP) and lipoproteins playing central roles in this process in experimental animal models. To date, the relevance of this pathway has never been studied in humans. Cardiac surgery with cardiopulmonary bypass is known to favor LPS digestive translocation. Our objective was to determine whether pre-operative PLTP activity and triglyceride or cholesterol-rich lipoprotein concentrations were associated to LPS concentrations in patients undergoing ca…
Phospholipid transfer protein (PLTP) and metabolic diseases
International audience; No abstract
Sterol Regulatory Element-binding Protein-1c Is Responsible for Cholesterol Regulation of Ileal Bile Acid-binding Protein Gene in Vivo
Ileal bile acid-binding protein (I-BABP) is a cytosolic protein that binds bile acid (BA) specifically. In the ileum, it is thought to be implied in their enterohepatic circulation. Because the fecal excretion of BA represents the main physiological way of elimination for cholesterol (CS), the I-BABP gene could have a major function in CS homeostasis. Therefore, the I-BABP gene expression might be controlled by CS. I-BABP mRNA levels were significatively increased when the human enterocyte-like CaCo-2 cells were CS-deprived and repressed when CS were added to the medium. A highly conserved sterol regularory element-like sequence (SRE) and a putative GC box were found in human I-BABP gene pr…
Actualisation des références nutritionnelles françaises en vitamines et minéraux
En 2016, l’Anses a proposé une mise à jour des références nutritionnelles pour la population adulte (femmes de 18 à 54 ans et hommes de 18 à 64 ans) dans le cadre de l’actualisation des repères de consommation alimentaire (saisine 2012-SA-0103). Par la suite, des rapports dédiés aux repères de consommation alimentaire pour les populations spécifiques (personnes âgées, enfants, femmes enceintes et allaitantes) ont été publiés en 2019, sans toutefois quede nouvelles références nutritionnelles ne soient définies par l’agence.Par ailleurs, la mise à jour de 2016 n’a concerné que les vitamines et minéraux indispensables pour lesquelles des données de consommation étaient disponibles. De ce fait,…
Glucagon-like peptide-1 is associated with poor clinical outcome, lipopolysaccharide translocation and inflammation in patients undergoing cardiac surgery with cardiopulmonary bypass.
International audience; Introduction: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with gut barrier dysfunction. Gut barrier dysfunction might be estimated non-invasively by lipopolysaccharide (LPS) plasma concentration. Glucagon-like peptide-1 (GLP-1) is a gut secreted hormone that is a potential marker of mucosal integrity. Our objective was to evaluate GLP-1 as a peri-operative marker of gut barrier dysfunction in patients undergoing cardiac surgery with CPB.Methods: GLP-1, intestinal fatty acid binding protein (I-FABP) and lipopolysaccharide were assayed: at induction, after CPB and 24 h after admission in the intensive care unit. The primary end-point was peri-operat…
Constitutive androstane receptor activation stimulates faecal bile acid excretion and reverse cholesterol transport in mice.
The constitutive androstane receptor (CAR) is a nuclear receptor expressed in the liver and involved in xenobiotic metabolism. The aim of this study was to assess whether pharmacological CAR activation could affect neutral sterol and bile acid elimination under conditions of cholesterol overload.Wild type, Car-/-, ApoE-/-, and low-density lipoprotein receptor (Ldlr)-/- mice fed a western-type diet were treated with the CAR agonist TCPOBOP.CAR activation was associated with a decrease in faecal cholesterol output related to the repression of the Abcg5/g8 cholesterol transporters. In contrast, TCPOBOP treatment induced a marked increase (up to three fold, p0.01) in the elimination of faecal b…
Farnesoid X receptor activation increases cholesteryl ester transfer protein expression in humans and transgenic mice
International audience; Cholesteryl ester transfer protein (CETP) activity results in a proatherogenic lipoprotein profile. In cholestatic conditions, farnesoid X receptor (FXR) signaling by bile acids (BA) is activated and plasma HDL cholesterol (HDL-C) levels are low. This study tested the hypothesis that FXR-mediated induction of CETP contributes to this phenotype. Patients with cholestasis and high plasma BA had lower HDL-C levels and higher plasma CETP activity and mass compared with matched controls with low plasma BA (each P < 0.01). BA feeding in APOE3*Leiden transgenic mice expressing the human CETP transgene controlled by its endogenous promoter increased cholesterol within apoB-c…
Lipopolysaccharides-mediated increase in glucose-stimulated insulin secretion: involvement of the GLP-1 pathway.
Lipopolysaccharides (LPS) of the cell wall of gram–negative bacteria trigger inflammation, which is associated with marked changes in glucose metabolism. Hyperglycemia is frequently observed during bacterial infection and it is a marker of a poor clinical outcome in critically ill patients. The aim of the current study was to investigate the effect of an acute injection or continuous infusion of LPS on experimentally induced hyperglycemia in wild-type and genetically engineered mice. The acute injection of a single dose of LPS produced an increase in glucose disposal and glucose-stimulated insulin secretion (GSIS). Continuous infusion of LPS through mini-osmotic pumps was also associated wi…
High Serum Cholesteryl Ester Transfer Rates and Small High-Density Lipoproteins Are Associated With Young Age in Patients With Acute Myocardial Infarction
Objectives Our aim was to characterize cholesteryl ester transfer protein (CETP) activity in the early phase of acute myocardial infarction (MI). Background Cholesteryl ester transfer protein catalyzes the transfer of cholesteryl esters from high-density lipoprotein (HDL) donors to apolipoprotein B-containing lipoprotein acceptors. Methods The CETP concentration, lipid profiles, and the rate of cholesteryl ester transfer (CET) from a tracer dose of radiolabeled HDL toward endogenous lipoproteins were determined within 24 h after symptom onset. Results Among 347 patients with first MI, CETP concentration, triglycerides, and non–HDL-cholesterol increased across tertiles of the CET rate, where…
Phospholipid transfer protein (PLTP), lipopolysaccharides detoxification and metabolic diseases: a connection ?
International audience
Disturbances in cholesterol, bile acid and glucose metabolism in peroxisomal 3-ketoacylCoA thiolase B deficient mice fed diets containing high or low saturated fat contents.
SPE IPM UB; International audience; : The peroxisomal 3-ketoacyl-CoA thiolase B (ThB) catalyzes the thiolytic cleavage of straight chain 3-ketoacyl-CoAs. Up to now, the ability of ThB to interfere with lipid metabolism was studied in mice fed a routinely laboratory chow enriched or not with the synthetic agonist Wy14,643, a pharmacological activator of the nuclear hormone receptor PPARα. The aim of the present study was therefore to determine whether ThB could play a role in obesity and lipid metabolism when mice are chronically fed a synthetic High Fat Diet (HFD) or a Low Fat Diet (LFD) as a control diet. To investigate this possibility, wild-type (WT) mice and mice deficient for Thb (Thb(…