Link between Intestinal CD36 Ligand Binding and Satiety Induced by a High Protein Diet in Mice

CD36 is a ubiquitous membrane glycoprotein that binds long-chain fatty acids. The presence of a functional CD36 is required for the induction of satiety by a lipid load and its role as a lipid receptor driving cellular signal has recently been demonstrated. Our project aimed to further explore the role of intestinal CD36 in the regulation of food intake. Duodenal infusions of vehicle or sulfo-N-succinimidyl-oleate (SSO) was performed prior to acute infusions of saline or Intralipid (IL) in mice. Infusion of minute quantities of IL induced a decrease in food intake (FI) compared to saline. Infusion of SSO had the same effect but no additive inhibitory effect was observed in presence of IL. No IL- or SSO-mediated satiety occurred in CD36-null mice. To determine whether the CD36-mediated hypophagic effect of lipids was maintained in animals fed a satietogen diet, mice were subjected to a High-Protein diet (HPD). Concomitantly with the satiety effect, a rise in intestinal CD36 gene expression was observed. No satiety effect occurred in CD36-null mice. HPD-fed WT mice showed a diminished FI compared to control mice, after saline duodenal infusion. But there was no further decrease after lipid infusion. The lipid-induced decrease in FI observed on control mice was accompanied by a rise in jejunal oleylethanolamide (OEA). Its level was higher in HPD-fed mice than in controls after saline infusion and was not changed by lipids. Overall, we demonstrate that lipid binding to intestinal CD36 is sufficient to produce a satiety effect. Moreover, it could participate in the satiety effect induced by HPD. Intestine can modulate FI by several mechanisms including an increase in OEA production and CD36 gene expression. Furthermore, intestine of mice adapted to HPD have a diminished capacity to modulate their food intake in response to dietary lipids

Extraction of pure components from overlapped signals in gas chromatography-mass spectrometry (GC-MS)

Gas chromatography-mass spectrometry (GC-MS) is a widely used analytical technique for the identification and quantification of trace chemicals in complex mixtures. When complex samples are analyzed by GC-MS it is common to observe co-elution of two or more components, resulting in an overlap of signal peaks observed in the total ion chromatogram. In such situations manual signal analysis is often the most reliable means for the extraction of pure component signals; however, a systematic manual analysis over a number of samples is both tedious and prone to error. In the past 30 years a number of computational approaches were proposed to assist in the process of the extraction of pure signals from co-eluting GC-MS components. This includes empirical methods, comparison with library spectra, eigenvalue analysis, regression and others. However, to date no approach has been recognized as best, nor accepted as standard. This situation hampers general GC-MS capabilities, and in particular has implications for the development of robust, high-throughput GC-MS analytical protocols required in metabolic profiling and biomarker discovery. Here we first discuss the nature of GC-MS data, and then review some of the approaches proposed for the extraction of pure signals from co-eluting components. We summarize and classify different approaches to this problem, and examine why so many approaches proposed in the past have failed to live up to their full promise. Finally, we give some thoughts on the future developments in this field, and suggest that the progress in general computing capabilities attained in the past two decades has opened new horizons for tackling this important problem

Desaturation of oleoyl and linoleoyl residues linked to phospholipids in growing roots of yellow lupin

AbstractWhen growing lupin roots were fed with [14C]oleate and [14C]linoleate most of the absorbed molecules remained in the free fatty acid pool. Part of the 14C-labelled fatty acid was integrated first into phosphatidylcholine and subsequently into phosphatidylethanolamine. Then, progressive desaturation took place. The kinetics of these processes suggests that desaturation in phosphatidylcholine was followed by transacylation of polyunsaturated fatty acids into phosphatidylethanolamine. To produce good yields of desaturation (about 48%), seeds had to be less than 1-year old. With respect to linoleate desaturation, seedlings had to be 2–7-days old. Increased percentages of oleate desaturation were obtained when the roots were grown on a medium enriched with calcium

Construire un modèle pluridisciplinaire autour de la gestion des casiers Girardon aquatiques

International audienc

Construire un modèle pluridisciplinaire autour de la gestion des casiers Girardon aquatiques

International audienc

Dike fields connectivity and diversity: a complex functioning on the Rhone River

International audienc

Dynamics and fates of trace metals chronically input in a Mediterranean coastal zone impacted by a large urban area

International audienceQuantification and characterization of chronic inputs of trace metals and organic carbon in a coastal Med-iterranean area (the city of Marseille) during the dry season was carried out. The 625 km 2 watershed includes two small coastal rivers whose waters are mixed with treated wastewater (TWW) just before their outlet into the sea. Dissolved and particulate Cu, Pb, Cd, Zn, Co, Ni and organic carbon concentra-tions in the rivers were comparable to those in other Mediterranean coastal areas, whereas at the outlet, 2-to 18-fold higher concentrations reflected the impact of the TWW. A non-conservative behavior observed for most of the studied metals in the mixing zone was validated by a remobilization experiment performed in the laboratory. The results showed that sorption/desorption processes could occur with slow kinetics with respect to the mixing time in the plume, indicating non-equilibrium in the dis-solved/particulate metal distribution. Thus, a sample filtration immediately after sampling is strictly required