Naissance d’une fédération

Abstract

Résumé : Renouant avec la tradition des initiatives conjointes DGF1 et AFECG2, le colloque de Würzburg, en octobre dernier, a été l'occasion de présenter les bases de l'European federation for the science and technology of lipids, la future Fédération européenne pour l'étude des corps gras (Eurofedlipid)3. ARTICLEWith the view on human lipid nutrition straight-chain fatty acids having 16 to 22 carbon atoms have attracted attention over 80 years by now and it has become common practice to group these nutrients into saturated, monounsaturated, n-6 and n-3 polyunsaturated fatty acid classes. Since the hallmark formulation of the "essential fatty acid concept" [1] health messages for these classes have been marshaled by scientists and public health authorities ever since [2]. They will not be repeated here, rather we draw attention to a class of isoprenoid branched-chain fatty acids of plant origin. They are minor lipid constituents of our food, but have not been investigated with regard to their nutritional value or non-value.Isoprenoid branched-chain fatty acids are derived from phytol which is produced by ester hydrolysis of the phytyl side-chain linked to chlorophyll ring IV. This cleavage is carried out by microorganisms which are present in the stomach of ruminants. Humans and non-ruminant mammals can neither cleave off phytol from chlorophyll nor endogenously synthesize phytol, however, they can rapidly oxidize this alcohol to phytanic acid and subsequently degrade it to pristanic acid ( Figure 1) and lower homologs. Thus one source of phytanic acid are dairy products and ruminant meat, a prominent example being butter which contains up to 0.1% (w/w) phytanic acid. Another source of phytanic and pristanic acids are liver oils from fish which feed on phytoplankton [3]. The mean amount of phytanic acid taken up by humans varies between 50 to 100mg per day [4].Lately, fatty acids have been addressed as signaling and regulator molecules [5,6]. Within this context isoprenoid branched-chain fatty acids are not known. Yet, they are very minor constituents of phospholipids and triglycerides and their degradation in peroxisomes has received attention with respect to underlying enzyme machinery and mechanisms [7] and in view of metabolic disorders pertaining to it [7,8].We have recently elaborated a signaling path for fatty acids to the nucleus which affects gene transcription and thus regulates gene expression [9]. Our findings provide a mechanism for nutrient fatty acid-gene interaction in which cooperation of a class of nuclear receptors, the peroxisome proliferator activated receptors (PPARs) with a class of cellular transport proteins, the fatty acid binding proteins (FABPs), is pivotal. We have learned in the course of these investigations that Article disponible sur le site http://www.ocl-journal.org ou http://dx