title: A role for lipid rafts in the protection afforded by docosahexaenoic acid against ethanol toxicity in primary rat hepatocytes.
abstract: Previously, we demonstrated that eicosapentaenoic acid enhanced ethanol-induced oxidative stress and cell death in primary rat hepatocytes via an increase in membrane fluidity and lipid raft clustering. In this context, another n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), was tested with a special emphasis on physical and chemical alteration of lipid rafts. Pretreatment of hepatocytes with DHA reduced significantly ethanol-induced oxidative stress and cell death. DHA protection could be related to an alteration of lipid rafts. Indeed, rafts exhibited a marked increase in membrane fluidity and packing defects leading to the exclusion of a raft protein marker, flotillin. Furthermore, DHA strongly inhibited disulfide bridge formation, even in control cells, thus suggesting a disruption of protein-protein interactions inside lipid rafts. This particular spatial organization of lipid rafts due to DHA subsequently prevented the ethanol-induced lipid raft clustering. Such a prevention was then responsible for the inhibition of phospholipase C-γ translocation into rafts, and consequently of both lysosome accumulation and elevation in cellular low-molecular-weight iron content, a prooxidant factor. In total, the present study suggests that DHA supplementation could represent a new preventive approach for patients with alcoholic liver disease based upon modulation of the membrane structures.
authors.affiliation: UMR Inserm 1085, IRSET, UFR des Sciences Pharmaceutiques et Biologiques, 2, av Pr Léon Bernard, 35043 Rennes Cédex, France; Université de Rennes 1, Biosit UMS3080, 2, av Pr Léon Bernard, 35043 Rennes Cédex, France. Electronic address: fatihaaliche@ymail.com.
authors.forename: Fatiha
authors.initials: F
authors.lastname: Aliche-Djoudi
authors.forename: Normand
authors.initials: N
authors.lastname: Podechard
authors.forename: Aurore
authors.initials: A
authors.lastname: Collin
authors.forename: Martine
authors.initials: M
authors.lastname: Chevanne
authors.forename: Emilie
authors.initials: E
authors.lastname: Provost
authors.forename: Martine
authors.initials: M
authors.lastname: Poul
authors.forename: Ludovic
authors.initials: L
authors.lastname: Le Hégarat
authors.forename: Daniel
authors.initials: D
authors.lastname: Catheline
authors.forename: Philippe
authors.initials: P
authors.lastname: Legrand
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Dimanche-Boitrel
authors.forename: Dominique
authors.initials: D
authors.lastname: Lagadic-Gossmann
authors.forename: Odile
authors.initials: O
authors.lastname: Sergent
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D000431:Ethanol / Q000633:toxicity*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects*; D015227:Lipid Peroxidation / Q000187:drug effects; D021962:Membrane Microdomains / Q000187:drug effects* / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D017382:Reactive Oxygen Species; C106354:flotillins; D004281:Docosahexaenoic Acids; D000431:Ethanol; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D010738:Type C Phospholipases; D005978:Glutathione
keywords: 4-hydroxynonenal; DHA; Docosahexaenoic acid; EPA; EPR; Ethanol; GM1; GPI; H(2)FDA; HNE; LMW iron; Lipid peroxidation; Lipid rafts; MAL-6; O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride; O-PFB; Oxidative stress; PFBHA·HCl; PLCγ1; ROS; dihydrofluorescein diacetate; docosahexaenoic acid; eicosapentaenoic acid; electron paramagnetic resonance; glycosylphosphatidylinositol; low-molecular-weight iron; monosialotetrahexosyl ganglioside; n-3 PUFA; n-3 Polyunsaturated fatty acids; n-3 polyunsaturated fatty acid; pentafluorobenzyl-oxime; phospholipase C γ1; reactive oxygen species, GSH: reduced glutathione; tetramethyl-4-maleimidopiperidine-1-oxyl