title: Membrane raft organization is more sensitive to disruption by (n-3) PUFA than nonraft organization in EL4 and B cells.
abstract: Model membrane and cellular detergent extraction studies show (n-3) PUFA predominately incorporate into nonrafts; thus, we hypothesized (n-3) PUFA could disrupt nonraft organization. The first objective of this study was to determine whether (n-3) PUFA disrupted nonrafts of EL4 cells, an extension of our previous work in which we discovered an (n-3) PUFA diminished raft clustering. EPA or DHA treatment of EL4 cells increased plasma membrane accumulation of the nonraft probe 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate by ~50-70% relative to a BSA control. Förster resonance energy transfer imaging showed EPA and DHA also disrupted EL4 nanometer scale nonraft organization by increasing the distance between nonraft molecules by ~25% compared with BSA. However, changes in nonrafts were due to an increase in cell size; under conditions where EPA or DHA did not increase cell size, nonraft organization was unaffected. We next translated findings on EL4 cells by testing if (n-3) PUFA administered to mice disrupted nonrafts and rafts. Imaging of B cells isolated from mice fed low- or high-fat (HF) (n-3) PUFA diets showed no change in nonraft organization compared with a control diet (CD). However, confocal microscopy revealed the HF (n-3) PUFA diet disrupted lipid raft clustering and size by ~40% relative to CD. Taken together, our data from 2 different model systems suggest (n-3) PUFA have limited effects on nonrafts. The ex vivo data, which confirm previous studies with EL4 cells, provide evidence that (n-3) PUFA consumed through the diet disrupt B cell lipid raft clustering.
authors.affiliation: Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC 27834, USA.
authors.forename: Benjamin Drew
authors.initials: BD
authors.lastname: Rockett
authors.forename: Andrew
authors.initials: A
authors.lastname: Franklin
authors.forename: Mitchel
authors.initials: M
authors.lastname: Harris
authors.forename: Heather
authors.initials: H
authors.lastname: Teague
authors.forename: Alexis
authors.initials: A
authors.lastname: Rockett
authors.forename: Saame Raza
authors.initials: SR
authors.lastname: Shaikh
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D004281:Docosahexaenoic Acids / Q000494:pharmacology; D015118:Eicosapentaenoic Acid / Q000494:pharmacology; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D031541:Fluorescence Resonance Energy Transfer; D008297:Male; D021962:Membrane Microdomains / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D015525:Fatty Acids, Omega-3; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid