title: Accumulation of dietary docosahexaenoic acid in the brain attenuates acute immune response and development of postischemic neuronal damage.
abstract: OBJECTIVE
  Consumption of fish has been shown to reduce risk of coronary heart disease and, possibly, of ischemic stroke. Because docosahexaenoic acid (DHA) is the most likely neuroactive component within fish oil, we hypothesized that exposing mice to a DHA-enriched diet may reduce inflammation and protect neurons against ischemic injury.
  
  
  METHODS
  To visualize the effects of DHA on neuroinflammation after stroke, TLR2-fluc-GFP transgenic mice were exposed to either a control diet, a diet depleted in n-3 polyunsaturated fatty acid, or a diet enriched in DHA during 3 months. Real-time biophotonic/bioluminescence imaging of the TLR2 response was performed before and after middle cerebral artery occlusion, whereas cytokines concentrations and stroke area analyses were performed at 3 and 7 days after middle cerebral artery occlusion, respectively.
  
  
  RESULTS
  We show that a 3-month DHA treatment prevented microglial activation after ischemic injury, reduced the ischemic lesion size, and increased levels of the antiapoptotic molecule Bcl-2 in the brain. Additional analysis revealed a significant decrease in the levels of COX2 and IL-1β, but not in other proinflammatory cytokines. Importantly, long-term DHA supplementation significantly changed the n-3:n-6 polyunsaturated fatty acid ratio in the brain.
  
  
  CONCLUSIONS
  Collectively, these data indicate that diet-induced accumulation of DHA in the brain protects against postischemic inflammation and injury. Because DHA is widely available at low cost and has an excellent safety profile, our data suggest that increased DHA intake may provide protection against acute immune response/brain damage in ischemic stroke.
authors.affiliation: Department of Psychiatry and Neuroscience, Faculty of Medicine, University Laval, 2705 boul. Laurier, Quebec City, QC, G1V 4G2 Canada.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Lalancette-Hébert
authors.forename: Carl
authors.initials: C
authors.lastname: Julien
authors.forename: Pierre
authors.initials: P
authors.lastname: Cordeau
authors.forename: Ivan
authors.initials: I
authors.lastname: Bohacek
authors.forename: Yuan-Cheng
authors.initials: YC
authors.lastname: Weng
authors.forename: Frédéric
authors.initials: F
authors.lastname: Calon
authors.forename: Jasna
authors.initials: J
authors.lastname: Kriz
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D002545:Brain Ischemia / Q000276:immunology* / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000008:administration & dosage* / Q000378:metabolism; D007110:Immunity, Active / Q000276:immunology*; D007249:Inflammation / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000276:immunology* / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000378:metabolism
chemical_list: D051195:Toll-Like Receptor 2; D004281:Docosahexaenoic Acids