title: Effects of docosahexaenoic acid on mouse brain synaptic plasma membrane proteome analyzed by mass spectrometry and (16)O/(18)O labeling.
abstract: Docosahexenoic acid (DHA, 22:6n-3) plays an important role in development of proper brain function in mammals. We have previously reported that DHA promotes synaptogenesis and synaptic function in hippocampal neurons while DHA-depletion in the brain due to n-3 fatty acid deficiency produces opposite effects. To gain insight into underlying molecular mechanisms, we investigated whether the brain DHA status affects the synaptic plasma membrane (SPM) proteome by using nanoLC-ESI-MS/MS and (16)O/(18)O labeling. The DHA level in mouse brains was lowered by dietary depletion of n-3 fatty acids, and SPM was prepared by differential centrifugation followed by osmotic shock. SPM proteins from DHA-adequate and depleted brains were analyzed by nanoLC-ESI-MS/MS after SDS-PAGE, in-gel digestion, and differential O(18)/O(16) labeling. This strategy allowed comparative quantitation of more than 200 distinct membrane or membrane-associated proteins from DHA-adequate or depleted brains. We found that 18 pre- and postsynaptic proteins that are relevant to synaptic physiology were significantly down-regulated in DHA-depleted mouse brains. The protein network analysis suggests involvement of CREB and caspase-3 pathways in the DHA-dependent modulation of synaptic proteome. Reduction of specific synaptic proteins due to brain DHA-depletion may be an important mechanism for the suboptimal brain function associated with n-3 fatty acid deficiency.
authors: Laboratory of Molecular Signaling, Division of Intramural Clinical and Biological Reasearch, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, United States.
authors: Vishaldeep K
authors: VK
authors: Sidhu
authors: Bill X
authors: BX
authors: Huang
authors: Hee-Yong
authors: HY
authors: Kim
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002498:Centrifugation / Q000379:methods; D002540:Cerebral Cortex / Q000737:chemistry / Q000187:drug effects*; D017362:Cyclic AMP Response Element-Binding Protein / Q000737:chemistry; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D015525:Fatty Acids, Omega-3 / Q000737:chemistry; D005260:Female; D007553:Isotope Labeling / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods; D008565:Membrane Proteins / Q000032:analysis / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D009997:Osmotic Pressure; D010103:Oxygen Isotopes / Q000737:chemistry; D011247:Pregnancy; D020543:Proteome / Q000032:analysis* / Q000737:chemistry; D013569:Synapses / Q000737:chemistry; D013570:Synaptic Membranes / Q000737:chemistry / Q000187:drug effects*
chemical_list: C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D015525:Fatty Acids, Omega-3; D008565:Membrane Proteins; D010103:Oxygen Isotopes; D020543:Proteome; D004281:Docosahexaenoic Acids