Browsing by Subject "Docosahexaenoic acids"

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    DHA Modifies the Size and Composition of Raftlike Domains: A Solid-State 2H NMR Study
    (Elsevier, 2018-01-23) Kinnun, Jacob J.; Bittman, Robert; Shaikh, Saame Raza; Wassall, Stephen R.; Physics, School of Science
    Docosahexaenoic acid is an omega-3 polyunsaturated fatty acid that relieves the symptoms of a wide variety of chronic inflammatory disorders. The structural mechanism is not yet completely understood. Our focus here is on the plasma membrane as a site of action. We examined the molecular organization of [2H31]-N-palmitoylsphingomyelin (PSM-d31) mixed with 1-palmitoyl-2-docosahexaenoylphosphatylcholine (PDPC) or 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), as a monounsaturated control, and cholesterol (chol) (1:1:1 mol) in a model membrane by solid-state 2H NMR. The spectra were analyzed in terms of segregation into ordered SM-rich/chol-rich (raftlike) and disordered PC-rich/chol-poor (nonraft) domains that are nanoscale in size. An increase in the size of domains is revealed when POPC was replaced by PDPC. Spectra that are single-component, attributed to fast exchange between domains (<45 nm), for PSM-d31 mixed with POPC and chol become two-component, attributed to slow exchange between domains (r > 30 nm), for PSM-d31 mixed with PDPC and chol. The resolution of separate signals from PSM-d31, and correspondingly from [3α-2H1]cholesterol (chol-d1) and 1-[2H31]palmitoyl-2-docosahexaenoylphosphatidylcholine (PDPC-d31), in raftlike and nonraft domains enabled us to determine the composition of the domains in the PDPC-containing membrane. Most of the lipid (28% SM, 29% chol, and 23% PDPC with respect to total lipid at 30°C) was found in the raftlike domain. Despite substantial infiltration of PDPC into raftlike domains, there appears to be minimal effect on the order of SM, implying the existence of internal structure that limits contact between SM and PDPC. Our results suggest a significant refinement to the model by which DHA regulates the architecture of ordered, sphingolipid-chol-enriched domains (rafts) in membranes.
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    Investigating omega-3 fatty acids' neuroprotective effects in repetitive subconcussive neural injury: Study protocol for a randomized placebo-controlled trial
    (Public Library of Science, 2025-04-24) Beauregard, Lauren H.; Bazarian, Jeffrey J.; Johnson, Blair D.; Cheng, Hu; Ellis, Gage; Kronenberger, William; Calder, Philip C.; Chen, Zhongxue; Silveyra, Patricia; Quinn, Patrick D.; Newman, Sharlene D.; Mickleborough, Timothy D.; Kawata, Keisuke; Psychiatry, School of Medicine
    Soccer (football) is the most popular sport globally, with 265 million players across all ages and sexes. Repetitive subconcussive head impacts due to heading of the soccer ball can pose threats to healthy brain development and aging. Omega-3 fatty acids, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may have neuroprotective effects, but it remains unclear what aspects of neural health benefit from DHA+EPA when faced with subconcussive head impacts. In a randomized placebo-controlled trial, 208 soccer players will complete baseline measures including demographics, blood sampling, dietary recalls, and psychological assessment. Participants will be randomly assigned to ingest DHA+EPA [3.4g/d: DHA 2.4g+EPA 1.0g] or placebo daily for 8 weeks followed by a subconcussion intervention phase. During the subconcussion intervention, participants will perform a session of 20 controlled soccer headings, with a second session 24 hours later. Blood samples, neuroimaging data, autonomic reactivity, and clinical measures (symptoms, oculomotor, cognition) will be collected pre-heading and 24-hour post-1st session, 24-hour post-2nd session, and 7-day post-2nd session. The primary hypothesis is that DHA+EPA pretreatment will promote neuronal and astrocyte resiliency to subconcussive head impacts, as assessed by blood biomarkers of brain injury, axonal microstructure measured by diffusion tensor imaging, and whole-brain resting-state connectivity. It is proposed that pretreatment will preserve autonomic function, as assessed by the cold pressor test (CPT), as well as oculomotor and cognitive function, even after head impacts. Data from this trial will help clarify the combined effect of DHA+EPA on brain molecular, cellular, and physiological health in response to subconcussive head impacts. If the hypotheses are confirmed, the findings will support a highly practical intervention for mitigating the neurodegenerative cascade triggered by head impacts.