Venue: Centre Broca
Melanie Plourde
Université de Sherbrooke
Canada
https://www.usherbrooke.ca/recherche/fr/specialistes/details/melanie.plourde2
Invited by Jean-Christophe Delpech (NutriNeuro)
Title
Understanding the blood-to-brain link of omega-3 to better support brain health during aging.
Abstract
The brain has high concentration of docosahexaenoic acid (DHA), a long chain omega-3 fatty acid (OM3). A diet rich in OM3 lower the risk of cognitive decline during aging although the mechanism is debated. However, there is a consensus that OM3 need to cross within the brain by one of the three different barriers: the blood-brain-barrier (BBB), the blood cerebrospinal fluid (CSF) barrier or the blood arachnoid barrier, an avascular barrier. During aging, the BBB leaks and unwanted molecules can reach the brain, thus promoting neuroinflammation and neuronal loss during aging and cognitive decline. The blood-CSF barrier is composed by the choroid plexus (ChP), acting as a physical barrier and secreting CSF, neurotrophic proteins, and removing toxic substances from the CSF. In a pilot project, we performed lipidomic analysis of the mice ChP and found that it contains 3 times more arachidonic acid (ARA, n-6) than DHA. ARA is a precursor of pro-inflammatory mediators. We also detected these pro-inflammatory mediators in the ChP and they increase during aging. Our team also found that the ChP lipidome can be modulated by OM3 dietary intake which change its transcriptomics. The next step of this program will be to focus on how the lipid composition of the barriers can modulate inflammation and generation of new neurons during aging. Altogether, my team wants to provide evidence and a mechanistic explanation of how dietary omega-3 intake can modify brain cell functions and how they can help maintain brain functions during aging.