Chuck Chen
Chuck Chen, Post-doctoral Researcher
Chuck completed his doctoral degree from the Department of Nutritional Sciences at the University of Toronto in Canada. His doctoral research focused on investigating the metabolic differences that attributes to the unique omega-3 polyunsaturated fatty acids (n-3 PUFA) composition in brain phospholipid membrane. Brain phospholipid membrane is highly enriched in n-3 PUFA; however, it is selectively enriched in docosahexaenoic acid (DHA) and low in eicosapentaenoic acid (EPA). The fold-difference can range from 250 to 500 depending on the diet. Over the last five decades, assumptions were made that there are difference in their uptake to the brain. However, recent evidence suggests that unesterified/free DHA and EPA are able to freely diffuse across brain phospholipid membrane at similar rate. Therefore to investigate alternative explanations, Chuck examined the differences between DHA and EPA β-oxidation in the brain, esterification into brain phospholipid membrane, turnover/recycling in brain phospholipid membrane and its associated loss from membranes as well as synthesis into specialized bioactive mediators. Through a series of kinetic modelling, the studies replicated the previous findings that there were no difference in the in vivo uptake of DHA and EPA into the brain but there were significant differences between DHA and EPA in the metabolism upon entry into the brain. Upon EPA entry into the brain, it is targeted for β-oxidation by the mitochondria in addition to less being incorporated and recycled in brain phospholipid membrane and more being loss from the membrane. Collectively, these differences in each of the metabolic pathways, collectively, attributed to the large difference in brain phospholipid levels of DHA and EPA.