Non-enzymatic oxygenated metabolite of docosahexaenoic acid, 4(RS)-4-F4t-neuroprostane, acts as a bioactive lipid molecule in neuronal cells

Abstract

Docosahexaenoic acid (DHA), an abundant fatty acid in the brain, is susceptible to autooxidation in situ and releases metabolites such as F4‐neuroprostane (4‐F4t‐NeuroP). The presence of 4‐F4t‐NeuroP in the brain is not well explored. In this study, 4‐F4t‐NeuroP was introduced into neuroblastoma cells (SH‐SY5Y) and, by in vivo infusion, into rodents. Targeted lipidomic analysis of liver and brain tissues show significant elevation of anti‐inflammatory hydroxylated‐DHA metabolites and an isomer of neuroprotectin D1, suggesting potential beneficial bioactivities of 4‐F4t‐NeuroP. Additionally, 4‐F4t‐NeuroP treatment in SH‐SY5Y cells and primary neuronal culture consistently upregulates the transcriptional level of the antioxidant enzyme hemeoxygenase‐1, but the effect is reduced when 4‐F4t‐NeuroP is further oxidized. Our data suggest that 4‐F4t‐NeuroP could be neuroprotective in the native state but may have disadvantageous bioactivity when oxidized extensively.