Phospholipid Incorporation of Non-Methylene-Interrupted Fatty Acids (NMIFA) in Murine Microglial BV-2 Cells Reduces Pro-Inflammatory Mediator Production

Sciadonic acid (SCA), pinolenic acid (PNA), and Δ7-eicosatrienoic acid (Δ7-ETrA) are three non-methylene-interrupted fatty acids (NMIFA). Using murine microglial BV-2 cells, this study determined how NMIFA incorporation modulated phospholipid fatty acid composition and the production of pro-inflammatory mediators. Each NMIFA was rapidly taken up and incorporated in BV-2 cells, resulting in the differential redistribution of total lipids. The cellular phospholipid fatty acid compositions were altered, and a significant decrease in the proportions of total monounsaturated fatty acids (MUFA) was observed while the proportions of NMIFA and its metabolites accounted for 38 % of the fatty acid total. Incubation of microglial cells with NMIFA suppressed production of LPS-stimulated pro-inflammatory mediators, including nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), as well as the over-expression of inducible nitric oxide synthase (iNOS) and type 2 cyclooxygenase (COX-2). These inhibitory effects could be accounted for, in part, by the inactivation of mitogen-activated protein kinases (MAPK) signaling. In conclusion, Δ7-ETrA, PNA, and SCA are anti-inflammatory NMIFA that may be useful in suppressing in vitro immune responses involved in neural inflammation.