In vitro fatty acid enrichment of macrophages alters inflammatory response and net cholesterol accumulation

Dietary long-chain {PUFA,} both n-3 and n-6, have unique benefits with respect to {CVD} risk. The aim of the present study was to determine the mechanisms by which n-3 {PUFA} {(EPA,} {DHA)} and n-6 {PUFA} (linoleic acid {(LA),} arachidonic acid {(AA))} relative to {SFA} (myristic acid {(MA),} palmitic acid {(PA))} alter markers of inflammation and cholesterol accumulation in macrophages {(MPhi).} Cells treated with {AA} and {EPA} elicited significantly less inflammatory response than control cells or those treated with {MA,} {PA} and {LA,} with intermediate effects for {DHA,} as indicated by lower levels of {mRNA} and secretion of {TNFalpha,} {IL-6} and monocyte chemoattractant protein-1. Differences in cholesterol accumulation after exposure to minimally modified {LDL} were modest. {AA} and {EPA} resulted in significantly lower {MPhi} scavenger receptor 1 {mRNA} levels relative to control or {MA-,} {PA-,} {LA-} and {DHA-treated} cells, and {ATP-binding} cassette A1 {mRNA} levels relative to control or {MA-,} {PA-} and {LA-treated} cells. These data suggest changes in the rate of bidirectional cellular cholesterol flux. In summary, individual long-chain {PUFA} have differential effects on inflammatory response and markers of cholesterol flux in {MPhi} which are not related to the n position of the first double bond, chain length or degree of saturation.