Polyunsaturated fatty acid metabolism and acetylated low density lipoprotein uptake in J774A.1 cells.
The mechanism of the antiatherogenic activity of n-3 polyunsaturated fatty acids is not well understood. In these studies, we studied the metabolism of unsaturated fatty acids in murine macrophage-like J774A.1 cells. The major metabolic pathway of 18- and 20-carbon chain unsaturated fatty acids in these cells is the sequence of 2-carbon chain elongation, successive two steps of delta 8- and delta 5-desaturation, and additional elongation. Polyunsaturated fatty acids, arachidonic acid [20:4 (n-6)] and eicosapentaenoic acid [20:5 (n-3)], are elongated into 22:4 (n-6) and 22:5 (n-3) fatty acids, respectively. Accumulation of 22:4 (n-6) and 22:5 (n-3) fatty acids shows that J774A.1 cells have an active chain elongation activity, but lack delta 4-desaturase activity. Furthermore, J774A.1 cells demonstrated almost negligible delta 6-desaturase activity. Enrichment of the membrane lipids of J774A.1 cells with polyunsaturated fatty acids, arachidonic acid [(20:4 (n-6)] and eicosapentaenoic acid [(20:5 (n-3)], increased membrane fluidity and decreased the uptake of acetylated low density lipoprotein.
Shichiri
G
G
Central Research Laboratory, Shiga University of Medical Science, Japan.
Kinoshita
M
M
Saeki
Y
Y
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D002460:Cell Line; D015118:Eicosapentaenoic Acid / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008042:Linolenic Acids / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D008560:Membrane Fluidity; D051379:Mice; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism; D017962:alpha-Linolenic Acid
D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D008042:Linolenic Acids; D008077:Lipoproteins, LDL; D009829:Oleic Acids; C032629:acetyl-LDL; D017962:alpha-Linolenic Acid; D016718:Arachidonic Acid; D019301:Oleic Acid; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid; D044943:Fatty Acid Desaturases