title: Phospholipid sources for adrenic acid mobilization in RAW 264.7 macrophages. Comparison with arachidonic acid.
abstract: Cells metabolize arachidonic acid (AA) to adrenic acid (AdA) via 2-carbon elongation reactions. Like AA, AdA can be converted into multiple oxygenated metabolites, with important roles in various physiological and pathophysiological processes. However, in contrast to AA, there is virtually no information on how the cells regulate the availability of free AdA for conversion into bioactive products. We have used a comparative lipidomic approach with both gas chromatography and liquid chromatography coupled to mass spectrometry to characterize changes in the levels of AA- and AdA-containing phospholipid species in RAW 264.7 macrophage-like cells. Incubation of the cells with AA results in an extensive conversion to AdA but both fatty acids do not compete with each other for esterification into phospholipids. AdA but not AA, shows preference for incorporation into phospholipids containing stearic acid at the sn-1 position. After stimulation of the cells with zymosan, both AA and AdA are released in large quantities, albeit AA is released to a greater extent. Finally, a variety of phosphatidylcholine and phosphatidylinositol molecular species contribute to AA; however, AdA is liberated exclusively from phosphatidylcholine species. Collectively, these results identify significant differences in the cellular utilization of AA and AdA by the macrophages, suggesting non-redundant biological actions for these two fatty acids.
authors: Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
authors: Carlos
authors: C
authors: Guijas
authors: Alma M
authors: AM
authors: Astudillo
authors: Luis
authors: L
authors: Gil-de-Gómez
authors: Julio M
authors: JM
authors: Rubio
authors: María A
authors: MA
authors: Balboa
authors: Jesús
authors: J
authors: Balsinde
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D002478:Cells, Cultured; D004883:Erucic Acids / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated; D008401:Gas Chromatography-Mass Spectrometry; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D010713:Phosphatidylcholines / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D015054:Zymosan / Q000494:pharmacology
chemical_list: D004883:Erucic Acids; D005231:Fatty Acids, Unsaturated; D010713:Phosphatidylcholines; D010716:Phosphatidylinositols; D010743:Phospholipids; C011395:adrenic acid; D016718:Arachidonic Acid; D015054:Zymosan