Effect of long-chain fatty acids in the culture medium on fatty acid composition of WEHI-3 and J774A.1 cells

摘要

As a first step in determining the mechanism of action of specific fatty acids on immunological function oJ macrophages, a comparative study) of the effect of long-chain polyunsaturated fatty acids (PUPA) in the medium wa~ conducted in two macrophage cell lines, J774A.1 and WEHI-3. The baseline fatty-acid profiles of the two cellline~ differed in the % distribution of saturated (SPA) and unsaturated fatty acids (UPA). J774A.1 cells had a higher % oJ SPA (primarily palmitic acid) than WEHI-3 cells. Conversely, WEHI-3 cells had a higher % of UPA (primarily oleic acid) than J774A.1 cells. Neither cell line had detectable amounts of u-linolenic acid (ALA) or eicosapentaenoic acic (EP A). The most abundant polyunsaturated fatty acid in both cells lines was arachidonic acid (AA). The efficiency oj transport of fatty acids from the medium to the macrophages by two delivery vehicles (BSA complexes and ethanolic suspensions) was compared. Overall, fatty acids were transported satisfactorily by both delivery systems. Alpha-linolenic acid and doscosahexenoic acid (DHA) were transported more efficiently by the qthanolic suspension system. Linolei( acid (LA) was taken up more completely than ALA, and DHA was taken up more completely than EP A by both cell cultures and delivery systems. A dose-response effect was demonstrated for LA, ALA, EPA and DHA in both J774A.] and WEHI-3 cells. Addition of polyunsaturated fatty acids (PUPA) to the cell cultures modified the total lipid fatty acid composition of the cells. The presence of ALA in the culture medium resulted in a significant decrease in AA in both cell lines. The omega-3/omega-6 fatty acid ratio ?(1)-3/(1)-6), polyunsaturated/saturated fatty acid ratio (P/S), anc unsaturation index (UI) increased directly with the amount of PUPA and (1)-3 fatty acid provided in the medium. The results indicate that the macrophage cell lines have similar, but not identical, fatty acid profiles that may be the result oj differences in fatty acid metabolism. These distinctions could in turn produce differences in immunological function The ethanol fatty-acid delivery system, when compared with the fatty acid-BSA complex system, is preferable fol measurement of dose-response effects, because the cellular fatty acid content increased in proportion to the amount oJ fatty acid provided in the medium. Similar dose-response results were observed in a previous in vivo study using flaxseed, rich in ALA, as a source of PUPA.