β-Oxidation of 12( S)-hydroxy-5,8,10,14-eicosatetraenoic acid by MOLT-4 Lymphocytes

MOLT-4 lymphocytes metabolize 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12( S)-HETE via β-oxidation with retention of the hydroxyl group at the ω9 carbon atom. The isolation of 6-hydroxy-4,8-tetradecadienoic acid documents that these cells have the capacity to catabolize the conjugated diene system. 12( S)-HETE was also metabolized to 3,12-dihydroxy-8,10,14-eicosatrienoic acid and 1,9-dihydroxy-5,7,11-heptadecatriene as well as to 17- and 19-carbon aldehydes. When MOLT-4 cells were incubated with the β-oxidation product, 10-hydroxy-6,8,12-octadecatrienoic acid, it was in part further catabolized but in addition it served as an anabolic precursor as defined by the accumulation 3,12-dihydroxy-8,10,14-eicosatrienoic acid as well as 1,11-dihydroxy-7,9,13-nonadecatriene. Neither 10-hydroxy-6,8,12-octadecatrienoic acid nor 13-hydroxy-5,8,11-octadecatrienic acid was as potent in inhibiting phytohemagglutin-induced lymphocyte mitogenesis as were their parent compounds—i.e., 12( S)- and 15( S)-HETE. These findings argue against the hypothesis that β-oxidation products of 12( S)- and 15( S)-HETE are the potential modulators of lymphocyte function. However, neither the pathway for synthesis, nor the role of odd chain aldehydes and diols as potential lipid mediators was determined in this study.