title: N-3 and n-6 fatty acid metabolism in undifferentiated and differentiated human intestine cell line (Caco-2).
abstract: Metabolism of n-6 and n-3 fatty acids in the undifferentiated and differentiated human adenocarcinoma colon cell line (Caco-2) was studied. In cells incubated with either 18:2n-6 or 18:3n-3, no significant amounts of long chain n-6 and n-3 metabolites were found. Incubation with either 18:3n-6 or 18:4n-3 raised significantly the levels of 20:3n-6 and 20:4n-3, respectively. In the undifferentiated cells, significant proportions of 20:3n-6 and 20:4n-3 were further delta 5-desaturated to form 20:4n-6 and 20:5n-3, respectively. Incubation with either 20:4n-6 or 20:5n-3 raised the levels of their direct elongation products, 22:4n-6 and 22:5n-3, respectively. Incubation with 22:4n-6 or 22:5n-3 increased the levels of 20:4n-6 and 20:5n-6. These results suggest that delta 6-desaturation in the Caco-2 cells is less active in comparison with elongation, delta 5-desaturation and retro-conversion. These enzymes were modulated by the state of differentiation, and appeared to be non-specific to n-3 and n-6 fatty acids. When cells were incubated with 18:3n-6 and 18:4n-3 concomitantly, the levels of incorporation of total n-6 fatty acids into cellular lipids were greater than those of the n-3 fatty acids, whereas the ratios of 20+22 carbon metabolites to 18-carbon precursor favored n-3 over n-6 fatty acids. These results suggest that n-3 and n-6 fatty acids were not metabolized identically in Caco-2 cells.
authors.affiliation: Medical Nutritional R&D, Ross Products Division, Abbott Laboratories, Columbus, OH 43215-1724, USA.
authors.forename: Y S
authors.initials: YS
authors.lastname: Huang
authors.forename: J W
authors.initials: JW
authors.lastname: Liu
authors.forename: K
authors.initials: K
authors.lastname: Koba
authors.forename: S N
authors.initials: SN
authors.lastname: Anderson
mesh_terms: D018938:Caco-2 Cells; D002454:Cell Differentiation; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D006801:Humans; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism; D017962:alpha-Linolenic Acid / Q000378:metabolism
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D010743:Phospholipids; D014280:Triglycerides; D017962:alpha-Linolenic Acid; D019787:Linoleic Acid