13-hydroxy octadecadienoic acid (13-HODE) inhibits triacylglycerol-rich lipoprotein secretion by CaCo-2 cells.
Oxidized lipids present in atherogenic lipoproteins are derived, in part, from the diet. To address the effects of an oxidized lipid on intestinal lipoprotein assembly and secretion, CaCo-2 cells were incubated with 13-HODE or its native fatty acid, linoleic acid, and triacylglycerol-rich lipoprotein synthesis and secretion were investigated. 13-HODE was readily taken up by cells and esterified to lipids. Although both fatty acids were largely esterified to neutral lipids, in comparison to neutral lipids containing linoleic acid, a greater proportion of cellular neutral lipids containing 13-HODE and/or its metabolites was secreted. Compared to linoleic acid, however, 13-HODE caused less triacylglycerol, derived from de novo synthesis, and less triacylglycerol mass to be secreted. Cells incubated with both linoleic acid and 13-HODE together secreted less triacylglycerol mass than did cells incubated with linoleic acid alone. Less newly synthesized apoB and apoB mass were secreted by cells incubated with 13-HODE without altering the abundance of apoB mRNA. The fraction of newly synthesized apoB translocated into the secretory pathway of cells exposed to 13-HODE was significantly less than that observed in cells incubated with linolenic acid, suggesting that 13-HODE interfered with the assembly and secretion of triacylglycerol-rich lipoprotein particles.
Murthy
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S
Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City 52242, USA.
Born
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Mathur
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Field
F J
FJ
D001055:Apolipoproteins B / Q000096:biosynthesis; D001692:Biological Transport; D018938:Caco-2 Cells; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D019787:Linoleic Acid / Q000378:metabolism; D008041:Linoleic Acids / Q000378:metabolism* / Q000494:pharmacology*; D050356:Lipid Metabolism; D008074:Lipoproteins / Q000096:biosynthesis*; D008077:Lipoproteins, LDL / Q000378:metabolism; D014158:Transcription, Genetic; D014280:Triglycerides / Q000378:metabolism*
D001055:Apolipoproteins B; D008041:Linoleic Acids; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D014280:Triglycerides; C024348:13-hydroxy-9,11-octadecadienoic acid; D019787:Linoleic Acid