Fatty acid composition of chylomicron remnant-like particles influences their uptake and induction of lipid accumulation in macrophages.
The influence of the fatty acid composition of chylomicron remnant-like particles (CRLPs) on their uptake and induction of lipid accumulation in macrophages was studied. CRLPs containing triacylglycerol enriched in saturated, monounsaturated, n-6 or n-3 polyunsaturated fatty acids derived from palm, olive, corn or fish oil, respectively, and macrophages derived from the human monocyte cell line THP-1 were used. Lipid accumulation (triacylglycerol and cholesterol) in the cells was measured after incubation with CRLPs for 5, 24 and 48 h, and uptake over 24 h was determined using CRLPs radiolabelled with [3H]triolein. Total lipid accumulation in the macrophages was significantly greater with palm CRLPs than with the other three types of particle. This was mainly due to increased triacylglycerol concentrations, whereas changes in cholesterol concentrations did not reach significance. There were no significant differences in lipid accumulation after incubation with olive, corn or fish CRLPs. Palm and olive CRLPs were taken up by the cells at a similar rate, which was considerably faster than that observed with corn and fish CRLPs. These findings demonstrate that CRLPs enriched in saturated or monounsaturated fatty acids are taken up more rapidly by macrophages than those enriched in n-6 or n-3 polyunsaturated fatty acids, and that the faster uptake rate results in greater lipid accumulation in the case of saturated fatty acid-rich particles, but not monounsaturated fatty acid-rich particles. Thus, dietary saturated fatty acids carried in chylomicron remnants may enhance their propensity to induce macrophage foam cell formation.
De Pascale
Clara
C
Department of Veterinary Basic Sciences, Royal Veterinary College, London, UK.
Avella
Michael
M
Perona
Javier S
JS
Ruiz-Gutierrez
Valentina
V
Wheeler-Jones
Caroline P D
CP
Botham
Kathleen M
KM
D002460:Cell Line; D002784:Cholesterol / Q000032:analysis; D053298:Chylomicron Remnants / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics*; D005227:Fatty Acids / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism; D008264:Macrophages / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D009000:Monocytes / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D014280:Triglycerides / Q000032:analysis
D053298:Chylomicron Remnants; D005227:Fatty Acids; D014280:Triglycerides; D002784:Cholesterol