title: n-3, but not n-6 lipid particle uptake requires cell surface anchoring.
abstract: Omega-3 (n-3) fatty acids are emerging as bioactive agents protective against cardiovascular disease. However, their cellular delivery pathways are poorly defined. Here we questioned whether the uptake of n-3 triglyceride-rich particles (TGRP) is mediated by cell surface proteoglycans (PG) using LDL receptor (LDLR)+/+ and LDLR-/- cell models. LDLR+/+ but not LDLR-/- cells showed higher n-6 over n-3 TGRP uptake. Removal of cell surface proteins and receptors by pronase markedly enhanced the uptake of n-3 but not n-6 TGRP. Lactoferrin blockage of apoE-mediated pathways decreased the uptake of n-6 TGRP by up to 85% (p<0.05) but had insignificant effect on n-3 TGRP uptake. PG removal by sodium chlorate in LDLR+/+ cells substantially reduced n-3 TGRP uptake but had little effect on n-6 TGRP uptake. Thus, while n-6 TGRP uptake is preferentially mediated by LDLR-dependent pathways, the uptake of n-3 TGRP depends more on PG and non-LDLR cell surface anchoring.
authors.affiliation: Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, USA.
authors.forename: Faith M
authors.initials: FM
authors.lastname: Murray-Taylor
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Ho
authors.forename: Narumon
authors.initials: N
authors.lastname: Densupsoontorn
authors.forename: Chuchun L
authors.initials: CL
authors.lastname: Chang
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Deckelbaum
authors.forename: Toru
authors.initials: T
authors.lastname: Seo
mesh_terms: D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D043371:Fatty Acids, Omega-6 / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007781:Lactoferrin / Q000494:pharmacology; D011509:Proteoglycans / Q000378:metabolism; D011973:Receptors, LDL / Q000235:genetics / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism*; D000511:alpha-Macroglobulins / Q000494:pharmacology
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D011509:Proteoglycans; D011973:Receptors, LDL; D014280:Triglycerides; D000511:alpha-Macroglobulins; D007781:Lactoferrin