title: Low density lipoprotein delays clearance of triglyceride-rich lipoprotein by human subcutaneous adipose tissue.
abstract: Delayed clearance of triglyceride-rich lipoprotein (TRL) by white adipose tissue (WAT) promotes hypertriglyceridemia and elevated apoB-lipoproteins, which are primarily in the form of LDL. This study examines whether LDL promotes delayed clearance of TRL by WAT. Following the ingestion of a (13)C-triolein-labeled high-fat meal, obese women with high plasma apoB (> median 0.93 g/l, N = 11, > 98% as IDL/LDL) had delayed clearance of postprandial (13)C-triglyceride and (13)C-NEFA over 6 h compared with controls. AUC6 h of plasma (13)C-triglyceride and (13)C-NEFA correlated with plasma apoB but not with LDL diameter or adipocyte area. There was no group difference in (13)C-triolein oxidation rate, which suggests lower (13)C-NEFA storage in peripheral tissue in women with high apoB. Ex vivo/in vitro plasma apoB correlated negatively with WAT (3)H-lipid following a 4 h incubation of women's WAT with synthetic (3)H-triolein-TRL. LDL-differentiated 3T3-L1 adipocytes had lower (3)H-TRL hydrolysis and (3)H-NEFA storage. Treatment of women's WAT with their own LDL decreased (3)H-TRL hydrolysis and (3)H-NEFA uptake. Finally, LDL, although not an LPL substrate, reduced LPL-mediated (3)H-TRL hydrolysis as did VLDL and HDL. Exposure to LDL decreases TRL clearance by human WAT ex vivo. This may promote production of apoB-lipoproteins and hypertriglyceridemia through a positive-feedback mechanism in vivo.
authors: Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.
authors: Simon
authors: S
authors: Bissonnette
authors: Huda
authors: H
authors: Salem
authors: Hanny
authors: H
authors: Wassef
authors: Nathalie
authors: N
authors: Saint-Pierre
authors: Annie
authors: A
authors: Tardif
authors: Alexis
authors: A
authors: Baass
authors: Robert
authors: R
authors: Dufour
authors: May
authors: M
authors: Faraj
mesh_terms: D000328:Adult; D001055:Apolipoproteins B / Q000097:blood; D059305:Diet, High-Fat; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood* / Q000473:pathology; D008074:Lipoproteins / Q000097:blood / Q000737:chemistry; D008077:Lipoproteins, LDL / Q000097:blood* / Q000737:chemistry; D008079:Lipoproteins, VLDL / Q000097:blood; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D050151:Subcutaneous Fat / Q000254:growth & development / Q000378:metabolism*; D014280:Triglycerides / Q000097:blood* / Q000737:chemistry
chemical_list: D001055:Apolipoproteins B; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D014280:Triglycerides; C030087:lipoprotein triglyceride