White adipose tissue apolipoprotein C-I secretion in relation to delayed plasma clearance of dietary fat in humans.

Abstract

OBJECTIVE:

White adipose tissue (WAT) dysfunction is characterized by delayed clearance of dietary triglyceride-rich lipoproteins (TRL). We reported that apolipoprotein (apo) C-I, a transferable apolipoprotein that inhibits lipoprotein lipase activity when bound to TRL, was produced by a human adipocyte model. Thus, we aimed to determine whether increased WAT apoC-I secretion is related to delayed dietary fat clearance in humans.

METHODS AND RESULTS:

After the ingestion of a (13)C-triolein-labeled high-fat meal, postmenopausal obese women with high-fasting WAT apoC-I secretion (median >0.81 μmol/L per g/4 hours, n=9) had delayed postprandial plasma clearance of (13)C-triglyceride and (13)C-nonesterified fatty acids over 6 hours compared with controls. WAT apoC-I secretion over 4 hours correlated with fasting total and non-high-density lipoprotein apoC-I but not with high-density lipoprotein apoC-I and was the primary predictor of 4-hour postprandial increases in TRL apoC-I. Correction for TRL apoC-I eliminated the association of WAT apoC-I with 6-hour area under the curve of plasma (13)C-triglyceride; correction for insulin sensitivity or inflammation did not. Finally, in addition to apoC-I, WAT secreted considerable amount of apoC-II, apoC-III, and apoE over 24 hours; however, only WAT apoC-I secretion was associated with 6-hour area under the curve of plasma (13)C-triglyceride.

CONCLUSIONS:

Increased WAT apoC-I secretion in obese women is associated with delayed postprandial dietary fat clearance mediated by increased TRL apoC-I. Thus, we hypothesize that reducing WAT apoC-I secretion ameliorates WAT dysfunction and associated cardiometabolic risks in humans.

• Authors: Hanny Wassef, Huda Salem, Simon Bissonnette, Alexis Baass, Robert Dufour, Jean Davignon, May Faraj
• Journal: Arteriosclerosis, thrombosis, and vascular biology (Arterioscler Thromb Vasc Biol) Vol. 32 Issue 11 Pg. 2785-93 (Nov 2012) ISSN: 1524-4636 [Electronic] United States
• PMID: 22995522 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• APOC1 protein, human
• Apolipoprotein C-I
• Dietary Fats
• Fatty Acids, Nonesterified
• Lipoproteins, HDL
• Triglycerides
• Triolein

Topics

• Adipose Tissue, White (metabolism)
• Aged
• Apolipoprotein C-I (blood, metabolism)
• Area Under Curve
• Biopsy
• Dietary Fats (administration & dosage, blood)
• Fatty Acids, Nonesterified (blood)
• Female
• Humans
• Lipoproteins, HDL (blood)
• Middle Aged
• Obesity (blood, physiopathology)
• Postprandial Period
• Quebec
• Time Factors
• Triglycerides (blood)
• Triolein (metabolism)