1. Inhibition of cholesteryl ester transfer protein by torcetrapib modestly increases macrophage cholesterol efflux to HDL.
- Author
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Yvan-Charvet L, Matsuura F, Wang N, Bamberger MJ, Nguyen T, Rinninger F, Jiang XC, Shear CL, and Tall AR
- Subjects
- Animals, Anticholesteremic Agents therapeutic use, Apolipoproteins E metabolism, Biological Transport physiology, Blotting, Western, Cholesterol Ester Transfer Proteins metabolism, Dose-Response Relationship, Drug, Humans, Hypercholesterolemia metabolism, Macrophages drug effects, Mice, Mice, Knockout, Quinolines therapeutic use, Sterol O-Acyltransferase metabolism, Treatment Outcome, Anticholesteremic Agents administration & dosage, Cholesterol Ester Transfer Proteins antagonists & inhibitors, Cholesterol, HDL metabolism, Hypercholesterolemia drug therapy, Macrophages metabolism, Quinolines administration & dosage
- Abstract
Objective: This study examines the effects of pharmacological inhibition of cholesteryl ester transfer protein (CETP) on the ability of high-density lipoprotein particles (HDL) to promote net cholesterol efflux from human THP-1 macrophage foam cells., Methods and Results: Two groups of 8 healthy, moderately hyperlipidemic subjects received the CETP inhibitor torcetrapib at 60 or 120 mg daily for 8 weeks. Torcetrapib increased HDL cholesterol levels in both groups by 50% and 60%, respectively. Compared with baseline, torcetrapib 60 mg daily increased HDL-mediated net cholesterol efflux from foam cells primarily by increasing HDL concentrations, whereas 120 mg daily torcetrapib increased cholesterol efflux both by increasing HDL concentration and by causing increased efflux at matched HDL concentrations. There was an increased content of lecithin:cholesterol acyltransferase (LCAT) and apolipoprotein E (apoE) in HDL-2 only at the 120 mg dose. ABCG1 activity was responsible for 40% to 50% of net cholesterol efflux to both control and T-HDL., Conclusions: These data indicate that inhibition of CETP by torcetrapib causes a modest increase in the ability of HDL to promote net cholesterol efflux at the 60 mg dose, and a more dramatic increase at the 120 mg dose in association with enhanced particle functionality.
- Published
- 2007
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