Diet-induced dyslipidemia impairs reverse cholesterol transport in hamsters

Authors


Khadija Ouguerram, INSERM UMR915, IRT-1, 8 quai Moncousu BP 70721, 44007 Nantes, France. Tel.: +33 228 080 173; fax: +33 228 080 130; e-mail: khadija.ouguerram@univ-nantes.fr

Abstract

Eur J Clin Invest 2011; 41 (9): 921–928

Abstract

Background  Reverse cholesterol transport (RCT) is an anti-atherogenic process by which cholesterol is effluxed from peripheral tissues by high-density lipoprotein (HDL) and returned to the liver for excretion into the bile and faeces. Dyslipidemia is thought to impair RCT through higher triglyceride-rich lipoprotein (TRL), low HDL-cholesterol and higher activity of cholesteryl ester transfer protein (CETP), which transfers cholesteryl esters from HDL to TRL for further hepatic uptake. As CETP pathway would represent a major route in human RCT, we therefore investigated whether diet-induced dyslipidemia impairs RCT in hamster, a CETP-expressing species.

Materials and methods  Golden Syrian hamsters were fed a chow or chow+0·3% cholesterol diet over 4 weeks. Biochemical parameters and in vivo VLDL-triglycerides secretion (Triton WR-1339 injection) were then measured. In vitro macrophage cholesterol efflux was measured, and in vivo macrophage-to-faeces RCT was also assessed after an intraperitoneal injection of 3H-cholesterol-labelled hamster primary macrophages.

Results  Cholesterol-enriched diet increased plasma total cholesterol (144%), triglycerides (101%), VLDL-triglycerides secretion (175%), CETP activity (44%) and reduced HDL-cholesterol/total cholesterol ratio by 20% (P < 0·01 vs. chow). Cholesterol-enriched diet significantly increased hepatic total cholesterol and triglycerides by 459 and 118% and increased aortic total cholesterol content by 304%. In vitro cholesterol efflux from macrophages to plasma was significantly reduced by 25% with plasma from cholesterol-fed hamsters. In vivo RCT experiments showed a significant 75% reduction of macrophage-derived cholesterol faecal excretion in cholesterol-fed hamsters.

Conclusions  Overall, these data demonstrate that diet-induced dyslipidemia severely impairs in vivo RCT in hamsters.

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