Oxidative Modification
Reduces HDL-induced Cholesterol Efflux from Cultured Human Arterial Smooth
Muscle Cells
FU Qiang, LIU Bing-Wen*
( Apolipoproteins Research Unit, Institute of Biochemistry and Molecular
Biology, West China University of Medical Sciences, Chengdu 610041, China )
Abstract To investigate
the effects of oxidative modification of high density lipoprotein (HDL) on
HDL-mediated cholesterol efflux from human arterial smooth muscle cells(SMC),
native HDL (N-HDL) and oxidized HDL(Ox-HDL) induced by copper or hypochlorite
were incubated with cultured SMC preloaded with 3H-cholesterol for
2―24 h. The radioactivities of 3H-cholesterol of the medium and SMC
were measured respectively, and the cholesterol efflux rate (CER) of HDL and
Ox-HDL were determined. The result showed that the CER of N-HDL was 43.1% after
24 h incubation, while the CER of Ox-HDL induced by copper or hypochlorite were
28.9% and 23.5% respectively, reduced by 30.0% and 43.1% compared with N-HDL.
The speed of 3H-cholesterol efflux of Ox-HDL from SMC were decreased
remarkably. Inhibition of oxidation with antioxidants butylated
hydroxytoluene(BHT), vitamin C or vitamin E recovered mostly the ability of HDL
to stimulate cholesterol efflux. The results suggest that oxidation of HDL may
attenuate its effect on cholesterol efflux from arterial SMC, and vitamin C and
vitamin E supplementation may protect artery from atherogenesis.
Key words high density lipoprotein； oxidative modification； smooth muscle cells； cholesterol efflux； antioxidants
Received:
November 17, 1999 Accepted: January 5, 2000
Supported by special research funds for doctoral conferree from
ministry of education, P. R. China and supported partly by china medical board,
New York
* Corresponding author: Tel, 86-28-5501289; Fax, 86-28-5583252;
e-mail, [email protected]