[Effects of high-density lipoprotein on the cholesterol efflux from endothelial cells].
OBJECTIVE
To study the effects of high-density lipoprotein (HDL) and oxidized high-density lipoprotein (ox-HDL) on the expression of ATP-binding cassette transporter A1 (ABCAl) and cholesterol efflux in human umbilical vein endothelial cells (HUVECs).


METHODS
In vitro cultured HUVECs were incubated in the presence of 100 microg/ml HDL or 100 microg/ml ox-HDL for 24 h, using PBS as the negative control. ABCA1 mRNA level and cholesterol efflux rate were determined using RT-PCR and a liquid scintillator, respectively.


RESULTS
HDL and ox-HDL significantly elevated the level of ABCA1 mRNA by 58% and 23% relative to the control level, respectively (P<0.05). The cholesterol efflux rate in ox-HDL group was significantly lower than that in HDL group (P<0.01).


CONCLUSIONS
HDL increases ABCAl expression and cholesterol efflux in HUVECs. Oxidative modification of HDL decrease cholesterol efflux by inhibiting the expression of ABCAl, suggesting a possible mechanism of ox-HDL in the pathogenesis of atherosclerosis.
Li
Gong-Xin
GX
Department of Cardiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. ligxin@163.com
Liu
Peng
P
Xu
Lin
L
Miao
Fei
F
Liu
Ying-Feng
YF
Zhao
Huan
H
Zhang
Zi-Wei
ZW
D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism*; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism / Q000502:physiology*; D014471:Umbilical Veins / Q000166:cytology
C577836:ABCA1 protein, human; D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; D008075:Lipoproteins, HDL; D002784:Cholesterol