Cholesterol efflux effect of high density lipoprotein is impaired by whole cigarette smoke extracts through lipid peroxidation.
It has been reported that high density lipoprotein (HDL) plays an anti-atherogenic role by stimulating cholesterol efflux from the foam cells in the atheromatous lesion. In this study, we prepared a novel modified form of HDL (CS-HDL) by incubating HDL with whole cigarette smoke (CS) extracts containing both particulate matter and gas-phase smoke, and examined its effect on cholesterol efflux. CS-HDL showed a marked increase of conjugated dienes and denaturation of apoA-I, a major protein component of HDL. The cholesterol efflux effect of CS-HDL was remarkably reduced to the same level as that of oxidatively modified HDL induced by copper ion (Ox-HDL). Addition of 20 microg/ml superoxide dismutase (SOD) during the CS-modification of HDL caused retrieval of cholesterol efflux activity by 53% and a remarkable decrease in the conjugated dienes level. SOD, however, had no ameliorative effect on apoA-I denaturation. When HDL was incubated only with gas-phase smoke (gasCS-HDL), neither increase of conjugated dienes nor impairment of the cholesterol efflux effect was observed, whereas apoA-I was denaturated to the same extent as seen in CS-HDL. These results indicate that whole CS-extracts, but not gas-phase smoke, reduces cholesterol efflux effect of HDL and that lipid peroxidation associated with superoxide anion is involved in this functional impairment.
Ueyama
K
K
Department of Geriatric Medicine, Faculty of Medicine, Kyoto University, Japan.
Yokode
M
M
Arai
H
H
Nagano
Y
Y
Li
Z X
ZX
Cho
M
M
Kita
T
T
D000818:Animals; D001053:Apolipoproteins / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000502:physiology*; D008075:Lipoproteins, HDL / Q000494:pharmacology*; D051379:Mice; D012907:Smoking / Q000009:adverse effects*
D001053:Apolipoproteins; D008075:Lipoproteins, HDL; D002784:Cholesterol