[Effect of oxLDL on the uptake and clearance rate of cholesterol in vascular smooth muscle cells originated from human apoAI transgenic mice].
OBJECTIVE
Study on (1) inhibition of oxidized low density lipoprotein (oxLDL) effect on the uptake and clearance of intra-cellular 3H-cholesterol in vascular smooth muscle cells (v-SMC) originated from the human-apoAI transgenic mice (C57BL/6); (2) change of human-apolipoprotein AI (h-apoAI) mRNA expression in v-SMC after oxLDL stimulation and the protective effect of expressed h-apoAI on v-SMC against oxLDL intoxication.


METHODS
(1) v-SMC isolated from human apoAI transgenic mice possessing a recombined gene connected beforehand with a mouse metallothionein-I (MT-I) as the promoter; (2) study of h-apoAI mRNA expression from v-SMC of the transgenic mice by RT-PCR and Northern blot.


RESULTS
oxLDL (30 micrograms/ml) strongly promoted v-SMC proliferation. No difference found on 3H-cholesterol uptake between smooth muscle from normal mouse aorta (n-SMC) and smooth muscle cells from transgenic mouse aorta (tr-SMC) of the control groups, the uptake rates of both kinds of SMC rose 100% after oxLDL stimulation. The efflux rates of 3H-cholesterol in tr-SMC were much higher than those of n-SMC (40%-50%). After oxLDL stimulation, the clearance rates fell by 28% and 10% respectively for n-SMC and tr-SMC. The result of RT-PCR and Northern blot showed a marked increase of h-apoAI gene expression after oxLDL stimulation.


CONCLUSIONS
Expression of h-apoAI gene in C57BL/6 mice enables to decrease the accumulation of cholesterol in v-SMC. tr-SMC are capable to alleviate the harmful effect of oxLDL on v-SMC due to the increase of h-apoAI expression.
Zeng
Y
Y
Department of Pathology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China.
Zhao
G F
GF
Qian
J
J
Wang
Z L
ZL
She
M P
MP
D000818:Animals; D016632:Apolipoprotein A-I / Q000235:genetics* / Q000502:physiology; D002784:Cholesterol / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008657:Metabolic Clearance Rate; D051379:Mice; D008822:Mice, Transgenic; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*
D016632:Apolipoprotein A-I; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D002784:Cholesterol