EFFECT OF ANTISENSE OLIGONUCLEOTIDES AGAINST CHOLESTERYL ESTER TRANSFER PROTEIN ON THE DEVELOPMENT OF ATHEROSCLEROSIS IN CHOLESTEROL-FED RABBITS

Cholesteryl ester transfer protein (CETP) is the enzyme that facilitat es the transfer of cholesteryl ester from high density lipoprotein (HD L) to apolipoprotein B (apoB)-containing lipoproteins, However, the ex act role of CETP in the development of atherosclerosis has not been de termined, In the present study, we examined the effect of the suppress ion of increased plasma CETP by intravenous injection with antisense o ligodeoxynucleotides (ODNs) against CETP targeted to the liver on the development of atherosclerosis in rabbits fed a cholesterol diet, The ODNs against rabbit CETP were coupled to asialoglycoprotein (ASOR) car rier molecules, which serve as an important method to regulate liver g ene expression, Twenty-two male Japanese White rabbits were used in th e experiment, Eighteen animals were fed a standard rabbit chow supplem ented with 0.3% cholesterol throughout the experiment for 16 weeks, At 8 weeks, they were divided into three groups (six animals in each gro up), among which the plasma total and HDL cholesterol concentrations d id not significantly change, The central group received nothing, the s ense group were injected with the sense ODNs complex, and the antisens e group were injected with the antisense ODNs complex, respectively, f or subsequent 8 weeks, ASOR poly(L-lysine) ODNs complex were injected via the ear veins twice a week, Four animals were fed a standard rabbi t diet for 16 weeks, The total cholesterol concentrations and the CETP mass in the animals injected with antisense ODNs were all significant ly decreased in 12 and 16 weeks compared with those injected with sens e ODNs and the control animals, The HDL cholesterol concentrations mea sured by the precipitation assay did not significantly change among th e groups fed a cholesterol diet, and triglyceride concentrations did n ot significantly change in the four groups, However, at the end of the study, when the HDL cholesterol concentrations were measured after th e isolation by ultracentrifugation and a column chromotography, they w ere significantly higher in the animals injected with antisense ODNs t han in the animals injected with sense ODNs and in the control animals , A reduction of CETP mRNA and an increase of LDL receptor mRNA in the liver were observed in the animals injected with antisense ODNs compa red with those injected with sense ODNs and the control animals, Aorti c cholesterol contents and the aortic percentage lesion to total surfa ce area were significantly lower in the animals injected with antisens e ODNs than in the animals injected with sense ODNs and in the control animals, These findings showed for the first time that suppression of increased plasma CETP by the injection with antisense ODNs against CE TP coupled to ASOR carrier molecules targeted to the liver could thus inhibit the atherosclerosis possibly by decreasing the plasma LDL + ve ry low density lipoprotein (VLDL) cholesterol in cholesterol-fed rabbi ts.