Cholesteryl ester transfer protein expressed in lecithin cholesterol acyltransferase-deficient mice.
OBJECTIVE
Regulation of plasma cholesteryl ester transfer protein (CETP) concentration was studied in lecithin-cholesterol acyltransferase (LCAT)-knockout mice.


RESULTS
LCAT-knockout mice were cross-bred with CETP transgenic mice. The offspring (n=63) were classified for LCAT genotype and plasma CETP levels (no CETP, low CETP, and high CETP). High density lipoprotein (HDL) decreased as LCAT decreased in each CETP-level group. In the lcat(+/+) and lcat(+/-) mice, plasma CETP varied from 0 to 30 micro g/mL, whereas it was <10 micro g/mL in the lcat(-/-) mice. HDL cholesterol and phospholipid decreased and HDL triglyceride and apolipoprotein B increased in CETP in the lcat(+/+) and lcat(+/-) mice, whereas there was no difference in HDL between low and high CETP. An effect of CETP on HDL was not detected in the lcat(-/-) mice because of the absence of mature HDL. Genomic DNA and mRNA of CETP were correlated and were similar in the lcat(-/-) and lcat(+/+) mice. Plasma CETP was correlated with its genomic DNA and mRNA, but the slope of the increase was much lower in the lcat(-/-) mice. Whereas plasma CETP mostly associates with HDL in the lcat(+/+) mouse, it is found free in the lcat(-/-) mouse.


CONCLUSIONS
Plasma CETP is posttranscriptionally downregulated in the lcat(-/-) mice, presumably by its extremely low HDL.
Wu
Cheng-ai
CA
Biochemistry, Cell Biology, and Metabolism, Nagoya City University Graduate School of Medical Science, Nagoya, Japan.
Tsujita
Maki
M
Okumura-Noji
Kuniko
K
Usui
Shinichi
S
Kakuuchi
Hajime
H
Okazaki
Mitsuyo
M
Yokoyama
Shinji
S
D000818:Animals; D002352:Carrier Proteins / Q000097:blood* / Q000235:genetics*; D053480:Cholesterol Ester Transfer Proteins; D008076:Cholesterol, HDL / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D015870:Gene Expression; D006023:Glycoproteins; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D008076:Cholesterol, HDL; D006023:Glycoproteins; D007862:Phosphatidylcholine-Sterol O-Acyltransferase