Overexpression of human lecithin:cholesterol acyltransferase in mice offers no protection against diet-induced atherosclerosis
Abstract:Human lecithin:cholesterol acyltransferase (LCAT) is a key enzyme in the metabolism of cholesterol. We have used homozygous transgenic mice overexpressing the human LCAT transgene to study the effect of a “Western-type” atherogenic diet (30% fat, 5% cholesterol and 2% cholic acid) on their LCAT expression, activity, lipoprotein profile and tendency to develop atherosclerosis. The LCAT activity was 35-fold higher in serum of the homozygous transgenic mice than in murine control serum, and decreased 11–20% in the transgenic mice when fed the atherogenic diet. The total cholesterol and high-density lipoprotein cholesterol (HDL-C) concentrations were approximately doubled in the transgenic mice compared with the controls when both groups were fed a regular chow diet. In mice on the atherogenic diet, the triglyceride concentration decreased about 50% to the same level in transgenic and control mice. Total cholesterol and HDL-C concentrations increased and were 60–80% higher in the transgenic mice. The expression of LCAT mRNA in the liver was decreased by 49–60% in the transgenic mice when fed the atherogenic diet. The development of atherosclerosis was similar in transgenic and control mice. Thus, the 14- to 27-fold higher LCAT activity and the higher HDL-C concentrations in the homozygous LCAT transgenic mice had no significant protective influence on the development of diet-induced atherosclerosis.
Document Type: Original Article
Affiliations: 1: Biotechnology Centre of Oslo, University of Oslo and the Department of Comparative Medicine, National Hospital, Oslo 2: Laboratory of Pathology, Oslo City Hospital, Oslo 3: Institute of Clinical Biochemistry, National Hospital, Oslo, Norway
Publication date: 2000-05-01