OBJECTIVE: Based on the observation that Fxr-/- mice exhibit a proatherogenic lipoprotein profile, we investigated the role of FXR in the development of atherosclerosis. METHODS AND RESULTS: Administration of a western diet to Fxr-/- mice or wild-type mice does not result in the development of significant atherosclerotic lesions. Consequently we generated Fxr-/- Ldlr-/- (DKO) mice and compared lesion development with Ldlr-/- mice. After 16 weeks on a Western diet, en face analysis of the aorta indicated that the male DKO mice had reduced atherosclerotic lesions as compared with Ldlr-/- mice. Plasma low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels were reduced by 40% to 50%, whereas triglyceride levels increased 4-fold in the male DKO mice. Finally, peritoneal macrophages freshly isolated from male DKO mice had reduced expression of CD36 mRNA and decreased neutral lipid accumulation, as compared with Ldlr-/- mice. CONCLUSIONS: FXR deficiency in male, but not female, Ldlr-/- mice results in a reduction in the size of atherosclerotic lesions in the aorta. The reduction in atherosclerosis may result from a decrease in plasma low-density lipoprotein cholesterol, coupled with reduced expression of CD36 in macrophages of DKO mice.
OBJECTIVE: Based on the observation that Fxr-/- mice exhibit a proatherogenic lipoprotein profile, we investigated the role of FXR in the development of atherosclerosis. METHODS AND RESULTS: Administration of a western diet to Fxr-/- mice or wild-type mice does not result in the development of significant atherosclerotic lesions. Consequently we generated Fxr-/- Ldlr-/- (DKO) mice and compared lesion development with Ldlr-/- mice. After 16 weeks on a Western diet, en face analysis of the aorta indicated that the male DKO mice had reduced atherosclerotic lesions as compared with Ldlr-/- mice. Plasma low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels were reduced by 40% to 50%, whereas triglyceride levels increased 4-fold in the male DKO mice. Finally, peritoneal macrophages freshly isolated from male DKO mice had reduced expression of CD36 mRNA and decreased neutral lipid accumulation, as compared with Ldlr-/- mice. CONCLUSIONS:FXR deficiency in male, but not female, Ldlr-/- mice results in a reduction in the size of atherosclerotic lesions in the aorta. The reduction in atherosclerosis may result from a decrease in plasma low-density lipoprotein cholesterol, coupled with reduced expression of CD36 in macrophages of DKO mice.
Authors: Helen B Hartman; Stephen J Gardell; Chris J Petucci; Shuguang Wang; Julie A Krueger; Mark J Evans Journal: J Lipid Res Date: 2009-01-27 Impact factor: 5.922