1. Hepatic caveolin-1 is enhanced in Cyp27a1/ApoE double knockout mice.
- Author
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Zurkinden, Line, Mansour, Yosef T., Rohrbach, Beatrice, Vogt, Bruno, Mistry, Hiten D., and Escher, Geneviève
- Subjects
CAVEOLINS ,LABORATORY mice ,STEROLS ,BILE acids ,ATHEROSCLEROSIS - Abstract
Sterol 27-hydroxylase (CYP27A1) is involved in bile acid synthesis and cholesterol homoeostasis. Cyp27a1
(−/−) / Apolipoprotein E(−/−) double knockout mice (DKO) fed a western diet failed to develop atherosclerosis. Caveolin-1 (CAV-1), the main component of caveolae, is associated with lipid homoeostasis and has regulatory roles in vascular diseases. We hypothesized that liver CAV-1 would contribute to the athero-protective mechanism in DKO mice. Cyp27a1(+/+) / ApoE(−/−) (ApoE KO), Cyp27a1(+/−) / ApoE(−/−) (het), and DKO mice were fed a western diet for 2 months. Atherosclerotic plaque and CAV-1 protein were quantified in aortas. Hepatic Cav-1 mRNA was assessed using qPCR, CAV-1 protein by immunohistochemistry and western blotting. Total hepatic and plasma cholesterol was measured using chemiluminescence. Cholesterol efflux was performed in RAW264.7 cells, using mice plasma as acceptor. CAV-1 protein expression in aortas was increased in endothelial cells of DKO mice and negatively correlated with plaque surface ( P < 0.05). In the liver, both CAV-1 protein and mRNA expression doubled in DKO, compared to ApoE KO and het mice ( P < 0.001 for both) and was negatively correlated with total hepatic cholesterol ( P < 0.05). Plasma from DKO, ApoE KO and het mice had the same efflux capacity. In the absence of CYP27A1, CAV-1 overexpression might have an additional athero-protective role by partly overcoming the defect in CYP27A1-mediated cholesterol efflux. [ABSTRACT FROM AUTHOR]- Published
- 2016
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