First Author | Hartman HB | Year | 2009 |
Journal | J Lipid Res | Volume | 50 |
Issue | 2 | Pages | 193-203 |
PubMed ID | 18820241 | Mgi Jnum | J:149005 |
Mgi Id | MGI:3847374 | Doi | 10.1194/jlr.M800323-JLR200 |
Citation | Hartman HB, et al. (2009) Loss of small heterodimer partner expression in the liver protects against dyslipidemia. J Lipid Res 50(2):193-203 |
abstractText | Multiple studies suggest increased conversion of cholesterol to bile acids by cholesterol 7alpha-hydroxylase (CYP7A1) protects against dyslipidemia and atherosclerosis. CYP7A1 expression is repressed by the sequential activity of two nuclear hormone receptors, farnesoid X receptor (FXR) and small heterodimer partner (SHP). Here we demonstrate 129 strain SHP(-/-) mice are protected against hypercholesterolemia resulting from either a cholesterol/cholic acid (chol/CA) diet or from hypothyroidism. In a mixed 129-C57Bl/6 background, LDLR(-/-) and LDLR(-/-)SHP(-/-) mice had nearly identical elevations in hepatic cholesterol content and repression of cholesterol regulated genes when fed a Western diet. However, the LDLR(-/-)SHP(-/-) mice had greatly reduced elevations in serum VLDL and LDL cholesterol levels and triglyceride (TG) levels as compared with LDLR(-/-) mice. Additionally, the hepatic inflammation produced by the Western diet in the LDLR(-/-) mice was abolished in the LDLR(-/-)SHP(-/-) mice. CYP7A1 expression was induced 10-fold by the Western diet in the LDLR(-/-)SHP(-/-) mice but not in the LDLR(-/-) mice. Finally, hepatocyte-specific deletion of SHP expression was also protective against dyslipidemia induced by either a chol/CA diet or by hypothyroidism. While no antagonist ligands have yet been identified for SHP, these results suggest selective inhibition of hepatic SHP expression may provide protection against dyslipidemia. |