Mice overexpressing hepatic Abcb11 rapidly develop cholesterol gallstones.
Cholelithiasis is a polygenic disease, although the genes responsible for gallstone formation have not yet been clearly identified. QTL analysis has identified the Lith 1 loci on mouse Chromosome 2, and the hepatic bile salt transporter Abcb11 maps to the Lith 1 locus. We have used recently developed TTR-Abcb11 transgenic mice that overexpress Abcb11 to determine the effects of Abcb11 overexpression on cholesterol gallstone formation. TTR-Abcb11 and FVB/NJ strain control mice were fed a lithogenic or chow diet and cholesterol crystal and gallstone formation were measured. Biliary lipids in gallbladder bile and gene expression of canalicular lipid transporters were also analyzed. TTR-Abcb11 mice fed a lithogenic diet had an increased rate of cholesterol crystal and gallstone formation. This was associated with an increase in both the hydrophobic bile salt and cholesterol content of gallbladder bile. Expression of Abcb4, Abcg5, and Abcg8 did not change before gallstone formation. These data indicate that hepatic overexpression of Abcb11 increases the rate of cholesterol gallstone formation. This is likely because of increases in bile salt hydrophobicity but not because of alterations of other biliary lipid transporters. These findings strongly support Abcb11 as a Lith 1 gene.
Henkel
Anne
A
Division of Hepatology, Department of Medicine, Northwestern University Feinberg School of Medicine, Tarry 14-711, 303 East Chicago Avenue, Chicago, Illinois, 60611, USA.
Wei
Zhixin
Z
Cohen
David E
DE
Green
Richard M
RM
D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism*; D002784:Cholesterol / Q000096:biosynthesis*; D005704:Gallbladder / Q000503:physiopathology; D042882:Gallstones / Q000235:genetics*; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic
D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; C490549:Abcb11 protein, mouse; D001647:Bile Acids and Salts; D002784:Cholesterol