Surgical liver biopsies were obtained from 11 patients with untreated cholesterol cholelithiasis and nine gallstone-free subjects; mRNA levels of cholesterol 7alpha-hydroxylase (CYP7A1) and related nuclear receptors and coactivators were assayed by quantitative real-time RT-PCR.
In this issue of the JCI, Ito and coworkers demonstrate that mice lacking betaKlotho, a membrane protein with 2 putative glycosidase domains, have increased Cyp7a1 mRNA levels and bile acid concentrations. betaKlotho-KO mice also have small gallbladders and are resistant to cholesterol gallstone formation.