The relationship between ABCA1 gene expression in gallbladder mucosa and the genesis of gallbladder cholesterol polyps

Objectives To detect the ABCA1 gene expression in gallbladder mucosa, and its relationship with the pathogenesis of gallbladder cholesterol polyps. Methods Gallstone, bile, gallbladder mucosa and full-thickness gallbladder wall were collected from 42 patients under going laparoscopic cholecystectomy, among which, 15 patients had gallbladder cholesterol polyps, 15 had cholesterol gallstones and the other 12 cases served as controls (5 patients with gallbladder adenoma, 7 patients with non-cholesterol gallstone). The cholesterol concentration in the gallstones and the concentrations of cholesterol, bile acid and phospholipid in the bile were measured. The ABCA1、LXRα、RXRα mRNA in the gallbladder mucosa was quantified with real-time PCR. The ABCA1 protein expression in the gallbladder wall was detected and localized by immunohistochemistry. Results Cholesterol saturation index was higher in patients with cholesterol polyps than those of the control group (1.0±0.2 vs 0.6±0.3, P0.01). ABCA1 protein was highly expressed in the gallbladder epithelial cells. Yet, no difference was found in ABCA1、LXRα、RXRα mRNA expression among the cholesterol poly group, the cholesterol stone group and the control group. Conclusions ABCA1 gene expression could hardly be regarded as a pathogenetic factor of the gallbladder cholesterol polyps.