Development of a standardized murine model for investigating cholesterol crystallization and deposition in the gallbladder wall: effects of dietary cholesterol and pharmacological modulation.

OBJECTIVE: The aim of this study is to establish a standardized murine model for cholesterol crystallization and deposition in the gallbladder wall and evaluate the effects of differential dietary cholesterol intake and pharmacological interventions on this pathophysiological process. METHODS: A total of 45 eight-week-old C57BL/6 mice were randomly assigned to nine experimental groups (n = 5 per group) receiving different dietary and pharmacological interventions designed to modulate mucin expression and reverse cholesterol transport over a 12-week period (details in Methods ). Blood and gallbladder tissues were collected under anesthesia for serum lipid profiling and histopathological evaluation. Oil Red O staining was used to detect lipid droplet accumulation in the submucosal layer of the gallbladder wall. RESULTS: No lipid droplets were observed in the control group or the group receiving prostaglandin. Minimal droplet formation was noted in the high-cholesterol (HC) and HC combined with bile acid groups (p > 0.05 vs. control). A significant increase in submucosal lipid accumulation was observed in the HC + celecoxib and HC + bile acid + celecoxib groups (p < 0.05). The addition of methionine to these regimens (HC + celecoxib + methionine and HC + bile acid + methionine) further enhanced lipid droplet formation (p < 0.05), with no statistically significant difference between the two. The most substantial lipid aggregation was detected in the HC + bile acid + celecoxib + methionine group (p < 0.05 vs. all other groups). CONCLUSION: Impaired mucosal cholesterol reverse transport, particularly under combined inhibition of both mucin expression and RCT, was associated with the most pronounced submucosal lipid deposition and the highest incidence of gallstone formation. To our knowledge, this study is the first to establish an animal model of GCPs integrating mucoprotein and RCT regulation, providing a platform for mechanistic studies and potential therapeutic exploration.