Abstract: Background: Gallbladder mucocele (GBM) is one of the most common diseases of the gallbladder in dogs. The pathogenesis of GBM is unclear due to lack of appropriate in vitro models. Recently, organoid technology has been applied in the gallbladder from humans, mice, and pigs as a novel in vitro disease model.
Hypothesis/Objectives: To develop, characterize, and assess the functions of a gallbladder organoid (GBO) in dogs with GBM.
Animals: GBOs were derived from gallbladder tissues isolated from one client-owned dog undergoing cholecystectomy.
Methods: Surgically removed gallbladder was treated with trypsin to collect stem cells, which were then embedded in Matrigel to form GBOs. Phase-contrast imaging and immunofluorescence (IF) were utilized to evaluate the size, morphology, and protein expression in GBOs. The function of cystic fibrosis transmembrane conductance regulator (CFTR), an ion channel mainly expressed in the gallbladder, was examined using Forskolin-induced swelling assay. Results were evaluated by Mann–Whitney U test.
Results: Successful GBO development and maintenance were achieved. Phase-contrast imaging demonstrated the budding structure of the organoids which were similar to what has been reported with the organoids from Cystic Fibrosis. IF staining revealed expression of epithelial cell marker and tight junction proteins. Furthermore, the Forskolin-induced swelling assay demonstrated that GBOs hold functional CFTR (2.2-fold swelling after 2 hours; p< 0.01).
Conclusions and clinical importance: We demonstrated a successful development of GBOs from a dog with GBM. Our novel GBO model can serve as a useful ex vivo system for GBM pathophysiology investigation as well as pharmaceutical drug transport studies.
.jpg "Itsuma Nagao, DVM photo")
