Acute Cholecystitis Reduces Interstitial Cells of Cajal in Porcine Gallbladder Through Decreased mRNA Synthesis.

BACKGROUND/AIMS: Acute cholecystitis is a common gastrointestinal disorder, often characterized by acute cholecystitis with gallbladder motility disorder. Interstitial cells of Cajal (ICCs) are the pacemaker cells of gut motility in the gastrointestinal tract. Disruption of ICC function is related to motility disorders. The aim of this study was to explore the cellular and molecular mechanisms of ICCs in acute cholecystitis and after the resolution of acute inflammation.

MATERIALS AND METHODS: Fifty adult guinea pigs were randomly divided into five groups: a sham-administered group (control group); two groups that were intraperitoneally administered an anti-polyclonal neutrophil (PMN) antibody 24 h before common bile duct ligation (CBDL); and two groups of guinea pigs that were subjected to CBDL without receiving the PMN antibody. Guinea pigs that underwent CBDL were held for 24 h or 48 h after surgery before being subjected to laparotomy and cholecystectomy. Immunohistochemistry, TUNEL assays, western blotting, and real-time PCR were performed to determine ICC morphology and density, to detect ICC apoptosis, and to examine stem cell factor (SCF) and c-kit protein expression and SCF and c-kit mRNA levels, respectively.

RESULTS: Both hematoxylin-eosin staining and histological inflammation scores in the PMN groups were lower than those in the control groups (P < 0.01). No differences were observed in ICC morphology between groups. During acute cholecystitis, ICCs numbers were reduced. Conversely, the density of ICCs increased after inflammation was relieved (P < 0.01). In addition, SCF and c-kit protein and mRNA expression levels decreased during acute cholecystitis (P < 0.05) and increased after inflammation was relieved (P < 0.05). Furthermore, ICC apoptosis increased during acute cholecystitis and decreased after resolution of acute cholecystitis (P < 0.01).

CONCLUSIONS: In acute cholecystitis, ICC injury may be related to gallbladder motility disorder.