Higher expression of phosphorylated myosin regulatory light chain in the common bile duct in pancreaticobiliary maljunction accompanied by bile duct dilatation in children: a post-mortem observational study

Wan-Liang Guo,Jian Wang,Mei-Fang Jin,Qi Zhang

doi:10.1007/s00383-012-3225-0

Wan-Liang Guo, Jian Wang + Show 2 more

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https://doi.org/10.1007/s00383-012-3225-0

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Journal: Pediatric surgery international	Publication Date: Dec 9, 2012
Citations: 23	License type: CC BY 2.0

Affiliation: Soochow University

Abstract

PurposeTo examine the content of phosphorylated myosin regulatory light chain (P-MLC20) and myosin light-chain kinase (MLCK) in the common bile duct of pediatric patients with pancreaticobiliary maljunction (PBM) accompanied by bile duct dilatation (BDD), and investigate their potential role in PBM accompanied by BDD.MethodsTwenty-one specimens of the common bile duct from pediatric patients with PBM accompanied by BDD were collected. P-MLC20 was examined with immunohistochemistry. The expression of P-MLC20 and MLCK was also examined with Western blot. Twenty-one specimens of the common bile duct from pediatric patients without PBM and BDD were used as controls.ResultsThe mean optical density (MOD), mean labeling intensity (MLI) and minimum qualifying scores (MQS) of P-MLC20 were 115.6856 ± 58.1634, 21.7125 % ± 9.6555 and 21.3531 ± 6.5255, respectively. In the control group, MOD, MLI and MQS were 96.5581 ± 9.7859, 11.1813 % ± 3.6208 and 10.7819 ± 3.5323, respectively. There was no significant difference in MOD between the two groups (P > 0.05), whereas there was a significant difference in MLI and MQS between the two groups (P < 0.05). The expression of P-MLC20 and MLCK, as determined with Western blot, was also significantly higher in the PBM group than in the control group (P < 0.05).ConclusionP-MLC20 is associated with increased contractile force of the smooth muscle of the common bile duct in pediatric patients with PBM accompanied by BDD. The enhanced expression of P-MLC20 in the common bile duct probably contributes to increased bile duct pressure in PBM via the MLCK pathway.

Highlights

Pancreaticobiliary maljunction (PBM) is a congenital anomaly in which the junction of the pancreatic and bile ducts is outside the duodenal wall
Purpose To examine the content of phosphorylated myosin regulatory light chain (P-MLC20) and myosin light-chain kinase (MLCK) in the common bile duct of pediatric patients with pancreaticobiliary maljunction (PBM) accompanied by bile duct dilatation (BDD), and investigate their potential role in PBM accompanied by BDD
There was no significant difference in mean optical density (MOD) between the two groups (P [ 0.05), whereas there was a significant difference in mean labeling intensity (MLI) and minimum qualifying scores (MQS) between the two groups (P \ 0.05)

Summary

Introduction

Pancreaticobiliary maljunction (PBM) is a congenital anomaly in which the junction of the pancreatic and bile ducts is outside the duodenal wall. Since the common duct of the pancreaticobiliary duct is too long, Oddi’s sphincter could not control the biliary–pancreatic confluence, and results in abnormal hydrodynamics in the biliary–pancreatic confluence [1, 2]. The bile activates a variety of enzymes, such as phospholipase A2 and proteases, in the pancreatic juice, and, leads to the breakdown, destruction and abscission of the epithelial elastic fiber of the common bile duct. Chronic stimulation of the common bile duct results in inflammation, thickening and fibrosis of the wall, epithelial hyperplasia, and even cancer of the common bile duct. The fibrosis of the common bile duct leads to poor bile flow, increased inner pressure in the common bile duct and cholestasis [3].

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