Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 7, 2018; 24(29): 3260-3272
Published online Aug 7, 2018. doi: 10.3748/wjg.v24.i29.3260
Downregulation of Hes1 expression in experimental biliary atresia and its effects on bile duct structure
Rui-Zhong Zhang, Xin-Hao Zeng, Ze-Feng Lin, Ming-Fu, Yan-Lu Tong, Vincent CH Lui, Paul KH Tam, Jonathan R Lamb, Hui-Min Xia, Yan Chen
Rui-Zhong Zhang, Xin-Hao Zeng, Ze-Feng Lin, Ming-Fu, Yan-Lu Tong, Hui-Min Xia, Yan Chen, Department of Pediatric Surgery, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong Province, China
Vincent CH Lui, Paul KH Tam, Yan Chen, Department of Surgery and Pathology, University of Hong Kong, Hong Kong, China
Jonathan R Lamb, Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
Author contributions: Zhang RZ, Zeng XH and Lin ZF contributed equally to this work; Zhang RZ, Lin ZF and Fu M performed the animal work; Lin ZF and Tong YL analyzed the immunohistochemistry; Lui VC, Tam PK, Lamb JR, Xia HM and Chen Y contributed to the study design, data collection, analysis, discussion and manuscript preparation.
Supported by the Science and Technology Project of Guangzhou, No. 201707010014; and the National Natural Science Foundation of China, No. 81600399 and No. 81671498.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of Guangzhou Women and Children’s Medical Center, Guangzhou, China, No. 2015090109.
Institutional animal care and use committee statement: All animal protocols were approved by the Institutional Animal Care and Use Committee of Guangzhou Medical University, Guangzhou, China, No. 2016-007.
Conflict-of-interest statement: The authors declare that there is no conflict of interest related to this study.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: In the manuscript, the ARRIVE Guidelines have been adopted.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Yan Chen, PhD, Honorary Research Felllow, Senior Scientist, Department of Surgery and Pathology, University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong, China. ychenc@hku.hk
Telephone: +86-852-28199602 Fax: +86-852-28199621
Received: April 23, 2018
Peer-review started: April 23, 2018
First decision: May 9, 2018
Revised: June 3, 2018
Accepted: June 25, 2018
Article in press: June 25, 2018
Published online: August 7, 2018
Processing time: 104 Days and 3.2 Hours
Abstract
AIM

To analyze the expression and function of the Notch signaling target gene Hes1 in a rhesus rotavirus-induced mouse biliary atresia model.

METHODS

The morphologies of biliary epithelial cells in biliary atresia patients and in a mouse model were examined by immunohistochemical staining. Then, the differential expression of Notch signaling pathway-related molecules was investigated. Further, the effects of the siRNA-mediated inhibition of Hes1 expression were examined using a biliary epithelial cell 3D culture system.

RESULTS

Both immature (EpCAM+) and mature (CK19+) biliary epithelial cells were detected in the livers of biliary atresia patients without a ductile structure and in the mouse model with a distorted bile duct structure. The hepatic expression of transcripts for most Notch signaling molecules were significantly reduced on day 7 but recovered to normal levels by day 14, except for the target molecule Hes1, which still exhibited lower mRNA and protein levels. Expression of the Hes1 transcriptional co-regulator, RBP-Jκ was also reduced. A 3D gel culture system promoted the maturation of immature biliary epithelial cells, with increased expression of CK19+ cells and the formation of a duct-like structure. The administration of Hes1 siRNA blocked this process. As a result, the cells remained in an immature state, and no duct-like structure was observed.

CONCLUSION

Our data indicated that Hes1 might contribute to the maturation and the cellular structure organization of biliary epithelial cells, which provides new insight into understanding the pathology of biliary atresia.

Keywords: Biliary atresia; Rhesus rotavirus; Hes1; EpCAM; Epithelial cells 3D culture

Core tip: Similar immature biliary epithelial cells and distorted bile ductules were observed in biliary atresia patients and a mouse biliary atresia model. Investigation of the Notch signaling pathway target gene Hes1 showed that mRNA and protein expression was reduced in mouse liver, which was partially due to reduced expression of transcriptional co-regulator RBP-Jκ. In biliary epithelial cells 3D gel culture system, the administration of Hes1 siRNA blocked the maturation and duct-like structure formation process, which resulted in the cells still being in an immature state and no duct-like structure was observed.