Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 28, 2018; 24(16): 1766-1778
Published online Apr 28, 2018. doi: 10.3748/wjg.v24.i16.1766
Mucosa repair mechanisms of Tong-Xie-Yao-Fang mediated by CRH-R2 in murine, dextran sulfate sodium-induced colitis
Shan-Shan Gong, Yi-Hong Fan, Shi-Yi Wang, Qing-Qing Han, Bin Lv, Yi Xu, Xi Chen, Yao-Er He
Shan-Shan Gong, Shi-Yi Wang, Qing-Qing Han, Xi Chen, Yao-Er He, The First Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang Province, China
Yi-Hong Fan, Bin Lv, Yi Xu, Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310006, Zhejiang Province, China
Author contributions: Gong SS and Wang SY performed the experiments, analyzed the data and wrote the paper; Fan YH and Han QQ designed the research, revised the paper and contributed equally to this study; Xu Y and Lv B performed parts of the experiments and provided valuable suggestions for this study; Chen X and He YE contributed new analytic tools; All authors have read and approved the final manuscript.
Supported by National Natural Science Foundation of China, No. 81473506; Natural Science Foundation of Zhejiang Province, No.LY13H030011 and No. LY17H290009; State Administration of Traditional Chinese Medicine of Zhejiang Province, No. 2013ZB050; Department of Zhejiang Province to Build Funded Project, No. WKJ-ZJ-1531; Zhejiang TCM Science and Technology Project, No. 2016ZB047, No. 2017ZA056 and No. 2018ZB046.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board of Zhejiang Chinese Medical University.
Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institutional Animal Care and Use Committee of Zhejiang Chinese Medical University.
Conflict-of-interest statement: No potential conflicts of interest exist.
Data sharing statement: No additional data are available.
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: Yi-Hong Fan, PhD, Associate Professor, Department of Gastroenterology, The First Affiliated Hospital of Zhejiang Chinese Medical University, No. 54, Youdian Road, Shangcheng District, Hangzhou 310006, Zhejiang Province, China. yhfansjr@163.com
Telephone: +86-571-87608001 Fax: +86-571-87608001
Received: February 12, 2018
Peer-review started: February 13, 2018
First decision: March 9, 2018
Revised: March 14, 2018
Accepted: March 31, 2018
Article in press: March 31, 2018
Published online: April 28, 2018
ARTICLE HIGHLIGHTS
Research background

Mucosal healing is a desired therapeutic end-point in the treatment of inflammatory bowel disease (IBD). However, thorough treatment of IBD is difficult and there are some adverse reactions. According to studies, corticotropin-releasing hormone (CRH)-receptor (R)2 can activate the inflammatory response of intestinal mucosa. Our preliminary study found that Tong-Xie-Yao-Fang could lower CRH-R1, increase the expression of CRH-R2, and participates in reconstruction of the intestinal barrier.

Research motivation

Mucosal healing is a desired therapeutic end-point in the treatment of IBD. However, the mechanism of mucosal healing is still unclear.

Research objectives

To explore the significance of CRH-R2 in the mucosal healing of dextran sulfate sodium (DSS)-induced colitis and study the effect of Tong-Xie-Yao-Fang (TXYF) on CRH-R2.

Research methods

Ulcerative colitis (UC) was induced in mice by administration of 3% (w/v) DSS for 7 d. Then, mice were administered urocortin (Ucn)-2 or various doses of aqueous TXYF extracts, the CRH-R2 antagonist Astressin (Ast)2B, Ast2B + Ucn2, or Ast2B with various doses of aqueous TXYF extracts for 9 d. The colitis disease activity index (DAI) was assessed to evaluate the condition of colitis. The expression level of Ki-67 represented the proliferation of colonic epithelial cells. The expression levels of inflammation cytokines IL-6, TNF-α and CXCL-1 were examined by PCR and enzyme-linked immunosorbent assay.

Research results

Compared with the DSS group, mice treated with the CRH-R2 antagonist Ast2B showed greater loss of body weight, shorter colon lengths, and higher DAI and histological scores. Additionally, the Ast2B group showed increased intestinal permeability, improved secretion of inflammatory cytokines in colon tissue and reduced colonic epithelial cell proliferation. Increased apoptosis was also demonstrated. The Ucn2 group demonstrated lower DAI and histological scores. Diminished weight loss, longer colon length, reduced intestinal permeability, inhibited secretion of inflammatory cytokines in colon tissue and increased colonic epithelial cell proliferation were all observed. Reduced apoptosis was also observed.

Research conclusions

CRH-R2 activates the intestinal mucosal antiinflammatory response and plays an important antiinflammatory role. TXYF promotes the mucosal repair process in colitis mice.

Research perspectives

The CRH-R2 signaling pathway plays a pivotal role in mucosal healing in experimental UC in mice. Mucosal healing is a desired therapeutic end-point in the treatment of IBD. Thus, the findings of this study indicate a new potential mechanism by which CRH-R2 treats UC. TXYF, which has fewer side effects than other medicines, promotes the mucosal repair process of colitis mice by regulating CRH-R2. Therefore, TXYF can be used in patients with UC to promote their mucosal repair.