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Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2017; 23(28): 5068-5085
Published online Jul 28, 2017. doi: 10.3748/wjg.v23.i28.5068
Gastrointestinal neuroendocrine peptides/amines in inflammatory bowel disease
Magdy El-Salhy, Tefera Solomon, Trygve Hausken, Odd Helge Gilja, Jan Gunnar Hatlebakk
Magdy El-Salhy, Division of Gastroenterology, Department of Medicine, Stord Hospital, Box 4000, 5409 Stord, Norway
Tefera Solomon, Department of Medicine, Haraldsplass Diakonale Hospital, 5009 Bergen, Norway
Magdy El-Salhy, Trygve Hausken, Odd Helge Gilja, Jan Gunnar Hatlebakk, Department of Clinical Medicine, University of Bergen, 5300 Bergen, Norway
Magdy El-Salhy, Trygve Hausken, Odd Helge Gilja, Jan Gunnar Hatlebakk, National Centre for Functional Gastrointestinal Disorders, Department of Medicine, Haukeland University Hospital, 5000 Bergen, Norway
Odd Helge Gilja, National Centre for Ultrasound in Gastroenterology, Department of Medicine, Haukeland University Hospital, 5300 Bergen, Norway
Author contributions: El-Salhy M collected the literature data and wrote the manuscript; Solomon T, Hausken T, Gilja OH and Hatlebakk JG contributed equally to discussions about the collected data and commented on the manuscript; all of the authors approved the submitted version of the manuscript.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest.
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: Dr. Magdy El-Salhy, Professor/Consultant Gastroenterologist, Division of Gastroenterology, Department of Medicine, Stord Hospital, Box 4000, 5409 Stord, Norway. magdy.el-salhy@helse-fonna.no
Telephone: +47-53491000 Fax: +47-53491001
Received: February 14, 2017
Peer-review started: February 16, 2017
First decision: April 5, 2017
Revised: April 13, 2017
Accepted: July 12, 2017
Article in press: July 12, 2017
Published online: July 28, 2017
Abstract

Inflammatory bowel disease (IBD) is a chronic recurrent condition whose etiology is unknown, and it includes ulcerative colitis, Crohn’s disease, and microscopic colitis. These three diseases differ in clinical manifestations, courses, and prognoses. IBD reduces the patients’ quality of life and is an economic burden to both the patients and society. Interactions between the gastrointestinal (GI) neuroendocrine peptides/amines (NEPA) and the immune system are believed to play an important role in the pathophysiology of IBD. Moreover, the interaction between GI NEPA and intestinal microbiota appears to play also a pivotal role in the pathophysiology of IBD. This review summarizes the available data on GI NEPA in IBD, and speculates on their possible role in the pathophysiology and the potential use of this information when developing treatments. GI NEPA serotonin, the neuropeptide Y family, and substance P are proinflammatory, while the chromogranin/secretogranin family, vasoactive intestinal peptide, somatostatin, and ghrelin are anti-inflammatory. Several innate and adaptive immune cells express these NEPA and/or have receptors to them. The GI NEPA are affected in patients with IBD and in animal models of human IBD. The GI NEPA are potentially useful for the diagnosis and follow-up of the activity of IBD, and are candidate targets for treatments of this disease.

Keywords: Enteric nervous system, Enteroendocrine cells, Immune cells, Inflammatory bowel disease, Musashi-1, Neurogenin 3, Stem cells

Core tip: Approximately 80% of the body immune cells (IC) are localized in the gastrointestinal (GI) tract close to the GI neuroendocrine regulatory system (NES). Many IC express GI neuroendocrine peptides/amines (NEPA) and possess receptors to several NEPA. Several GI NEPA are abnormal during active inflammatory bowel disease (IBD) in both patients and animal models of IBD. The changes in the GI NEPA are correlated with those of the IC during the inflammatory process. Studying the interactions between the GI NES and the immune system in IBD may improve our understanding of the pathophysiology of IBD and provide us with new tools for treatment.