Vasoactive intestinal polypeptide promotes intestinal barrier homeostasis and protection against colitis in mice

PLoS One. 2015 May 1;10(5):e0125225. doi: 10.1371/journal.pone.0125225. eCollection 2015.

Abstract

Inflammatory bowel disease is a chronic gastrointestinal inflammatory disorder associated with changes in neuropeptide expression and function, including vasoactive intestinal peptide (VIP). VIP regulates intestinal vasomotor and secretomotor function and motility; however, VIP's role in development and maintenance of colonic epithelial barrier homeostasis is unclear. Using VIP deficient (VIPKO) mice, we investigated VIP's role in epithelial barrier homeostasis, and susceptibility to colitis. Colonic crypt morphology and epithelial barrier homeostasis were assessed in wildtype (WT) and VIPKO mice, at baseline. Colitic responses were evaluated following dinitrobenzene sulfonic acid (DNBS) or dextran-sodium sulfate (DSS) exposure. Mice were also treated with exogenous VIP. At baseline, VIPKO mice exhibited distorted colonic crypts, defects in epithelial cell proliferation and migration, increased apoptosis, and altered permeability. VIPKO mice also displayed reduced goblet cell numbers, and reduced expression of secreted goblet cell factors mucin 2 and trefoil factor 3. These changes were associated with reduced expression of caudal type homeobox 2 (Cdx2), a master regulator of intestinal function and homeostasis. DNBS and DSS-induced colitis were more severe in VIPKO than WT mice. VIP treatment rescued the phenotype, protecting VIPKO mice against DSS colitis, with results comparable to WT mice. In conclusion, VIP plays a crucial role in the development and maintenance of colonic epithelial barrier integrity under physiological conditions and promotes epithelial repair and homeostasis during colitis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CDX2 Transcription Factor
  • Cell Count
  • Colitis / pathology
  • Colitis / prevention & control*
  • Dinitrofluorobenzene / analogs & derivatives
  • Disease Susceptibility
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Goblet Cells / pathology
  • Homeodomain Proteins / metabolism
  • Homeostasis / drug effects*
  • Intestines / drug effects
  • Intestines / pathology*
  • Male
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Protective Agents / pharmacology*
  • Real-Time Polymerase Chain Reaction
  • Signal Transduction / drug effects
  • Transcription Factors / metabolism
  • Vasoactive Intestinal Peptide / deficiency
  • Vasoactive Intestinal Peptide / metabolism*

Substances

  • CDX2 Transcription Factor
  • Cdx2 protein, mouse
  • Homeodomain Proteins
  • Protective Agents
  • Transcription Factors
  • 2,4-dinitrofluorobenzene sulfonic acid
  • Vasoactive Intestinal Peptide
  • Dinitrofluorobenzene

Grants and funding

This work was supported by Crohn's and Colitis Foundation of Canada (www.crohnsandcolitis.ca) to BV and KJ. VM holds a joint Michael Smith Foundation for Health Research/Crohn's and Colitis Foundation of Canada postdoctoral fellowship (http://www.msfhr.org and www.crohnsandcolitis.ca). BAV is the Children with Intestinal and Liver Disorders (CHILD) Foundation Chair in Pediatric Gastroenterology and the Canada Research Chair in Pediatric Gastroenterology (http://www.child.ca/). KJ and WG are Senior Clinician Scientists supported by the Child and Family Research Institute (CFRI) Clinician Scientists Award Program, University of British Columbia (www.cfri.ca). KJ is supported by the CHILD Foundation, (http://www.child.ca/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.