Effects of Taste Signaling Protein Abolishment on Gut Inflammation in an Inflammatory Bowel Disease Mouse Model

Ya-Wen Du; Qun Liu; Xiao-Cui Luo; Dong-Xiao Zhao; Jian-Bo Xue; Pu Feng; Robert F. Margolskee; Hong Wang; Liquan Huang

doi:10.3791/58668

A subscription to JoVE is required to view this content. Sign in or start your free trial.

Method Article

Effects of Taste Signaling Protein Abolishment on Gut Inflammation in an Inflammatory Bowel Disease Mouse Model

8.3K views

⸱

DOI:

10.3791/58668

⸱

November 9th, 2018

Ya-Wen Du^*¹ , Qun Liu^*¹ , Xiao-Cui Luo¹ , Dong-Xiao Zhao¹ , Jian-Bo Xue¹ , Pu Feng² , Robert F. Margolskee² , Hong Wang² , Liquan Huang¹^,²

¹College of Life Sciences, Zhejiang University, ²Monell Chemical Senses Center

^* These authors contributed equally

Summary

Here we present a protocol to investigate the effect of the nullification of gustation-related genes on immune responses in a dextran sulfate sodium (DSS)-induced inflammatory bowel disease (IBD) mouse model.

Abstract

Inflammatory bowel disease (IBD) is one of the immune-related gastrointestinal disorders, including ulcerative colitis and Crohn's disease, that affects the life quality of millions of people worldwide. IBD symptoms include abdominal pain, diarrhea, and rectal bleeding, which may result from the interactions among gut microbiota, food components, intestinal epithelial cells, and immune cells. It is of particular importance to assess how each key gene expressed in intestinal epithelial and immune cells affects inflammation in the colon. G protein-coupled taste receptors, including G protein subunit α-gustducin and other signaling proteins, have been found in the intestines. Here, we use α-gustducin as a representative and describe a dextran sulfate sodium (DSS)-induced IBD model to evaluate the effect of gustatory gene mutations on gut mucosal immunity and inflammation. This method combines gene knockout technology with the chemically induced IBD model, and thus can be applied to assess the outcome of gustatory gene nullification as well as other genes that may exuberate or dampen the DSS-induced immune response in the colon. Mutant mice are administered with DSS for a certain period during which their body weight, stool, and rectal bleeding are monitored and recorded. At different timepoints during administration, some mice are euthanized, then the sizes and weights of their spleens and colons are measured and gut tissues are collected and processed for histological and gene expression analyses. The data show that the α-gustducin knockout results in excessive weight loss, diarrhea, intestinal bleeding, tissue damage, and inflammation vs. wild-type mice. Since the severity of induced inflammation is affected by mouse strains, housing environment, and diet, optimization of DSS concentration and administration duration in a pilot experiment is particularly important. By adjusting these factors, this method can be applied to assess both anti- and pro-inflammatory effects.

Introduction

The two major forms of inflammatory bowel disease (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are characterized by chronic remittent or progressive inflammatory conditions of the intestine with multifactorial etiology¹^,². The development of IBD depends on genetic as well as certain environmental factors such as diet, antibiotic use, and importantly, pathogenic infections. However, the etiology and regulatory molecular mechanisms underlying IBD are still unclear. Hence, numerous chemically induced IBD animal models have been constructed and applied to delineate the pathogenesis and regulatory m....