Expression of intestinal mucins may be affected by the dietary protein source

Abstract

Mucin glycoproteins cover epithelial surfaces of ducts, including the digestive tract, in the body. The study investigated the effect of dietary protein on the expression of mucins in intestinal epithelia of mice. Male weanling mice were randomized into 4 groups of 8 mice each. The source of protein (plant or animal origin) and the level of each protein (10% or 20% crude protein) were arranged in a factorial manner to produce 4 diets which were randomly assigned to the four groups of mice. Mice were provided the diets for 14 days and euthanized on the fifteenth day. Mucosa and histological sections were prepared from the jejunum and colon of the intestines. Total RNA was prepared from the mucosa using Trizol®. cDNA was prepared using random hexamers and specific primers were used for real time PCR amplification of the message for Muc2 and Muc3. Expression of Muc2 in the jejunum was higher (1.45 fold) in mice fed plant protein compared to those fed animal protein. There was no difference in expression of Muc2 in the colon with the different protein sources. Expression of Muc2 did not vary with the level of dietary protein in both the jejunum and colon. Expression of Muc3 in the jejunum and colon did not vary with the level or source of dietary protein. It is concluded that expression of intestinal mucins may be affected by the source of protein in the diet.Research was supported by a RDC grant from East Tennessee State University.