Lack of the intestinal Muc1 mucin impairs cholesterol uptake and absorption but not fatty acid uptake in Muc1-/- mice

Helen H. Wang, Nezam H. Afdhal, Sandra J. Gendler, David Q.H. Wang

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Before cholesterol and fatty acid molecules in the small intestinal lumen can interact with their possible transporters for uptake and absorption, they must pass through a diffusion barrier, which may modify the kinetics of nutrient assimilation. This barrier includes an unstirred water layer and a surface mucous coat, which is located at the intestinal lumen-membrane interface. In the present study, we investigated whether disruption of the mucin gene (Muc)1 may influence intestinal uptake and absorption of cholesterol and fatty acid in male Muc1-/- mice. The wild-type mice displayed relatively high levels of Muc1, Muc2, Muc3, and Muc4 mRNAs and relatively low levels of Muc5ac and Muc5b mRNAs in the small intestine. The absence of Muc1 mRNA and protein in the small intestines of Muc1-/- mice confirmed complete knockout of the Muc1 gene, but the mRNA expression for other mucin genes remained unchanged. Intestinal uptake and absorption of cholesterol but not palmitic acid were significantly reduced in Muc1-/- mice compared with the wild-type mice. However, knockout of the Muc1 gene did not impair either expression levels of the genes that encode intestinal sterol efflux transporters Abcg5 and Abcg8 and fatty acid transporter Fatp4 or small intestinal transit rates. We conclude that physiological levels of the epithelial mucin produced by the Muc1 gene are necessary for normal intestinal uptake and absorption of cholesterol in mice. Our study implies that because cholesterol absorption efficiency is reduced by ∼50% in Muc1-deficient mice, there may be one or more additional pathways for cholesterol absorption.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume287
Issue number3 50-3
DOIs
StatePublished - Sep 1 2004
Externally publishedYes

Fingerprint

Mucin-1
Fatty Acids
Cholesterol
Intestinal Absorption
Messenger RNA
Mucins
Small Intestine
Genes
Gene Expression
Gene Knockout Techniques
Palmitic Acid
Sterols
Food
Membranes
Water

Keywords

  • ATP-binding cassette (transporter)
  • Intestinal uptake
  • Micelle
  • Mucin gel
  • Nutrition
  • Surface mucous coat

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)

Cite this

Lack of the intestinal Muc1 mucin impairs cholesterol uptake and absorption but not fatty acid uptake in Muc1-/- mice. / Wang, Helen H.; Afdhal, Nezam H.; Gendler, Sandra J.; Wang, David Q.H.

In: American Journal of Physiology - Gastrointestinal and Liver Physiology, Vol. 287, No. 3 50-3, 01.09.2004.

Research output: Contribution to journalArticle

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