The inner of the two Muc2 mucin-dependent mucus layers in colon is devoid of bacteria
- 30 September 2008
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 105 (39), 15064-15069
- https://doi.org/10.1073/pnas.0803124105
Abstract
We normally live in symbiosis with similar to 10(13) bacteria present in the colon. Among the several mechanisms maintaining the bacteria/host balance, there is limited understanding of the structure, function, and properties of intestinal mucus. We now demonstrate that the mouse colonic mucus consists of two layers extending 150 mu m above the epithelial cells. Proteomics revealed that both of these layers have similar protein composition, with the large gel-forming mucin Muc2 as the major structural component. The inner layer is densely packed, firmly attached to the epithelium, and devoid of bacteria. In contrast, the outer layer is movable, has an expanded volume due to proteolytic cleavages of the Muc2 mucin, and is colonized by bacteria. Muc2(-/-) mice have bacteria in direct contact with the epithelial cells and far down in the crypts, explaining the inflammation and cancer development observed in these animals. These findings show that the Muc2 mucin can build a mucus barrier that separates bacteria from the colon epithelia and suggest that defects in this mucus can cause colon inflammation.Keywords
This publication has 27 references indexed in Scilit:
- Aberrant Mucin Assembly in Mice Causes Endoplasmic Reticulum Stress and Spontaneous Inflammation Resembling Ulcerative ColitisPLoS Medicine, 2008
- Gel-forming mucins appeared early in metazoan evolutionProceedings of the National Academy of Sciences of the United States of America, 2007
- Increased susceptibility to colitis and colorectal tumors in mice lacking core 3–derived O-glycansThe Journal of Experimental Medicine, 2007
- Large Scale Identification of Proteins, Mucins, and Their O-Glycosylation in the Endocervical Mucus during the Menstrual CycleMolecular & Cellular Proteomics, 2007
- Increased levels of mucins in the cystic fibrosis mouse small intestine, and modulator effects of the Muc1 mucin expressionAmerican Journal of Physiology-Gastrointestinal and Liver Physiology, 2006
- Entamoeba histolytica cysteine proteases cleave the MUC2 mucin in its C-terminal domain and dissolve the protective colonic mucus gelProceedings of the National Academy of Sciences of the United States of America, 2006
- Spatial Organization and Composition of the Mucosal Flora in Patients with Inflammatory Bowel DiseaseJournal of Clinical Microbiology, 2005
- Host-Bacterial Mutualism in the Human IntestineScience, 2005
- Studies on the “Insoluble” Glycoprotein Complex from Human ColonOnline Journal of Public Health Informatics, 1999
- Cloning and Identification of the Gene Gob-5, Which Is Expressed in Intestinal Goblet Cells in MiceBiochemical and Biophysical Research Communications, 1999