Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

An inner mucus layer prevents bacteria from causing inflammation in the large intestine

01.10.2008
The inner of the two mucus layers in colon is an barrier that protects us from the large number of bacteria in our intestine.

In the absence of the molecule that builds these two mucus layers allows the bacteria can reach the epithelial cells, cause inflammation and later on colon cancer as shown by research at the Sahlgrenska Academy at University of Gothenburg in collaboration with Uppsala University and Albert Einstein, New York.

All human beings have more than two pounds of bacteria in their large intestine and the number of bacteria outnumbers the total number of cells in the body by a factor of 10. How we can live with all these bacteria without deleterious effects or diseases have not been understood until now.

A couple of years ago, the research group of Lena Holm at Uppsala University could show that that there were two mucus layers in the colon that together gave a millimeter thick mucus layer.

- We understood already at that time that this must be important for protecting the large intestine, but we could not guess that the inner layer was such a good barrier for bacteria, says Professor Lena Holm at Uppsala University that has taken part in the current research.

In the article it is shown that both mucus layers have an identical composition where an enormous mucin protein called Muc2 is the main constituent. This is a protein that the Gothenburg group has been working on for more than 10 years to understand its function. The Muc2 mucin and other components is formed in the goblet cells where the inner mucus layer is attached. This layer is continuously renewed from below and after a tenth of a millimeter it is released and expanded in volume at least four times. This outer layer can then be transported away together with the intestinal content.

When the authors studied were all the intestinal bacteria were located, it was observed that the inner mucus layer was devoid of bacteria and that all bacteria were in the outer layer.

- It was really fascinating to find that the inner mucus layer lacked bacteria and that it was such a sharp border between the inner and outer mucus layers, says Ph.D. student Malin Johansson that has done most of the studies.

The mucus layer of colon build by the Muc2 mucin is a dense network that makes a physical obstacle for the bacteria to penetrate down through the mucus to reach the intestinal cells. When this mucus layer expands in volume in the outer layer it becomes a thriving milieu for the intestinal bacteria that also feed on the Muc2 mucin.

When the research group studied what happens in mice that lack the Muc2 mucin, the bacteria were not only found to be in direct contact with the intestinal cells, but could also penetrate down into the crypts and into the intestinal epithelial cells. These animals got an inflammation and later on colon cancer, a scenario that is similar to the human disease ulcerative colitis.

- Ulcerative colitis is a serious disease, but researchers have still not understood the cause of this disease. We believe that the solution to this puzzle is to be found in defects in the mucus layer that protects the large intestine, says Professor Gunnar C. Hansson that has directed the current research.

Journal: Proceedings of the National Academy of Sciences USA
Title: The inner of the two Muc2 mucin dependent mucus layers in colon is devoid of bacteria

Authors: Malin E.V. Johansson, Mia Phillipson, Joel Petterson, Anna Velcich, Lena Holm, and Gunnar C. Hansson

For more information, please contact:
Professor Gunnar C. Hansson, Dept. Medical Biochemistry, University of Gothenburg, tel: +46-31-773 3488, email: gunnar.hansson@medkem.gu.se

Ph. D. student Malin Johansson, Dept. Medical Biochemistry, University of Gothenburg, tel: +46-31-773 3070, email: malin.johansson@medkem.gu.se

Professor Lena Holm, Dept. Medical cellbiology, Uppsala University, tel: +46-18-471 43 25, email: lena.holm@mcb.uu.se

Eva Lundgren | idw
Further information:
http://www.vr.se

Further reports about: Biochemistry Muc2 bacteria colon cancer mucus layer ulcerative colitis

More articles from Health and Medicine:

nachricht Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>