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 Millions through license revenues
27.04.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>