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 Can 'smart toilets' be the next health data wellspring?
13.11.2019 | Morgridge Institute for Research

nachricht Novel mathematical framework provides a deeper understanding of how drugs interact
13.11.2019 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

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: New opportunities in additive manufacturing presented

Fraunhofer IFAM Dresden demonstrates manufacturing of copper components

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...

Im Focus: New Pitt research finds carbon nanotubes show a love/hate relationship with water

Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.

New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...

Im Focus: Magnets for the second dimension

If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.

Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...

Im Focus: A new quantum data classification protocol brings us nearer to a future 'quantum internet'

The algorithm represents a first step in the automated learning of quantum information networks

Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...

Im Focus: Distorted Atoms

In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.

An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

Smart lasers open up new applications and are the “tool of choice” in digitalization

30.10.2019 | Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

 
Latest News

New opportunities in additive manufacturing presented

14.11.2019 | Materials Sciences

Massive photons in an artificial magnetic field

14.11.2019 | Physics and Astronomy

Fraunhofer Radio Technology becomes part of the worldwide Telecom Infra Project (TIP)

14.11.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>