Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UI study discovers cells segregate molecules to control signaling

20.03.2003


The human body has barriers such as skin and the lining of airways and gut that protect and separate us from the outside world. If these barriers are breached, our survival is threatened. Therefore it is critical that the cells that form these barriers have mechanisms that can instantly repair any injury.



University of Iowa researchers have discovered a surprisingly simple but effective repair system in airway barrier cells. The UI study shows that by placing a messenger molecule on one side of the barrier and a receiver molecule on the other side, these cells have in place a repair mechanism that is poised to leap into action whenever the barrier is breached. The study findings are published in the March 20 issue of Nature.

One of the researchers, Joseph Zabner, M.D., associate professor of internal medicine, likened the repair mechanism to a situation where a broken fence allows a neighbor’s dog to come in and bother a farmer’s chickens. The dog causes the chickens to squawk, which signals the farmer to go and fix the fence. In the same way, breaks in the cell barrier allow the messenger molecule to get to the receiver, which then sends a signal to the cell to repair the broken barrier.


"If everything is healthy, the message never gets to its receptor because the barrier keeps them apart," said Paola Vermeer, Ph.D., UI assistant research scientist and the lead author of the study. "The instant that barrier is broken, the message can get to its receptor and that receptor sends the signal to start the repair process."

The findings explain how healthy barrier cells can rapidly repair injuries. The results may also have important implications for disease processes.

If a disease weakens the barrier in such a way that allows the message to get to its receptor when it shouldn’t, then the repair mechanism may be turned on inappropriately. Such continuous signaling could lead to cellular abnormalities and may play a role in diseases where barriers are important.

"’If this mechanism is disrupted in disease, then these findings might suggest targets for therapeutic intervention," added Michael Welsh, M.D., the Roy J. Carver Biomedical Research Chair in Internal Medicine and Physiology and Biophysics, UI Professor, and Howard Hughes Medical Institute Investigator. "It might be possible to interfere with the message or its receptor to break the line of communication."

The UI team studied airway epithelial cells, which form the barrier lining the bronchial passages. In this system the researchers looked at a message molecule called heregulin, which is a growth factor, and receiver molecules known as erbB receptors. Heregulin was present on the upper, mucosal surface of the epithelial cells and in the liquid overlying the airway surface. In contrast, the erbB receptors were segregated to the other side of the epithelium where they were located exclusively on the bottom or basolateral surface of the cells.

The UI study found that with the barrier intact, there was no communication between heregulin and its erbB receptor. However, when the researchers damaged the epithelial cell barrier, heregulin immediately gained access to its receptor. This communication triggered cell growth and differentiation leading to rapid repair of the injury.

Certain airway diseases such as asthma, cystic fibrosis and smoking-associated bronchitis are known to impair the airway barrier. The UI study suggests that under these disease conditions heregulin or other messenger molecules might not be well segregated from their receptors, and the receptors might be activated abnormally.

"We asked what would happen in our cell cultures if the erbB receptors were permanently turned on," Vermeer said. "After 10 days the cells were overgrown and showed abnormal structure."

The airways of individuals with these airway diseases also undergo many cellular changes, including a thickening of the airway lining caused by excessive cell growth.

Welsh commented that the results of this study might also be relevant to many other biological systems where a barrier separates a message molecule from its receptor.

"When cancer cells grow, they often lose their barrier function," Welsh said. "We speculate that might mean that signaling molecules could gain access to their receptors, and this might stimulate cell growth."

The separation mechanism may also be important in controlling developmental processes because immature cells do not possess the barriers found in mature cells.


In addition to Vermeer, Zabner and Welsh, the UI researchers involved in the study included Lisa Einwalter, Thomas Moninger, and Tatiana Rokhlina. Jeffrey Kern, M.D., division chief of pulmonary and critical care medicine at University Hospitals of Cleveland, also was part of the team.

The research was funded in part by grants from the National Institutes of Health and the Cystic Fibrosis Foundation.

University of Iowa Health Care describes the partnership between the UI Roy J. and Lucille A. Carver College of Medicine and UI Hospitals and Clinics and the patient care, medical education and research programs and services they provide. Visit UI Health Care online at http://www.uihealthcare.com.

Becky Soglin | EurekAlert!
Further information:
http://www.uihealthcare.com
http://www.uiowa.edu/

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>