Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Mechanism for Cardiac Arrhythmia discovered

18.09.2008
It has long been thought that virus infections can cause cardiac arrhythmia.

But why has not been understood. Ulrike Lisewski, Dr. Yu Shi, Michael Radke and Professor Michael Gotthardt of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch, Germany, have now discovered the molecular mechanism.

The researchers demonstrated that the receptor which the virus uses to infect heart cells is normally necessary for regular heart beat in mice. Likewise, when the receptor is absent or non-functioning, arrhythmia occurs. They assume that both the virus infection and the autoimmune disease can block the receptor which, in turn, disrupts the heart's normal rhythm. The study has now been published online in the Journal of Experimental Medicine (10.1084/jem.20510iti3).

The heart consists of two ventricles and two atria. In order to beat correctly and to pump blood through the body, specialized heart fibres generate electric signals that control the heart beat. Cardiac arrhythmia occurs when these signals are not correctly generated or forwarded. There, a receptor, which scientists call CAR, plays an important role.

CAR stands for Coxsackievirus-Adenovirus-Receptor. It is embedded in specific cell-cell-contacts (tight junctions) of the specialized heart fibres. CAR was discovered as the critical protein responsible for virus entry during infection with Coxsackie and Adenoviruses. Its role in the adult heart was previously unknown.

To investigate CAR's task in a healthy organism, the MDC-scientists switched off the CAR-gene in adult mice. As a result, the rodents could no longer produce the receptors and developed cardiac arrhythmia. "That is an interesting observation because these special cell-cell-contacts, the tight junctions, have not been connected to arrhythmia so far", Professor Gotthardt says.

A detailed analysis of the animals showed that the transfer of electric signals from the atria to the ventricles does not work properly. "When CAR is missing, the signal can not be passed on and the heart does not beat properly," Dr. Shi says.

Professor Gotthardt now wants to investigate whether CAR is blocked in patients with arrhythmia. "However, it does not always have to be connected to a virus infection," he says. "The body's own antibodies directed against CAR could cause the disease as well."

The tight junction protein CAR regulates cardiac conduction and cell-cell communication

Ulrike Lisewski1, Yu Shi1, Uta Wrackmeyer1, Robert Fischer2, Chen Chen1, Alexander Schirdewan2, Rene Jüttner3, Fritz Rathjen3, Wolfgang Poller4, Michael H. Radke1 and Michael Gotthardt1,5

1Neuromuscular and Cardiovascular Cell Biology, Max-Delbrück-Center for Molecular Medicine (MDC),
13122 Berlin-Buch, Germany, 2 HELIOS Kliniken GmbH, Franz-Volhard Klinik, Charité, Humboldt-
University, 13125 Berlin, Germany, 3Department of Molecular Pathology, University Hospital Tübingen,
D-72073 Tuebingen, Germany, 4 Department of Cardiology, Campus Benjamin Franklin, D-12200 Berlin,
Germany, 5Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology,

Washington State University, Pullman, Washington, 99164 USA.

Barbara Bachtler
Press and Public Affairs
Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch
Robert-Rössle-Str. 10¸13125 Berlin, Germany
Phone: +49 (0) 30 94 06 - 38 96
Fax: +49 (0) 30 94 06 - 38 33
e-mail: presse@mdc-berlin.de

Barbara Bachtler | idw
Further information:
http://www.mdc-berlin.de/en/news

More articles from Life Sciences:

nachricht New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University

nachricht UK chemistry researchers develop catalyst that mimics the z-scheme of photosynthesis
26.06.2017 | University of Kentucky

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Dune ecosystem modelling

26.06.2017 | Ecology, The Environment and Conservation

Insights into closed enzymes

26.06.2017 | Life Sciences

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>