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 Gotthardt1,51Neuromuscular and Cardiovascular Cell Biology, Max-Delbrück-Center for Molecular Medicine (MDC),
Washington State University, Pullman, Washington, 99164 USA.Barbara Bachtler
Barbara Bachtler | idw
Repairing damaged hearts with self-healing heart cells
22.08.2017 | National University Health System
Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Health and Medicine
22.08.2017 | Materials Sciences
22.08.2017 | Life Sciences