An enzyme makes the mouse heart prone to chronic cardiac insufficiency – if it is suppressed, the heart remains strong despite increased stress.
Cardiologists at the Internal Medicine Clinic at Heidelberg University Hospital in cooperation with scientists at the University of Texas Southwestern Medical Center at Dallas and Göttingen University Hospital have now explained this key mechanism in a mouse model and thus discovered a promising approach for the systematic prevention of chronic cardiac insufficiency.
The study has now been published online before print in the prestigious journal “Proceedings of the National Academy of Sciences”.
Long-term high pressure and stenoses of the valves or aorta make the heart work harder. When it compensates by excessive muscle growth (cardiac hypertrophy), the pump function is affected – rhythm disorders or heart failure can be the result. Other risk factors are overweight and age – more than 40 percent of people over age 70 suffer from cardiac muscle hypertrophy.
Despite progress in medication, around 95,000 people in Germany die annually from the consequences of chronic cardiac insufficiency. “It is essential to find the molecules that are key to the development of cardiac insufficiency in order to develop new, more efficient treatment“ states Dr. Johannes Backs, head of a research group in the Department of Cardiology, Angiology, and Pneumonology (Director Prof. Dr. med. Hugo A. Katus) at Heidelberg University Hospital.
Enzyme activates stress response and hypertrophy of the heart
A key molecule for cardiac hypertrophy brought on by stress is the naturally occurring enzyme CaMKII delta (Calcium/Calmodulin-dependent kinase II delta). Dr. Backs’ international research team proved this in genetically modified mice that could no longer produce this enzyme by surgically obstructing the main aorta to put the heart under greater stress and thus simulate permanent high blood pressure or valve stenosis in humans. The anticipated enlargement of the heart was very slight – the animals were protected.
“With these mice, we succeeded for the first time in specifically suppressing the CaMKII delta enzyme and clarifying its function in detail,” said Dr. Backs. CaMKII delta has a direct effect on the cells’ stress response. If it is missing, certain information in cell DNA is not accessed that is normally activated by stress, leading to hypertrophy of the heart. “There was still some slight enlargement of the heart, but presumably not enough to cause cardiac insufficiency,” said Dr. Backs. Under normal conditions, the genetically modified mice are inconspicuous – their hearts function and react normally.
The function of CaMKII delta as an intermediate of the heart’s stress response is a possible approach for effective therapy – the Heidelberg researchers anticipate that agents that block only this function of the enzyme would prevent the heart muscle from reacting to overload. Other functions of CaMKII delta should not be affected in order to avoid harmful side effects.
Contact person:Dr. Johannes Backs
For questions from journalists:Dr. Annette Tuffs
Dr. Annette Tuffs | EurekAlert!
Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory
‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
11.12.2017 | Information Technology
11.12.2017 | Power and Electrical Engineering
11.12.2017 | Event News