Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Repair in the Developing Heart

15.10.2008
If the heart becomes diseased during its embryonic/fetal development, it can regenerate itself to such an extent that it is fully functional by birth, provided some of the heart cells remain healthy.

Dr. Jörg-Detlef Drenckhahn of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch, Germany and colleagues from Australia were able to demonstrate in female mice that the healthy cells of the heart divide more frequently and thus displace the damaged tissue. "Hopefully, our results will lead to new therapies in the future," he said. (Developmental Cell, 15, 521-533, October 14, 2008)*.

For the heart to be able to beat, it needs energy. If the energy production in the heart cells is disturbed, then the embryo will actually die of heart dysfunction. But if only a portion of the cells is affected, this is not the case: With the aid of the remaining healthy cells, the embryo manages to regenerate the heart.

The scientists switched off a gene (Holocytochrome C synthase, abbreviated Hccs) in the developing hearts of mice - a gene that is essential for energy production. Results showed that the embryos died when all cells in the heart were affected by the defective energy production. However, the animals that still had some healthy myocardial cells survived, and at the time of birth they had a heart that was fully able to function.

The gene Hccs is located on one of the sex chromosomes, the X chromosome. In contrast to male animals who have only one X chromosome, females have two X chromosomes. Some of the altered female mice have an X chromosome with the defective Hccs gene and one with the intact Hccs gene. However, in the cells of the female animals, only one X chromosome is active. Depending on which one is expressed, either healthy or diseased heart cells develop. "At this point in time, the heart of the mice is like a mosaic," Dr. Drenckhahn said. "Half of the cells are healthy, the other half not."

Up until birth, the fetal heart manages to improve the ratio of healthy cells to defective cells from the original 50:50 ratio. The defective cells then only comprise ten percent of the entire heart volume. That is possible because the healthy myocardial cells divide much more frequently than the defective cells. Their percentage in the heart increases so that, at the time of birth, the ratio is large enough to allow the heart of the newborn mouse to beat normally. "But even for a while after birth, the heart is capable of compensatory growth of healthy cardiac cells," Dr. Drenckhahn explained.

Later the heart loses this ability. Thus, after approximately one year, some of the mice (13 percent) died of myocardial insufficiency and almost half developed arrhythmia. Why only some of the mice develop heart problems is still unclear. The scientists, therefore, want to inactivate the gene in adult mice as well in order to investigate its influence.

Furthermore, they want to identify the embryonic/fetal signal substances that stimulate healthy cells to proliferate and inhibit diseased cells. The scientists hope that, in the future, these signal substances may help stimulate the body's own repair mechanisms of the heart, for example after a heart attack or in the case of heart insufficiency.

In 2007 Dr. Drenckhahn received the Oskar Lapp Prize for his research on the repair of the fetal heart.

*Compensatory growth of healthy cardiac cells in the presence of diseased cells restores tissue homeostasis during heart development

Jörg-Detlef Drenckhahn1,2,3, Quenten P. Schwarz2,9, Stephen Gray1, Adrienne Laskowski4, Helen Kiriazis5, Ziqiu Ming5, Richard P. Harvey6, Xiao-Jun Du5, David R. Thorburn4,7 and Timothy C. Cox1,2,8

1Department of Anatomy & Developmental Biology, Monash University, Wellington Road, Clayton VIC 3800, Melbourne, Australia
2School of Biomedical & Molecular Science, University of Adelaide, North Terrace, Adelaide SA 5005, Adelaide, Australia
3Max-Delbrück Center for Molecular Medicine, Robert-Rössle-Straße 10, 13125 Berlin, Germany
4Murdoch Children's Research Institute, Royal Children´s Hospital, Flemington Road, Parkville VIC 3052, Melbourne, Australia
5Baker Heart Research Institute, Commercial Road, Melbourne VIC 3004, Melbourne, Australia
6Victor Chang Cardiac Research Institute, Victoria Street, Darlinghurst NSW 2010, Sydney, Australia
7Department of Paediatrics, University of Melbourne, Parkville VIC 3052, Melbourne, Australia

8Division of Craniofacial Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, 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 | Max-Delbrück-Centrum
Further information:
http://www.mdc-berlin.de/de/news/2008/index.html

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

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

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>