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 The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>