Navigation Links
Repair in the developing heart
Date:10/15/2008

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. Jrg-Detlef Drenckhahn of the Max Delbrck Center for Molecular Medicine (MDC) Berlin-Buch made this discovery together with colleagues from Australia. They 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," Dr. Drenckhahn said. "With the right signals, a heart that has been damaged for example through infarction might be stimulated to heal itself." (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.


'/>"/>

Contact: Barbara Bachtler
bachtler@mdc-berlin.de
49-309-406-3896
Helmholtz Association of German Research Centres
Source:Eurekalert

Related biology news :

1. Cholesterol-lowering drugs and the effect on muscle repair and regeneration
2. Cardiac cell transplant studies show promise in cardiac tissue repair
3. Duke-NIEHS team shows how DNA repairs may reshape the genome
4. Milkweeds evolutionary approach to caterpillars: Counter appetite with fast repair
5. Researchers reveal structure of protein that repairs damage to cancer cells
6. Stem cells offer cartilage repair hope for arthritis sufferers
7. Is DNA repair a substitute for sex?
8. Wildcat Power Cord repairs cruciate ligament in dairy cows knee
9. Researchers probe a DNA repair enzyme
10. Building the future -- 21st century nano tools to repair the nervous system
11. Yale receives $8.4 million to study DNA repair in cancer cells
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... 2016 Research and Markets has announced the ... report to their offering. The ... to grow at a CAGR of 12.28% during the period ... an in-depth market analysis with inputs from industry experts. The report ... years. The report also includes a discussion of the key vendors ...
(Date:6/21/2016)... VANCOUVER, British Columbia , June 21, 2016 ... been appointed to the new role of principal ... has been named the director of customer development. ... , NuData,s chief technical officer. The moves reflect ... development teams in response to high customer demand ...
(Date:6/9/2016)... 9, 2016  Perkotek an innovation leader in attendance control systems is proud to ... hours, for employers to make sure the right employees are actually signing in, and ... ... ... ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... 2016 Savannah River Remediation LLC group ... NewTechBio,s NT-MAX Lake & Pond Sludge and ... in conjunction with Hexa Armor/ Rhombo cover manufactured ... Pollutant Discharge Elimination System requirements. The ... history of elevated pH levels, above 8.5, especially ...
(Date:12/7/2016)... ... December 07, 2016 , ... A new study ... setting of previously treated, advanced pancreatic cancer, liquid biopsies are not yet an ... and timing of blood sampling may improve the value of a blood-based test.” ...
(Date:12/7/2016)... 2016  Nordion, a standalone business of Sterigenics ... today,s award by the United States Department of ... the Phase II cooperative agreement funding to GA ... University of Missouri Research Reactor Center (MURR ® ... establishment of a new, reliable supply of molybdenum ...
(Date:12/7/2016)... , Dec. 7, 2016  Muse bio, a privately-held ... today announced that Dr. Kevin Ness has ... Board of Directors. Kevin succeeds Muse ... the company,s Chief Science Officer as well as remains ... of the BioDesign Center at the RAS Energy Institute ...
Breaking Biology Technology: