Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers induce heart cells to proliferate

03.05.2005


Could lead to strategies to regenerate tissue after heart attack



In the best documented effort to date, researchers from the Howard Hughes Medical Institute at Children’s Hospital Boston and Harvard Medical School have successfully induced adult heart-muscle cells to divide and multiply.

Heart-muscle cells, or cardiomyocytes, were previously considered incapable of replicating in mammals after birth, which is why heart attack is such a problem: once killed, heart tissue can’t regenerate. Dr. Mark Keating and Dr. Felix Engel now show that an enzyme known as p38 MAP kinase suppresses cardiomyocyte replication, and that inhibiting p38 enables these cells to proliferate. Their report appears in the May 15 issue of Genes & Development (published online May 3).


Keating, Engel and colleagues first showed in fetal rats that increased p38 activity correlates with reduced cardiac growth, and that reduced p38 activity correlates with accelerated cardiac growth. Then, working with adult cardiomyocytes, they demonstrated p38’s role in every major step of cell replication.

First, in cultures of cardiomyocytes from rats, they showed that activation of p38 reduced DNA synthesis, the first key step in cell replication, and that inhibition of p38 increased DNA synthesis. Second, they showed that p38 regulates the activity of genes required for mitosis (division of the cell nucleus in two), a second key step in replication. When mice were bred to lack p38, mitosis in their cardiomyocytes increased by more than 90 percent. Finally, p38 inhibition promoted cytokinesis, the last step of replication in which the entire cell divides to form two separate cells. Growth factors were needed to get the full effect.

"This is just one baby step toward regenerative therapy, but it’s an important one," says Keating. "Inhibiting p38 is now a candidate therapeutic strategy."

When a human heart is injured, it cannot ’’grow back’’ the damaged muscle, which is instead replaced by scar tissue. Too much scarring can impair the heart’s ability to pump and can lead to life-threatening arrhythmias. "If you want to prevent hearts from becoming scarred, a regenerative therapy is needed," Keating says.

Keating, Engel and colleagues are now studying rodents with simulated heart attacks to see whether agents that inhibit p38 would improve heart function and induce heart regeneration with reduced scar formation. Keating believes this approach, if successful, would prove more practical than stem-cell therapy, which would involve implanting whole cardiomyocytes.

"From a practical perspective, we think that delivering proteins or small molecules is much more likely to succeed," he says. "It would be like taking the drug epoetin alfa to stimulate red blood cell production, as opposed to getting a blood transfusion. Instead of borrowing cells, you’re making them yourself."

p38 was chosen for study because it is known to be important in the differentiation of cardiomyocytes. Once cells differentiate into their mature form, they usually lose their ability to proliferate. This study shows that ability can be revived.

Bess Andrews | EurekAlert!
Further information:
http://www.childrens.harvard.edu

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>