Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Process for expansion and division of heart cells identified

19.02.2009
Could provide key to regenerative therapies

Researchers at the Gladstone Institute of Cardiovascular Disease (GICD) and the University of California, San Francisco have unraveled a complex signaling process that reveals how different types of cells interact to create a heart.

It has long been known that heart muscle cells (cardiomyocytes) actively divide and expand in the embryo, but after birth this proliferative capacity is permanently lost. How this transition occurs has not been known.

In the current issue of the journal Developmental Cell, the scientists show that the secret to this switch lies in the cells that surround the muscle cells, known as fibroblasts, which send signals that tell cardiomyocytes to divide or get bigger in size. Manipulation of these signals may be able to induce cardiomyocytes to divide again for regenerative purposes after heart attacks.

Cells exist in a three-dimensional matrix with other cells. Reciprocal signaling between the neighboring cells, along with internally generated factors and signals, insure that the tissues attain the correct shape, size, and function. In heart development, prior to birth (embryogenesis) heart cells (cardiomyocytes) proliferate and develop into different parts of the heart. After birth, the cells no longer proliferate. Although they continue to grow, the inability to proliferate renders the heart unable to regenerate cells after they have been damaged as occurs in heart attacks. It has been suggested that cardiac fibroblasts, which are cells that surround the muscle cells and make up over half of the heart cells, might be important in embryogenesis, but little is known about their development and roles in the embryonic heart.

"We've always suspected that different cell types are involved in determining how a heart is built," said GICD Director and senior author Deepak Srivastava, MD. "Our research showed that the signals from cardiac fibroblasts contribute to the different responses of cardiomyocytes."

To replicate the cell interactions in the developing heart, the scientists developed a novel method of growing two distinct cell types together. By observing the cells in this system, they found that the embryonic cardiac fibroblasts promoted cell division by the cardiomyocytes more efficiently than adult cardiac fibroblasts. Furthermore, they found that fibronectin, collagen and a heparin-binding EGF-like growth factor are secreted specifically by the embryonic cardiac fibroblasts as signals to promote this cell division. These molecules act through another signaling molecule called b1 integrin, found on the surface of cardiomyocytes. The team confirmed their observations in mutant mice that lacked b1 integrin. The mutant mice had fewer myocardial cells and disruptions of the muscle integrity that eventually led to prenatal death.

"We found a major difference in the function of embryonic and adult cardiac fibroblasts. Embryonic cardiac fibroblasts promote myocyte proliferation, while adult fibroblasts promote myocyte hypertrophy," said Masaki Ieda, MD, PhD, Gladstone postdoctoral fellow and lead author on the study. "We are now trying to make adult cardiac fibroblasts more like their embryonic counterparts to induce cardiomyocyte proliferation in the adult."

"Fibroblasts are also abundant and integrally involved in many other tissues, including skin, breast, lung and some cancers. Our results may be relevant to the broader understanding of tissue development, function, and disease," said Dr. Srivastava.

Valerie Tucker | EurekAlert!
Further information:
http://www.gladstone.ucsf.edu

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>