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 Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

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

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>