Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A loofah for the heart?

21.07.2005


If you’ve ever used a loofah in the shower, you’ve stirred up some stem cells. As the outer layer skin of sloughs off, stem cells in the dermis rush to repair and replace those buffed away.



Now imagine a tiny loofah that works in much the same way inside the corridors of the human heart. As it scrubs, it alerts heart stem cells to rush to the site of dying cells to begin renewal and repair of cardiomyocytes - cells that pump blood through the heart.

While a heart loofah may remain the stuff of medical fantasy, Steven Houser, Ph.D., Director of Cardiovascular Center for Temple University School of Medicine and Senior Associate Dean of Research, is sold on the idea that the heart - like the skin - contains its own stem cells: cells that are self-renewing and can be differentiated into different types of heart tissue. It’s a controversial subject in cardiovascular circles, but for Houser, who spent thirty years studying the molecular biology of heart cells, the stakes are worth it when it comes to combating congestive heart failure (CHF).


CHF, which afflicts 4.8 million Americans, occurs when the heart no longer has the strength to pump blood efficiently, resulting in an increasingly diminished quality of life. While a wide variety of well-understood conditions such as high blood pressure or excess weight can lead to CHF, a cure for the debilitating disease is less clear. Invasive surgical procedures such as a bypass operation or the insertion of a stent can extend a patient’s life, but the essential damage to the heart caused by the condition remains. Pharmacological therapies to improve the function of cardiac muscle cells improve heart function, but the treatments often lead to fatal arrhythmias, canceling out any benefits. To Houser, the problem proved frustrating.

"Cells were dying in the heart and there were simply not enough new cells to replace them," he says. "They were tired soldiers who could no longer work efficiently, and there were no new soldiers coming to take their place."

Although stem cells have been found in many other organs in the body, including the brain, many cardiac researchers remain unconvinced that the heart contains stem cells. For one, stem cells can over multiply and cause tumors, and the heart rarely gets tumors. These facts and the observations that adult cardiac myocytes do not have the capacity to proliferate have led most investigators to accept the dogma that no new cardiac myocytes are manufactured in the normal heart.

Houser respectfully disagrees. Abandoning his prior cell research, he joined forces with one of the foremost investigators in cardiac stem cells, Pierro Anversa, Ph.D. professor of medicine and Director of the Cardiovascular Institute at the New York Medical College at Valhalla, New York. Anversa, who has been on the forefront of stem cell research for the past five years, has suggested that heart cells undergo an ongoing turnover fueled by cardiac stem cells. In June of this year, Anversa published a study that actually identified cardiac stem cells in animal models that repaired tissue damaged by a heart attack.

One element that convinced Houser of Anversa’s work was his own research into how the heart reacts under the stress of hypertensive diseases that can lead to congestive heart failure. Early in the disease, the heart muscle mass increases and the chambers stretch in a vain attempt to increase contracting power. While part of the enlargement is due to increased muscle mass, the question of how the chambers grow is less certain.

The traditional view holds that cardiac cells simply grow larger to accommodate the increased need, but Houser and Anversa developed a different theory - that spurred by the cardiac stem cells, cardiomyocytes actually increase in number in their response to the heart’s traumatic condition.

"It was striking that with hypertension there were actually more cardiomyocytes than were originally lost," says Houser. "New myocytes were forming in excess of the cells that were dying."

And if that were true, these were the new soldiers to replace those missing in action.

To test this theory, Houser, with the help of Anversa, has received a new NIH grant to study if there are autologous stem cells in the heart. The two researchers have arrived at a deceptively simple idea. After inducing hypertension in an animal model to produce a distressed heart they will study the heart tissue and count cells, first in the normal heart and then in a heart that must work harder to develop excess pressure. If, according to the scientists’ thesis, there are more cardiomyocytes in the heart as opposed to simply larger cells, they will conclude that stem cells had a hand in an attempt to repair and restore the heart.

If their hunch proves correct, the implications for treatment of heart disease are profound. In the future, for example, Houser envisions people banking their own stem cells, so that when a problem arises, new tissue can be made by injecting these cells into the damaged heart. The idea is simple, use the patients own cardiac stem cells to repair their damaged heart.

"We’ve made a tremendous impact on cardiovascular diseases such as congestive heart failure through the hard work of physicians, better service, stents and bypasses," he says. "But what we need to do now is to reverse this disease rather than just slow its progression."

Although his colleagues may remain skeptical, Houser has committed himself to the stem cell model. Inducing cells to promote repair can answer the question that has haunted his career.

"We don’t know how to fix the broken heart, but stem cells might be a large part of the answer."

Eryn Jelesiewicz | EurekAlert!
Further information:
http://www.temple.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>