“Latest Stem Cells News”

It has long been thought that damage to the heart is irreversible, but new research is challenging that assumption.
Investigators from Children’s Hospital Boston were able to reverse heart damage in mice by stimulating the growth of new heart muscle cells.

They did this by injecting the mice with the growth factor neuregulin1, which is a key player in heart cell growth.
Until recently, most experts believed that the heart muscle could not repair itself, in part because the cells responsible for its development stop proliferating after birth.

But recent studies have shown that these heart muscle cells, known as cardiomyocytes, do have a limited ability to replace themselves.
The hope is that neuroregulin1 can one day be used to ramp up this process in humans and help heal damaged hearts, as it seems to do in mice, study co-author Bernhard Kuhn, MD, tells WebMD.

“Contemporary heart failure treatment is directed at making the remaining cardiomyocytes function better, and improvements in outcomes are harder and harder to achieve because these therapies have become so good,” he says. “But despite this, heart failure is still a fatal disease. Therapies that replace lost heart muscle cells have the potential to greatly advance the field.”
Injections Reversed Heart Attack Damage

Many other research teams are looking for ways to repair damaged heart muscle, but most of these efforts have focused on coaxing stem cells to become new heart cells.

The research by Kuhn and colleagues shows that stimulating heart muscle cells to proliferate in other ways may prove to be a viable alternative to stem cells, Duke cardiologist Richard C. Becker, MD, tells WebMD.
Becker, who is a spokesman for the American Heart Association, called the new research compelling.

“This is something that I suspect people in the field of cardiology will be very excited about, and I suspect this interest will stimulate additional research,” he says.
The mice in the study were treated with daily injections of neuregulin1 starting a week after experiencing laboratory-induced heart attacks.

Twelve weeks later, they showed evidence of better heart function, reductions in heart muscle scar size, and an increase in heart muscle cells, Kuhn says.
And unlike untreated controls, the treated mice showed no evidence of heart failure.

“Most of the [heart attack] related cell death had already occurred,” he says. “When we began the injections we saw replacement of a significant number of cardiomyocytes resulting in significant structural and functional improvements in the heart muscle.”
Researchers Studying Other Compounds
Neuregulin1 is not the first substance identified by the authors that promotes heart muscle cell growth.

In 2007, they reported that the protein periostin, found in the developing fetal heart and injured skeletal muscles, also induced cardiomyocyte production and improved heart function in rats.
Periostin cannot be injected, so the researchers developed patches infused with the compound, which were placed directly on the damaged area of the heart.

Kuhn says the two therapies may one day prove useful in the treatment of heart attack patients.
“During initial treatment patients might receive neuregulin injections, and once they are stable and out of the ICU they might be taken to the cath lab for a periostin patch,” Kuhn says.

But before that happens, the two treatments must be proven safe and effective in large animal and human studies.
The researchers recently completed a study of periostin in pigs, but the findings have not been published.

from webMD

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Concha Herrera Arroyo, from El Pais

The Cardiology department and the Area of Cell Therapy of Cordoba hospital Reina Sofia are carrying out clinical tests with patients who have suffered from a severe heart attack. With the implantation of the patient’s stem cells, the heart regenerates thus improving its wall motion, that is, its cardiac performance.

Indeed for the last four years, the Area of Cell Therapy of Cordoba hospital, led by haematologist Dr. Concha Herrera, has been implementing a therapy program with adult stem cells in patients with heart-related problems. However, this therapy is not a service the hospital offers yet. More specifically, at the end of 2007 the hospital ended a clinical test with patients who had suffered a severe myocardial infarction, that is, an obstruction of one of the main coronary arteries that stops the blood pump to the heart.

The test consisted of treating 30 people split into three groups of ten each at random. The first group was the control group, where patients received standard treatment for acute myocardial infarction; the second group was treated with stem cells directly implanted into the coronary artery affected using a catheterization; the third group was treated with a medicine called G-CSF, which makes cells move from the marrow to the blood, so that they get to the heart in a natural way, without having to do so through a catheter.

At the end of the test, the results revealed that the two groups treated without cells improved slightly, whereas patients transplanted with stem cells through the coronary arteries (vessels which bring the blood to the Herat muscle) did improve their ventricular function much more. This was interpreted as a significant decrease of the cardiac failure symptoms such as pain, fatigue and breathlessness when making small efforts.

Moreover, with this process it is possible to prevent some acute arrhythmias (change or irregularity in the rhythm of the heartbeat), which in many cases could result in the patient’s death. ‘However, it does not prevent a future heart attack’, Dr. Herrera assures.

In short, the stem cells transplanted from the marrow into the heart muscle have a double function: on the one hand they regenerate the heart cells, the cardiomiocites. In addition to this, they segregate a series of proangiogenic factors that produce blood vessels (angiogenesis) and can also produce the recruitment of stem cells that are in the myocardium itself.

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MIAMI, Fla. (Ivanhoe Newswire) — Some are calling it the next big frontier in cardiac treatment — injecting stem cells to regenerate the heart. But the experimental procedure means major surgery. Doctors are opening the door for heart patients who want to test the benefits of stem cells — without an operation.

One heart attack behind him, Max Eaton is now struggling with heart failure. He’s hoping stem cells are the answer to heal his ailing heart. “I happened to run into this article, which was the second or third time I heard about this stem cell research, and decided nothing ventured, nothing gained,” Eaton told Ivanhoe.

Instead of surgery, where the chest is opened and stem cells are injected into the heart, Alan W. Helman, M.D., an interventional cardiologist at the University of Miami, delivers the cells through a catheter that’s threaded through the groin. The spiral-shaped needle at the tip is screwed into the heart.

“We can now inject the cells exactly where we want to in the inside part of the heart, and we can do it in multiple different locations,” Joshua Hare, M.D., a cardiologist at the University of Miami, told Ivanhoe.
Doctors say it’s a more efficient way of delivering stem cells (…) Now, Eaton is hoping his wager on stem cells will pay off.

Doctors say Eaton is responding well to his stem cell treatment. All of the stem cells being used in this trial are adult stem cells. Studies have shown injecting heart attack patients with adult stem cells can increase the pumping power of the heart. However, it is not an approved treatment for re-growing heart tissue.

Full-length interview with Dr. Hare

from http://ivanhoe.com/channels/p_channelstory.cfm?storyid=22514

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