British scientists discover new way to heal heart tissue

HEALTH - For decades scientists and doctors have thought damage to the human heart was irreparable, beyond repairing. Minor damage to the heart would heal over time but major damage to the heart was considered absolutely permanent.

British scientists however are now reporting the discovery of a protein molecule that helps regenerate heart tissue, including damage once thought to be permanent.

Dr Peter Weissberg, medical director of the British Heart Foundation, spoke at a press conference 2 days ago to reveal that while the heart has no capacity to heal itself, the protein they discovered can fix the heart... as a metaphor it is similar to a team of mechanics fixing a car.

"We have always believed that, but this research suggests that this is not the case. We think we have discovered a natural process that brings about repair of the heart. Until now, this has been science fiction. We are trying to understand what the triggers are for this process. The cells that are capable of this healing are already there in the epicardium. They just need to be tweaked and primed and the effect scaled up. If this works, we might be able to heal cardiac injury caused by heart attacks without resorting to stem cells."

Epicardial cells become cardiomyocytes, so says the research published online June 8th, 2011 in Nature. The team of scientists decided to investigate progenitor cells from the epicardium, as it is these cells in the embryo that become cardiomyocytes. "During pregnancy, these cells contribute to heart muscle and coronary blood vessels. In the adult, these cells sit in a dormant state. We think there is a possibility that these cells might be able to be activated to switch on the embryonic gene that causes them to make new myocardial cells."

In the lab the researchers restored the embryonic potential of these cells in mice by treating them with a peptide molecule called thymosin 4. When damage to the heart occurred, a booster dose of T4 was given. After treatment with T4, the epicardial progenitor cells transformed into new cardiomyocytes and integrated with existing healthy muscle... thus healing the damaged tissue.

"After treatment, the cells home to the site of injury and can couple and contract in the same way as normal cardiac myocytes, so structurally and functionally they represent a bone fide source of new heart-muscle cells."

The cells also reduced scarring, remodeling and showed a 25% improvement in ejection fraction. The researchers are now testing T4 in human cells to see if they can replicate these results.

"But even if we could achieve a 10% improvement, that would make a major difference to quality of life," says Weissberg.

If you like heart / cardiology related news check out theheart.org.