Proteins protect against heart attack

PILLS that keep the body's repair system on constant alert could limit damage from heart attacks.

Paul Riley at University College London and colleagues identified a rich source of dormant stem cells in the epicardium, the innermost layer of the sac which surrounds the heart. They also found that thymosin beta-4, a peptide naturally produced by the body, could reawaken and mobilise these stem cells to repair heart damage.

Mice in the lab were more likely to survive a heart attack if they had received daily injections of thymosin beta-4 a week beforehand. Their stem cells were active within 24 hours of the attack instead of a week, and they produced larger numbers. The treated mice regrew more heart muscle than the untreated mice and their hearts pumped better

Constantly priming the same reservoirs of stem cells in people could help them survive heart attacks. "We envisage taking an oral tablet to keep these cells in a primed state, so if you did have a heart attack, you might be able to better repair your heart," says Riley.