A "heartbreak" gene that stops the heart recovering from injury has been identified by scientists.
Experts believe regulating the Meis1 gene could lead to revolutionary new treatments for heart failure.
The gene normally kicks in soon after birth to stop heart cells dividing uncontrollably. But this also prevents the adult heart from regenerating and repairing itself after damage, for instance by heart attacks.
Laboratory experiments show that deleting Meis1 re-activates the repair process in the hearts of adult mice without harming heart function.
Lead scientist Dr Hesham Sadek, from the University of Texas Southwestern Medical Center in the US, said: "Meis1 is a transcription factor, which acts like a software program that has the ability to control the function of other genes.
"In this case, we found that Meis1 controls several genes that normally act as brakes on cell division. As such, Meis1 could possibly be used as an on/off switch for making adult heart cells divide. If done successfully, this ability could introduce a new era in treatment for heart failure."
Heart failure occurs when the heart is too weak to pump blood around the body efficiently, leading to exhaustion and the inability to perform even simple tasks such as walking to the shops. It often follows the damage inflicted by heart attacks.
The new research is reported today in the online edition of the journal Nature.
In 2011, Dr Sadek's team showed that the newborn mammalian heart is capable of vigorous regeneration after suffering injury. As a newborn animal develops it quickly loses the ability to repair its heart.
Meis1 offers a possible alternative approach to experimental heart failure treatments which currently focus on stem cells, said Dr Sadek.