Molecules fix heart attack damage
Sunday 8th September 2013, 6:10PM BST.
Artificial genetic molecules can be used to repair damage caused by heart attacks, scientists have shown.
The new technology, successfully tested in mice, opens up the possibility of hearts healing themselves.
Treatment consists of a single injection of the messenger RNA molecule, which contains the code for making a growth protein.
Mice given the molecule within 48 hours of a heart attack showed markedly improved survival and heart function. The effect appeared to be long-lasting.
Study leader Professor Kenneth Chien, from the Karolinska Institute in Sweden, said: “This is the beginning of using the heart as a factory to produce growth factors for specific families of cardiovascular stem cells, and suggests that it may be possible to generate new heart parts without delivering any new cells to the heart itself.”
Messenger RNA (mRNA) acts like a memory stick, transferring DNA instructions to protein-building machinery in the cell.
Because the mRNA used in the research was synthetic, it escaped the immune system defences that would normally treat it as a foreign invader.
The molecule caused heart stem cells to alter their development pathway. Instead of generating harmful scar tissue, they began to rebuild vital blood vessels within the heart.
There was also some evidence of renewed heart muscle, though not enough to have contributed to the improved outcomes.
But the scientists believe further work may lead to significant heart muscle reconstruction.
The research is reported in the latest edition of the journal Nature Biotechnology.
“This moves us very close to clinical studies to regenerate cardiovascular tissue with a single chemical agent without the need for injecting any additional cells into the heart,” said Prof Chien.