Skin cells converted to heart muscle cells

By simply switching on three critical genes, scientists turned mouse skin cells into heart muscle cells. So far, this has been only possible with embryonic cells.

If the technique works in humans, it could provide new heart muscle for the millions of people who suffer from heart failure each year. It is also a new example of a process called 'transdifferentiation', in which adult cells take on an entirely different identity.

Once it is damaged, heart muscle cannot repair itself. Further damage makes the heart weaker, eventually causing it to fail. In the United States, 5 million patients have heart failure, but only 2,000 heart transplants are performed each year.

A team of scientists searched for genes that are expressed at high levels in heart muscle cells, and then narrowed the list down to three that were sufficient to convert another type of heart cell, structural cells called cardiac fibroblasts, into heart muscle cells. Activating those three genes was sufficient to convert the cardiac fibroblasts or similar cells in skin to heart muscle cells. When implanted into mouse hearts, the cells made from cardiac fibroblasts contracted normally.

The results raise the possibility that a similar approach could be used to convert cardiac fibroblasts already in the heart to muscle cells, without the need for cell transplants. The team is now investigating whether the same three genes are enough to switch cell identity in humans. 

Adapted from an article by Heidi Ledford in Nature. IStockphoto