Researchers at Children's Hospital Boston believe finding these stem cells, located on the surface of the heart, or epicardium, may lead to ways to regenerate injured heart tissue. Earlier research had shown that epicardial cedlls give rise to smooth muscle and endothelial cells during coronary vessel formation. This finding that epicardial cells might turn into cardiomyocytes came as a surprise.
According to a press release, the researchers had previously found that two types of stem cells (progenitors) marked by activity of the genes Nkx2-5 and IsI1 form many components of the heart. In this new study, the team identified another progenitor, marked by expression of a gene called Wt1, which gives rise to heart muscle cells.
This finding, published online by the journal Nature on June 22, comes on the heels of parallel cardiac stem cell discoveries in 2006 at both Children's and Massachusetts General Hospital.
Not only do the progenitor cells marked by Wt1 expression differentiate into cardiomyocytes, they also turn into smooth muscle cells, endothelial cells and fibroblasts (found in connective tissue), researchers said.
When a person suffers from heart failure, he loses the cardiomyocytes and the only way to reverse heart failure is to make more of these cells, which could now be possible through this new discovery, scientists believe.
