Finding a Master Heart Cell

Scientists have identified a cardiac stem cell that could be the basis for new heart therapies.

Although embryonic stem cells have certainly grabbed most of the attention — and headlines — in the stem cell field in recent years, embryos aren't the only source of these versatile mother-cells. Political leanings aside, researchers are beginning to appreciate that many tissues in the body have their own stem cells. Blood cells, for example, derive from a single hematopoietic stem cell in the bone marrow, and now two groups of scientists from Boston report that they have identified a similar mother stem cell from which most heart cells arise. Working with mice, one group at Massachusetts General Hospital isolated a cardiac stem cell that generates the three major cell types of the mammalian heart, while another group at the hospital found a stem cell that gives rise to the contracting and smooth muscle cells found in heart vessel walls.