This sphere of stem cells (marked red with blue centres) holds great potential for stem cell research and regenerative medicine. Until recently any damage to the heart following a heart attack or lack of oxygen was considered irreparable. But scientists have discovered that, tucked away in the heart itself are stem cells like these that could be reprogrammed to become new heart cells. These rat heart stem cells are growing in a lab culture dish, where they cluster into a cardiosphere. Cells around the sphere’s perimeter are producing a protein called CD90 (labelled green) and spreading across the dish. Using soluble growth factors, scientists can influence them to turn into mature heart cells. But although stem cells might in future have the power to transform the way we treat disease, researchers sound a note of caution. Many questions need answering before such therapies reach the clinic.
Written by Caroline Cross