Pacemaker Cells from a Virus

The rhythm of a beating heart is controlled by a cluster of cells – known as the sinoatrial node – which act as a natural pacemaker. When these cells are damaged by disease or injury, an electronic pacemaker can restore a normal rhythm and prevent cardiac arrest, but the potential for mechanical complications still leaves a patient at risk.

Recently, a team of researchers discovered that regular heart cells could be converted into pacemaker cells using a gene known as Tbx18. This gene is activated in the embryo when the sinoatrial node is developing. By inserting it into a virus and then injecting the virus into the fully grown heart tissue of guinea pigs, the heart began to beat in rhythm with the newly formed pacemaker cells. In addition, the infected cells, which had taken on a tapered shape distinctive of pacemaker cells, retained that shape even after the Tbx18 was no longer present, indicating that the procedure could provide a lasting solution for damaged sinoatrial cells. Human trials are on the near horizon.