Rodent heart cells have been converted by gene therapy to specialized heart pacemaker cells, reports a paper published online this week in Nature Biotechnology. If this approach can be optimized and adapted for use in humans, it could eventually provide an alternative to artificial pacemakers.

A small population of specialized cells located in the sinoatrial node of the heart controls the pacing of heart beats. If the function of these cells wanes, owing to disease or aging, the heartbeat can become too slow or dysrythmic to sustain life. Currently, the only available therapy requires implantation of an artificial pacemaker.

Eduardo Marban and colleagues tested a handful of genes that are critically important for the formation of natural pacemaker cells during embryonic development. They show that one of these genes, when delivered to rodent heart cells by an inactive virus, converts the cells to functional pacemaker cells.