Researchers at the Cedars-Sinai Heart Institute had another idea. They knew a gene called Tbx18 is normally activated during the sinoatrial node’s development, when an embryo is forming. So they set out to add Tbx18 into a functioning, fully grown heart. To do it, they inserted the code for this gene into a virus, which they then inserted into the hearts of guinea pigs. The infected hearts beat according to this newly formed pacemaker, Eduardo Marbán and colleagues report in Nature Biotechnology. It also worked in a Petri dish.
The team used ventricular cells, one of three main types of heart cells (along with pacemaker cells and atrial cells). The infected cells changed their appearance, taking on a distinctive tapered shape, and this lasts even after the Tbx18 has faded away. That suggests it’s a permanent structural change, which means this could be a lasting treatment for diminished sinoatrial cells.
“This technology thus represents a promising alternative to electronic pacing devices,” Marbán et al. write. Longer-term experiments are still needed, but the work so far is promising, they say.