Scientists have long thought that the cells that ultimately give rise to the heart all respond to the same cue before turning into the muscle tissue of this vital organ.
But now researchers at the University of North Carolina at Chapel Hill's School of Medicine have shown that not all heart cells are created equal; in response to one signal to differentiate, some will act, while others lie in wait.
The discovery, made in frogs, or Xenopus, may lead to advances in understanding – and ultimately treating – congenital heart disease and heart attacks.
“This is profoundly important work,” said Cam Patterson, M.D., professor of medicine, chair of cardiology and director of the Carolina Cardiovascular Biology Center. “Not only does it tell us about how stem cells differentiate to create the heart, but it provides us with knowledge that may very well help us to repair heart muscle after a heart attack.”
The study appears today (April 14) in the online issue of the journal Developmental Cell. It will be published in the print edition of the journal April 15.
To investigate the development of the heart, the researchers focused on a gene – called CASTOR – that has been implicated in stem cell differentiation in the fruit fly. Here, they manipulated the gene in a different organism – frogs.
“The study of the heart has its longest history in frogs. In fact, most of what we know about heart development has been learned in frogs,” said Frank Conlon, Ph.D., assistant professor of genetics in the UNC School of Medicine and senior author of the study.
First, Conlon and colleagues used small strings of nucleotides, or oligonucleotides, to mask the portions of genetic material that call for the assembly of the CASTOR protein in frogs. Once CASTOR was depleted in the frog embryos, the scientists watched to see how the heart would develop.