Scientists also have high hopes that one day healthy lab-grown heart cells can be used to replace the cardiomyocytes that die as a result of heart disease, the leading cause of death in the United States.
"Many forms of heart disease are due to the loss or death of functioning cardiomyocytes, so strategies to replace heart cells in the diseased heart continue to be of interest," notes Timothy Kamp, another senior author of the new PNAS report and a professor of cardiology in the UW School of Medicine and Public Health. "For example, in a large heart attack up to 1 billion cardiomyocytes die. The heart has a limited ability to repair itself, so being able to supply large numbers of potentially patient-matched cardiomyocytes could help."
"These cells will have many applications," says Xiaojun Lian, a UW-Madison graduate student and the lead author of the new study. The beating cells made using the technique he devised have, so far, been maintained in culture in the lab for six months and remain as viable and stable as the day they were created.
Lian and his colleagues found that manipulating a major signaling pathway known as Wnt -- turning it on and off at prescribed points in time using just two off-the-shelf small molecule chemicals -- is enough to efficiently direct stem cell differentiation to cardiomyocytes.
"The fact that turning on and then off one master signaling pathway in the cells can orchestrate the complex developmental dance completely is a remarkable finding as there are many other signaling pathways and molecules involved," says Kamp.
"The biggest advantage of our method is that it uses small molecule chemicals to regulate biological signals," says Palecek. "It is completely defined, and therefore more reproducible. And the small molecules are much less expensive than protein growth factors."
|Contact: Sean Palecek |
University of Wisconsin-Madison