Researchers at Children's Hospital of Pittsburgh have discovered that adult, or post-natal, stem cells have the same ability as embryonic stem cells to multiply, indicating that post-natal stem cells may play an important therapeutic role.

Adult and post-natal stem cells are often overlooked in favor of embryonic stem cells in the national debate over the therapeutic use of stem cells.

Until now, it has been generally believed that embryonic stem cells had a greater capacity to multiply than post-natal stem cells, making them more desirable to research as a potential treatment, according to Johnny Huard, director of the Growth and Development Laboratory at Children's Hospital of Pittsburgh.

"Scientists have typically believed that adult or post-natal stem cells grow old and die much sooner than embryonic stem cells, but this study demonstrates that is not the case," said Huard, senior author of the study. "The entire world is closely following the advances in stem cell research, and everyone is interested in the potential of stem cells to treat everything from diabetes to Parkinson's disease. But there are also many ethical concerns surrounding the use of embryonic stem cells, concerns that you don't have with post-natal or adult stem cells. My belief is that this study should erase doubts scientists may have had about the potential effectiveness of post-natal stem cells."

Researchers from Children's and the University of Pittsburgh in Huard's laboratory were able to expand post-natal stem cells to a population level comparable to that reached by researchers using embryonic stem cells. Previous research has found that embryonic stem cells could undergo more than 200 population doublings before the cells began to die. A population doubling is a method of measuring the age of a population of cells.

Bridget Deasy, PhD, at the University of Pittsburgh School of Medicine, discovered that a unique population of muscle-derived stem cells was able to undergo more than 200 population doublings, as well. These post-natal cells were able to undergo population doublings while maintaining their ability to regenerate muscle in an animal model, a key finding indicating that they could maintain their treatment potential.

This ability to self-replenish is significant because in order for stem cells to be used for treatment, a large quantity of the cells would be required.

There also may be important advantages to post-natal stem cells when it comes to autoimmunity, according to Huard.
The use of embryonic stem cells could be complicated by issues of rejection, with the recipient's immune system rejecting the foreign embryonic stem cells. With post-natal stem cells taken from the recipient and then reintroduced in an autologous manner, rejection would not be an issue.

Source: Children's Hospital of Pittsburgh, 2005


XagenaMedicine2005