When embryonic stem cells are being coaxed toward becoming brain cells that could be transplanted, that lipid, ceramide, helps eliminate cells that could later form tumors called teratomas, researchers say in the Nov. 22 issue of The Journal of Cell Biology.

"The body has amazing mechanisms to eliminate cells that are no longer wanted and that if they remain will harm the body by developing into tissues that are not meant to be," says Dr. Erhard Bieberich, MCG biochemist and the study's lead author. "Our studies show this particular mechanism can help stem cells safely become the cells we want them to be."

"This is another approach to controlling differentiation and getting the cell types that you want," says Dr. Brian G. Condie, developmental neurobiologist at UGA and MCG and senior author on the paper.

While it's the ability of embryonic stem cells to make all types of tissue from brain cells to heart cells that has scientists worldwide exploring their potential to treat devastating diseases, their pluripotency can also be harmful if uncontrolled, says Dr. Bieberich.

Drs. Bieberich and Condie demonstrated in the Aug. 4, 2003 issue of The Journal of Cell Biology that a natural process occurs during development to eliminate excessive and potentially harmful cells. Just before neurons begin forming, there is a massive production of proteins and up-regulation of lipids. At that point, about half the cells have high levels of the protein PAR-4, half have high levels of the protein, nestin, and all have high levels of ceramide.

The researchers found cells that inherited PAR-4 died when partnered with ceramide. Fortunately, the nestin-bearing cells are most likel
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Contact: Toni Baker
tbaker@mcg.edu
706-721-4421
Medical College of Georgia
29-Nov-2004