Stem cells bring hope for brain disorder
Mouse trials show small gain from implanted human cells.
A company set to begin clinical trials of a stem-cell treatment for a fatal brain disease has announced that the treatment boosts survival in a mouse model.
The company, StemCells of Palo Alto, California, received approval from the US Food and Drug Administration in October 2005 to use human neural stem cells to treat infants with neuronal ceroid lipofuscinosis, or Batten disease. Infants with this hereditary disorder lack enzymes to break down a chemical called lipofuscin. In those affected, the chemical kills brain cells, and eventually proves fatal.
StemCells plans to give newborns neural stem cells that make enzymes to break down lipofuscin. The neural stem cells, made from cells harvested from human fetuses, are more developed than embryonic stem cells, which can give rise to all the cell types of the body, but more flexible than adult brain cells.
On 1 July, Nobuko Uchida, a scientist with StemCells, presented data on tests in mice at the meeting of International Society for Stem Cell Research in Toronto, Canada.
Few days more
Affected mice were implanted with human neural stem cells. Treated mice fared slightly better than the control group, living for about 32 days instead of 25. The treated mice made low levels of the protective enzyme, had lower levels of the toxic lipofuscin in their brains, and had many more surviving brain cells than the untreated mice.
"It's nice because they understand the mechanism, and that is lacking in so many of these animal experiments with human cells," says Sean Morrison, a biologist at the University of Michigan in Ann Arbor.
The company has not yet treated human patients; an ethical review board only approved human trials in March. It is still unclear how much the treatment could help people, given the small boost it gave to the mice.
"That is the outstanding question," Uchida says.
Other scientists are hopeful. "If I had a kid with this disease it would be encouraging to me that people are addressing the problem and starting to develop therapies that could make a difference," Morrison said.
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