Mouse tests show stem cells treat brain disease

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Human stem cells taken from both embryos and fetuses delayed a fatal brain and nerve disease in mice, moving throughout the brain to take on the jobs of damaged neurons, scientists reported on Sunday.

They said their study, published in the journal Nature Medicine, represents the first time a human embryonic stem cell has successfully treated a disease in an animal.

Dr. Evan Snyder of the Burnham Institute for Medical Research in La Jolla, California, who led the study, says his team hopes to move quickly to test their method in children with a fatal and incurable brain disease called Sandhoff disease.

Writing in the journal Nature Medicine, they also said their approach could lead to ways to treat a range of neurodegenerative diseases such as Parkinson's, Alzheimer's and amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig's disease.

For their study, Snyder and colleagues used mice bred with the equivalent of Sandhoff disease.

"Children with the disease have severe mental retardation and motor dysfunction, and death typically occurs in infancy," the researchers, who included a team at Oxford University in Britain, Yonsei University in Seoul, Korea and elsewhere, wrote in their report.

It is marked by inflammation that kills brain cells.

Snyder's team used both human embryonic stem cells, taken from days-old human embryos left over at fertility clinics, and human fetal stem cells.