Stem cells aid nerve cells by contact

STOCKHOLM, Sweden, Feb. 2 (UPI) -- A Swedish-led team of medical scientists says it has discovered how transplanted stem cells can connect with and rescue threatened neurons and brain tissue.

Researchers from Sweden's Karolinska Institute, the Sanford-Burnham Medical Research Institute in La Jolla, Calif., Harvard Medical School in Boston and Belgium's Universite Libre de Bruxelles said the finding might lead to new treatments for brain damage and neurodegenerative diseases.

A possible strategy for treating neurodegenerative diseases is to transplant stem cells into the brain to prevent existing nerve cells from dying. That method has proved successful in different models, but the mechanisms behind it are still unknown.

In the new study, researchers showed stem cells transplanted into damaged or threatened nerve tissue quickly establish direct channels, called gap junctions, to the nerve cells. The stem cells actively bring diseased neurons back to health via "cross-talk" through gap junctions, the connections between cells that allow molecular signals to pass back and forth.

The study found the nerve cells were prevented from dying only when gap junctions were formed.

"Many different molecules can be transported through gap junctions," Dr. Eric Herlenius, who led the study, said. "This means that a new door to the possible future treatment of neuronal damage has been opened, both figuratively and literally."

The research is reported in the early online edition of the Proceedings of the National Academy of Sciences.