NEW YORK, Nov 03 (Reuters Health) -- Scientists have moved one step
closer to
using neural stem cells (NSC) from humans to combat neurodegenerative
diseases,
according to two studies in the November issue of Nature Biotechnology.
In the studies, researchers isolated NSCs from human fetal tissue.
Previously, these types
of cells had only been isolated from rodents.
Neural stem cells give rise to more specialized cells of the central
nervous system. These
cells, found in developing or degenerating regions of the central
nervous system, are able
to differentiate into a variety of cell types. The stem cells "could
ultimately be used in cell
replacement and gene therapies for patients with neurodegenerative
disease or paralysis,"
according to a statement from the journal editors.
The first study, by Dr. Jonathan D. Flax of Harvard Medical School in
Boston,
Massachusetts, and colleagues, showed that clones of NSCs from fetal
brain tissue
regenerate repeatedly in a Petri dish and differentiate into all types
of nerve cells when
treated with growth factors or manipulated genetically.
For example, the cells followed "established migratory pathways to
disseminated central
nervous system regions" and differentiated into appropriate cell types
when transplanted
into the brains of newborn mice, report the study authors.
According to an accompanying editorial, this study "provides strong
evidence that human
NSCs are able to perform in vitro (in lab testing) and in vivo (in
studies of animals) all the
critical functions previously described for their rodent counterparts."
Researchers in a second study also isolated NSCs from fetal tissue and
incorporated
them into the brains of rats. Results showed that the cells migrate to
the major regions of
the brain and differentiate into three main nerve cell types.
According to Oliver Brustle and colleagues with the National Institutes
of Health, the
University of Bonn Medical Center in Germany and the Institute Pasteur
in France, their
research may be used "as a prelude to the design of therapeutic
strategies for
neurodegenerative diseases."
SOURCE: Nature Biotechnology 1998;16:1033-1044.