Jan 15, 2004
Stem-like cells have been used to restore proper nerve insulation in the brains of mice, a step towards new cellular treatments for such diseases as multiple sclerosis.
The research, led by scientist Steven Goldman of the University of Rochester Medical Center in New York, is considered a milestone for the use of stem cells and related cells known as progenitors to treat myelin diseases.
"The results are much better than we expected," says Goldman. "The percentage of cells in this experiment that began producing myelin is extraordinary, probably thousands of times as many as in previous experiments."
Essential for transmission
Myelin is a fatty substance that insulates nerves and allows rapid and efficient transmission of impulses along nerve cells.
Damaged myelin disrupts impulses and is a symptom of such diseases as multiple sclerosisódiseases that involve imperfect growth or development of the myelin sheath.
In an attempt to remyelinate the brain cells of mice, Goldman and colleagues injected them with specific "progenitor" cells.
These cells become oligodendrocytes, which are cells that make myelin.
The researchers found that the progenitor cells quickly migrated throughout the brain and then developed into oligodendrocytes.
"These cells infiltrate exactly those regions of the brain where one would normally expect oligodendrocytes to be present," says Goldman. "As they spread, they begin creating myelin which wraps around and ensheaths the axons."
Goldman says that while scientists have used other methods to remyelinate cells in small portions of the mouse brain, the remyelination seen in this study is much more extensive.
He estimates that about 10% of the axons in the mouse brains were remyelinated, compared to one percent in previous studies.
In addition to multiple sclerosis, diseases such as diabetes, heart disease and high blood pressure also involve myelin problems.
"The implantation of oligodendrocyte progenitors could someday be a treatment strategy for these diseases," says Goldman.
While the experiment represents an advance for nerve reinsulation, Goldman says that further studies are necessary before considering tests in humans.
Currently he's attempting to remyelinate not just the brain but also the entire nervous system in mice.
The research is reported in the journal Nature Medicine
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