Certain stem cells in the spinal cord, when persuaded to differentiate into more healing cells and less scarring tissue after an injury, could lead to a new, non-surgical treatment for debilitating spinal-cord
injuries, according to researchers at MIT's Picower Institute for Learning and Memory.
The study, reported in the July issue of the journal PLoS Biology, was led by Konstantinos Meletis, and could lead to drugs that restore some amount of mobility to the 30,000 people around the world each year who sustain spinal-cord injuries.
Stem cells in a developing embryo differentiate into specialized tissues; in adults, they act as a repair mechanism, replacing specialized cells and helping to maintain blood, skin and intestinal tissues. Recent experiments show that the stem cells in the spinal cord, grown in the lab and injected into the site of an injury, can restore some function in paralyzed rodents and primates. There are very few neural stem cells in the adult spinal cord, just a layer of cilia-coated cells called ependymal cells.
"We have been able to genetically mark this neural stem cell population and then follow their behavior," Meletis said. "We find that these cells proliferate upon spinal cord injury, migrate toward the injury site and differentiate over several months."
By identifying for the first time where this subpopulation of cells is located, the researchers moved toward manipulating them with drugs to boost their repair abilities.
"The ependymal cells' ability to turn into several different cell types upon injury makes them very interesting from an intervention aspect: Imagine if we could regulate the behavior of this stem cell population to repair damaged nerve cells," Meletis said.
If scientists could genetically alter ependymal cells to produce more protective coating and less scar tissue after a spinal cord injury, they could perhaps avoid or reverse many of the damaging effects, the researchers wrote.