Scientists discover new type of spinal cord stem cell

Research provides new target for regenerating parts of the central nervous system

A group led by a University of British Columbia and Vancouver Coastal Health scientist has discovered a type of spinal cord cell that could function as a stem cell, with the ability to regenerate portions of the central nervous system in people with spinal cord injuries, multiple sclerosis or amyotrophic lateral sclerosis (Lou Gehrig's disease).

The radial glial cells, which are marked by long projections that can forge through brain tissue, had never previously been found in an adult spinal cord. Radial glia, which are instrumental in building the brain and spinal cord during an organism's embryonic phase, vastly outnumber other potential stem cells in the spinal cord and are much more accessible. Their findings were published online this week in PLoS One.

Stem cells have the capability of dividing into more specialized types of cells, either during the growth of an organism or to help replenish other cells. Scientists consider stem cells a promising way to replace injured or diseased organs and tissues.

The search for spinal stem cells of the central nervous system has until now focused deep in the spinal cord. Jane Roskams, a professor in the UBC Dept. of Zoology, broadened the search by using genetic profiles of nervous system stem cells that were developed and made publicly accessible by the Allen Institute for Brain Science in Seattle.

Roskams, collaborating with researchers at the Allen Institute, McGill University and Yale University, found cells with similar genes - radial glial cells - along the outside edge of spinal cords of mice.

"That is exactly where you would want these cells to be if you want to activate them with drugs while minimizing secondary damage," says Roskams, a member ICORD (International Collaboration on Repair Discoveries) and the Brain Research Center, both partnerships of UBC and the Vancouver Coastal Health Research Institute.

Roskams' team also found that radial glial cells in the spinal cord share a unique set of genes with other neural stem cells. Several of these - when mutated - can lead to human diseases, including some that target the nervous system. That discovery opens new possibilities for potential gene therapy treatments that would replace mutated, dysfunctional spinal cord cells with healthier ones produced by the radial glial cells.

"These long strands of radial glial cells amount to a potentially promising repair network that is perfectly situated to help people recover from spinal cord injuries or spinal disorders," Roskams says. "For some reason, they aren't re-activated very effectively in adulthood. The key is to find a way of stimulating them so they reprise their role of generating new neural cells when needed."