University of British Columbia and Vancouver researchers have discovered a new type of spinal cord stem cells that seems to possess the ability to regenerate components of the central nervous system in patients with spinal cord injuries and neurological diseases like Lou Gehring’s Disease. These newly characterized cells, called radial glial cells, have long projections that can find their way through brain tissue. They had never been observed in adult spinal cord, and these cells are instrumental in building the brain and spinal cord during embryonic development of the nervous system. Radial glial cells vastly outnumber other potential stem cells in the spinal cord and are much more accessible.
Stem cells can divide replacement cells and can also differentiate into more specialized types of cells. This differentiation can occur either during the growth of an organism or when there is a need to help replenish other cells. The search for spinal stem cells of the central nervous system has previously focused upon cells located deep within the spinal cord. Jane Roskams, 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, in collaboration 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.
Roskams noted, “That is exactly where you would want these cells to be if you want to activate them with drugs while minimizing secondary damage.” Roskams’ team also found that radial glial cells in the spinal cord express a unique set of genes that are also expressed in particular types of neural stem cells. Mutations in several of these genes can lead to human diseases, including those that target the nervous system. This 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.
Roskams continued, “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. 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.”