Future spine surgery, treatments for spinal cord injury may include stem cells

Sep 19 2011
Scientists have discovered a new type of stem cell in the spinal cord, opening the door to new possibilities in spine surgery and other treatments to repair spinal cord injuries and other diseases of the central nervous system.

Every day in the U.S., at least 30 people become paralyzed due to spinal cord injury, totaling to about 11,000 Americans every year, according to the Think First National Injury Prevention Foundation. More than 38 percent of these injuries are from car accidents. In people older than 45 years old, the most common cause is falling down. The higher up along the spinal column an injury takes place, the greater the potential loss of bodily control and sensation. There is no cure for this condition, and less than 1 percent of patients fully recover.

Up to 230,000 Americans are currently living with spinal cord injuries, according to Think First. The lifetime costs of having quadriplegia starting at age 25 can reach more than $2 million.

Stem cells are important because they can form different types of tissues throughout the body, which is central to the concept of regenerative medicine to replace dead or diseased structures. Pluripotent stem cells are able to divide into any type of cell, while multipotent stem cells can give rise to several, but not all, varieties, according to the National Institutes of Health (NIH). The latter class of stem cells are meant to last a lifetime, though each type of tissue has only a small number of them. Scientists who study regenerative medicine work to find ways of making these cells more active.

One special area of interest is neural stem cells (NSCs), which divide into the many cells of the central nervous system, including neurons, and are found in the brain. Studies on NSCs can create laboratory models that show the progression of illnesses such as Parkinson's disease, or lead to cell replacement therapy for such conditions.

Previous research suggested that there are cells in the spinal cord that behave like NSCs, but scientists knew little about them. Researchers at the Allen Institute for Brain Science in Seattle collaborated with others in Canada to search for these NSCs in the spinal cord. They conducted their investigation with the help of the Allen Spinal Cord Atlas, a public database of more than 17,000 genes found in the spinal cord cells of mice, and published their results in PLoS ONE.

The authors used the database to compare the genes of NSCs to those of other cells in the spinal cord. Their analyses found that a population of cells known as radial glia share 122 genes with NSCs. With further research, the scientists believe they may be able to manipulate these radial glia, located at the edge of the spinal cord, into making new cells to repair an injury.

In addition to treating injured spinal cords, the researchers believe this study could also have implications for neurodegenerative diseases, such as spinal muscular atrophy, multiple sclerosis and Lou Gehrig's disease, an illness that affects 5,600 new patients every year.