Growth Factor Powered Neural Stem Cells Restore Myelin Sheath and Rescue Rats from Spinal Cord Injury
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NR-08-05 (07/20/05). For more information, please contact Sara Harris at (202) 462-6688 or sharris@sfn.org.
GROWTH FACTOR POWERED NEURAL STEM CELLS RESTORE MYELIN SHEATH AND RESCUE RATS FROM SPINAL CORD INJURY
WASHINGTON, DC July, 20, 2005 - Scientists have successfully repaired spinal cord injury in rats by restoring the lost myelin sheath of spinal cord nerve fibers. The finding may help quicken the pace of cell transplant based therapeutic approaches to repair spinal cord injuries in humans.
Replacement of the damaged cells with stem cells has long been considered the holy grail for treating spinal cord injury. “These findings suggest the possibility that transplantation therapy using a subset of neural stem cells and neurotrophic factors might improve functional recovery in human spinal cord injury,” says Michael Selzer, MD, PhD, professor of neurology at the University of Pennsylvania Medical Center, Philadelphia.
The new study appears in the July 27 issue of The Journal of Neuroscience. “These results should enable more detailed and directed design of cellular based therapies for the repair of the injured spinal cord,” says study author Scott R. Whittemore, PhD, of the Kentucky Spinal Cord Injury Research Center at the University of Louisville School of Medicine.
Spinal cord injuries due to trauma, inflammation, or infection affect 250,000 people within the U.S and costs about $4 billion every year in patient care management, according to the National Institute of Neurological Disorders.
One of the major reasons for the sensory and motor dysfunction resulting from spinal cord injury is the death of a group of cells called oligodendrocytes. These cells make the insulating myelin sheath that wraps itself around nerve fibers and is responsible for the rapid and proper conduction of nerve impulses. When oligodendrocytes die after traumatic spinal cord injury, the nerve fibers are left without their armor of myelin and can no longer conduct electrical signals normally.
Whittemore and his team of researchers genetically modified a subset of neural stem cells, or glial restricted precursor cells (GRPs), from the rat embryonic spinal cord to express a novel growth factor, a multineurotrophin, D15A. This multineurotrophin possesses the dual activity of two important growth factors, NT3 and BDNF that can coax immature neural stem cells to mature and specialize into oligodendrocytes. The genetically modified neural stem cells were then grafted into the injured spinal cords of rats. Aided by the multineurotrophin, the grafted GRPs successfully matured into oligodendrocytes. The oligodendrocytes in turn remyelinated the nerve fibers and rescued two-thirds of the injured rats from the devastating hind limb paralysis.
Whittemore is a member of the Society for Neuroscience, an organization of more than 36,000 basic scientists and clinicians who study the brain and nervous system. The Society publishes The Journal of Neuroscience. Whittemore can be contacted at:swhittemore@louisville.edu .
