A three-dimensional, reconstructed magnetic resonance image (upper) shows a cavity caused by a spinal injury nearly filled with grafted neural stem cells, colored green. The lower image depicts neuronal outgrowth from transplanted human neurons (green) and development of putative contacts (yellow dots) with host neurons (blue).
Stem Cell Injections Improve Spinal Injuries in Rats
An international team led by researchers at the University of California, San Diego School of Medicine reports that a single injection of human neural stem cells produced neuronal regeneration and improvement of function and mobility in rats impaired by an acute spinal cord injury (SCI).
The findings are published in the May 28, 2013 online issue of Stem Cell Research & Therapy.
Martin Marsala, MD, professor in the Department of Anesthesiology, with colleagues at UC San Diego and in Slovakia, the Czech Republic and The Netherlands, said grafting neural stem cells derived from a human fetal spinal cord to the rats’ spinal injury site produced an array of therapeutic benefits – from less muscle spasticity to new connections between the injected stem cells and surviving host neurons.
“The primary benefits were improvement in the positioning and control of paws during walking tests and suppression of muscle spasticity,” said Marsala, a specialist in spinal cord trauma and spinal injury-related disorders. Spasticity – exaggerated muscle tone or uncontrolled spasms – is a serious and common complication of traumatic injury to the spinal cord.
The human stem cells, said the scientists, appeared to vigorously take root at the injury site.
“In all cell-grafted animals, there was robust engraftment, and neuronal maturation of grafted human neurons was noted,” Marsala said. “Importantly, cysts or cavities that can form in or around spinal injuries were not present in any cell-treated animal. The injury-caused cavity was completely filled by grafted cells.”
The rats received the pure stem cell grafts three days after injury (no other supporting materials were used) and were given drugs to suppress an immune response to the foreign stem cells. Marsala said grafting at any time after the injury appears likely to work in terms of blocking the formation of spinal injury cavities, but that more work would be required to determine how timing affects functional neurological benefit.
