May 28, 2013
Breakthrough In Use Of Stem Cells To Treat Spinal Cord Injuries
Brett Smith for redOrbit.com - Your Universe Online
For years, stem-cell based therapies have been described as a potential way to treat spinal cord injuries in humans, and a new study published in the journal Stem Cell Research and Therapy describes an exciting step forward in that pursuit.
According to the report, a single injection of human stem cells was able to induce neuronal regeneration and improved mobility in rats that were afflicted with a severe spinal cord injury.
"This is exciting, especially because, historically, there has been very little to offer patients with acute spinal cord injury," said co-author Dr. Joseph Ciacci, chief of neurosurgery for the Veterans Affairs San Diego Healthcare System.
The research team observed as the injected rats regained motor skills and experienced a loss of the uncontrollable muscle spasms typically associated with traumatic spinal cord injury.“¯The stem cell therapy also improved the integrity of the spine, allowing for signals to pass through the injury location.
"The primary benefits were improvement in the positioning and control of paws during walking tests and suppression of muscle spasticity," said Dr. Martin Marsala, a medical doctor and professor at the University of California, San Diego and a specialist in treating spinal injury-related disorders.
In the study, the researchers sorted 42 three-month-old female rats with recently induced spinal compression injuries into one of three groups. The first group received a stem cell injection, the second group received a placebo injection, and the third group was left alone.
Weekly assessments were performed on the three groups over eight weeks following the treatment using a combination of tests. The rats´ motor and sensory functions, presence of muscle spasticity and rigidity were all tested. Using MRI images, visual inspections, and staining techniques, the team also assessed how well the grafted cells had integrated into the rat spines.
The team found that the stem-cell treated mice experienced a progressive improvement in their walking ability, a reduction in muscle spasticity, and improved sensitivity to mechanical and thermal stimuli. The researchers also saw lasting improvements in the structural reliability of previously injured spinal cord sections.
According to Marsala, the grafted cells appear to be both stimulating the rodents´ neuronal regeneration and partially replacing the neurons that were lost.
"Grafted spinal stem cells are rich source of different growth factors which can have a neuroprotective effect and can promote sprouting of nerve fibers of the host neurons,” he explained.
“We have also demonstrated that grafted neurons can develop contacts with the host neurons and, to some extent, restore the connectivity between centers, above and below the injury, which are involved in motor and sensory processing."
The scientists conducted their experiments using a line of human embryonic stem cells that have been approved for human trials. Marsala said scientists need to develop neural precursors from stem cells, which would eliminate the need for immunosuppression treatments that prevented the rats´ bodies from attacking the foreign cells in his team´s study.
According to the scientists, the next step will be to conduct a small phase 1 trial in order to test for safety and effectiveness with patients who have suffered a thoracic spinal cord injury within the previous one or two years, and who have no motor or sensory function at or below the spinal injury site.