Washington – Injections of human stem cells seem to directly repair some of the damage caused by spinal-cord injury, according to research that helped partly paralyzed mice walk again.
The experiment, reported Monday, isn’t the first to show that stem cells offer tantalizing hope for spinal-cord injury – other scientists have helped mice recover too.
But the new work went an extra step, suggesting that the connections that the stem cells form to help bridge the damaged spinal cord are key to recovery. Surprisingly, they didn’t just form new nerve cells. They also formed cells that create the biological insulation that nerve fibers need to communicate. A number of neurological diseases, such as multiple sclerosis, involve loss of that insulation, called myelin.
“The actual cells that we transplanted, the human cells, are the ones that are making myelin,” said lead researcher Aileen Anderson of the University of California, Irvine. “We’re extremely excited about these cells.”
The research was reported in Monday’s issue of Proceedings of the National Academy of Sciences.
Stem cells are building blocks that turn into different types of tissue. Embryonic stem cells in particular have made headlines recently, as scientists try to harness them to regenerate damaged organs or other body parts. They essentially are a blank slate, able to turn into any tissue given the right biochemical instructions.
The researchers injured the spinal cords of mice and nine days later injected some with the human neural stem cells.
Four months later, the treated mice could again step normally with their hind paws. Mice given no treatment or an injection with an unrelated cell showed no improvement. Much more research must be done before testing stem cells in people with spinal-cord injuries, Anderson said. One question is how soon after an injury cells must be administered to have any effect.
