When scientists at the University of Utah injected human stem cells into mice disabled by a condition similar to multiple sclerosis, they expected the cells to be rejected by the animals' bodies. It turned out that the cells were indeed rejected, but not before they got the mice walking again. The unexpected finding could have major implications for human MS sufferers.
In multiple sclerosis, the body's immune system attacks the myelin sheath that covers and insulates nerve fibers in the spinal cord, brain and optic nerve. With that insulation gone, the nerves short-circuit and malfunction, often compromising the patient's ability to walk – among other things.
In the U Utah study (which was begun at the University of California, Irvine) human neural stem cells were grown in a Petri dish, then injected into the afflicted mice. The cells were grown under less crowded conditions than is usual, which reportedly resulted in their being "extremely potent."
As early as one week after being injected, there was no sign of the cells in the animals' bodies – evidence that they had been rejected, as was assumed would happen. Within 10 to 14 days, however, the mice were walking and running. After six months, they still hadn't regressed.
This was reportedly due to the fact that the stem cells emitted chemical signals that instructed the rodents' own cells to repair the damaged myelin. Stem cells grown under the same conditions have since been shown to produce similar results, in tests performed by different laboratories.
Additional mouse trials are now planned to assess the safety and durability of the treatment, with hopes for human clinical trials down the road. "We want to try to move as quickly and carefully as possible," said Dr. Tom Lane, who led the study along with Dr. Jeanne Loring from the Center for Regenerative Medicine at The Scripps Research Institute. "I would love to see something that could promote repair and ease the burden that patients with MS have."
A paper on the research was recently published in the journal Stem Cell Reports.
Source: University of Utah
