Human primitive spinal cord cells delayed symptoms and paralysis by a week when implanted in the spinal cord of rats destined to develop amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, researchers from Johns Hopkins report.
Amyotrophic lateral sclerosis is a progressive, fatal neurological disease affecting as many as 20,000 Americans with 5,000 new cases occurring in the United States each year. The disorder belongs to a class of disorders known as motor neuron diseases. ALS occurs when specific nerve cells in the brain and spinal cord that control voluntary movement gradually degenerate. The loss of these motor neurons causes the muscles under their control to weaken and waste away, leading to paralysis. ALS manifests itself in different ways, depending on which muscles weaken first. Symptoms may include tripping and falling, loss of motor control in hands and arms, difficulty speaking, swallowing and/or breathing, persistent fatigue, and twitching and cramping, sometimes quite severely. ALS strikes in mid-life. Men are about one-and-a-half times more likely to have the disease as women.
The human neuronal stem cells were obtained from embryos by scientists at biotech company Neurostem Inc., transferred to Hopkins and implanted into the lower part of the rats' spinal cords about a month before the animals usually develop muscle control problems characteristic of ALS. The treatment delayed the animals' death by 11 days. Research associate Leyan Xu, Ph.D., is scheduled to present the results Oct. 23 at the annual meeting of the Society for Neuroscience in San Diego.
"This rat model of ALS progresses very rapidly -- within two or three weeks of symptoms appearing, the rats have to be euthanized -- so the delay we saw is quite significant," says the study's senior author, Vassilis Koliatsos, M.D., associate professor of pathology, neurology, neuroscience and psychiatry and behavioral sciences at Hopkins. "Our study is proof of principle, that neuronal stem cells do have potential in conditions caused by separation within the nervous system, whether by disease or injury."
The next step, he says, is to see whether a more aggressive treatment approach might further improve the outcome -- for example, combining low spinal cord implants as done in this study and grafts higher in the spinal cord to target the nerves that control breathing.